Aryl or heteroaryl derived compounds for the treatements of microbial infections he invention relates to microbial infections, and in particular to novel compositions, therapies and methods for treating, preventing or ameliorating a microbial infection. The Neglected Tropical Disease (NTD) leishmaniasis is endemic in over 90 countries worldwide, affecting approximately 12 million people per year with 350 million people living at risk of disease. The causative agent, Leishmania species, are sand fly borne kinetoplastid protozoan parasites and infection leads to a wide spectrum of clinical manifestations in endemic areas, from self-healing but scarring cutaneous leishmaniasis (CL) to fatal visceral disease (VL). Largely due to elimination efforts in south Asia, the global burden of VL has decreased substantially in the past decade. However, due to forced migration, the cases of CL have substantially increased in the same period (0.7-1 million per year). Current treatment of CL largely relies on the pentavalent antimonials such as sodium stibogluconate (Pentostam) and meglumine antimoniate (Glucantime) which have been in clinical use for over 70 years despite their associated problems, which include severe side-effects such as cardiotoxicity and the fact that they require parenteral administration. Animals can also be infected and serve as reservoirs of disease. In particular, the disease affects dogs throughout southern Europe, South America and the southern USA. Furthermore, the owners of infected companion animals seek their treatment and veterinary drugs are extremely limited in both number and efficacy. Accordingly, there is a recognised need to develop new and effective therapies for this NTD which may be synthesised easily and cheaply. The present invention arose from the inventors’ work in attempting to address this problem. The over-the-counter antihistamine Clemastine has been reported to be active against leishmaniasis. However, clemastine is difficult to synthesise in enantiomerically pure form, which increases the cost of the drug. In accordance with a first aspect of the invention, there is provided a compound of formula (I): , wherein X ¹ is CR ³ , N or SiR ³ ; L ¹ and L ² are independently absent or a linker with a backbone consisting of between 1 and 5 atoms, the linker comprising at least one group, the or each group being independently selected from the list consisting of an optionally substituted C _1-7 alkylene, an optionally substituted C2-7 alkenylene, an optionally substituted C2-7 alkynylene, NR ⁵ , O, S, SO and SO2; R ¹ and R ² are independently an optionally substituted C _6-12 aryl, an optionally substituted 5 to 10 membered heteroaryl, an optionally substituted C1-12 alkyl, an optionally substituted C2-12 alkenyl or an optionally substituted C2-12 alkynyl; R ³ is H, an optionally substituted C1-6 alkyl, an optionally substituted C2-6 alkenyl or an optionally substituted C _2-6 alkynyl; L ³ is a linker with a backbone consisting of between 2 and 7 atoms, the linker comprising at least one group, the or each group being independently selected from the list consisting of an optionally substituted C _1-7 alkylene, an optionally substituted C _2-7 alkenylene, an optionally substituted C _2-7 alkynylene, NR ⁵ , O, S, SO and SO ₂ ; and R ⁴ is an optionally substituted 5 or 6 membered heterocycle or heteroaryl comprising a nitrogen atom, wherein the nitrogen atom in the heterocycle is bonded directly to L ³ ; R ⁵ is H, C _1-6 alkyl, C _2-6 alkenyl or C _2-6 alkynyl; or a pharmaceutically acceptable salt, solvate, tautomeric form or polymorphic form thereof. Advantageously, the inventors have found that a compound of formula (I) is easy to manufacture. Furthermore, compounds of formula (I) have been found to be equipotent to clemastine against L. amazonensis promastigotes and more active than clemastine against L. major promastigotes. Compounds of formula (I) have been found to be less toxic to macrophages than clemastine and showed similar activity to clemastine against L. amazonensis intramacrophage amastigotes. Therefore, compounds of formula (I) can be a more accessible and selective compound than clemastine. The inventors have found that liposomal formulations comprising the compound of formula (I) are particularly effective. Accordingly, in accordance with a second aspect, there is provided a liposomal formulation comprising a compound of formula (I) as defined by the first aspect, or a pharmaceutically acceptable salt, solvate, tautomeric form or polymorphic form thereof and a liposomal carrier. The liposomal carrier may comprise a phospholipid. The phospholipid may be or comprise phosphatidylcholine (PC). The PC may be egg PC. The liposomal carrier may comprise a cationic lipid. The cationic lipid may be or comprise octadecan-1-amine (SA), hexadecyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), didodecyldimethylammonium bromide (DDAB) and/or N-[1-(2,3-Dioleoyloxy)propyl]-N,N,N-trimethylammonium chloride (DOTAP). In some embodiments, the liposomal carrier comprises a phospholipid and a cationic lipid. Accordingly, in some embodiments, the liposomal carrier comprises phosphatidylcholine (PC) and octadecan-1-amine (SA). The molar ratio of the phospholipid to the cationic lipid may be between 1:10 and 50:1, between 1:5 and 25:1, between 1:2 and 10:1, between 1:1 and 8:1, between 2:1 and 6:1 or between 3:1 and 4:1. In some embodiments, the molar ratio of the phospholipid to the cationic lipid is 7:2. The weight ratio of the liposomal carrier to the compound of formula (I) between 1:1 and 100:1, between 2:1 and 75:1, between 5:1 and 50:1, between 10:1 and 25:1, between 12:1 and 20:1 or between 14:1 and 18:1. The liposomal formulation may further comprise a pharmaceutically acceptable vehicle. The compound of formula (I) or the liposomal formulation may be used as a medicament. Accordingly, in accordance with a third aspect, there is provided a compound of formula (I), or a pharmaceutically acceptable salt, solvate, tautomeric form or polymorphic form thereof, or the liposomal formulation of the second aspect, for use as a medicament. In particular, the inventors have found that the compounds of formula (I) may be used to treat a microbial infection or as an antihistaminic. Accordingly, in accordance with a fourth aspect, there is provided a compound of formula (I), or a pharmaceutically acceptable salt, solvate, tautomeric form or polymorphic form thereof, or the liposomal formulation of the second aspect, for use in treating a microbial infection or an allergic reaction. According to a fifth aspect of the invention, there is provided a method of treating, preventing or ameliorating a microbial infection or an allergic reaction in a subject, the method comprising administering to a subject in need of such treatment, a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable salt, solvate, tautomeric form or polymorphic form thereof or the liposomal formulation of the second aspect. Preferably, the microbial infection is a parasitic infection. Preferably, the parasitic infection is a protozoan parasitic infection. The parasitic infection may be leishmaniasis, Chagas disease or African sleeping sickness. Preferably, the parasitic infection is leishmaniasis. The allergic reaction may be allergic rhinitis. The term “preventing” may be understood to mean reducing the likelihood of the patient developing a microbial infection. The term “alkyl” as used herein, unless otherwise specified, refers to a saturated straight or branched hydrocarbon. The alkyl may be a primary, secondary, or tertiary hydrocarbon. C1-C12 alkyls include methyl, ethyl, n-propyl (1-propyl), isopropyl (2- propyl, 1-methylethyl), butyl, pentyl, hexyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, isohexyl, heptyl, octyl, nonyl, decyl, undecyl and dodecyl. An alkyl group can be unsubstituted or substituted. A substituted alkyl may be substituted with one or more substituents selected from the group consisting of halogen, OR ⁶ , NR ⁶ R ⁷ , C(O)R ⁶ , C(O)OR ⁶ and/or oxo, wherein R ⁶ and R ⁷ are independently H, an optionally substituted C1-C6 alkyl group, an optionally substituted C2-C6 alkenyl or an optionally substituted C2-C6 alkynyl. The halogen may be fluorine. Accordingly, the optionally substituted alkyl may be a fluorinated alkyl. For instance, a fluorinated methyl may be –CH ₂ F, CHF ₂ or -CF ₃ . The term “alkenyl” refers to an olefinically unsaturated hydrocarbon groups which can be unbranched or branched. In certain embodiments, the alkenyl group has 2 to 6 carbons, i.e. it is a C ₂ -C ₆ alkenyl. C ₂ -C ₆ alkenyl includes for example vinyl, allyl, propenyl, butenyl, pentenyl and hexenyl. An alkenyl group can be unsubstituted or substituted more substituents selected from the group consisting of halogen, OR ⁶ , NR ⁶ R ⁷ , C(O)R ⁶ , C(O)OR ⁶ and/or oxo, wherein R ⁶ and R ⁷ are independently H, an optionally substituted C1-C6 alkyl group, an optionally substituted C2-C6 alkenyl or an optionally substituted C2-C6 alkynyl. The halogen may be fluorine. Accordingly, the optionally substituted alkyl may be a fluorinated alkenyl. The term “alkynyl” refers to an acetylenically unsaturated hydrocarbon groups which can be unbranched or branched. In certain embodiments, the alkynyl group has 2 to 6 carbons, i.e. it is a C ₂ -C ₆ alkynyl. C ₂ -C ₆ alkynyl includes for example propargyl, propynyl, butynyl, pentynyl and hexynyl. An alkynyl group can be unsubstituted or substituted more substituents selected from the group consisting of halogen, OR ⁶ , NR ⁶ R ⁷ , C(O)R ⁶ , C(O)OR ⁶ and/or oxo, wherein R ⁶ and R ⁷ are independently H, an optionally substituted C ₁ -C ₆ alkyl group, an optionally substituted C ₂ -C ₆ alkenyl or an optionally substituted C ₂ -C ₆ alkynyl. The halogen may be fluorine. Accordingly, the optionally substituted alkyl may be a fluorinated alkynyl. The term “alkylene”, as used herein, unless otherwise specified, refers to a bivalent saturated straight or branched hydrocarbon. An alkylene group may be as defined above in relation the alkyl group, but with a hydrogen atom removed therefrom to cause the group to be bivalent. The term “alkenylene”, as used herein, unless otherwise specified, refers to a bivalent olefinically unsaturated straight or branched hydrocarbon. An alkenylene group may be as defined above in relation the alkenyl group, but with a hydrogen atom removed therefrom to cause the group to be bivalent. The term “alkynylene”, as used herein, unless otherwise specified, refers to a bivalent acetylenically unsaturated straight or branched hydrocarbon. An alkynylene group may be as defined above in relation the alkynyl group, but with a hydrogen atom removed therefrom to cause the group to be bivalent. The term “heterocycle” refers to a monocyclic, bicyclic or bridged molecules in which at least one ring atom is a heteroatom. Unless otherwise specified, the or each heteroatom may be independently selected from the group consisting of oxygen, sulphur and nitrogen. A heterocycle may be saturated or partially saturated. Exemplary 3 to 8 membered heterocyclyl groups include but are not limited to aziridine, oxirane, oxirene, thiirane, pyrroline, pyrrolidine, dihydrofuran, tetrahydrofuran, dihydrothiophene, tetrahydrothiophene, dithiolane, piperidine, 1,2,3,6- tetrahydropyridine-1-yl, tetrahydropyran, pyran, morpholine, piperazine, thiane, thiine, piperazine, azepane, diazepane and oxazine. A heterocycle group can be unsubstituted or substituted. A substituted heterocycle may be substituted with one or more substituents selected from the group consisting of halogen, NO ₂ , OR ⁶ , NR ⁶ R ⁷ , oxo, C(O)R ⁶ , C(O)OR ⁶ , optionally substituted C1-6 alkyl, optionally substituted C2-6 alkenyl and/or optionally substituted C2-6 alkynyl, wherein R ⁶ and R ⁷ are independently H, an optionally substituted C ₁ -C ₆ alkyl group, an optionally substituted C ₂ -C ₆ alkenyl or an optionally substituted C ₂ -C ₆ alkynyl. The halogen may be fluorine. The term “aryl” refers to an aromatic 6 to 12 membered hydrocarbon group. Examples of a C ₆ -C ₁₂ aryl group include, but are not limited to, phenyl, α-naphthyl, β-naphthyl, biphenyl, tetrahydronaphthyl and indanyl. An aryl group can be unsubstituted or substituted. A substituted aryl may be substituted with one or more substituents selected from the group consisting of halogen, NO2, OR ⁶ , NR ⁶ R ⁷ , C(O)R ⁶ , C(O)OR ⁶ , C(O)NR ⁶ R ⁷ , SO ₂ R ⁶ , SO ₂ NR ⁶ R ⁷ , optionally substituted C _1-6 alkyl, optionally substituted C _2-6 alkenyl and/or optionally substituted C _2-6 alkynyl, wherein R ⁶ and R ⁷ are independently H, an optionally substituted C1-C6 alkyl group, an optionally substituted C2-C6 alkenyl or an optionally substituted C2-C6 alkynyl. The halogen may be fluorine. The term “heteroaryl” refers to a monocyclic or bicyclic aromatic 5 to 10 membered ring system in which at least one ring atom is a heteroatom. The or each heteroatom may be independently selected from the group consisting of oxygen, sulphur and nitrogen. Examples of 5 to 10 membered heteroaryl groups include furan, thiophene, indole, azaindole, oxazole, thiazole, isoxazole, isothiazole, imidazole, N-methylimidazole, pyridine, pyrimidine, pyrazine, pyrrole, N-methylpyrrole, pyrazole, N-methylpyrazole, 1,3,4-oxadiazole, 1,2,4-triazole, 1- methyl-1,2,4-triazole, 1H-tetrazole, 1-methyltetrazole, benzoxazole, benzothiazole, benzofuran, benzisoxazole, benzimidazole, N- methylbenzimidazole, azabenzimidazole, indazole, quinazoline, quinoline and isoquinoline. Bicyclic 5 to 10 membered heteroaryl groups include those where a phenyl, pyridine, pyrimidine, pyrazine or pyridazine ring is fused to a 5 or 6-membered monocyclic heteroaryl ring. A heteroaryl group can be unsubstituted or substituted. A substituted heteroaryl may be substituted with one or more substituents selected from the group consisting of halogen, NO ₂ , OR ⁶ , NR ⁶ R ⁷ , oxo, C(O)R ⁶ , C(O)OR ⁶ , C(O)NR ⁶ R ⁷ , SO2R ⁶ , SO2NR ⁶ R ⁷ , optionally substituted C1-6 alkyl, optionally substituted C2-6 alkenyl and/or optionally substituted C2-6 alkynyl, wherein R ⁶ and R ⁷ are independently H, an optionally substituted C ₁ -C ₆ alkyl group, an optionally substituted C ₂ -C ₆ alkenyl or an optionally substituted C2-C6 alkynyl. The halogen may be fluorine. It may be appreciated that the term “backbone of the linker” refers to the shortest continuous chain of bonded atoms between the two components of formula (I) which are connected by the linker. In some embodiments, X ¹ is CR ³ or SiR ³ . Accordingly, the compound may be a compound of formula (Ia): , wherein X ² is C or Si. The compound of formula (Ia) may be a compound of formula (Iai), formula (Iaii) or formula (Iaiii): In a preferred embodiment, the compound of formula (I) is a compound of formula (Iaii). In alternative embodiments, X ¹ is N. L ¹ and/or L ² may be O, NH or CH2. In some embodiments, L ¹ is absent. In some embodiments, L ² is absent. In some embodiments, L ¹ and L ² are absent. Accordingly, the compound may be a compound of formula (Ib): More preferably, the compound is a compound of formula (Ic): The compound of formula (Ic) may be a compound of formula (Ici), formula (Icii) or formula (Iciii): In a preferred embodiment, the compound of formula (I) is a compound of formula (Icii). In a preferred embodiment, X ² is C. Preferably, at least one of R ¹ and R ² is an optionally substituted C _6-12 aryl or an optionally substituted 5 to 10 membered heteroaryl. R ¹ may be an optionally substituted C6-12 aryl or an optionally substituted 5 to 10 membered heteroaryl. More preferably, R ¹ is an optionally substituted phenyl or an optionally substituted 5 or 6 membered heteroaryl. R ¹ may be an optionally substituted phenyl, an optionally substituted pyrrolyl, an optionally substituted pyrazolyl, an optionally substituted imidazolyl, an optionally substituted triazolyl, an optionally substituted tetrazolyl, an optionally substituted oxazolyl, an optionally substituted isoxazolyl, an optionally substituted thiazolyl, an optionally substituted isothiazolyl, an optionally substituted pyridinyl, an optionally substituted pyridazinyl, an optionally substituted pyrimidinyl or an optionally substituted pyrazinyl. The aryl or heteroaryl may be unsubstituted or substituted with one or more substituents. The or each substituent may be selected from the group consisting of halogen, NO2, OR ⁶ , NR ⁶ R ⁷ , C(O)R ⁶ , C(O)OR ⁶ , C(O)NR ⁶ R ⁷ , SO2R ⁶ , SO2NR ⁶ R ⁷ , optionally substituted C1-3 alkyl, optionally substituted C2-3 alkenyl, optionally substituted C2-3 alkynyl and/or an optionally substituted C _1-3 alkoxy, wherein R ⁶ and R ⁷ are independently H, an optionally substituted C1-C3 alkyl group, an optionally substituted C2-C3 alkenyl or an optionally substituted C2-C3 alkynyl. The halogen may be fluorine, chlorine or bromine. R ⁶ and/or R ⁷ may be H or –CH ₃ . More preferably, the aryl