Phenylpropanoid derivatives Technical Field The invention relates to novel phenylpropanoid derivatives, use thereof in medicine, cosmetics and biotechnology, and compositions containing these derivatives. Background Art Phenylpropanoids are the largest group of secondary metabolites produced by plants, in particular in response to biotic or abiotic stresses, wounding, UV irradiation, exposure to ozone, pollutants, and other environmental conditions. It is thought that the molecular basis for the protective action of phenylpropanoids in plants are their antioxidant and free radical scavenging properties. The phenylpropanoids are also major biologically active components of human diet and traditional medicines. Recently, much interest has been attracted to natural and synthetic phenylpropanoids for medicinal use as antioxidant, UV screens, anticancer, anti-virus, anti-inflammatory, wound healing, and antibacterial agents. They are also of great interest for cosmetic and perfume industries as active natural ingredients. Dental plaque is an adherent bacterial film, and is the main pathological agent for periodontal diseases. The formation of dental plaque can occur both supragingivally and subgingivally. The development of plaque is a three-step process. Following the formation of a pellicle, pioneer micro-organisms adhere to the pellicle, proliferate and form colonies. The final stage involves the aggregation of filamentous organisms and spirochetes into a cohesive biofilm. Many products of the plaque bacteria reach the subepithelial tissue, causing inflammatory responses such as increased vascularity and leukocyte diapedesis. Both supragingival and subgingival plaque may form a hard, mineralized mass called calculus. The surface of calculus harbours bacteria, which may exacerbate the inflammatory response. An effective oral antiseptic must be active against a wide range of Gram-positive and Gram-negative bacterial species, including streptococci and fusobacteria. Ideally, an effective agent would also penetrate the plaque biofilm. Data show that essential oil and chlorhexidine mouthwashes have the broadest antimicrobial effects (Elkerbout et al., Int. J. Dent. Hyg.17, 3–15, 2019). Bacteria present in the oral biofilm are implicated in the pathogenesis of oral diseases, such as dental caries, periodontal diseases such as gingivitis and periodontitis, and even halitosiss. Thus, effective biofilm control is important for preventing these conditions. Manual or power tooth brushing is recommended as the primary means of reducing plaque and gingivitis; however, effective mechanical plaque control is time consuming and requires motivation and dexterity-related skills (Farah et al., Australian Prescriber vol. 32 162–164 (2009). This is why chemical plaque control utilizing antimicrobial agents is important to complement the results of mechanical oral hygiene measures (Chye et al., Implant Dentistry vol.2874–85, 2019). In dentistry, oral rinses containing antimicrobials function by chemomechanical action, and are used for both preventative and therapeutic purposes. Mouthwashes act as an ideal medium for all inaccessible areas in the mouth and are necessary in order to allow proper wound healing in situations where oral hygiene is difficult or compromised (Van Der Weijden et al., Dent. Clin. NA 59, 799–829, 2015). Generally speaking, there are two types of mouthwash products: cosmetic and therapeutic. Cosmetic mouthwashes lack active ingredients that provide a true chemical or biological application, they may temporarily control bad breath by leaving a pleasant taste, but they do not kill the bacteria associated with it (Joshipuraet al., Nitric Oxide 71, 14–20, 2017). On the other hand, therapeutic mouthwashes contain active ingredients, such as cetylpyridinium chloride (CPC), chlorhexidine (CHX), fluoride, and peroxide. In other words, cosmetic mouthwashes cannot act as an antimicrobial and lack the bacteriostatic and bacteriocidal benefits that are provided by therapeutic mouthwashes. When a therapeutic mouthwash is prescribed by a clinician, it is often short-term, and always evidence based for addressing specific conditions. When used correctly, the therapeutic mouthwashes are clinically