or heteroaryl is unsubstituted or substituted with one or two substituents. Preferably, the aryl or heteroaryl is substituted with one substituent. The substituents may be disposed in the ortho, meta and/or para positions. Preferably, the substituents are disposed in the meta and/or para positions. Most preferably, the aryl or the heteroaryl is substituted with one substituent in the para position. Accordingly, the aryl or heteroaryl may be unsubstituted or substituted with one or two substituents selected from the group consisting of fluorine, chlorine, bromine, –OCH3 and NO2. In a most preferred embodiment, R ¹ is R ² may be an optionally substituted C6-12 aryl or an optionally substituted 5 to 10 membered heteroaryl. More preferably, R ² is an optionally substituted phenyl or an optionally substituted 5 or 6 membered heteroaryl. R ² may be an optionally substituted phenyl, an optionally substituted pyrrolyl, an optionally substituted pyrazolyl, an optionally substituted imidazolyl, an optionally substituted triazolyl, an optionally substituted tetrazolyl, an optionally substituted oxazolyl, an optionally substituted isoxazolyl, an optionally substituted thiazolyl, an optionally substituted isothiazolyl, an optionally substituted pyridinyl, an optionally substituted pyridazinyl; an optionally substituted pyrimidinyl or an optionally substituted pyrazinyl. The aryl or heteroaryl may be unsubstituted or substituted with one or more substituents. The or each substituent may be selected from the group consisting of halogen, NO ₂ , OR ⁶ , NR ⁶ R ⁷ , C(O)R ⁶ , C(O)OR ⁶ , C(O)NR ⁶ R ⁷ , SO2R ⁶ , SO2NR ⁶ R ⁷ , optionally substituted C1-3 alkyl, optionally substituted C2-3 alkenyl, optionally substituted C2-3 alkynyl and/or an optionally substituted C _1-3 alkoxy, wherein R ⁶ and R ⁷ are independently H, an optionally substituted C ₁ -C ₃ alkyl group, an optionally substituted C ₂ -C ₃ alkenyl or an optionally substituted C2-C3 alkynyl. The halogen may be fluorine, chlorine or bromine. R ⁶ and/or R ⁷ may be H or –CH3. Preferably, the aryl or heteroaryl is unsubstituted or substituted with one or two substituents. Most preferably, the aryl or heteroaryl is unsubstituted. The substituents may be disposed in the ortho, meta and/or para positions. Preferably, the substituents are disposed in the meta and/or para positions. Accordingly, the aryl or heteroaryl may be unsubstituted or substituted with one or two substituents selected from the group consisting of fluorine, chlorine, bromine, –OCH ₃ and NO2. In a preferred embodiment, R ² is an unsubstituted phenyl. R ³ may be H, an optionally substituted C _1-3 alkyl, an optionally substituted C _2-3 alkenyl or an optionally substituted C _2-3 alkynyl. Preferably, R ³ is H or methyl. Most preferably, R ³ is H. R ⁴ is an optionally substituted heterocycle. The heterocycle may be unsubstituted or substituted with one or more substituents selected from the group consisting of halogen, NO2, OR ⁶ , NR ⁶ R ⁷ , oxo, C(O)R ⁶ , C(O)OR ⁶ , C(O)NR ⁶ R ⁷ , SO2R ⁶ , SO2NR ⁶ R ⁷ , optionally substituted C1-3 alkyl, optionally substituted C2-3 alkenyl and/or optionally substituted C _2-3 alkynyl, wherein R ⁶ and R ⁷ are independently H, an optionally substituted C ₁ -C ₃ alkyl group, an optionally substituted C ₂ -C ₃ alkenyl or an optionally substituted C2-C3 alkynyl. The optionally substituted alkyl, optionally substituted alkenyl and/or optionally substituted alkynyl may be unsubstituted or substituted with a halogen, OR ⁶ and/or NR ⁶ R ⁷ , wherein R ⁶ and R ⁷ are independently H, an optionally substituted C1-C3 alkyl group, an optionally substituted C2-C3 alkenyl or an optionally substituted C2-C3 alkynyl. Preferably, the optionally substituted alkyl, optionally substituted alkenyl and/or optionally substituted alkynyl is unsubstituted or substituted with a halogen and/or OR ⁶ , wherein R ⁶ is H, a C ₁ -C ₃ alkyl group, a C ₂ -C ₃ alkenyl or a C ₂ -C ₃ alkynyl. The halogen may be fluorine. Accordingly, the heterocycle may be unsubstituted or substituted with one or more of CH ₃ , CH ₂ OH, CH ₂ OCH ₃ and/or COOCH3. The heterocycle R ⁴ may be an optionally substituted pyrrolidinyl, an optionally substituted pyrrolinyl, an optionally substituted pyrazolidinyl, an optionally substituted imidazolidinyl, an optionally substituted piperidinyl or an optionally substituted piperazinyl. Preferably, R ⁴ is an optionally substituted pyrrolidinyl or an optionally substituted piperidinyl. More preferably, R ⁴ is an optionally substituted pyrrolidinyl. In a preferred embodiment, R ⁴ is L ³ may have the structure –L ⁴ -L ⁵ -, wherein L ⁵ is bonded directly to R ⁴ , L ⁴ is NR ⁵ , O, S, SO or SO2 and L ⁵ is an optionally substituted C1-7 alkylene, an optionally substituted C2-7 alkenylene or an optionally substituted C _2-7 alkynylene. In one embodiment, L ⁴ is O. L ⁵ may be an optionally substituted C _2-4 alkylene, an optionally substituted C _2-4 alkenylene or an optionally substituted C2-4 alkynylene. More preferably, L ⁵ is an optionally substituted linear C2-4 alkylene, an optionally substituted linear C2-4 alkenylene or an optionally substituted linear C2-4 alkynylene. Even more preferably, L ⁵ is –CH ₂ CH ₂ -, -CH ₂ CH ₂ CH ₂ - or –CH ₂ CH ₂ CH ₂ CH ₂ -. Most preferably, L ⁵ is -CH ₂ CH ₂ CH ₂ - . Alternatively, L ³ may be an optionally substituted C _1-7 alkylene, an optionally substituted C _2-7 alkenylene or an optionally substituted C _2-7 alkynylene. L ³ may be an optionally substituted C2-5 alkylene, an optionally substituted C2-5 alkenylene or an optionally substituted C2-5 alkynylene. More preferably, L ³ is an optionally substituted linear C _2-5 alkylene, an optionally substituted linear C _2-5 alkenylene or an optionally substituted linear C _2-5 alkynylene. Even more preferably, L ³ is –CH ₂ CH ₂ -, - CH2CH2CH2-, –CH2CH2CH2CH2- or –CH2CH2CH2CH2CH2-. Most preferably, L ³ is - CH2CH2CH2CH2-. The compound of formula I may be a compound selected from: Pharmaceutically acceptable salts include any salt of a compound of formula (I) provided herein which retains its biological properties and which is not toxic or otherwise undesirable for pharmaceutical use. The pharmaceutically acceptable salt may be derived from a variety of organic and inorganic counter-ions well known in the art. The pharmaceutically acceptable salt may comprise an acid addition salt formed with organic or inorganic acids such as hydrochloric, hydrobromic, sulfuric, nitric, phosphoric, sulfamic, acetic, trifluoroacetic, trichloroacetic, propionic, hexanoic, cyclopentylpropionic, glycolic, glutaric, pyruvic, lactic, malonic, succinic, sorbic, ascorbic, malic, maleic, fumaric, tartaric, citric, benzoic, 3-(4-hydroxybenzoyl)benzoic, picric, cinnamic, mandelic, phthalic, lauric, methanesulfonic, ethanesulfonic, 1,2- ethane-disulfonic, 2-hydroxyethanesulfonic, benzenesulfonic, 4-chlorobenzenesulfonic, 2-naphthalenesulfonic, 4-toluenesulfonic, camphoric, camphorsulfonic, 4- methylbicyclo[2.2.2]-oct-2-ene-1-carboxylic, glucoheptonic, 3-phenylpropionic, trimethylacetic, tert-butylacetic, lauryl sulfuric, gluconic, benzoic, glutamic, hydroxynaphthoic, salicylic, stearic, cyclohexylsulfamic, quinic, muconic acid and the like acids. Alternatively, the pharmaceutically acceptable salt may comprise a base addition salt formed when an acidic proton present in the parent compound is either replaced by a metal ion, e.g., an alkali metal ion, an alkaline earth ion, an aluminium ion, alkali metal or alkaline earth metal hydroxides, such as sodium, potassium, calcium, magnesium, aluminium, lithium, zinc, and barium hydroxide, or coordinates with an organic base, such as aliphatic, alicyclic, or aromatic organic amines, such as ammonia, methylamine, dimethylamine, diethylamine, picoline, ethanolamine, diethanolamine, triethanolamine, ethylenediamine, lysine, arginine, ornithine, choline, N,N′-dibenzylethylene-diamine, chloroprocaine, diethanolamine, procaine, N- benzylphenethylamine, N-methylglucamine piperazine, tris(hydroxymethyl)- aminomethane, tetramethylammonium hydroxide, and the like. A pharmaceutically acceptable solvate refers to a compound of formula (I) provided herein, or a salt thereof, that further includes a stoichiometric or non-stoichiometric amount of solvent bound by non-covalent intermolecular forces. Where the solvent is water, the solvate is a hydrate. It will be appreciated that the compound of formula (I) described herein, or a pharmaceutically acceptable salt or solvate thereof, may be used in a medicament which may be used in a monotherapy (i.e. use of the compound of formula (I) alone), for treating, ameliorating, or preventing a microbial infection. Alternatively, the compound of formula (I) or a pharmaceutically acceptable salt or solvate thereof may be used as an adjunct to, or in combination with, known therapies for treating, ameliorating, or preventing a microbial infection. The compound of formula (I) may be combined in compositions having a number of different forms depending, in particular, on the manner in which the composition is to be used. Thus, for example, the composition may be in the form of a powder, tablet, capsule, liquid, ointment, cream, gel, hydrogel, aerosol, spray, micellar solution, transdermal patch, liposome suspension or any other suitable form that may be administered to a person or animal in need of treatment. It will be appreciated that the vehicle of medicaments according to the invention should be one which is well- tolerated by the subject to whom it is given. Medicaments comprising the compound of formula (I) described herein may be used in a number of ways. Compositions comprising the compound of formula (I) of the invention may be administered by inhalation (e.g. intranasally). Compositions may also be formulated for topical use. For instance, creams or ointments may be applied to the skin. The compound of formula (I) according to the invention may also be incorporated within a slow- or delayed-release device. Such devices may, for example, be inserted on or under the skin, and the medicament may be released over weeks or even months. The device may be located at least adjacent the treatment site. Such devices may be particularly advantageous when long-term treatment with the compound of formula (I) used according to the invention is required and which would normally require frequent administration (e.g. at least daily injection). The compound of formula (I) and compositions according to the invention may be administered to a subject by injection into the blood stream or directly into a site requiring treatment. Injections may be intravenous (bolus or infusion) or subcutaneous (bolus or infusion), or intradermal (bolus or infusion). In a preferred embodiment, the compound of formula (I) is administered orally. Accordingly, the compound of formula (I) may be contained within a composition that may, for example, be ingested orally in the form of a tablet, capsule or liquid. It will be appreciated that the amount of the compound of formula (I) that is required is determined by its biological activity and bioavailability, which in turn depends on the mode of administration, the physiochemical properties of the compound of formula (I), and whether it is being used as a monotherapy, or in a combined therapy. The frequency of administration will also be influenced by the half-life of the compound of formula (I) within the subject being treated. Optimal dosages to be administered may be determined by those skilled in the art, and will vary with the particular compound of formula (I) in use, the strength of the pharmaceutical composition, the mode of administration, and the advancement of the microbial infection. Additional factors depending on the particular subject being treated will result in a need to adjust dosages, including subject age, weight, sex, diet, and time of administration. The compound of formula (I) may be administered during or after onset of the microbial infection to be treated. Daily doses may be given as a single administration. Alternatively, the compound of formula (I) may be given two or more times during a day. Generally, a daily dose of between 0.01µg/kg of body weight and 500mg/kg of body weight of the compound of formula (I) according to the invention may be used for treating, ameliorating, or preventing a microbial infection. More preferably, the daily dose is between 0.01mg/kg of body weight and 400mg/kg of body weight, more preferably between 0.1mg/kg and 200mg/kg body weight, and most preferably between approximately 1mg/kg and 100mg/kg body weight. A patient receiving treatment may take a first dose upon waking and then a second dose in the evening (if on a two dose regime) or at 3- or 4-hourly intervals thereafter. Alternatively, a slow release device may be used to provide optimal doses of the compound of formula (I) according to the invention to a patient without the need to administer repeated doses. Known procedures, such as those conventionally employed by the pharmaceutical industry (e.g. in vivo experimentation, clinical trials, etc.), may be used to form specific formulations comprising the compound of formula (I) according to the invention and precise therapeutic regimes (such as daily doses of the compound of formula (I) and the frequency of administration). The inventors believe that they are the first to describe a pharmaceutical composition for treating a microbial infection, based on the use of the compound of formula (I) of the invention. Hence, in a sixth aspect, there is provided a pharmaceutical composition for treating a microbial infection comprising a compound of formula (I), or a pharmaceutically acceptable complex, salt, solvate, tautomeric form or polymorphic form thereof, or a pharmaceutically acceptable salt or solvate thereof, and a pharmaceutically acceptable vehicle. The pharmaceutical composition can be used in the therapeutic amelioration, prevention or treatment in a subject of a microbial infection. The invention also provides, in a seventh aspect, a process for making the composition according to the sixth aspect, the process comprising contacting a therapeutically effective amount of a compound of formula (I), or a pharmaceutically acceptable complex, salt, solvate, tautomeric form or polymorphic form thereof, or a pharmaceutically acceptable salt or solvate thereof, and a pharmaceutically acceptable vehicle. A “subject” may be a vertebrate, mammal, or domestic animal. Hence, the compound of formula (I), compositions and medicaments according to the invention may be used to treat any mammal, for example livestock (e.g. a horse), pets (e.g. a dog), or may be used in other veterinary applications. Most preferably, however, the subject is a human being. A “therapeutically effective amount” of the compound of formula (I) is any amount which, when administered to a subject, is the amount of drug that is needed to treat the microbial infection. For example, the therapeutically effective amount of the compound of formula (I) used may be from about 0.01 mg to about 800 mg, and preferably from about 0.01 mg to about 500 mg. It is preferred that the amount of the compound of formula (I) is an amount from about 0.1 mg to about 250 mg, and most preferably from about 0.1 mg to about 20 mg. A “pharmaceutically acceptable vehicle” as referred to herein, is any known compound or combination of known compounds that are known to those skilled in the art to be useful in formulating pharmaceutical compositions. In one embodiment, the pharmaceutically acceptable vehicle may be a solid, and the composition may be in the form of a powder or tablet. A solid pharmaceutically acceptable vehicle may include one or more substances which may also act as flavouring agents, lubricants, solubilisers, suspending agents, dyes, fillers, glidants, compression aids, inert binders, sweeteners, preservatives, dyes, coatings, or tablet- disintegrating agents. The vehicle may also be an encapsulating material. In powders, the vehicle is a finely divided solid that is in admixture with the finely divided active agents (i.e. the compound of formula (I)) according to the invention. In tablets, the active compound of formula (I) may be mixed with a vehicle having the necessary compression properties in suitable proportions and compacted in the shape and size desired. The powders and tablets preferably contain up to 99% of the active compound of formula (I). Suitable solid vehicles include, for example calcium phosphate, magnesium stearate, talc, sugars, lactose, dextrin, starch, gelatin, cellulose, polyvinylpyrrolidine, low melting waxes and ion exchange resins. In another embodiment, the pharmaceutical vehicle may be a gel and the composition may be in the form of a cream or the like. However, the pharmaceutical vehicle may be a liquid, and the pharmaceutical composition is in the form of a solution. Liquid vehicles are used in preparing solutions, suspensions, emulsions, syrups, elixirs and pressurized compositions. The compound of formula (I) according to the invention may be dissolved or suspended in a pharmaceutically acceptable liquid vehicle such as water, an organic solvent, a mixture of both or pharmaceutically acceptable oils or fats. The liquid vehicle can contain other suitable pharmaceutical additives such as solubilisers, emulsifiers, buffers, preservatives, sweeteners, flavouring agents, suspending agents, thickening agents, colours, viscosity regulators, stabilizers or osmo-regulators. Suitable examples of liquid vehicles for oral and parenteral administration include water (partially containing additives as above, e.g. cellulose derivatives, preferably sodium carboxymethyl cellulose solution), alcohols (including monohydric alcohols and polyhydric alcohols, e.g. glycols) and their derivatives, and oils (e.g. fractionated coconut oil and arachis oil). For parenteral administration, the vehicle can also be an oily ester such as ethyl oleate and isopropyl myristate. Sterile liquid vehicles are useful in sterile liquid form compositions for parenteral administration. The liquid vehicle for pressurized compositions can be a halogenated hydrocarbon or other pharmaceutically acceptable propellant. Liquid pharmaceutical compositions, which are sterile solutions or suspensions, can be utilized by, for example, intramuscular, intrathecal, epidural, intraperitoneal, intravenous and particularly subcutaneous injection. The compound of formula (I) may be prepared as a sterile solid composition that may be dissolved or suspended at the time of administration using sterile water, saline, or other appropriate sterile injectable medium. The compound of formula (I) and compositions of the invention may be administered in the form of a sterile solution or suspension containing other solutes or suspending agents (for example, enough saline or glucose to make the solution isotonic), bile salts, acacia, gelatin, sorbitan monoleate, polysorbate 80 (oleate esters of sorbitol and its anhydrides copolymerized with ethylene oxide) and the like. The compound of formula (I) used according to the invention can also be administered orally either in liquid or solid composition form. Compositions suitable for oral administration include solid forms, such as pills, capsules, granules, tablets, and powders, and liquid forms, such as solutions, syrups, elixirs, and suspensions. Forms useful for parenteral administration include sterile solutions, emulsions, and suspensions. All of the features described herein (including any accompanying claims, figures and abstract), and/or all of the steps of any method or process so disclosed, may be combined with any of the above aspects in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying Figures, in which:- Figure 1 shows the structures of a nor-clemastine analogue, (R)112, and an N-linked analogue, (R)147; Figure 2a and b shows the synthetic route for N-linked analogues; Figure 3 shows a further step in the synthetic route for N-linked analogues (S)-149 and (R)-149; Figure 4 shows the asymmetric synthetic route to N-linked analogues (R,S)-147 and (R,R)-147; Figure 5 is a graph showing the half the maximal effective concentration (EC ₅₀ ) of (R)-147, (R,S)-147 and (R,R)-147 against L. major promastigotes, values are mean ± 95% CI from at least three experiments; Figure 6 shows the synthetic route for obtaining compounds (S)-147, (S)-157 and (S)-158; Figure 7 dose response curves of (S)-147, (S)-157 and (S)-158 against L. major promastigotes, assays were performed in triplicate; Figure 8 is a graph showing EC50 values of clemastine and compounds (S)-157 and (S, R)-157 against L. amazonensis and L. major promastigotes, values are mean ± 95% CI from at least three experiments; Figure 9 is a graph showing half the cytotoxic concentration (CC50) values of clemastine, (R, R)-112 and (S, R)-157 against Bone Marrow Derived Macrophages (BMDM), values are mean ± 95% CI from at least three experiments; Figure 10 is a graph showing EC ₅₀ (μM) values of clemastine and analogue (S, R)-157 against wild type (WT), Δ LCB2 (a defined mutant lacking sphingolipid biosynthesis) and PX (Δ LCB2 genetically restored) L. major promastigotes, cycloheximide is used as a positive control, values are mean ± 95% CI from at least three experiments; Figure 11 provides the structures of NBD-C ₆ -ceramide 80 and NBD-C ₆ -IPC 81; Figure 12 shows the separation of NBD-C ₆ -IPC 81 product from NBD-C ₆ -ceramide 80 substrate by HPTLC, microsomes were treated with 5mM of (S, R)-157 and negative and positive controls were DMSO and 5mM of clemastine; and Figure 13 provides results from an in vivo study of BALB/c mice infected with 2x10 ⁶ L. amazonensis GFP promastigotes in the right ear, mice were randomized into drug- treated and control groups of 5/6 mice each. During 28 days of treatment a) weight variation of mice and b) progression of lesion thickness were measured. After completion of treatment, c) representative photographs of the infected ear for each group were taken and the parasite burden was evaluated by, and d) LDA; asterisks indicate that the difference between control and drug-treated groups are statistically significant. * P £ 0.05, ** P £ 0.01, *** P £ 0.001, **** P £ 0.0001. Examples The inventors wished to synthesise a library of nor-clemastine analogues to better understand the structure activity relationship (SAR). However, a specific challenge arose in the synthesis of the head group. This required four steps and produced the head group in a moderate overall yield. In addition, the final S _N 2 reaction generated a desired analogue (R)-112 (shown in Figure 1) but suffered from low yields. Therefore, an alternative more accessible series was explored in which the pyrrolidine nitrogen was moved round one position to form novel N-linked analogues such as analogue (R)- 147 (Figure 1). Example 1 - Synthesis of N-linked analogues The N-linked analogues were initially prepared, in 2 steps, using an Au(I) catalysed SN1 reaction developed by the inventors and shown in Figure 2. For example, coupling of benzhydrol 113 with bromoethanol, followed by an alkylation with 2-methylpyrrolidine at elevated temperature or at rt with KI as a catalyst gave N-linked analogue (R)-147. The higher overall yield for (R)-147 of 57% compared favourably to the 15% yield for the synthesis of nor-clemastine (R)-112. Ether formation and N-alkylation was confirmed by analysis of the 2D HMBC correlations. A number of compounds were produced using this two-step mechanism, and details are provided in table 1. Table 1: N-linked analogues produced Additionally, reduction of ester 150 using LiAlH4 formed compound 149 in a moderate yield (Figure 3). Confirmation of the pyrrolidinyl methanol 149 was obtained by a characteristic OH stretch at 3408 cm ^-1 in the IR spectrum, the absence of a carbonyl signal at 174.5 ppm in the ¹³ C NMR spectrum and the disappearance of the methyl group at 3.55 ppm in the ¹ H spectrum. Example 2 – Activity of N-linked analogues With this initial set of analogues, the approach was validated by assaying the compounds against L. major promastigotes and L. amazonensis promastigotes. The results are provided in table 2. Table 2: Activity of compounds against L. amazonensis promastigote and L. major promastigote

Example 3 - Role of stereochemistry The inventors decided to investigate the role of stereochemistry in the structure activity relationship (SAR). In view of the results obtained in example 2, the inventors determined that the stereocentre on the pyrrolidine ring has little effect on antileishmanial activity as both (R)-147 and (S)-147 have an activity of approximately 2 mM against L. major promastigotes, see Table 1. The enantioselective synthesis illustrated in Figure 4 was performed to access analogues which explore stereochemistry on the benzhydryl carbon. The enantiopure benzhydrol, (R)-113 or (S)-113, were synthesised as explained below in the material and methods section. The head group was prepared, in two steps, by carrying out an N- alkylation with 2-bromoethanol under reflux to afford compound (R)-155 in a moderate yield of 48 %. The IR spectrum was used to confirm the formation of (R)-155 with an OH signal at 3385 cm ^-1 . A subsequent chlorination with thionyl chloride formed head group (R)-154 in a yield of 37 %. Formation of (R)-154 was confirmed by the mass spectrum which showed a chlorine isotope pattern with an intensity ratio of 3:1 (m/z = 148 (M( ³⁵ Cl)H ⁺ ), 150 (M( ³⁷ Cl)H ⁺ )). The final step was the S _N 2 etherification to form analogue (R, R)-147 or (R, S)-147 in a moderate yield. This provides access to N-linked clemastine analogues in higher yield as no by-product is formed. These single diastereomer N-linked analogues were then tested against L. major promastigotes and demonstrate that the (S)-configuration on the benzhydryl carbon, (R, S)-147, is about 4 times less active than analogue (R)-147 with mixed stereochemistry at this position (Figure 5). Hence, the benzhydryl stereocentre contributes to the antileishmanial activity to a greater extent than the chiral centre on the pyrrolidine ring. The (R)-configuration at the benzhydryl carbon in isomer (R, R)- 147 provided the highest activity (EC50 = 1.7 ± 0.3 μM) against L. major promastigotes. Example 3 – Extending the carbon linker It was hypothesised, that extending the linker to 3 carbon units, to form analogue (S, R)-157, could improve the antileishmanial activity of the compounds. As explained above, the stereocentre on the pyrrolidine ring has little effect on antileishmanial activity. The (S)-configuration in the pyrrolidine ring of analogues 157 and 158, with 3 and 4 carbon unit linker chains respectively, were synthesised with a racemic benzhydryl centre. Hence, (S)-157 and (S)-158 were synthesised by performing an SN1 reaction on benzhydrol 113 with bromopropanol and bromobutanol respectively, followed by an alkylation with 2-methylpyrrolidine (S)-148, see Figure 6. The compounds generated dose response curves against promastigotes, as shown in Figure 7. For analogue (S)-157 the antileishmanial activity drops to sub-micromolar (EC50 = 0.09 ± 0.02 μM), which is now equipotent to clemastine (EC50 = 0.172 ± 0.003 μM) and nor-clemastine (R, R)-112 (EC ₅₀ = 0.13 ± 0.01 μM). This suggests that the optimum chain length is 3 carbons. Example 4 – Improving the activity of (S)-157 Based upon the results obtained in Example 2 for analogue 147, the inventors proposed that the (R)-configuration on the benzhydryl carbon would result in the isomer with the highest activity. Therefore, the single diastereomer, analogue (S, R)-157, was synthesised following the same procedure described above. Anti-promastigote assays Compounds (S)-157 and (S, R)-157 were tested against L. major and L. amazonensis promastigotes. The EC50 values shown in Figure 8 demonstrate that analogue (S, R)- 157 is about three times more active against L. major promastigotes (EC ₅₀ = 0.058 ± 0.007 μM) than clemastine and equipotent to clemastine when tested against L. amazonensis promastigotes (EC50= 0.02 ± 0.01 μM). The inventors then wanted to further investigate the antileishmanial activity of (S, R)- 157 by testing it against the clinically relevant amastigote form of the disease. Cytotoxicity to BMDM Before the anti-amastigote assay could be conducted the cytotoxicity of compound (S, R)-157 against BMDM needed to be investigated using a resazurin-based cell-viability assay. As shown in Figure 9, compound (S, R)-157 proved to be 3-4 times less cytotoxic to host macrophages than clemastine. The low levels of cytotoxicity of (S, R)- 157 to BMDM (CC ₅₀ = 73 ± 14 μM) suggest that this compound has the potential to be a more selective antileishmanial drug than clemastine. Overall, (S, R)-157 is a more accessible and selective compound (SI = 146) than clemastine (SI = 50). On-target effects On-target effects of (S, R)-157 required validation before it could be progressed into an animal model. The dose-dependent growth inhibition of L. major WT, Δ LCB2 and PX cell line were assessed and compared to validate on target effects of (S, R)-157 (Figure 10). Using cycloheximide as a control these assays showed that, similar to clemastine, (S, R)-157 is approximately 3 times more active against WT and PX cell lines than the mutant Δ LCB2 promastigotes. This suggested that both clemastine and (S, R)-157 are disrupting the sphingolipid pathway. The mutant assay indicates that analogue (S, R)-157 is having an effect on sphingolipid biosynthesis, however, IPCS still needed to be validated as the target. To achieve this, a biochemical assay adopted from the literature (J. G. Mina, J. A. Mosely, H. Z. Ali, H. Shams-Eldin, R. T. Schwarz, P. G. Steel and P. W. Denny, Int. J. Biochem. Cell Biol., 2010, 42, 1553–1561) was employed. In the assay NBD-C ₆ - ceramide 80 and NBD-C6-IPC 81 (Figure 11) were separated via HPTLC and analysed through fluorescence spectroscopy. This experiment demonstrated that (S, R)-157 acted as an inhibitor of IPCS, because product IPC was not observed on the HPTLC plate (Figure 12). In vivo infection study As sub-micromolar activity has been observed for (S, R)-157 against Leishmania in vitro, it was hypothesised that this compound would be effective in an animal model infected with L. amazonensis parasites. Hence, a study was undertaken analysing in vivo efficacy of (S, R)-157 in the treatment mice infected with L. amazonensis. The intralesional route was chosen as it is immediately absorbed at the site action and therefore the most effective means of delivering the drug. The oral route was studied as an oral drug would be most accessible to those infected with leishmaniasis living in deprived communities. The in vivo study involved treatment of BALB/c mice infected with L. amazonensis expressing green fluorescent protein (GFP). Treatment of four groups of mice was initiated one week post infection: clemastine (intralesional, IL), (S, R)-157 (intralesional, IL), glucatime solution (GLU) and untreated (UN). Clemastine (IL) was administered at a dose of 1.17 mg kg ^‐1 twice a week. Analogue (S, R)-157 was also administered at a dose of 1.17 mg kg ^-1 via IL injection twice a week, the same treatment regime as used in the clemastine IL group enabling the two therapies to be directly compared. Finally, glucantime solution was used as the positive control at an IP dose of 1.30 g kg ^‐1 twice a week. Mice were treated for 28 days and weight variation and lesion size were measured at least once a week to monitor the progression of the disease. On day 41 the animals were sacrificed and the fluorescence measured and parasite load quantified using limiting dilution assay (LDA). There was little variation in the weight of the treated mice (Figure 13a). However, (S, R)-157 appears less toxic than clemastine due to the higher weight gain observed as compared with the clemastine. Furthermore, on day 35 post-infection, mice treated with analogue (S, R)-157 IL showed a significant reduction in lesion size when compared to the untreated group. The lesion growth trend is similar for the groups treated with analogue (S, R)-157 and clemastine IL (Figure 13b). It should be noted that mice treated with glucantime solution, i.e. the positive control group, showed the greatest reduction in lesion size. This is partly due to glucantime solution being administered as an IP therapy, whereas IL treatments can cause inflammation to the ear increasing lesion measurements. Images in Figure 13c show similar improvements in the appearance of the lesion for analogue (S, R)-157 IL, clemastine IL and glucantime solution IP groups when compared to the untreated group. Similar to clemastine IL, results from the LDA showed statistical significance between the untreated group and analogue (S, R)-157 IL group (P £ 0.0001) (Figure 13d). This positive in vivo result supports the hypothesis that analogue (S, R)-157 could be an effective treatment for CL in an animal model. Example 5 – Testing further compounds The inventors synthesised the eleven further compounds identified in the table below. The structures of all of the compounds were confirmed using ¹ H and ¹ C NMR spectroscopy and mass spectrometry. It will be noted that compound NTP-61 is the same as (S,R)-157, identified above. This compound was included in the (later) assay as a reference standard. Table 3: Structure of compounds and activity against L. amazonensis promastigote and L. major promastigote

As shown in the table, all of the compounds were found to be active against L. amazonensis promastigote, and the vast majority were also active against L. major promastigote. Example 6 – Further compounds The inventors synthesised four further compounds identified below. The structures of all of the compounds were confirmed using ¹ H and ¹³ C NMR spectroscopy and mass spectrometry.