effective in reducing dental biofilm accumulation, as well as an adjunct in the treatment of halitosis and periodontal disease, such as gingivitis and periodontitis (Elkerbout et al., Int. J. Dent. Hyg.17, 3– 15, 2019). It is an object of this invention to provide compounds suitable for use in mouthwashes, effective against periodontal bacteries and consequences of increased oxidative stress. Disclosure of the Invention The present invention provides novel phenylpropanoid compounds showing strong antioxidative properties and/or exhibiting the ability to regulate expression of an importat stress transcription factor NRF2. The phenylpropanoid compounds of the invention are suitable for use in prevention and treatment of a number of diseases associated with oxidative stress in skin, for example, psoriasis. Oxidative stress and its processes also play a key role in development of fibrosis in fibrotic disorders such as scleroderma, GVHD, hypertrophic scars, NSF, and other skin pathologies. This invention further provides the novel phenylpropanoid derivatives for treating periodontal disease and preventing tooth decay, for removing, killing, or inhibiting the growth of pathogens causing periodontal disease and tooth decay. The phenylpropanoid compounds of the present invention are thus suitable for use in the treatment of tooth and skin diseases induced by periodontal bacteria and increased oxidative stress. The object of this invention are derivatives of phenylpropanoids of the general formula I, wherein each of R ¹ , R ² , R ³ is indenpendently selected from the group consisting of H, hydroxy, and C1-C8 alkoxy; R ⁴ is selected from –O-R ⁵ and –N(R ⁶ )(R ⁷ ); R ⁵ is selected from the group consisting of H, C1-C8 alkyl, C2-C7 alkenyl, and -CH[(CH ₂ ) _{0- 2} (COO(C1-C4 alkyl))][(CH ₂ ) _0-2 (COO(C1-C4 alkyl))]; R ⁶ and R ⁷ is selected from the group consisting of H, C1-C8 alkyl, and C2-C7 alkenyl, or R ⁶ and R ⁷ together form -(CH ₂ ) _3-6 -; and pharmaceutically acceptable salts thereof. The parentheses with the numerals „2-3“ in formula I refer to 2 ethylenediyl units or 3 ethylenediyl units. The lower indexes „0-2“ or „3-6“ or similar indicate the ranges of repetition of the relevant bivalent chemical groups. Preferably, each of R ¹ , R ² , R ³ is indenpendently selected from the group consisting of H, hydroxy, methoxy and ethoxy. In some preferred embodiments, R ¹ is hydrogen, hydroxy, methoxy or ethoxy, R ² is hydroxy, or methoxy, and/or R ³ is hydrogen, hydroxy, methoxy or ethoxy. Preferably, R ⁵ is selected from methoxy, ethoxy, allyl, and -CH[(CH ₂ )(COO(C1-C4 alkyl))][(COO(C1-C4 alkyl))]. Preferably, R ⁶ and R ⁷ together form -(CH ₂ ) ₅ -. Some compounds of formula I may be optically active. When R ⁴ contains a center of chirality, formula I includes these compounds in the form of racemates, in the form of optically active isomers, as well as in the form of any mixtures of the optically active isomers. As used herein, and unless modified by the immediate context, the generic substituent groups have the following meanings: alkyl denotes a branched or linear alkyl chain containing the indicated number carbon atoms, preferably selected from the group comprising methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl, isohexyl; alkenyl denotes a branched or linear alkenyl chain containing 2 to 7 carbon atoms, preferably selected from the group comprising vinyl, allyl, 1-propenyl, 1-methylethenyl, but-1 to 3-enyl, pent-1 to 4-enyl, isopentenyl, hex-1 to 5-enyl, hept-1 to 6-enyl; alkoxy denotes –O-R _a , wherein R _a is alkyl as defined herein, preferably alkoxy is selected from the group comprising methoxy, ethoxy, propoxy, butoxy, pentoxy; hydroxy denotes -OH. In a preferred embodiment, the phenylpropanoid derivatives of the general formula I are: methyl (2E,4E)-5-(4-hydroxyphenyl)penta-2,4-dienoate, methyl (2E,4E)-5-(4-methoxyphenyl)penta-2,4- dienoate, methyl (2E,4E)-5-(3,4-dihydroxyphenyl)penta-2,4-dienoate, methyl (2E,4E)-5-(4-hydroxy- 3-methoxyphenyl)penta-2,4-dienoate, methyl (2E,4E)-5-(3,4-dihydroxy-5-methoxyphenyl)penta-2,4- dienoate, methyl (2E,4E)-5-(4-hydroxy-3,5-dimethoxyphenyl)penta-2,4-dienoate, methyl (2E,4E)-5- (3,4,5-trimethoxyphenyl)penta-2,4-dienoate, ethyl (2E,4E)-5-(4-hydroxy-3-methoxyphenyl)penta-2,4- dienoate, allyl (2E,4E)-5-(4-methoxy-3-propoxyphenyl)penta-2,4-dienoate, isopropyl (2E,4E)-5-(3,4- dihydroxy-5-methoxyphenyl)penta-2,4-dienoate, butyl (2E,4E)-5-(3-ethoxy-4,5- dimethoxyphenyl)penta-2,4-dienoate, dimethyl (S)-2-(((2E,4E)-5-phenylpenta-2,4- dienoyl)oxy)succinate, diethyl (S)-2-(((2E,4E)-5-phenylpenta-2,4-dienoyl)oxy)succinate, diisopropyl (S)-2-(((2E,4E)-5-phenylpenta-2,4-dienoyl)oxy)succinate, methyl (2E,4E)-5-(3,4- dimethoxyphenyl)penta-2,4-dienoate, but-3-en-1-yl (2E,4E)-5-(3,4-dihydroxyphenyl)penta-2,4- dienoate, methyl (2E,4E,6E)-7-(4-hydroxy-3,5-dimethoxyphenyl)hepta-2,4,6-trie noate, ethyl (2E,4E)- 5-(3,4,5-trimethoxyphenyl)penta-2,4-dienoate, methyl (2E,4E,6E)-7-(4-methoxyphenyl)hepta-2,4,6- trienoate, methyl (2E,4E,6E)-7-(4-hydroxy-3,5-dimethoxyphenyl)hepta-2,4,6-trie noate, ethyl (2E,4E,6E)-7-(4-hydroxy-3-methoxyphenyl)hepta-2,4,6-trienoat e, isopropyl (2E,4E,6E)-7-(3,4- dihydroxyphenyl)hepta-2,4,6-trienoate, allyl (2E,4E,6E)-7-(3-ethoxy-4-methoxyphenyl)hepta-2,4,6- trienoate, (2E,4E)-1-(piperidin-1-yl)-5-(3,4,5-trimethoxyphenyl)penta-2 ,4-dien-1-one, (2E,4E)-5-(4- methoxyphenyl)-1-(piperidin-1-yl)penta-2,4-dien-1-one, (2E,4E)-5-(4-hydroxyphenyl)-1-(piperidin-1- yl)penta-2,4-dien-1-one, (2E,4E)-5-(3,4-dihydroxyphenyl)-1-(piperidin-1-yl)penta-2,4- dien-1-one, (2E,4E)-N,N-diethyl-5-(4-hydroxy-3-methoxyphenyl)penta-2,4-d ienamide, (2E,4E)-N,N-diallyl-5-(3- ethoxy-4-hydroxy-5-methoxyphenyl)penta-2,4-dienamide, (2E,4E)-5-(3-butoxy-5-ethoxy-4- methoxyphenyl)-N,N-diisopropylpenta-2,4-dienamide, (2E,4E,6E)-7-(4-methoxyphenyl)-1-(piperidin- 1-yl)hepta-2,4,6-trien-1-one, (2E,4E,6E)-7-(3,4-dimethoxyphenyl)-N,N-diethylhepta-2,4,6-tr ienamide, (2E,4E,6E)-N,N-diethyl-7-(3,4,5-trimethoxyphenyl)hepta-2,4,6 -trienamide, (2E,4E,6E)-7-(3,5- diethoxy-4-hydroxyphenyl)-N,N-diethylhepta-2,4,6-trienamide. Generally, the most preferred phenylpropanoid derivatives of the general formula I are selected from: methyl (2E,4E)-5-(4-hydroxyphenyl)penta-2,4-dienoate, methyl (2E,4E)-5-(4-methoxyphenyl)penta- 2,4-dienoate, methyl (2E,4E)-5-(4-hydroxy-3,5-dimethoxyphenyl)penta-2,4-dienoate, methyl (2E,4E)- 5-(3,4,5-trimethoxyphenyl)penta-2,4-dienoate, methyl (2E,4E,6E)-7-(4-hydroxy-3,5- dimethoxyphenyl)hepta-2,4,6-trienoate, ethyl (2E,4E,6E)-7-(4-hydroxy-3-methoxyphenyl)hepta-2,4,6- trienoate, dimethyl (S)-2-(((2E,4E)-5-phenylpenta-2,4-dienoyl)oxy)succinate, diethyl (S)-2-(((2E,4E)- 5-phenylpenta-2,4-dienoyl)oxy)succinate, diisopropyl (S)-2-(((2E,4E)-5-phenylpenta-2,4- dienoyl)oxy)succinate. The phenylpropanoid derivatives of the general formula I have a wide range of biological activities, including antioxidant, antibacterial, anti-inflammatory activities which are especially useful in pharmaceutical and cosmetic applications. In one aspect, the present invention provides phenylpropanoid derivatives of the general formula I for use as medicaments. More specifically, the present invention provides phenylpropanoid derivatives of the general formula I for use in the treatment of psoriasis, scleroderma, GVHD, hypertrophic scars, NSF, periodontal disease and in the prevention of tooth decay. In one aspect, the present invention includes the phenylpropanoid derivatives of the general formula I for use for inhibition of oral microorganisms and of plaque formation on teeth and dental restorations, thus simultaneously improving oral hygiene and suppressing inflammation of gums (gingivitis). In one aspect, the present invention includes the phenylpropanoid derivatives of the general formula I for use in inhibition of growth of plaque. In one aspect, the present invention includes the phenylpropanoid derivatives of the general formula I for inhibiting the growth or for killing bacteria within the oral cavity of an animal, including a human, wherein a therapeutically effective amount of at least one phenylpropanoid derivative of the general formula I is administered within the oral cavity for a time sufficient to effectively eradicate said bacteria. In an embodiment, this invention also provides phenylpropanoid derivatives of the general formula I for preventing or treating a disease caused by bacterial infection by administering an effective amount of a compound