The inventors investigated the activity and cytotoxicity of NTP-85 compared to clemastine fumarate, and the results are provided in Table 4 below. Table 4: Activity and cytotoxicity of NTP-85 compared to clemastine fumarate As shown above, after 72 hours NTP-85 had an ED ₅₀ of 143 nM against L.donovani AG83 promastigotes and an ED50 of 95 nM against L.donovani AG83 amastigotes. Both of these results are superior to the activity exhibited by clemastine fumarate. Furthermore, NTP-85 was not cytotoxic. Example 7 – Liposomal formulations The inventors then tested the activity of NTP-85 and clemastine fumarate in a phosphatidylcholine-stearylamine (PCSA) liposomal formulation. Amphotericin B (AmB) was used as a positive control. The formulations were prepared as described in Sinha et al. (“Cationic Liposomal Sodium Stibogluconate (SSG), a Potent Therapeutic Tool for Treatment of Infection by SSG-Sensitive and -Resistant Leishmania donovani”, Antimicrobial Agents and Chemotherapy, January 2015, Volume 59, Number 1, pages 344-355). The results are provided in table 5. Table 5: Activity and cytotoxicity of NTP-85 compared to clemastine fumarate It will be noted that the compounds offered significantly improved efficacy when provided in a liposomal formulation. Conclusion The inventors were able to develop simple synthetic routes to easily and quickly access N-linked analogues of clemastine. All of the compounds synthesised were active. In particular, with a 3-carbon chain linker and the appropriate (S, R) stereochemistry, compound (S, R)-157, was equipotent to clemastine against L. amazonensis promastigotes and more active than clemastine against L. major promastigotes. This compound was less toxic to macrophages than clemastine and showed similar activity to clemastine against L. amazonensis intramacrophage amastigotes. Therefore, compound (S, R)-157 was a more accessible and selective compound. The target of compound (S, R)-157 was validated as IPCS using mutant Δ LCB2 promastigotes and an LmjIPCS biochemical HPTLC assay. Compound (S, R)-157 was progressed into an in vivo infection study and showed efficacy as an IL therapy against CL. Materials and Methods Chemical experimental General experimental details SOLVENTS AND REAGENTS: All analytical grade solvents and commercially available regents were used as received from their respective suppliers or dried as required, using standard procedures. All reactions were performed under an inert atmosphere of argon unless otherwise stated. CHARACTERISATION: Reactions were monitored by LC-MS, GC-MS or by TLC using aluminium backed plates. Methods to visualise the spots included ultra-violet light (254 nm) and colour reagents. The visualising stains used were potassium permanganate, phosphomolybdic acid or ninhydrin. Column chromatography was performed using a Teledyne Isco CombiFlash® System with RediSep® Rf normal-phase and C-18 reversed-phase columns. Both carbon and hydrogen NMR spectra were acquired at 295 K on Varian VNMRS 700 (1H at 700 MHz, 13C at 176 MHz), Varian VNMRS 600 (1H at 600 MHz, 13C at 151 MHz), with sample dissolved in the analytical solvent CDCl3.2D COSY, HSQC, HMBC and NOESY were run to aid assignment of peaks. Chemical shifts are reported in parts per million, ppm, to 2 decimal places; with the multiplicity of the signal reported as s, singlet; d, doublet; t, triplet; coupling constants, J, are quoted to the nearest ± 0.5 Hz. Ar refers to aryl resonances which could not be accurately assigned. Infrared (IR) spectra were acquired using a Perkin-Elmer Paragon 1000 FT-IR and absorption maxima (νmax) are reported in wavenumbers (cm-1) and assigned as strong (s), medium (m), weak (w) or broad (br). Mass spectra were recorded using Shimadzu gas chromatography via electron ionization (EI) or on a Waters TQD spectrometer coupled to an Acquity UPLC. Melting points are measured using Fisher ScientificTM IA9000 melting point apparatus. Experimental procedure and compound characterisation General procedure A: Pd-catalysed etherification To a solution of alcohol (1 equiv.) and diphenylmethanol (1 equiv.) in DCE (5 mL mmol ^-1 ) was added PdCl ₂ (0.1 equiv.). The reaction mixture was heated at 80 °C for 48 h. The solvent was then removed under reduced pressure to afford the crude product. General procedure B: SN2 reaction of 4-chlorobenzhydrol and alkyl chloride The 4-chlorobenzhydrol (1 equiv.) and NaH (60%, 3 equiv.) were dissolved in anhydrous toluene (5 mL mmol ^-1 ) and heated under reflux for 3 h under nitrogen. The solution was cooled to rt and chloroethylpyrrolidine (1 equiv.) in toluene (2.5 mL mmol ^-1 ) was added. The reaction mixture was then reacted under reflux overnight. The reaction mixture was cooled, quenched with H2O (X mL) and diluted with EtOAc (X mL). The aqueous layer was separated and extracted with EtOAc (2 x X mL). The combined organic layers were then dried over Na ₂ SO ₄ , filtered, and then concentrated in vacuo. General procedure C: Fieser’s method for the workup of LiAlH ₄ reactions A reaction mixture generated from X g of lithium aluminium hydride was cooled to 0 °C and diluted with ether. It was then carefully quenched with H2O (X mL), followed by 3 M NaOH(aq) (3X mL) and finally H2O (3X mL). This was warmed to rt and stirred for 15 min before the addition of anhydrous MgSO4 and then stirring for another 5 min. The salts were then removed by filtration and solvent was removed in vacuo to afford the crude product. (R)-(4-chlorophenyl)(phenyl)methanol - (R)-113 Et ₂ Zn (2.4 mL, 3.6 mmol) was added dropwise to a solution of phenylboronic acid (146 mg, 1.2 mmol) in toluene (3 mL) under an argon atmosphere. After stirring for 12 h at 60 °C, the mixture is cooled to 0 °C and a toluene solution of [(2R)-1-methylpyrrolidin-2- yl]diphenylmethanol (27 mg, 0.1 mmol) was introduced. The reaction was stirred for an additional 15 min and the 4-chlorobenzaldehyde (70 mg, 0.5 mmol) then added. After stirring for 12 h at 0 °C the reaction was quenched with H ₂ O (2 mL) and extracted with DCM (3 x 5 mL). The combined organic layers were dried over MgSO ₄ , filtered, and solvent evaporated. Purification by chromatography (10% EtOAc in hexanes) to afford the desired product (77 mg, 56%) as a white solid. [α] _D ^{(c = 1.00 g/100 mL, CHCl} 3 ⁾ _{-27.0 ° (lit.:} ^[α] _D ^{(c = 1.00 g/100 mL, CHCl} 3 ⁾ _{-16 °);} ^{95 % ee} (determined by chiral HPLC analysis). nmax (ATR) 3347 (br, m), 1489 (s), 1453 (m), 1089 (s), 1012 (s). δ _H (400 MHz, CDCl ₃ ) 7.41 - 7.28 (9H, m, ArH), 5.81 (1H, s, Ar ₂ CH), 2.42 (1H, s, OH). δ _C (101 MHz, CDCl ₃ ) 143.5 (ArC), 142.3 (ArC), 133.4 (ArC), 128.8 (ArC), 128.7 (ArC), 127.9(9) (ArC), 127.9(6) (ArC), 126.6 (ArC), 75.7 (Ar ₂ CH). m/z (LC-MS, ESI ⁺ ) 201 (M( ³⁵ Cl)–OH ⁺ ), 203 (M( ³⁷ Cl)–OH+). (S)-(4-chlorophenyl)(phenyl)methanol - (S)-113 Et ₂ Zn (2.4 mL, 3.6 mmol) was added dropwise to a solution of phenylboronic acid (146 mg, 1.2 mmol) in toluene (3 mL) under an argon atmosphere. After stirring for 12 h at 60 °C, the mixture is cooled to 0 °C and a toluene solution of [(2S)-1-methylpyrrolidin-2- yl]diphenylmethanol (27 mg, 0.1 mmol) was introduced. The reaction was stirred for an additional 15 min and the 4-chlorobenzaldehyde (70 mg, 0.5 mmol) then added. After stirring for 12 h at 0 °C the reaction was quenched with H ₂ O (2 mL) and extracted with DCM (3 x 5 mL). The combined organic layers were dried over MgSO4, filtered, and solvent evaporated. Purification by chromatography (10% EtOAc in hexanes) to afford the desired product (134 mg, 97%) as a white solid. [α] _D ^{(c = 1.00 g/100 mL, CHCl3)} _{+17.9 ° (lit.:} ^[α] _D ^{(c = 1.00 g/100 mL, CHCl3)} _+19°); ^{96 % ee} (determined by chiral HPLC analysis). nmax (ATR) 3347 (br, m), 1489 (s), 1453 (m), 1089 (s), 1012 (s). NMR and mass spectra were consistent with the R enantiomer. 1-[(2-Bromoethoxy)(phenyl)methyl]-4-chlorobenzene261 - 180 General procedure A was followed with 2-bromoethanol (0.1 mL, 1.41 mmol) and (4- chlorophenyl)(phenyl)methanol 113 (218 mg, 1.00 mmol) with the modification of AuCl (24 mg, 0.14 mmol) as the catalyst in the place of PdCl2 with a reaction time of 20 h. The product was purified by flash column chromatography (0 → 20 % EtOAc in hexanes) to afford the title compound (282 mg, 87%) as a colourless oil. nmax (ATR) 2858 (w), 1490 (m), 1453 (w), 1276 (w), 1185 (w), 1089 (m), 1029 (w), 1015 (m) cm ^-1 . δ _H (700 MHz, CDCl ₃ ) 7.37 – 7.33 (4H, m, ArH), 7.32 – 7.27 (5H, m, ArH), 5.41 (1H, s, Ar ₂ CH), 3.82 – 3.74 (2H, m, 2’-H), 3.53 (2H, t, J = 6.0 Hz, 1’-H). δ _C (176 MHz, CDCl ₃ ) 141.3 (ArC), 140.5 (ArC), 133.5 (ArC), 128.7(2) (ArC), 128.7(1) (ArC), 128.4(5) (ArC), 128.0 (ArC), 127.1 (ArC), 83.4 (Ar2CH), 69.1 (C-2’), 30.7 (C-1’). m/z (LC-MS, ESI ⁺ ) 347 (M( ³⁵ Cl)( ⁷⁹ Br) Na ⁺ ), 349 (M( ³⁷ Cl)( ⁷⁹ Br) Na ⁺ ) (M( ³⁵ Cl)( ⁸¹ Br) Na ⁺ ), 351 (M( ³⁷ Cl)( ⁸¹ Br) Na ⁺ ). 1-{2-[(4-Chlorophenyl)(phenyl)methoxy]ethyl}pyrrolidine - 152 1-[(2-Bromoethoxy)(phenyl)methyl]-4-chlorobenzene 180 (117 mg, 0.36 mmol) is dissolved in MeCN (3 mL) and pyrollidine (0.04 mL, 0.43 mmol) and K2CO3 (69 mg, 0.50 mmol) are added. The reaction is heated to 60 °C and left to stir overnight. The reaction was extracted with EtOAc (3 x 5 mL) and washed with H2O (5 mL) and dried over Na2SO4. The crude product was purified by reversed phase column chromatography (5 → 100% MeCN in H2O with 0.1% formic acid) to afford the title compound (61 mg, 54%) as a yellow oil. nmax (ATR) 2962 (w), 2787 (w), 1490 (m), 1453 (w), 1088 (s), 1015 (m) cm ^-1 . δH (700 MHz, CDCl ₃ ) 7.33 – 7.23 (9H, m, ArH), 5.35 (1H, s, Ar ₂ CH), 3.62 (2H, t, J = 6.0 Hz, 2’-H ₂ ), 2.82 (2H, t, J = 6.0 Hz, 1’-H ₂ ), 2.66 – 2.61 (4H, m, 2-H ₂ , 5-H ₂ ), 1.82 – 1.76 (4H, m, 3-H ₂ , 4-H ₂ ). δ _C (176 MHz, CDCl ₃ ) 141.8 (ArC), 141.0 (ArC), 133.3 (ArC), 128.6(2) (ArC), 128.5(9) (ArC), 128.4 (ArC), 127.8 (ArC), 127.1 (ArC), 83.4 (Ar ₂ CH), 68.2 (C-2’), 55.7 (C-1’), 54.8 (C-2, C-5), 23.6 (C-3, C-4). m/z (LC-MS, ESI ⁺ ) 316 (M( ³⁵ Cl)H ⁺ ), 318 (M( ³⁷ Cl)H ⁺ ). Accurate mass: Found (M( ³⁵ Cl)H ⁺ ), 316.1461: C19H23 ³⁵ ClNO requires M, 316.1468. Methyl (2S)-1-{2-[(4-chlorophenyl)(phenyl)methoxy]ethyl}pyrrolidine -2-carboxylate - (S)-150 1-[(2-Bromoethoxy)(phenyl)methyl]-4-chlorobenzene 180 (170 mg, 0.52 mmol) is dissolved in MeCN (5 mL) and L-proline methyl ester hydrochloride (104 mg, 0.63 mmol) and K2CO3 (144 mg, 1.04 mmol) are added. The reaction is heated to 60 °C and left to stir overnight. The reaction was extracted with EtOAc (3 x 5 mL) and washed with H ₂ O (5 mL) and dried over Na ₂ SO ₄ . The crude product was purified by reversed phase column chromatography (5 → 100% MeCN in H2O with 0.1% formic acid) to afford the title compound (104 mg, 54%) as a colourless oil. n _max (ATR) 2950 (w), 1732 (m), 1489 (m), 1452 (w), 1435 (w), 1262 (w), 1170 (m), 1087 (s), 1014 (m) cm ^-1 . δH (700 MHz, CDCl3) 7.32 – 7.20 (9H, m, ArH), 5.31 (0.5H, s, Ar2CH), 5.30 (0.5H, s, Ar2CH), 3.61 – 3.56 (2H, m, 2’-H2), 3.55 (3H, s, OCH3), 3.42 – 3.33 (1H, m, 2-H), 3.24 – 3.15 (1H, m, 1’-HH’), 3.01 – 2.91 (1H, m, 5-HH’), 2.89 – 2.80 (1H, m, 5-HH’), 2.61 – 2.49 (1H, m, 1’- HH’), 2.19 – 2.09 (1H, m, 3HH’), 1.95 – 1.84 (2H, m, 4H ₂ ), 1.84 – 1.75 (1H, m, 3HH’). δ _C (176 MHz, CDCl ₃ , mixture of diastereomers) 174.5(4) (CO), 174.4(9) (CO), 141.9 (ArC), 141.0(2) (ArC), 141.0(0) (ArC), 133.3 (ArC), 133.2 (ArC), 128.6(1) (ArC), 128.5(9) (ArC), 128.5(6) (ArC), 128.5(5) (ArC), 128.5 (ArC), 128.3 (ArC), 127.8 (ArC), 127.7 (ArC), 127.1 (ArC), 126.9 (ArC), 83.4 (Ar ₂ CH), 68.1 (C-2’), 65.9 (C-2), 54.5(1) (C-5), 54.4(9) (C-5), 54.0 (C-1’), 53.9 (C-1’), 51.7(8) (OCH ₃ ), 51.7(7) (OCH ₃ ), 29.7 (C-3), 29.6 (C-3), 23.3 (C-4). m/z (LC-MS, ESI ⁺ ) 396.105 (M( ³⁵ Cl)Na ⁺ ), 398.016 (M( ³⁷ Cl)Na ⁺ ). Accurate mass: Found (M( ³⁵ Cl)H ⁺ ), 374.1516: C ₂₁ H ₂₅ ³⁵ ClNO ₃ requires M, 374.1523. Methyl (2R)-1-{2-[(4-chlorophenyl)(phenyl)methoxy]ethyl}pyrrolidine -2-carboxylate - (R)-150 1-[(2-Bromoethoxy)(phenyl)methyl]-4-chlorobenzene 180 (462 mg, 1.42 mmol) is dissolved in MeCN (7 mL) and D-proline methyl ester hydrochloride (282 mg, 1.70 mmol) and K2CO3 (471 mg, 3.41 mmol) are added. The reaction is heated to 60 °C and left to stir overnight. The reaction was extracted with EtOAc (3 x 10 mL) and washed with H2O (10 mL) and dried over Na2SO4. The crude product was purified by reversed phase column chromatography (5 → 100% MeCN in H ₂ O with 0.1% formic acid) to afford the title compound (161 mg, 30%) as a colourless oil. n _max (ATR) 2950 (w), 2870 (w), 1733 (m), 1489 (m), 1455 (w), 1435 (w), 1196 (m), 1169 (m), 1087 (s), 1072 (m), 1012 (m) cm ^-1 . δH (700 MHz, CDCl3) 7.32 – 7.20 (9H, m, ArH), 5.31 – 5.29 (1H, m, Ar2CH), 3.58 – 3.53 (5H, m, 2’-H2, OCH3), 3.35 – 3.30 (1H, m, 2-H), 3.21 – 3.16 (1H, m, 1’- HH’), 2.97 – 2.91 (1H, m, 5-H), 2.84 – 2.78 (1H, m, 5-H), 2.53 – 2.46 (1H, m, 1’-HH’), 2.15 – 2.06 (1H, m, 3-HH’), 1.93 – 1.83 (2H, m, 4-H2), 1.81 – 1.74 (1H, m, 3-HH’). δC (176 MHz, CDCl3, mixture of diastereomers) 174.6(8) (CO), 174.6(5) (CO), 141.8(8) (ArC), 141.8(5) (ArC), 141.1 (ArC), 141.0 (ArC), 133.2 (ArC), 133.1 (ArC), 128.5(7) (ArC), 128.5(5) (ArC), 128.5(2) (ArC), 128.5(0) (ArC), 128.4 (ArC), 128.3 (ArC), 127.7(3) (ArC), 127.6(5) (ArC), 127.1 (ArC), 