of general formula I. This invention further provides phenylpropanoid derivatives of the general formula I for inhibiting the growth or for killing bacteria wherein said bacteria are selected from the group of Streptococcus mitis, Streptococcus mutans, Streptococcus sanguinis, Lactobacillus acidophilus, Actinomyces odontolyticus, Peptostrepococcus anaerobius, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Listeria monocytogenes, Bacillus cereus, Escherichia coli, Clostridium perfringens, Fusobacterium simiae, Candida albicans, Aspergilus niger. The activity of the compounds of formula I against bacteria can be used in both medical and biotechnological applications. This invention further provides a toothpaste or mouthwash containing phenylpropanoid derivatives of the general formula I and phenylpropanoid for treating periodontal disease and preventing tooth decay, wherein an effective amount of the toothpaste formulation to a human´s or animal's teeth and gums for a time sufficient to remove, kill, or inhibit the growth of pathogens causing said periodontal disease and tooth decay. This invention finally provides novel antibacterial toothpaste or mouthwash formulations comprising therapeutically effective amounts of one or more novel phenylpropanoid derivatives of general formula I and at least one auxiliary substance. The toothpaste or mouthwash are suitable in particular for inhibiting the growth of or for eradicating pathogens in the oral cavity of humans and animals. In one aspect, the present invention includes the phenylpropanoid derivatives of the general formula I for use for antiseptic treatment of oral cavity, for inhibition of inflammation of oral mucosae and/of for deodorizing the oral cavity. This invention further provides pharmaceutical (including toothpaste and mouthwash) compositions comprising one or more phenylpropanoid derivative of the general formula I and a pharmaceutically acceptable carrier system. COMPOSITIONS Suitable routes for administration include oral, topical, dermal, buccal and sublingual. Suitable formulations for scalp and skin disease therapy include solutions, creams and ointments. Suitable formulations for oral cavity disease treatment include mouthwashes, toothpastes, chewing gums and solutions. The therapeutic and/or cosmetic compositions generally comprise about 1% to about 95% of the active ingredient. Single-dose forms of administration preferably comprise about 20% to about 90% of the active ingredient and administration forms which are not single-dose preferably comprise about 5% to about 20% of the active ingredient. Unit dose forms are, for example, coated tablets, tablets, ampoules, vials or capsules. Other forms of administration are, for example, ointments, creams, pastes, foams, tinctures, lipsticks, drops, sprays, dispersions and the like. Examples are capsules containing from about 0.05 g to about 1.0 g of the active ingredient. The pharmaceutical and cosmetic compositions of the present invention are prepared in a manner known per se, for example by means of conventional mixing, granulating, coating, dissolving or lyophilising processes. Preferably, solutions of the active ingredient, and in addition also suspensions or dispersions, especially isotonic aqueous solutions, dispersions or suspensions, are used, it being possible for these to be prepared before use, for example in the case of lyophilised compositions which comprise the active substance by itself or together with a carrier, for example mannitol. The compositions can be sterilized and/or comprise excipients, for example, preservatives, stabilisers, wetting agents and/or emulsifiers, solubilizing agents, salts for regulating the osmotic pressure and/or buffers, and they are prepared in a manner known per se, for example by means of conventional dissolving or lyophilising processes. The solutions or suspensions mentioned can comprise viscosity-increasing substances, such as sodium carboxymethylcellulose, carboxymethylcellulose, dextran, polyvinylpyrrolidone or gelatine. Suspensions in oil comprise, as the oily component, vegetable, synthetic or semi-synthetic oils customary for injection purposes. Oils which may be mentioned are, in particular, liquid fatty acid esters which contain, as the acid component, a long-chain fatty acid having 8-22, in particular 12-22, carbon atoms (e., lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, acid, arachidonic acid, behenic acid, and the like) or corresponding unsaturated acids (e.g., oleic acid, elaidic acid, euric acid, brasidic acid or linoleic acid). Other additional ingredients known in the art can be included if desired (e.g., antioxidants such as vitamin E, β-carotene, or 3,5-di- tert-butyl-4-hydroxytoluene, and the like). The alcohol component of these fatty acid esters generally contains no more than about 6 carbon atoms and can be mono- or polyhydric. Mono-, di-, or trihydric alcohols such as methanol, ethanol, propanol, butanol, or pentanol, or isomers thereof, can be used; glycols and glycerols are generally preferred. Fatty acid esters can therefore include, for example, ethyl oleate, isopropyl myristate, isopropyl palmitate, "Labrafil M 2375" (polyoxyethylene glycerol trioleate from Gattefoseé, Paris), "Labrafil M 1944 CS" (unsaturated polyglycolated glycerides prepared by an alcoholysis of apricot kernel oil and made up of glycerides and polyethylene glycol esters; from Gattefoseé, Paris), "Labrasol" (saturated polyglycolated glycerides prepared by an alcoholysis of TCM and made up of glycerides and polyethylene glycol esters; from Gattefoseé, Paris), and/or "Miglyol 812" (triglyceride of saturated fatty acids of chain length C8 to C12 from Hüls AG, Germany), and in particular vegetable oils, such as cottonseed oil, almond oil, olive oil, castor oil, sesame oil, soybean oil and, in particular, groundnut oil as well as mixtures thereof. The preparation of the compositions intended for human use should, of course, be carried out in the customary and approved manner under sterile conditions, and maintained under appropriate conditions up to and including the time of use. For example, pharmaceutical compositions for oral use can be obtained by combining the active ingredient with one or more solid carriers, if appropriate granulating the resulting mixture, and, if desired, processing the mixture or granules to tablets or coated tablet cores, if appropriate by addition of additional excipients. Suitable carriers are, in particular, fillers, such as sugars, for example lactose, sucrose, mannitol or sorbitol, cellulose preparations and/or calcium phosphates, for example tricalcium diphosphate, or calcium hydrogen phosphate, and furthermore binders, such as starches, for example maize, wheat, rice or potato starch, methylcellulose, hydroxypropylmethylcellulose, sodium carboxymethylcellulose and/or polyvinylpyrrolidone, and/or, if desired, desintegrators, such as the above mentioned starches, and furthermore carboxymethyl-starch, cross-linked polyvinylpyrrolidone, alginic acid or a salt thereof, such as sodium alginate. Additional excipients are, in particular, flow regulators and lubricants, for example salicylic acid, talc, stearic acid or salts thereof, such as magnesium stearate or calcium stearate, and/or polyethylene glycol, or derivatives thereof. Ointments are oil-in-water emulsions, which comprise not more than 70%, but preferably 20 - 50% of water or aqueous phase. The fatty phase consists, in particular, hydrocarbons, for example vaseline, paraffin oil or hard paraffin's, which preferably comprise suitable hydroxy compounds, such as fatty alcohol's or esters thereof, for example cetyl alcohol or wool wax alcohols, such as wool wax, to improve the water-binding capacity. Emulsifiers are corresponding lipophilic substances, such as sorbitan fatty acid esters (Spans), for example sorbitan oleate and/or sorbitan isostearate. Additives to the aqueous phase are, for example, humectants, such as polyalcohols, for example, glycerol, propylene glycol, sorbitol and/or polyethylene glycol, or preservatives and odoriferous substances. Fatty ointments are anhydrous and comprise, as the base, in particular, hydrocarbons, for example paraffin, vaseline or paraffin oil, and furthermore naturally occurring or semi-synthetic fats, for example, hydrogenated coconut-fatty acid triglycerides, or, preferably, hydrogenated oils, for example hydrogenated groundnut or castor oil, and furthermore fatty