126.9 (ArC), 83.3 (Ar ₂ CH), 68.2(1) (C-2’), 68.1(8) (C-2’), 65.9(4) (C-2), 65.9(2) (C-2), 54.5 (C-5), 54.0(3) (C-1’), 53.9(9) (C-1’), 51.7 (OCH ₃ ), 29.7 (C-3), 29.6 (C-3), 23.4(0) (C-4), 23.3(9) (C-4). m/z (LC-MS, ESI ⁺ ) 396.343 (M( ³⁵ Cl)Na ⁺ ), 398.256 (M( ³⁷ Cl)Na ⁺ ). Accurate mass: Found (M( ³⁵ Cl)H ⁺ ), 374.1530: C ₂₁ H ₂₅ ³⁵ ClNO ₃ requires M, 374.1523. [(2S)-1-{2-[(4-Chlorophenyl)(phenyl)methoxy]ethyl}pyrrolidin -2-yl]methanol - (S)-149 To a 0 °C solution of methyl (2S)-1-{2-[(4-chlorophenyl)(phenyl)methoxy]ethyl}pyrrolidine -2- carboxylate (S)-150 (50 mg, 0.13 mmol) in THF (2 mL) was slowly added LiAlH4 (2.4 M solution in THF, 0.14 mL, 0.33 mmol), before being warmed to rt and stirred for 3h. The reaction mixture was then cooled in an ice bath and any reactive salts were quenched according to Fieser’s method (general procedure C). The product was purified by reversed phase column chromatography (5 → 100% MeCN in H ₂ O with 0.1% formic acid). To afford the title compound (22.5 mg, 50%) as a yellow oil. nmax (ATR) 3408 (br, w), 2870 (w), 1490 (m), 1088 (s) cm ^-1 . δH (700 MHz, CDCl3) 7.34 - 7.23 (9H, m, ArH), 5.33 (1H, s, Ar ₂ CH), 3.65 – 3.60 (1H, m, HOCHH’), 3.58 – 3.52 (2H, m, 2’-H ₂ ), 3.41 – 3.36 (1H, m, HOCHH’), 3.21 – 3.14 (1H, m, 5–HH’), 3.10 – 3.02 (1H, m, 1’-HH’), 2.77 – 2.69 (1H, m, 2-H), 2.66 – 2.59 (1H, m, 1-HH’), 2.42 – 2.34 (1H, m, 5-HH’), 1.90 – 1.82 (1H, m, 4-HH’), 1.77 – 1.68 (3H, m, 4-HH’, 3-H ₂ ). δ _C (176 MHz, CDCl ₃ , mixture of diastereomers) 141.8(3) (ArC), 141.7(7) (ArC), 141.0 (ArC), 140.9 (ArC), 133.3(3) (ArC), 133.3(1) (ArC), 128.7(0) (ArC), 128.6(7) (ArC), 128.3(2) (ArC), 128.3(0) (ArC), 127.9 (ArC), 127.8 (ArC), 127.0(0) (ArC), 126.9(5) (ArC), 83.5(2) (Ar ₂ CH), 83.4(9) (Ar ₂ CH), 68.2(4) (C-2’), 68.1(9) (C-2’), 65.2 (C-2), 62.6 (CH ₂ OH), 62.5 (CH ₂ OH), 55.2 (C-5), 55.1 (C-5), 54.3(6) (C-1’), 54.3(5) (C-1’), 27.6 (C-3), 24.1 (C-4). m/z (LC-MS, ESI ⁺ ) 368 (M( ³⁵ Cl)Na ⁺ ), 370 (M( ³⁷ Cl)Na ⁺ ). Accurate mass: Found (M( ³⁵ Cl)H ⁺ ), 346.1571: C ₂₀ H ₂₅ ³⁵ ClNO ₂ requires M, 346.1574 [(2R)-1-{2-[(4-Chlorophenyl)(phenyl)methoxy]ethyl}pyrrolidin -2-yl]methanol - (R)-149 To a 0 °C solution of methyl (2R)-1-{2-[(4-chlorophenyl)(phenyl)methoxy]ethyl}pyrrolidine -2- carboxylate (R)-150 (115 mg, 0.30 mmol) in THF (4 mL) was slowly added LiAlH ₄ (2.4M solution in THF, 0.31 mL, 0.75 mmol), before being warmed to rt and stirred for 3h. The reaction mixture was then cooled in an ice bath and any reactive salts were quenched according to Fieser’s method (general procedure B). The product was purified by reversed phase column chromatography (5 → 100% MeCN in H ₂ O with 0.1% formic acid). To afford the title compound (64 mg, 62%) as a yellow oil. n _max (ATR) 3392 (br, w), 2946 (w), 2870 (w), 1489 (m), 1453 (w), 1403 (w), 1295 (w), 1185 (w), 1086 (s), 1028 (m), 1014 (s) cm ^-1 . δH (700 MHz, CDCl3) 7.35 - 7.23 (9H, m, ArH), 5.35 (1H, s, Ar2CH), 3.68 – 3.63 (1H, m, HOCHH’), 3.63 – 3.56 (2H, m, 2’-H2), 3.45 – 3.40 (1H, m, HOCHH’), 3.27 – 3.18 (1H, m, 5–HH’), 3.14 – 3.06 (1H, m, 1’-HH’), 2.85 – 2.75 (1H, m, 2-H), 2.71 – 2.65 (1H, m, 1-HH’), 2.48 – 2.38 (1H, m, 5-HH’), 1.93 – 1.85 (1H, m, 4-HH’), 1.81 – 1.70 (3H, m, 4-HH’, 3-H ₂ ). δ _C (176 MHz, CDCl ₃ , mixture of diastereomers) 141.7 (ArC), 141.6 (ArC), 140.9 (ArC), 140.8 (ArC), 133.4 (ArC), 133.3 (ArC), 128.6(9) (ArC), 128.6(8) (ArC), 128.6(6) (ArC), 128.3(2) (ArC), 128.2(8) (ArC), 127.9 (ArC), 127.8 (ArC), 127.0 (ArC), 126.9 (ArC), 83.5(3) (Ar ₂ CH), 83.5(1) (Ar ₂ CH), 67.9(5) (C-2’), 67.8(9) (C-2’), 65.7 (C-2), 62.4(1) (CH ₂ OH), 62.3(8) (CH ₂ OH), 55.1(8) (C-5), 55.1(6) (C-5), 54.5 (C-1’), 27.5 (C-3), 24.1 (C-4). m/z (LC-MS, ESI ⁺ ) 368 (M( ³⁵ Cl)Na ⁺ ), 370 (M( ³⁷ Cl)Na ⁺ ). Accurate mass: Found (M( ³⁵ Cl)H ⁺ ), 346.1579: C ₂₀ H ₂₅ ³⁵ ClNO ₂ requires M, 346.1574. (2R)-1-{2-[(4-chlorophenyl)(phenyl)methoxy]ethyl}-2-(methoxy methyl)pyrrolidine - (R)-153 1-[(2-bromoethoxy)(phenyl)methyl]-4-chlorobenzene 180 (160 mg, 0.49 mmol) in DMF (0.8 mL) was added dropwise to a suspension of the (R)-methoxymethylpyrrolidine (0.06 mL, 0.49 mmol), KI (8.3 mg, 0.08 mmol) and K2CO3 (135 mg, 0.98 mmol) in DMF (0.5 mL). The reaction mixture was stirred at rt for 4 h. Following the addition of H2O (5 mL) and extraction with EtOAc (3 x 5mL), the combined organic layers were dried over Na2SO4 and concentrated in vacuo. The crude product was purified by column chromatography (10% MeOH in CHCl3) to afford the title compound (114 mg, 65 %) as a brown oil. nmax (ATR) 2871 (w), 2810 (w), 1489 (m), 1453 (w), 1185 (w), 1088 (s), 1015 (m). δH (700 MHz, CDCl ₃ ) 7.33 – 7.23 (9H, m, ArH), 5.37 (1H, s, Ar ₂ CH), 3.74 – 3.57 (2H, m, 2’-H ₂ ), 3.56 - 3.41 (1H, m, 1-HH’), 3.37 – 3.29 (4H, m, CH ₃ , 1-HH’), 3.29 – 3.11 (2H, m, 1’-HH’, 5-HH’), 2.95 – 2.60 (2H, m, 1’-HH’, 2-H), 2.58 – 2.32 (1H, m, 5-HH’), 1.97 – 1.86 (1H, m, 3-HH’), 1.86 – 1.70 (2H, m, 4-H ₂ ), 1.70 – 1.57 (1H, m, 3-HH’). δ _C (176 MHz, CDCl ₃ , mixture of diastereomers) 141.8 (ArC), 141.7 (ArC), 141.0 (ArC), 140.9 (ArC), 133.3 (ArC), 133.2 (ArC), 128.6(3) (ArC), 128.6(1) (ArC), 128.5(9) (ArC), 128.4(4) (ArC), 128.3(8) (ArC), 127.8(2) (ArC), 127.7(7) (ArC), 127.1 (ArC), 127.0 (ArC), 83.4 (Ar2CH), 75.4 (C-1), 67.8 (C-2’), 64.3 (C-2), 59.2 (CH3), 55.6 (C-5), 55.5 (C-5), 54.9 (C-1’), 28.0 (C-3), 23.2 (C-4). m/z (LC-MS, ESI ⁺ ) 382 (M( ³⁵ Cl)Na ⁺ ), 384 (M( ³⁷ Cl)Na ⁺ ). Accurate mass: Found (MH ⁺ ), 360.1734: C21H27NO2 ³⁵ Cl requires M, 360.1730. (2S)-1-{2-[(4-chlorophenyl)(phenyl)methoxy]ethyl}-2-(methoxy methyl)pyrrolidine - (S)-153 1-[(2-bromoethoxy)(phenyl)methyl]-4-chlorobenzene 180 (160 mg, 0.49 mmol) in DMF (0.8 mL) was added dropwise to a suspension of the (S)-methoxymethylpyrrolidine (0.06 mL, 0.49 mmol), KI (8.3 mg, 0.08 mmol) and K ₂ CO ₃ (135 mg, 0.98 mmol) in DMF (0.5 mL). The reaction mixture was stirred at rt for 4 h. Following the addition of H ₂ O (5 mL) and extraction with EtOAc (3 x 5mL), the combined organic layers were dried and concentrated in vacuo. The crude product was purified by flash column chromatography (10% MeOH in CHCl ₃ ) to afford the title compound (68 mg, 39 %) as a brown oil. n _max (ATR) 2871 (w), 2811 (w), 1489 (m), 1452 (w), 1185 (m), 1087 (s), 1014 (m). δ _H (700 MHz, CDCl3) 7.33 - 7.30 (4H, m, ArH), 7.30 – 7.26 (4H, m, ArH), 7.26 -7.23 (1H, m, ArH), 5.36 (1H, s, Ar2CH), 3.67 - 3.55 (2H, m, 2’-H2), 3.53 - 3.38 (1H, m, 1-HH’), 3.33 – 3.27 (4H, m, CH3, 1-HH’), 3.25 – 3.14 (2H, m, 1’-HH’, 5-HH’), 2.80 - 2.63 (2H, m, 1’-HH’, 2-H), 2.45 – 2.30 (1H, m, 5- HH’), 1.94 – 1.85 (1H, m, 3-HH’), 1.84 – 1.68 (2H, m, 4-H ₂ ), 1.66 – 1.57 (1H, m, 3-HH’). δ _C (176 MHz, CDCl ₃ , mixture of diastereomers) 141.9 (ArC), 141.8 (ArC), 141.1 (ArC), 141.0 (ArC), 133.2(2) (ArC), 133.1(9) (ArC), 128.5(9) (ArC), 128.5(8) (ArC), 128.5(7) (ArC), 128.5(6), 128.4(2) (ArC), 128.3(8) (ArC), 127.8 (ArC), 127.7 (ArC), 127.1 (ArC), 127.0 (ArC), 83.3 (Ar ₂ CH), 75.8 (C-1), 68.2 (C-2’), 64.2 (C-2), 59.2 (CH ₃ ), 55.5(1) (C-5), 55.4(5) (C-5), 54.9 (C-1’), 28.1 (C-3), 23.2 (C-4). m/z (LC-MS, ESI ⁺ ) 382 (M( ³⁵ Cl)Na ⁺ ), 384 (M( ³⁷ Cl)Na ⁺ ). Accurate mass: Found (MH ⁺ ), 360.1732: C ₂₁ H ₂₇ NO ₂ ³⁵ Cl requires M, 360.1730. (2R)-1-{2-[(4-Chlorophenyl)(phenyl)methoxy]ethyl}-2-methylpy rrolidine - (R)-147 1-[(2-bromoethoxy)(phenyl)methyl]-4-chlorobenzene 180 (326 mg, 1.03 mmol) in DMF (1 mL) was added dropwise to a suspension of the (R)-2-methyl-pyrrolidine hydrochloride (125 mg, 1.03 mmol), KI (17 mg, 0.10 mmol) and K2CO3 (285 mg, 2.06 mmol) in DMF (1.5 mL). The reaction mixture was stirred at rt for 24 h. Following the addition of H2O (5 mL) and extraction with EtOAc (3 x 5 mL), the combined organic layers were dried and concentrated in vacuo. The crude product was purified by column chromatography (10% MeOH in CHCl ₃ ) to afford the title compound (217 mg, 65 %) as a brown oil. nmax (ATR) 2962 (w), 2869 (w), 2786 (w), 1490 (m), 1453 (w), 1375 (w), 1185 (w), 1088 (s) 1015 (m). δ _H (700 MHz, CDCl ₃ , mixture of diastereomers) 7.33 – 7.23 (9H, m, ArH), 5.36 (1H, s, Ar ₂ H), 3.62 – 3.55 (2H, m, 2’-H ₂ ), 3.16 – 3.11 (1H, m, 5-HH’), 3.09 – 3.03 (1H, m, 1’-HH’), 2.44 - 2.38 (1H, m, 5-HH’), 2.38 – 2.31 (1H, m, 2-H), 2.24 – 2.16 (1H, m, 1’ –HH’), 1.93 – 1.85 (1H, m, 3-HH’), 1.80 – 1.62 (2H, m, 4-H ₂ ), 1.43 – 1.34 (1H, m, 3-HH’), 1.09 (1.5H, d, J = 6.0 Hz, CH ₃ ), 1.08 (1.5H, d, J = 6.0 Hz, CH ₃ ). δ _C (176 MHz, CDCl ₃ , mixture of diastereomers) 142.0(2) (ArC), 141.9(6) (ArC), 141.2 (ArC), 141.1 (ArC), 133.2(2) (ArC), 133.1(9) (ArC), 128.6(2) (ArC), 128.5(7) (ArC), 128.5 (ArC), 128.4 (ArC), 127.8 (ArC), 127.7 (ArC), 127.1(0) (ArC), 127.0(6) (ArC), 83.4 (Ar ₂ CH), 68.6(0) (C-2’), 68.5(6) (C-2’), 60.4(3) (C-2), 60.4(0) (C-2), 55.0 (C-5), 54.9 (C-5), 53.5 (C-1’), 53.4 (C-1’), 32.6 (C-3), 22.0 (C-4), 19.2 (CH ₃ ). m/z (LC-MS, ESI ⁺ ) 330 (M( ³⁵ Cl)Na ⁺ ), 332 (M( ³⁷ Cl)Na ⁺ ). Accurate mass: Found (M( ³⁵ Cl)H ⁺ ), 330.1630: C ₂₀ H ₂₅ ³⁵ ClNO requires M, 330.1625. (2S)-1-{2-[(4-Chlorophenyl)(phenyl)methoxy]ethyl}-2-methylpy rrolidine - (S)-147 1-[(2-bromoethoxy)(phenyl)methyl]-4-chlorobenzene 180 (310 mg, 0.95 mmol) in DMF (1 mL) was added dropwise to a suspension of the (S)-2-methyl-pyrrolidine hydrochloride (115 mg, 0.95 mmol), KI (17 mg, 0.10 mmol) and K2CO3 (263 mg, 1.90 mmol) in DMF (1.5 mL). The reaction mixture was stirred at rt for 24 h. Following the addition of H2O (5 mL) and extraction with EtOAc (3 x 5 mL), the combined organic layers were dried and concentrated in vacuo. The crude product was purified by column chromatography (10% MeOH in CHCl ₃ ) to afford the title compound (195 mg, 62 %) as a brown oil. nmax (ATR) 2962 (w), 2869 (w), 2785 (w), 1489 (m), 1453 (w), 1375 (w), 1293 (w), 1184 (w), 1087 (s), 1014 (m). δ _H (700 MHz, CDCl ₃ ) 7.32 - 7.22 (9H, m, ArH), 5.36 (1H, s, Ar ₂ CH), 3.65 – 3.55 ^{(2H, m, 2’-H} ₂ ^{), 3.20 – 3.13 (1H, m, 5-HH’), 3.10 – 3.04 (1H, m, 1’-HH’), 2.47 – 2.35 (2H, m, 5-} HH’, 2-H), 2.28 – 2.20 (1H, m, 1’ –HH’), 1.94 – 1.85 (1H, m, 3-HH’), 1.81 - 1.72 (1H, m, 4- HH’), 1.71 – 1.63 (1H, m, 4-HH’), 1.46 – 1.36 (1H, m, 3-HH’), 1.10 (3H, d, J = 6.0, CH3). δC (176 MHz, CDCl3, mixture of diastereomers) 141.9(3) (ArC), 141.8(6) (ArC), 141.1 (ArC), 141.0 (ArC), 133.2(2) (ArC), 133.1(9) (ArC), 128.6(0) (ArC), 128.5(8) (ArC), 128.5(5) (ArC), 128.4(2) (ArC), 128.3(8) (ArC), 127.8 (ArC), 127.7 (ArC), 127.1 (ArC), 127.0 (ArC), 83.4 (Ar2CH), 68.3(2) (C-2’), 68.2(9) (C-2’), 60.5(9) (C-2), 60.5(6) (C-2), 54.9 (C-5), 54.8 (C-5), 53.4 (C-1’), 53.3 (C-1’), 32.5 (C-3), 32.4 (C-3), 22.0(0) (C-4), 21.9(9) (C-4), 18.9(3) (CH3), 18.9(1) (CH3). m/z (LC-MS, ESI ⁺ ) 330 (M( ³⁵ Cl)Na ⁺ ), 332 (M( ³⁷ Cl)Na ⁺ ). Accurate mass: Found (M( ³⁵ Cl)H ⁺ ), 330.1636: C20H25 ³⁵ ClNO requires M, 330.1625. 2-((2R)-2-methylpyrrolidin-1-yl)ethan-1-ol263 - (R)-155 2-Bromoethanol (0.23 mL, 3.20 mmol) in dry MeCN (2 mL) was added dropwise to a mixture of (R)-2-methylpyrrolidine (415mg, 3.32 mmol) and K ₂ CO ₃ (918 mg, 6.64 mmol) in dry MeCN (2 mL) heated under reflux. After 15 h the mixture was cooled to rt, filtered and concentrated. Et ₂ O (5 mL) was then added and the product extracted with 1M HCl (2 x 5 mL). The aqueous phase was made basic with solid NaOH, then extracted with DCM (3 x 5 mL). The organic layers were combined, dried over Na ₂ SO ₄ , filtered and concentrated to afford the product (200 mg, 48%) as a colourless oil. Carried through without further purification. [α] _D ^{(c = 1.00 g/100 mL, CHCl} ₃ ⁾ _-58.8°. ⁿ _max ^{(ATR) 3385 (br, m), 2963 (m), 2875 (m), 2806 (m),} 1677 (m), 1416 (m), 1509 (m). δH (400 MHz, CDCl3) 4.03 – 3.86 (3H, m, 2-H2, 5’-HH’), 3.42 – 3.35 (1H, m, 1-HH’), 3.33 – 3.23 (1H, m, 2’-H), 3.01 – 2.91 (2H, m, 1-HH’, 5’-HH’), 2.29 – 2.18 (2H, m, 3’-HH’, 4-HH’), 2.08 – 1.98 (1H, m, 4-HH’), 1.97 - 1.87 (2H, m, 3’-HH’), 1.54 (3H, d, J = 6.5 Hz, CH3). δC (176 MHz, CDCl3) 64.6 (C-2’), 57.6 (C-2), 57.2 (C-5’), 54.6 (C-1), 31.4 (C-3’), 21.7 (C-4’), 15.9 (CH3). m/z (LC-MS, ESI ⁺ ) 130 (MH+). Accurate mass: Found (MH ⁺ ), 130.1232: C ₇ H ₁₆ NO requires M, 130.1232. 2-((2S)-2-methylpyrrolidin-1-yl)ethan-1-ol263 - (S)-155 2-Bromoethanol (0.14 mL, 1.93 mmol) in dry MeCN (1 mL) was added to a refluxing mixture of (S)-2-methylpyrrolidine (257 mg, 2.00 mmol), K ₂ CO ₃ (535 mg, 3.87 mmol) in dry MeCN (2 mL). After 15 h the mixture was cooled to rt, filtered and concentrated. Et2O (5 mL) was then added and the product extracted with 1M HCl (2 x 5 mL). The aqueous phase was made basic with solid NaOH, then extracted with DCM (3 x 5 mL). The organic layers were dried over Na ₂ SO ₄ , filtered and concentrated to afford the product (200 mg, 48%) as a colourless oil. Carried through without further purification. [α] _D ^{(c = 1.00 g/100 mL, CHCl} ₃ ⁾ _+60.0°. ⁿ _max ^{(ATR) 3337 (br, m), 2948 (m), 2657 (m), 1451 (m),} 1053 (m). NMR and mass spectra were consistent with the R enantiomer. (2R)-1-(2-chloroethyl)-2-methylpyrrolidine hydrochloride - (R)-154 A solution of thionyl chloride (0.57 mL, 7.87 mmol) in chloroform (3 mL) was added dropwise to a solution of 2-((2R)-2-methylpyrrolidin-1-yl)ethan-1-ol (R)-155 (377 mg, 2.92 mmol) in chloroform (4 mL) at 0 °C. The resulting mixture was heated under reflux for 2 h and then concentrated under reduced pressure. Precipitation from a mixture of EtOH and Et ₂ O afforded the title compound contaminated with 19% 2-((2R)-2-methylpyrrolidin-1-yl)ethan-1-ol hydrochloride (353 mg, 35%) as a brown semi-solid. [α] _D ^{(c = 1.00 g/100 mL, CHCl} ₃ ⁾ _-23.7°. ⁿ _max ^{(ATR) 3392 (br, m), 2974 (m), 2554 (m), 2453 (m),} 1452 (m), 1422 (m), 1393 (m). δH (700 MHz, CDCl3, 19% 2-((2R)-2-methylpyrrolidin-1-yl)ethan- 1-ol hydrochloride) 12.56 (1H, s, NH ⁺ ), 4.15 – 4.10 (1H, m, 4’-HH’), 4.05 – 3.99 (1H, m, 4-HH’), 3.97 – 3.90 (1H, m, 5’-HH’), 3.72 – 3.66 (1H, m, 3’-HH’), 3.31 – 3.24 (1H, m, 2’-H), 3.12 – 3.05 (1H, m, 3’-HH’), 3.04 – 2.97 (1H, m, 5’-HH’), 2.30 – 2.17 (2H, m, 2-H2), 2.08 – 1.95 (2H, m, 1- H2), 1.64 (3H, d, J = 6.5 Hz, CH3). δC (176 MHz, CDCl3, 19% 2-((2R)-2-methylpyrrolidin-1- yl)ethan-1-ol hydrochloride) 65.3 (C-2’), 54.0 (C-3’), 53.8 (C-5’), 37.6 (C-4’), 31.1 (C-2), 21.6 (C- 1), 15.7 (CH ₃ ). m/z (LC-MS, ESI ⁺ ) 148 (M( ³⁵ Cl)H ⁺ ), 150 (M( ³⁷ Cl)H ⁺ ). (2S)-1-(2-chloroethyl)-2-methylpyrrolidine hydrochloride - (S)-154 A solution of thionyl chloride (0.87 mL, 12 mmol) in chloroform (5 mL) was added dropwise to a solution of 2-((2S)-2-methylpyrrolidin-1-yl)ethan-1-ol (S)-155 (575 mg, 4.45 mmol) in chloroform (5 mL) at 0 °C. The resulting mixture was heated under reflux for 2 h and then concentrated under reduced pressure. Precipitation from a mixture of EtOH and Et ₂ O afforded the title compound contaminated with 19% 2-((2S)-2-methylpyrrolidin-1-yl)ethan-1-ol hydrochloride (302 mg, 37%) as a brown semi-solid. [α] _D ^{(c = 1.00 g/100 mL, CHCl} ₃ ⁾ _+20.4°. ⁿ _max ^{(ATR) 3389 (br, m), 2974 (m), 2557 (m), 2461} (m), 1452 (m), 1423 (m), 1393 (m). NMR and mass spectra were consistent with the R enantiomer. (2S)-1-{2-[(S)-(4-chlorophenyl)(phenyl)methoxy]ethyl}-2-meth ylpyrrolidine - (S, S)-147 General procedure B was used in the reaction of (S)-4-chlorophenyl(phenyl)methanol (S)-113 (119 mg, 0.43 mmol) and (2S)-1-(2-chloroethyl)-2-methylpyrrolidine (S)-154 (63 mg, 0.43 mmol). The crude product was purified by flash column chromatography (0 → 100% EtOAc in hexanes with 1% NEt3) to afford the title compound (78mg, 55%) as a colourless oil. nmax (ATR) 2962 (w), 2869 (w), 2787 (w), 1489 (m), 1453 (w), 1375 (w), 1086 (s), 1014 (m). δH (700 MHz, CDCl ₃ ) 7.31 - 7.22 (9H, m, ArH), 5.34 (1H, s, Ar ₂ CH), 3.57 (2H, t, J = 6.5 Hz, 2’-H ₂ ), 3.15 – 3.09 (1H, m, 5-HH’), 3.04 (1H, dt, J = 12.5, 6.5 Hz, 1’-HH’), 2.39 (1H, dt, J = 12.5, 6.5 Hz, 1’-HH’), 2.36 – 2.30 (1H, m, 2-H), 2.22 – 2.16 (1H, m, 5-HH’), 1.91 – 1.84 (1H, m, 3-HH’), 1.78 – 1.69 (1H, m, 4-HH’), 1.69 - 1.61 (1H, m, 4-HH’), 1.41 - 1.33 (1H, m, 3-HH’), 1.07 (3H, d, J = 6.0 Hz, CH ₃ ). δ _C (176 MHz, CDCl ₃ ) 142.0 (ArC), 141.2 (ArC), 133.2 (ArC), 128.6(1) (ArC), 128.6(0) (ArC), 128.4 (ArC), 127.8 (ArC), 127.1 (ArC), 83.4 (Ar ₂ CH), 68.6 (C-2’), 60.5 (C-2), 54.9 (C-5), 53.4 (C-1’), 32.6 (C-3), 22.0 (C-4), 19.1 (CH3). m/z (LC-MS, ESI ⁺ ) 330 (M( ³⁵ Cl)H ⁺ ), 332 (M( ³⁷ Cl)H ⁺ ). Accurate mass: Found (MH ⁺ ), 330.1624: C20H25NO ³⁵ Cl requires M, 330.1625. (2R)-1-{2-[(S)-(4-chlorophenyl)(phenyl)methoxy]ethyl}-2-meth ylpyrrolidine - (R, S)-147 General procedure B was used in the reaction of (S)-4-chlorophenyl(phenyl)methanol (S)-113 (67 mg, 0.24 mmol) and (2R)-1-(2-chloroethyl)-2-methylpyrrolidine (R)-154 (12 mg, 0.08 mmol). The crude product was purified by flash column chromatography (0 → 100% EtOAc in hexanes with 1% NEt3) to afford the title compound (15 mg, 57 %) as a colourless oil. n _max (ATR) 2963 (w), 2870 (w), 2789 (w), 1490 (w), 1453 (w), 1375 (w), 1089 (m), 1015 (w). δ _H (700 MHz, CDCl3) 7.33 – 7.29 (4H, m, ArH), 7.29 - 7.27 (4H, m, ArH), 7.26 – 7.23 (1H, m, ArH), 5.36 (1H, s, Ar2CH), 3.69 – 3.54 (2H, m, 2’-H2), 3.22 - 3.14 (1H, m, 5-HH’), 3.12 – 3.05 (1H, m, 1’-HH’), 2.54 – 2.36 (2H, m, 1-HH’, 2-H), 2.34 – 2.22 (1H, m, 5-HH’), 1.98 – 1.86 (1H, m, 3-HH’), 1.84 – 1.74 (1H, m, 4-HH’), 1.73 – 1.64 (1H, m, 4-HH’), 1.49 – 1.36 (1H, m, 3-HH’), 1.12 (3H, d, J = 6.0 Hz, CH3). δC (176 MHz, CDCl3) 141.9 (ArC), 141.0 (ArC), 133.3 (ArC), 128.7 (ArC), 128.6 (ArC), 128.5 (ArC), 127.8 (ArC), 127.1 (ArC), 83.5 (Ar ₂ CH), 68.2 (C-2’), 60.7 (C-2), 54.8 (C-5), 53.4 (C-1’), 32.4 (C-3), 22.0 (C-4), 18.9 (CH ₃ ). m/z (LC-MS, ESI ⁺ ) 330 (M( ³⁵ Cl)H ⁺ ), 332 (M( ³⁷ Cl)H ⁺ ). Accurate mass: Found (MH ⁺ ), 330.1634: C ₂₀ H ₂₅ NO ³⁵ Cl requires M, 330.1625. (2R)-1-{2-[(R)-(4-chlorophenyl)(phenyl)methoxy]ethyl}-2-meth ylpyrrolidine - (R, R)-147 General procedure B was used in the reaction of (R)-4-chlorophenyl(phenyl)methanol (R)-113 (100 mg, 0.36 mmol) and (2R)-1-(2-chloroethyl)-2-methylpyrrolidine (R)-154 (53 mg, 0.36 mmol). The crude product was purified by flash column chromatography (0 → 100% EtOAc in hexanes with 1% NEt3) to afford the title compound as a colourless oil (72 mg, 61%). nmax (ATR) 2962 (w), 2869 (w), 2788 (w), 1490 (w), 1088 (m), 1015 (w). δH (700 MHz, CDCl3) 7.32 - 7.20 (9H, m, ArH), 5.35 (1H, s, Ar ₂ CH), 3.58 (2H, td, J = 6.5, 1.5 Hz, 2’-H ₂ ), 3.16 – 3.12 (1H, m, 5-HH’), 3.06 (1H, dt, J = 12.5, 6.5 Hz, 1’-HH’), 2.41 (1H, dt, J = 12.5, 6.5 Hz, 1’-HH’), 2.38 – 2.32 (1H, m, 2-H), 2.24 – 2.18 (1H, m, 5-HH’), 1.91 – 1.85 (1H, m, 3-HH’), 1.80 – 1.71 (1H, m, 4-HH’), 1.70 - 1.63 (1H, m, 4-HH’), 1.42-1.35 (1H, m, 3-HH’), 1.09 (3H, d, J = 6.0 Hz, CH3). δC (176 MHz, CDCl3) 141.9 (ArC), 141.1 (ArC), 133.2 (ArC), 128.5(8) (ArC), 128.5(7) (ArC), 128.4 (ArC), 127.7 (ArC), 127.1 (ArC), 83.4 (Ar2CH), 68.5 (C-2’), 60.5 (C-2), 54.9 (C-5), 53.4 (C- 1’), 32.5 (C-3), 22.0 (C-4), 19.1 (CH3). m/z (LC-MS, ESI ⁺ ) 330 (M( ³⁵ Cl)H ⁺ ), 332 (M( ³⁷ Cl)H ⁺ ). Accurate mass: Found (MH ⁺ ), 330.1632: C20H25NO ³⁵ Cl requires M, 330.1625. 1-[(3-bromopropoxy)(phenyl)methyl]-4-chlorobenzene - 183 To a solution of 4-chlorophenyl(phenyl)methanol 113 (500 mg, 2.29 mmol) and AuCl (33 mg, 0.23 mmol) in DCE was added 3-bromopropanol (318 mg, 2.29 mmol). This reaction was heated to 80 °C for 16 h. The solvent was then removed under reduced pressure and purified by flash column chromatography (0 → 20% EtOAc in hexanes) to afford the product as a colourless oil (244 mg, 54%). n _max (ATR) 3029 (w), 2866 (w), 1489 (m), 1088 (s), 1014 (m). δ _H (700 MHz, CDCl ₃ ) 7.37 – 7.27 (9H, m, ArH), 5.5 (1H, s, Ar2CH), 3.61 – 3.56 (4H, m, 3’-H2, 1’-H2), 2.18 (2H, p, J = 6.0 Hz, 2’- H2). δC (176 MHz, CDCl3) 141.8 (ArC), 140.9 (ArC), 133.3 (ArC), 128.7 (ArC), 128.6 (ArC), 128.4 (ArC), 127.9 (ArC), 127.0 (ArC), 83.3 (Ar2CH), 66.6 (C-3’), 33.1 (C-2’), 30.8 (C-1’). m/z (LC-MS, ESI ⁺ ) 201 (M( ³⁵ Cl)-OC3H6Br ⁺ ), 203 (M( ³⁷ Cl)- OC3H6Br ⁺ ). Accurate mass: Found (M-OC3H6Br ⁺ ), 201.0474: C13H10 ³⁵ Cl requires M, 201.0471. (2S)-1-{3-[(4-chlorophenyl)(phenyl)methoxy]propyl}-2-methylp yrrolidine - (S)-157 1-[(3-bromopropoxy)(phenyl)methyl]-4-chlorobenzene 183 (320 mg, 0.94 mmol) in DMF (5 mL) was added dropwise to a suspension of (2S)-2-methylpyrrolidine hydrochloride (115 mg, 0.94 mmol), KI (17g, 0.1 mmol) and K2CO3 (210mg, 1.88 mmol) in DMF (10 mL). The reaction was then stirred at rt for 24 h. Following the addition of EtOAc (10 mL), the organic layer was washed with H ₂ O (5 x 10 mL), dried over Na ₂ SO ₄ , filtered and concentrated in vacuo. The crude product was purified by column chromatography (10% MeOH in CHCl ₃ ) to afford the title compound (217 mg, 65 %) as a colourless oil. n _max (ATR) 2960 (w), 2869 (w), 2789 (w), 1489 (m), 1087 (s), 1014 (m). δ _H (600 MHz, CDCl ₃ , mixture of diastereomers) 7.32 – 7.29 (4H, m, ArH), 7.28 – 7.26 (4H, m, ArH), 7.26 – 7.22 (1H, m, ArH), 5.30 (1H, s, Ar2CH), 3.51 – 3.47 (2H, m, 3’-H2), 3.17 – 3.09 (1H, m, 5-HH’), 2.95 – 2.86 (1H, m, 1’-HH’), 2.31 – 2.22 (1H, m, 2-H), 2.16 – 2.10 (1H, m, 1’-HH’), 2.10 – 2.04 (1H, m, 5-HH’), 1.93 – 1.81 (3H, m, 2’-H2, 3-HH’), 1.80 – 1.71 (1H, m, 4-HH’), 1.70 – 1.62 (1H, m, 4- HH’), 1.46 – 1.36 (1H, m, 3-HH’), 1.08 (1.5H, d, J = 6.0, CH3), 1.08 (1.5H, d, J = 6.0, CH3). δC (151 MHz, CDCl3, mixture of diastereomers) 142.2 (C-1’ ^Ph ), 141.2(8) (C-1 ^Ph ), 141.2(8) (C-1 ^Ph ), 133.1(3) (C-4 ^Ph ), 133.1(2) (C-4 ^Ph ), 128.5(7) (ArC), 128.5(5) (ArC), 128.5(4) (ArC), 128.5(2) (ArC), 128.4 (ArC), 127.6(6) (C-4’ ^Ph ), 127.6(5) (C-4’ ^Ph ), 127.0 (ArC), 83.0 (Ar2CH), 67.8(3) (C- 3’), 67.8(0) (C-3’), 60.3 (C-2), 54.0(7) (C-5), 54.0(6) (C-5), 51.3 (C-1’), 51.2 (C-1’), 32.8 (C-3), 29.2 (C-2’).21.7 (C-4), 19.1 (CH3). m/z (LC-MS, ESI ⁺ ) 344 (M( ³⁵ Cl)H ⁺ ), 346 (M( ³⁷ Cl)H ⁺ ). Accurate mass: Found (M( ³⁵ Cl)H ⁺ ), 344.1784: C21H27 ³⁵ ClNO requires M, 344.1781. 3-[(2S)-2-methylpyrrolidin-1-yl]propan-1-ol - (S)-184 3-Bromopropanol (0.72 mL, 7.9 mmol) in dry MeCN (5 mL) was added dropwise to a mixture of (S)-2-methylpyrrolidine (1 g, 8.2 mmol) and K2CO3 (2.27g, 16.4 mmol) in dry MeCN (5 mL) heated under reflux. After 15 h the mixture was cooled to rt, filtered and concentrated. Et ₂ O (10 mL) was then added and the product extracted with 1M HCl (2 x 10 mL). The aqueous phase was made more basic with solid NaOH, then extracted with DCM (3 x 10 mL). The organic layers were combined, dried over Na2SO4, filtered and concentrated to afford product (620 mg, 55%) as a colourless oil. Carried through without further purification. n _max (ATR) 3372 (br), 2961 (m), 2872 (w), 1114 (w). δ _H (400 MHz, CDCl ₃ ) 3.81 – 3.72 (2H, m, 3- H ₂ ), 3.35 – 3.26 (1H, m, 1-HH’), 3.02 – 2.91 (1H, m, 5’-HH’), 2.43 – 2.34 (1H, m, 5’-HH’), 2.33 – 2.23 (1H, m, 2’-HH’), 2.13 - 2.02 (1H, m, 1-HH’), 2.01 - 1.81 (2H, m, 2-HH’, 3’-HH’), 1.79 – 1.60 (2H, m, 4’-H ₂ ), 1.58 - 1.46 (1H, m, 2-HH’), 1.43 - 1.29 (1H, m, 3’-HH’), 1.11 (3H, d, J = 6.0 Hz, CH ₃ ). δ _C (176 MHz, CDCl ₃ ) 69.3 (C-2’), 61.9 (C-5’), 54.0 (C-1), 50.9 (C-3), 32.2 (C-3’), 27.3 (C-2), 21.6 (C-4’), 18.1 (CH ₃ ). m/z (LC-MS, ESI ⁺ ) 144 (MH ⁺ ). Accurate mass: Found (MH ⁺ ), 144.1393: C ₈ H ₁₈ NO requires M, 144.1388. (2S)-1-(3-chloropropyl)-2-methylpyrrolidine hydrochloride - (S)-185 A solution of thionyl chloride (0.74 mL, 10.24 mmol) in chloroform (2 mL) was added dropwise to a solution of 3-[(2S)-2-methylpyrrolidin-1-yl]propan-1-ol (S)-184 (491 mg, 3.43 mmol) in chloroform (6 mL) at 0 °C. The mixture was heated to reflux for 2 h and concentrated under reduced pressure. The product was precipitated from ethanol and diethylether to afford the title compound (172 mg, 25%) contaminated with 19% 3-[(2S)-2-methylpyrrolidin-1-yl]propan-1-ol hydrochloride. nmax (ATR) 3404 (br), 2964 (m), 2600 (w), 2511 (w), 1633 (w), 1453 (w), 1063 (w). M.p.125 – 127 °C (lit. ²⁶⁵ : 150.5 – 152.0 °C). δ _H (700 MHz, CDCl ₃ , 19% 3-[(2S)-2-methylpyrrolidin-1-yl]propan- 1-ol hydrochloride) 12.15 (1H, s, N ⁺ H), 3.93 - 3.83 (1H, m, 5’-HH’), 3.74 – 3.62 (2H, m, 3-H ₂ ), 3.44 - 3.37 (1H, m, 1-HH ^’ ), 3.24 – 3.12 (1H, m, 2’-H), 3.00 – 2.92 (1H, m, 1-HH ^’ ), 2.89 – 2.79 (1H, m, 5’-HH’), 2.72 – 2.61 (1H, m, 2-HH’), 2.29 - 2.16 (3H, m, 3’-HH’, 4’- HH’, 2-HH’), 2.11 – 1.96 (2H, m, 3’-HH’, 4’- HH’), 1.64 (3H, d, J = 6.5 Hz, CH ₃ ). δ _C (176 MHz, CDCl ₃ , 19% 3-[(2S)- 2-methylpyrrolidin-1-yl]propan-1-ol hydrochloride) 65.3 (C-2’), 53.5 (C-5’), 51.4 (C-1), 42.1 (C- 3), 31.5 (C-3’), 28.2 (C-2), 21.5 (C-4’), 15.7 (CH ₃ ). m/z (LC-MS, ESI ⁺ ) 162 (M( ³⁵ Cl)H ⁺ ), 164 (M( ³⁷ Cl)H ⁺ ). Accurate mass: Found (MH ⁺ ), 162.1041: C ₈ H ₁₇ N ³⁵ Cl requires M, 162.1050. (2S)-1-{3-[(R)-(4-chlorophenyl)(phenyl)methoxy]propyl}-2-met hylpyrrolidine - (S, R)-157 General procedure B was used for the reaction of (R)-4-chlorophenyl(phenyl)methanol 113 (76 mg, 0.27 mmol) and (2R)-1-(2-chloropropyl)-2-methylpyrrolidine (S)-185 (101 mg, 0.62 mmol). The crude product was purified by flash column chromatography (0 → 100% EtOAc in hexanes with 1% NEt3) to afford the title compound (78 mg, 55%) as a colourless oil. nmax (ATR) 2960 (w), 1489 (w), 1089 (w). δH (700 MHz, CDCl3) 7.32 – 7.29 (4H, m, ArH), 7.27 – 7.22 (5H, m, ArH), 5.30 (1H, s, Ar ₂ CH), 3.49 (2H, td, J = 6.0, 1.5 Hz, 3’-H ₂ ), 3.21 – 3.15 (1H, m, 5-HH’), 2.98 – 2.90 (1H, m, 1’-HH’), 2.39 – 2.31 (1H, m, 2-H), 2.22 – 2.10 (2H, m, 1’-HH’, 5- HH’), 1.96 – 1.85 (3H, m, 2’-H ₂ , 3-HH’), 1.83 – 1.75 (1H, m, 4-HH’), 1.73 – 1.65 (1H, m, 4- HH’), 1.50 – 1.42 (1H, m, 3-HH’), 1.12 (3H, d, J = 6.0 Hz, CH3). δC (176 MHz, CDCl3) 142.1 (C- 1’ ^Ph ), 141.2 (C-1 ^Ph ), 133.2 (C-4 ^Ph ), 128.5(7) (ArC), 128.5(6) (ArC), 128.4 (ArC), 127.7 (C-4’ ^Ph ), 127.0 (ArC), 83.0 (Ar2CH), 67.6 (C-3’), 60.7 (C-2), 53.9 (C-5), 51.2 (C-1’), 32.7 (C-3), 28.9 (C- 2’), 21.7 (C-4), 18.7 (CH3). m/z (LC-MS, ESI ⁺ ) 344 (M( ³⁵ Cl)H ⁺ ), 346 (M( ³⁷ Cl)H ⁺ ). Accurate mass: Found (MH ⁺ ), 344.1783: C21H27NO ³⁵ Cl requires M, 344.1781. 1-[(4-bromobutoxy)(phenyl)methyl]-4-chlorobenzene - 186 General procedure A was used for 4-chlorophenyl(phenyl)methanol 113 (531 mg, 2.43 mmol) and 4-bromobutanol (372 mg, 2.43 mmol) with the modification of AuCl (56 mg, 0.24 mmol) as the catalyst in the place of PdCl ₂ with a reaction time of 20 h. The crude product was purified by column chromatography (0 → 20% EtOAc in hexanes) to afford the title compound (350 mg, 41%) as a colourless oil. nmax (ATR) 3029 (w), 2941 (w), 2863 (w), 1489 (m), 1086 (s), 1014 (m). δH (600 MHz, CDCl3) 7.36 – 7.24 (9H, m, ArH), 5.30 (1H, s, Ar ₂ CH), 3.47 (2H, t, J = 6.5 Hz, 4’-H ₂ ), 3.43 (2H, t, J = 6.5 Hz, 1’-H ₂ ), 2.00 (2H, p, J = 6.5 Hz, 2’-H), 1.79 (2H, p, J = 6.5 Hz, 3’-H). δ _C (176 MHz, CDCl ₃ ) 142.0 (C-1 ^Ph ), 141.1 (C-1’ ^Ph ), 133.2 (C-4 ^Ph ), 128.6(4) (C-3’ ^Ph ), 128.6(1) (C-3 ^Ph ), 128.3 (C-2 ^Ph ), 127.8 (C-4’ ^Ph ), 127.0 (C-2’ ^Ph ), 83.1 (Ar ₂ CH), 68.1 (C-4’), 33.8 (C-1’), 29.9 (C-2’), 28.5 (C-3’). m/z (LC-MS, ESI ⁺ ) 201 (M( ³⁵ Cl)-OC ₄ H ₈ Br] ⁺ ), 203 (M( ³⁷ Cl)-OC ₄ H ₈ Br] ⁺ ). Accurate mass: Found ([M- OC ₄ H ₈ Br] ⁺ ), 201.0480: C ₁₃ H ₁₀ ³⁵ Cl requires M, 201.0471. (2S)-1-{4-[(4-chlorophenyl)(phenyl)methoxy]butyl}-2-methylpy rrolidine - (S)-158 1-[(4-bromobutoxy)(phenyl)methyl]-4-chlorobenzene 186 (106 mg, 0.3 mmol) in DMF (0.5 mL) was added dropwise to a suspension of (2R)-2-methylpyrrolidine hydrochloride (46 mg, 0.38 mmol), KI (7 mg, 0.04 mmol) and K ₂ CO ₃ (105 mg, 0.76 mmol) in DMF (1 mL). The reaction was stirred at rt for 24 h. Following the addition of EtOAc (10 mL), the organic layer was washed with H2O (5 x 10 mL), dried over Na2SO4, filtered and concentrated in vacuo. The crude product was purified by column chromatography (0 → 100% EtOAc in hexanes with 1% NEt3) to afford the title compound as a colourless oil (49 mg, 46 %). nmax (ATR) 2954 (w), 2867 (w), 2789 (w), 1490 (m), 1453 (w), 1089 (s), 1015 (m). δH (600 MHz, CDCl ₃ ) 7.31 – 7.28 (4H, m, ArH), 7.27 - 7.21 (5H, m, ArH), 5.28 (1H, s, Ar ₂ CH), 3.47 – 3.41 (2H, m, 3’-H ₂ ), 3.18 – 3.12 (1H, m, 5-HH’), 2.81 – 2.74 (1H, m, 1’-HH’), 2.29 – 2.19 (1H, m, 2- H), 2.09 –1.96 (2H, m, 5-HH’, 1’-HH’), 1.93 – 1.85 (1H, m, 3-HH’), 1.81 – 1.72 (1H, m, 4-HH’), 1.72 – 1.55 (5H, m, 4-HH’, 3’-H ₂ , 2’-H ₂ ), 1.45 – 1.38 (1H, m, 3-HH’), 1.07 (3H, d, J = 6.0, CH ₃ ). δ _C (176 MHz, CDCl ₃ , mixture of diastereomers) 142.2(1) (C-1’ ^Ph ), 142.2(0) (C-1’ ^Ph ), 141.3 (C-1 ^Ph ), 133.2 (C-4 ^Ph ), 128.6(0) (ArC), 128.5(9) (ArC), 128.5(7) (ArC), 128.5(6) (ArC), 128.3(9) (ArC), 128.3(8) (ArC), 127.7 (C-4’ ^Ph ), 127.0(3) (ArC), 127.0(1) (ArC), 83.1 (Ar ₂ CH), 69.1(6) (C-4’), 69.1(5) (C-4’), 60.5 (C-2), 54.3 (C-1’), 54.2 (C-1’), 54.1 (C-5), 32.8 (C-3), 28.2(4) (C-2’), 28.2(3) (C-2’), 25.7 (C-3’), 21.7 (C-4), 19.0 (CH ₃ ). m/z (LC-MS, ESI ⁺ ) 358 (M( ³⁵ Cl)H ⁺ ), 360 (M( ³⁷ Cl)H ⁺ ). Accurate mass: Found (MH ⁺ ), 358.1949: C ₂₂ H ₂₈ ³⁵ ClNO requires M, 358.1938. General Reaction Schemes Below are general reaction schemes showing the synthesis of various compounds. Reaction Scheme 1 – Synthesis of compounds NTP-5, 8 and 9 Procedure D: Synthesis of 4‐bromo‐N‐(4‐bromobutyl)‐N‐phenylaniline (NTP-2). NaH (1.3 equiv.) was added to a 25 ml round bottom flask containing 4-bromo-N-phenylaniline (1 equiv.) in dry DMF (8.0 mL) and the reaction mixture was stirred for 15 min followed by the addition of 1,4-dibromobutane (1 equiv.). The reaction vessel was sealed, and the content was heated at 80 ºC overnight. Upon completion of the reaction, DMF was removed by air flow. The residue was re-suspended in dichloromethane (20 mL) and filtered. The filtrate was washed with aqueous NaCl (5%) (3x20 mL), dried over Na2SO4 and concentrated in vacuum. The obtained residue was purified by flash column chromatography with hexane/ethyl acetate (90:10) to afford the titled product. Procedure E: Synthesis of 4‐bromo‐N‐{4‐[(2S)‐2‐methylpyrrolidin‐1‐yl]b utyl}‐N‐phenylaniline (NTP-5). A solution of 4‐bromo‐N‐(4‐bromobutyl)‐N‐phenylaniline (NTP-2, 80.0 mg, 0.21 mmol), (R)-2- Methyl-pyrrolidine hydrochloride (25.4 mg, 0.21 mmol), Na2CO3 (101.8 mg, 0.96 mmol) and catalytic amount of KI (0.3 mg, 0.002 mmol) in acetonitrile (125 mL) were refluxed for 12h. Upon reaction completion, precipitate was removed by filtration and solvent was concentrated in vacuum to obtain crude residue which was purified by flash chromatography with dichloromethane/methanol to afford 4-bromo-N-{4-[(2R)-2-methylpyrrolidin-1-yl]butyl}-N- phenylaniline (NTP-5, 51.0 mg, 63.1%) as a white solid.. Reaction scheme 1 shows the synthesis of NTP-5, 8 and 9. Additionally, procedures D and E, above explain how NTP-5 was produced. Procedure D was used to produce building blocks N‐(4‐bromobutyl)‐4‐nitro‐N‐phenylaniline (NTP-3) and N‐(4‐bromobutyl)‐4‐chloro‐N‐phenylaniline (NTP-7), except 4-nitro-N-phenylaniline or 4- chloro-N-phenylaniline, respectively, were used instead of 4-bromo-N-phenylaniline. Similarly, procedure E was used to produce NTP-8 and 9, except NTP-3 and NTP-7, respectively, were used instead of instead of NTP-2. Procedure E was also used to produce NTP-10, except NTP-7 was used instead of instead of NTP-2 and (R)-2-methylpiperidine was used instead of (S)-2-methylpyrrolidine. Table 6: Structure of compounds and NMR data

Reaction Scheme 2 – Synthesis of compounds NTP-61 Reaction scheme 2 shows the synthesis of NTP-61. Procedure F: Synthesis of (R)‐(4‐chlorophenyl)(phenyl)methanol (NTP-59). Et2Zn (22.6 mL, 33.9 mmol) was added dropwise to a solution of 4-chloro-phenylboronic acid (1.76 mg, 11.30 mmol) in toluene under a nitrogen atmosphere. After stirring for 12 h at 60 °C, the mixture was cooled to 0 °C and a toluene solution of [(2S)-1-methyl pyrrolidine-2- yl]diphenylmethanol (252 mg, 0.94 mmol) was introduced. The reaction was stirred for an additional 15 min and the benzaldehyde (500 mg, 4.71 mmol) then added. After stirring for 12 h at 0 °C the reaction was quenched with H2O (5 mL) and extracted with DCM (3 x 15 mL). The combined organic layers were dried over MgSO4, filtered, and the solvent evaporated. Purification by flash chromatography (10% EtOAc in hexanes) afforded the title product as a white solid (724 mg, 70.3 %). The spectral data was in agreement with the reported data. Alternatively, if the 4-chloro-phenylboronic acid used as a starting product is replaced with 3- chloro-phenylboronic acid or 2-chloro-phenylboronic acid then the reaction scheme will produce (R)‐(3‐chlorophenyl)(phenyl)methanol or (R)‐(2‐chlorophenyl)(phenyl)methanol, respectively. Procedure G: Synthesis of (S)‐(4‐chlorophenyl)(phenyl)methanol (NTP-78). Et2Zn (20.5 mL, 30.73 mmol) was added dropwise to a solution of phenylboronic acid (1.249 mg, 10.24 mmol) in toluene under a nitrogen atmosphere. After stirring for 12 h at 60 °C, the mixture is cooled to 0 °C and a toluene solution of [(2S)-1-methyl pyrrolidine-2- yl]diphenylmethanol (228 mg, 0.85 mmol) was introduced. The reaction was stirred for an additional 15 min and the 4-chloro-benzaldehyde (600 mg, 4.26 mmol) then added. After stirring for 12 h at 0 °C the reaction was quenched with H2O (5 mL) and extracted with DCM (3 x 15 mL). The combined organic layers were dried over MgSO4, filtered, and the solvent evaporated. Purification by chromatography (10% EtOAc in hexanes) to afford the title product as a white solid (660 mg, 71%). The spectral data was in agreement with the reported data. Procedure H: Synthesis of building blocks NTP-52, NTP64, NTP-67, NTP-70 & NTP-83. 3-Bromo-1-propanol (0.72 mL, 7.9 mmol) in dry MeCN (5 mL) was added dropwise to a mixture of (S)-2-methylpyrrolidine (1 g, 8.2 mmol) and K ₂ CO ₃ (2.27g, 16.4 mmol) in dry MeCN (5 mL). The reaction mixture was heated under reflux. After 15 h the mixture was cooled to rt, filtered and concentrated. Et ₂ O (10 mL) was then added and the product was extracted with 1M HCl (2 x 10 mL). The aqueous phase was made more basic with solid NaOH, then extracted with DCM (3 x 10 mL). The organic layers were combined, dried over Na ₂ SO ₄ , filtered, and concentrated to afford product (NTP-52) in moderate to good yields as a colourless oils. Which was confirmed with LCMS and carried through without further purification. It will be appreciated that if the (S)-2-methylpyrrolidine is replaced with (R)-2- methylpyrrolidine, 2,2-dimethylpyrrolidine, pyrrolidine or (R)-2-methylpiperidine then the procedure will produce NTP-64, NTP-66, NTP-70 or NTP-83, respectively. Procedure I: Synthesis of Clemastine mimics: SN2 reaction of chlorobenzhydrol and alkyl chloride. The chlorobenzhydrol (1 equiv.) was dissolved in anhydrous DMF (3 mL) in an oven dried sealed tube and the solution was degassed with nitrogen. Then tBuOK (2.2 equiv.), NTP-52, 64, 67, 70 or 83 (1.2 equiv.) and tetra-n-butylammonium iodide (0.2 equiv.) were added to it and the mixture was degassed again and stirred at 50 ºC overnight. The reaction mixture was cooled, quenched with H ₂ O (10 mL) and diluted with EtOAc (10 mL). The aqueous layer was separated and extracted with EtOAc (2 x 15 mL). The combined organic layers were then dried over Na ₂ SO ₄ , filtered, and then concentrated in vacuo. The crude product was purified by flash column chromatography (0 → 100% EtOAc in hexanes with 1% NEt3) to afford the above compounds. Table 7: Structure of compounds and NMR data Biological experimental General experimental details MATERIALS: Biological grade materials, solvents, reagents and media components were purchased from commercial suppliers and used as provided. NBD-C6-ceramide 80 was from Invitrogen and AG 4-X4 ion exchange resin was from Bio-Rad. Reactions and media were prepared using ultrapure water from Milli-Q® water purification system. FBS refers to heat- inactivated foetal bovine serum. Solutions of test compounds were made up in DMSO, unless otherwise stated. INSTRUMENTS AND EQUIPMENT: 1.5 mL Eppendorfs were used during the preparation of serial dilutions. Media were filter-sterilised using a vacuum filter with a 0.22 μm pore CA membrane. Centrifugation steps were carried out using Sorvall® Legend RT centrifuge, Sorvall® Legend Micro 17R centrifuge, Beckman Coulter® centrifuges and ultracentrifuges. Eppendorf tubes were centrifuged using Sigma 1-14 microfuge. Disruption of yeast cells was performed using an IKA® Vortex Genius 3. Protein content and optical density (OD) were determined using a Boeco S-32 spectrophotometer. Eppendorf contents were dried using an Eppendorf Vacuum Concentrator 5301. Cells were counted using a Neubauer haemocytometer. 96-well plates used were Nest Biotechnology Co., Ltd cell culture plates (clear); Corning® Costar® cell culture plates (clear); Corning® V-bottom (clear); MultiScreen® Solvinert filter plates (Merck Millipore) and PerkinElmer OptiPlate-96 (black).24-well plates were supplied by Nest Biotechnology Co., Ltd and cover slips from Thomas Scientific®. Fluorescence quantification was carried out using SpectraMax® microplate reader with SoftMax® Pro 6.4 data analysis software from Molecular Devices and Synergy H4 and FLx800 microplate readers with Gen5® 1.08 data analysis software from Biotek. HPTLC silica plates were from Merck Millipore and imaged using a Fuji FLA-3000 plate reader with AIDA image analyser® (version 3.52). Solutions, buffers and media compositions are given in tables 8 and 9. Table 8: Details of the buffers and solutions used

Table 9: Details of the growth media used

Protocols All of the following biological procedures were carried out under sterile conditions unless otherwise stated. Leishmania culture Leishmania amazonensis (MHOM/Br/75/JOSEFA) promastigotes were maintained at 26 °C in Medium 199, supplemented with 15% FBS. Leishmania amazonensis (MHOM/Br/75/JOSEFA), Leishmania major (FV1) WT and Δ LCB2 promastigotes were maintained at 26 °C in Schneider’s insect medium at pH 7, supplemented with 15% FBS. Leishmania major (FV1) PX promastigotes were maintained at 26 °C in Schneider’s insect medium at pH 7, supplemented with 15% FBS and 40 μg mL-1 G418 (Gibco BRL). Leishmania amazonensis-GFP were selected for bright green fluorescence by 48 h-incubation in the presence of 1000 μg mL-1 G418 (Gibco BRL). Animals and ethics statement All mice used in the experiments were maintained under controlled temperature, filtered air and water, autoclave bedding, and commercial food at the animal facilities at Federal University of Rio de Janeiro. The animal protocols for this study were approved by the Federal University of Rio de Janeiro Institutional Animal Care and Use Committee under the number 030/17. The research was conducted in compliance with the principles stated in the Guide for the Care and Use of Laboratory Animals (NIH). Isolation of Bone Marrow Derived Macrophages (BMDM) BMDM were differentiated from bone marrow of BALB/C, C57BL/6 and knock out C57BL/6 mice using L929-cell conditioned medium (LCCM) as a source of macrophage colony- stimulating factor (M-CSF) as described by Zamboni et al. (F. M. Marim, T. N. Silveira, D. S. Lima and D. S. Zamboni, PLOS ONE, 2010, 5, e15263). Briefly, bone marrow was extracted from the femurs and tibias and re-suspended in bone marrow differentiated media (which is RPMI 1640 medium supplemented with 20% LCCM) in Petri dishes for 7 days at 37 °C with 5% CO2. After, the plates were washed with warm PBS to remove detached cells, the adherent BMDM were gently scraped off the surface and re-suspended in RPMI (without LCCM). These cells are ready to use in the anti-amastigote intramacrophage assay and the macrophage cytotoxicity assay described below. Drugs Clemastine fumarate and cycloheximide were purchased from Sigma-Aldrich. Glucantime solution (meglumine antimoniate, 300 mg mL 1) was a gift from Sanofi Aventis. Clemastine derivatives were synthesised using the procedure outline in the previous section. Stock solutions of clemastine and its derivatives (10 mM) were prepared in dimethyl sulfoxide (DMSO) and kept at 0 - 4° C. Subsequent dilutions were done in culture media. For in vitro assays, all drugs were serially diluted in 100% DMSO, and then diluted 1:100 in culture medium, so that all final drug concentrations contained 1% DMSO. Preparation of LmjIPCS microsomal material Auxotrophic AUR1 mutant S. cerevisiae was complemented by the expression of the L. major IPCS to create YPH499-HIS-GAL-AUR1 pRS246 LmjIPCS. These steps were carried out under non-sterile conditions. Step 1: Preparation of cell extract Crude membranes from this mutant S. cerevisiae were prepared as described by Fischl et al. (A. S. Fischl, Y. Liu, A. Browdy and A. E. Cremesti, Methods in Enzymology, Academic Press, Massachusetts, 2000). The complemented yeast cells were propagated in SGR-W-L media until OD ³ 0.8. Cells were harvested by centrifugation (4,000 x g, 4 °C, 10 min) and washed with cold PBS (3 x 20 mL). The cell pellet was weighed and re-suspended in STE buffer (1.5 mL per 1g wet cell mass (WCM)). The yeast cells were disrupted using pre-chilled, acid washed glass beads (425-600 μm, 1.5 mL per 1g WCM), using a vortex mixer. Disruption step involved 30 cycles of 1 min vortex mixing followed by a 1 min rest on ice. Glass beads, unbroken cells and cell-wall debris were pelleted by centrifugation (3,800 x g, 4 °C, 15 min) to obtain cell extract (supernatant) which was removed and stored on ice. The pellet was re-suspended in STE buffer (0.5 mL per 1g WCM) and subjected to 20 further disruption cycles. Following centrifugation (3,800 x g, 4 °C, 15 min), the supernatant was removed and cell extracts combined. Step 2: Preparation of crude microsomal membrane fraction The microsomal membrane faction, enriched in IPCS, was isolated from the cell extract by differential centrifugation. An initial centrifugation of the cell extract (23,000 x g, 4 °C, 15 min) pelleted large organelles and cell debris. The supernatant was removed and re-centrifuged (150,000 x g, 4 °C, 90 min) to obtain a pellet enriched with microsomal membranes. The pellet was re-suspended in storage buffer (approximately 100 μL) and the protein content was determined according to Bradford’s protocol.274 The concentration was adjusted to 20 mg ml-1 and 100 μL aliquots were stored in LoBind Eppendorf tubes at -80 °C. Step 3: Preparation of washed microsomal membranes The crude microsomal membranes were adjusted to a concentration of 10 mg mL-1 using STE buffer. Equal volume of the microsomal membranes and 2.5% CHAPS solution were mixed together and kept on ice for 1 h without shaking. The mixture was centrifuged (150,000 x g, 4 °C, 90 min) and the pellet re-suspended in storage buffer. The protein content was quantified according to Bradford’s protocol274 and the membranes were stored in LoBind Eppendorf tubes at -80 °C. Step 4: Determination of the Protein Content in Enzyme Units To standardise the assay and remove variability from sample preparation, microsome samples were normalised with respect to active enzyme content. The data is presented in enzyme units (U), where one unit (U) of enzyme converts 1 pmol of substrate per minute under the conditions described (1U = 1 pmol(product) min-1). A stock solution of NBD-C6-ceramide 80 at a concentration of 10 pmol μL ^-1 was used to produce a standard curve ranging from 0.2 pmol to 80 pmol. The volumes were adjusted to 200 μL with 1M potassium formate in MeOH and the fluorescence was read (Ex460/Em540). Samples of the washed microsomal membranes were incubated with NBD-C6-ceramide 80 and PI under assay conditions described for the 96-well plate–based LmjIPCS assay. and the product fluorescence measured (Ex460/Em540). Correlation with the standard curve allowed the activity of the microsome preparation to be determined in U μL-1. The membranes were adjusted to 1.5 U μL-1 with storage buffer and stored in LoBind Eppendorf tubes at -80 °C. Assays Anti-promastigote assays L. major promastigotes in Schneider’s insect medium (100 μL at 1 × 106 mL−1) were incubated in 96-well plates with compounds in triplicate (amphotericin B and cycloheximide were used as positive controls, and untreated parasites with 1% DMSO as a negative control) at 26 °C for 48 h. Resazurin Solution (10 μL) was then added and the plate incubated at 26 °C for 4 h prior to measurement using a fluorescence plate reader (555 - 585 nm). EC ₅₀ values were calculated using sigmoidal regression analysis (GraphPad Prism). L. amazonensis promastigotes in Schneider’s insect medium (100 μL at 5 × 105 mL−1) were incubated in 96-well plates with compounds in triplicate (amphotericin B was used as a positive control, and untreated parasites with DMSO as a negative control) at 26 °C for 48 h. Resazurin Solution (10 μL) was then added and the plate incubated at 26 °C for 4 h prior to measurement using a fluorescence plate reader (555 - 585 nm). EC50 values were calculated using sigmoidal regression analysis (GraphPad Prism). Anti-amastigote intramacrophage assay Bone marrow derived macrophages were diluted in RPMI 1640 medium to a concentration of 2 x 10 ⁵ well ^-1 in a 24-well plate with round cover slips and incubated for 24 h at 37 °C and 5% CO2. They were infected with L. amazonensis promastigotes (10:1) at 37 °C for 4 h. Then washed with PBS twice to remove extracellular promastigotes and fresh RPMI medium supplemented with 5% FBS was added. After 24 h serial dilutions of the test compounds in RPMI medium (350 μL) were added and the cells were incubated at 37 °C for 48 h. The adherent infected cells were then stained with Giemsa modified solution and amastigotes were counted using an optical Nikon® microscope. Macrophage cytotoxicity assay Bone marrow derived macrophages in RPMI 1640 medium were seeded (1 × 10 ⁶ mL ⁻¹ , 100 μL well ^-1 ) in 96-well plates and incubated for 24 h at 37 °C and 5% CO ₂ . Following removal of media, serial dilutions of the test compounds in fresh RPMI medium (100 μL) were added and the cells were incubated for 48 h at 37 °C and 5% CO2. Aliquots of resazurin solution (10 μL) were then added and the cells were incubated at 37 °C and 5% CO ₂ for 4 h. Cell-viability measurement was carried out using a fluorescence plate reader. Triton was used as a reference compound. EC50 values were calculated using sigmoidal regression analysis. NO assay The generation of nitrite in bone marrow derived macrophages was assessed by the Griess Reagent System (1% sulfanilamide / 0.1% N-(1-naphthyl)-ethylenediaminedihydrochloride/ 2.5% H ₃ PO ₄ ). Uninfected macrophages (1 × 10 ⁶ mL ⁻¹ , 100 μL well ^-1 ) in 96-well plates were incubated for 24 h at 37 °C and 5% CO2. Following removal of media, serial dilutions of the test compounds in fresh RPMI medium (100 μL) were added and the plate was incubated for 48 h at 37 °C and 5% CO2. The plates were centrifuged at 500 g/5 min and culture supernatants were then incubated with the Griess Reagent for 30 min at 37 °C. The absorbance was measured at 570 nm, and the nitrite concentration was determined using a standard curve of sodium nitrite (0 to 50 µM). The positive control was macrophages incubated with 1 µg mL-1 of LPS (Sigma- Aldrich, Brazil) and 10% conditioned medium of lymphocytes as a source of IFN. Negative controls were cells treated with DMSO and untreated cells. In vivo assay Two month old BALB/c female mice, weighing 20 - 25 g and of approximately the same age were used for the study. For infection of mice, stationary phase GFP L. amazonensis promastigotes were collected, washed and suspended in sterile PBS. A volume of 10 μl of sterile PBS containing 2 x 10 ⁶ parasites was injected into the right ear. On day seven of infection, animals were randomly distributed into 4 groups; IL (S,R)-157 (5 animals), IL clemastine fumarate (5 animals), IP glucantime solution (5 animals) and untreated (6 animals). Mice were treated with glucantime solution at a dose of 1.30 g kg ^-1 by intraperitoneal injection twice a week for 28 days. Mice were treated with (S,R)-157 or clemastine fumarate at a dose of 1.17 mg kg ^-1 by intralesional injection twice a week for 28 days. Infected ear thicknesses were measured once or twice a week with a caliper gauge, and the lesion sizes were expressed as the difference between the thickness of infected and non-infected ear. On day 41 animals were sacrificed and the fluorescence measured (485 - 528 nm) and parasite load quantified using a limiting dilution assay (LDA). Data on lesion progression were analysed for statistical significance by using the Dunnett test as part of the one-way ANOVA (GraphPad Prism 8 software). A result was considered significant at * P £ 0.05, ** P £ 0.01, *** P £ 0.001, **** P £ 0.0001.225 High performance thin layer chromatography (HPTLC) based LmjIPCS assay The following protocol was adapted from a literature procedure (J. G. Mina, J. A. Mosely, H. Z. Ali, H. Shams-Eldin, R. T. Schwarz, P. G. Steel and P. W. Denny, Int. J. Biochem. Cell Biol., 2010, 42, 1553–1561) and carried out under non-sterile conditions.145 Stock 1: Dry PI (1 mM, 30 μL) in a LoBind Eppendorf tube using a vacuum concentrator. To the dried PI, phosphate buffer (71.4 mM , pH 7.0, 105 μL), CHAPS (3 mM, 30 μL) and NBD-C6- ceramide 80 (200 μM, 1.7 μL) was added. The solution was mixed by vortex and stored on ice. Stock 2: Phosphate buffer (71.4 mM , pH 7.0, 105 μL), CHAPS (3 mM, 30 μL), storage buffer (6 μL) and microsomal membranes (1.5 μL) were combined in a LoBind Eppendorf tube. Stock 2 (23.75 μL) was added to n LoBind Eppendorf tubes (where n is the number of test compounds + controls), followed by the addition test compounds in DMSO (5 mM, 1 μL). After pre-incubation at 30 °C for 20 min, the reaction was started by the addition of stock 1 (23.75 μL) to each tube and incubation at 30 °C for 30 min. The reaction mixtures were quenched with CHCl ₃ :MeOH:H ₂ 0 (10:10:3, 150 μL). The mixtures were centrifuged to separate phases, the organic layer was removed and dried using a vacuum concentrator. The residue was re-suspended in CHCl ₃ :MeOH:H ₂ 0 (10:10:3, 20 μL) and loaded (3 x 3 μL ) onto HPTLC plates (silica gel 60 F ₂₅₄ ). This was run using the solvent system CHCl ₃ :MeOH:0.25% KCl _(aq) (55:45:10) and the R _f values for the excess NBD-C ₆ -ceramide 80 and the product NBD-C6-IPC 81 were 0.96 and 0.57 respectively. Product quantification was carried out using a fluorescence plate reader (Ex473/Em520). 96-well plate–based LmjIPCS assay The following protocol was adapted from a literature procedure (J. G. Mina, J. A. Mosely, H. Z. Ali, H. Shams-Eldin, R. T. Schwarz, P. G. Steel and P. W. Denny, Int. J. Biochem. Cell Biol., 2010, 42, 1553–1561) and carried out under non-sterile conditions. Stock 1: Dry PI (1 mM, 48 μL) in a glass vial using a vacuum concentrator. To the dried PI, phosphate buffer (71.4 mM , pH 7.0, 1680 μL), CHAPS (3 mM, 480 μL) and NBD-C6-ceramide 80 (200 μM, 120 μL) was added. The solution was mixed by vortex and stored on ice. Stock 2: Phosphate buffer (71.4 mM , pH 7.0, 1680 μL), CHAPS (3 mM, 480 μL), storage buffer (72 μL) and CHAPS-washed microsomal membranes (0.6 U) were combined in a glass vial. The solution was mixed by vortex and stored on ice. In a V-bottom 96-well plate, stock 1 (19 μL well ^-1 ) and test compounds (0.8 μL) were added. The reaction was initiated by the addition of stock 2 (20 μL well-1) and was incubated at 30 °C for 25 min before quenching with MeOH (200 μL well ^-1 ). Separation of the reaction product, NBD-C ₆ -ceramide 80, from the starting material, IPC-C6- caramide 81, was achieved using anion exchange chromatography.20% w/v AG4-X4 resin in EtOH (200 μL well ^-1 ) was added to a 96-well filter plate and centrifuged (2,450 x g, rt, 27 seconds). The resin was incubated with formic acid (50 μL well-1) for 5 minutes before being centrifuged (2,450 x g, rt, 27 seconds). The resin was then washed with water and dried by centrifugation (2,450 x g, rt, 27 seconds). The reaction mixture (200 μL) was loaded onto the resin and the starting material, NBD-C6- ceramide 80, removed by centrifugation (2,450 x g, rt, 1 min). The resin was washed with MeOH (5 x 200 μL) and subsequent centrifugation (2,450 x g, rt, 1 min). The product, NBD-C6- IPC 81, was eluted into black plates with potassium formate in MeOH (1M, 4 x 50 μL) followed by centrifugation (2,450 x g, rt, 1 min). Product quantification was carried out using a fluorescence plate reader (Ex460/Em540) and IC ₅₀ values were calculated using sigmoidal regression analysis (GraphPad Prism). Anti-leishmanial activity upon Leishmania donovani AG83 strain The compounds were prepared in DMSO. The inventors incubated the L. donovani promastigotes with the 21 compounds for different time-points, i.e., 1h, 24 and 72h and checked the viability of the parasites using MTT tetrazolium assay. The inventors then proceeded to study the efficacy of these selected compounds at clearing L. donovani amastigotes from macrophage. For that they first estimated the toxicity of the compounds upon healthy RAW 264.7 macrophage cell line. The inventors then infected RAW cells with L. donovani parasites and 72 h post-infection, they treated these infected cells with the compounds for 1 h. Geimsa staining based analysis of amastigotes burden per 100 macrophages was used to determine the toxic effect upon the amastigotes.