acid partial esters of glycerol, for example glycerol mono- and/or distearate, and for example, the fatty alcohols. They also can contain emulsifiers and/or additives mentioned in connection with the ointments which increase uptake of water. Creams are oil-in-water emulsions, which comprise more than 50% of water. Oily bases used are, in particular, fatty alcohols, for example, lauryl, cetyl or stearyl alcohols, fatty acids, for example palmitic or stearic acid, liquid to solid waxes, for example isopropyl myristate, wool wax or beeswax, and/or hydrocarbons, for example vaseline (petrolatum) or paraffin oil. Emulsifiers are surface-active substances with predominantly hydrophilic properties, such as corresponding non-ionic emulsifiers, for example fatty acid esters of polyalcohols or ethyleneoxy adducts thereof, such as polyglyceric acid fatty acid esters or polyethylene sorbitan fatty esters (Tweens), and furthermore polyoxyethylene fatty alcohol ethers or polyoxyethylene fatty acid esters, or corresponding ionic emulsifiers, such as alkali metal salts of fatty alcohol sulphates, for example, sodium lauryl sulphate, sodium cetyl sulphate or sodium stearyl sulphate, which are usually used in the presence of fatty alcohols, for example cetyl stearyl alcohol or stearyl alcohol. Additives to the aqueous phase are, inter alia, agents which prevent the creams from drying out, for example polyalcohols, such as glycerol, sorbitol, propylene glycol and/or polyethylene glycols, and furthermore preservatives and odoriferous substances. Pastes are creams and ointments having secretion-absorbing powder constituents, such as metal oxides, for example, titanium oxide or zinc oxide, and furthermore talc and/or aluminium silicates, which have the task of binding the moisture or secretions present. In certain embodiments, the formulations comprise at least one base component and an active ingredient comprising phenolic compound, preferably, highly purified (i.e. 98% and greater purity, more preferably about 98.5% to 99% purity). A preferred concentration range of lthe phenolic compound in the toothpaste formulations is from about 10% to about 40%. The one or more base components employed in the tooth paste formulation include those typically found in conventional toothpastes, and thus the amounts and types of such base components are known by those of ordinary skill in the art. Exemplary base components include, but are not limited to, (a) sorbitol, a polyol which functions as a humectant/sweetener; (b) water, which functions as a diluent; (c) silica (e.g. ZEODENT, vended by Huber Corp.), which functions as an abrasive to help remove particles from the teeth; (d) glycerin, which also serves as a humectant; (e) surfactants, such as sodium lauryl sulfate or Polysorbate 20, for example; (f) binders and viscosity agents, such as CEKOL cellulose gum, xantham gum; and (g) preservatives, such as sodium benzoate and methyl parabens, for example. Flavoring and coloring agents (or whitening agents, like titanium dioxide) may be employed, as well. It will be appreciated by those of ordinary skill in the art that while the identified base components may indeed by employed in the present invention, other base components commonly employed in toothpaste formulations, now known or later discovered, may be used without departing from the scope and spirit of the present invention. Preferably, the toothpaste formulation further comprises a pharmaceutically acceptable calcium compound, preferably pure calcium and/or a pharmaceutically acceptable magnesium compound, such as magnesium phosphate, for promoting stronger teeth. Preferable tooth paste formulations comprise from about 18% to about 22% percent limonene. Preferable percentage amounts of calcium range from about 1.25% to about 1.50%. Preferable percentage amounts of magnesium phosphate range from about 1.25% to about 1.50%. Mouthwash formulations for the inventive mouthwash effective in treating bacterial infections in the mouth (or inhibiting the growth of bacteria responsible for such infections) include an active ingredient comprising phenolic compound of the general formula I, preferably a highly purified form (i.e 98.0% or greater purity, more preferably 98.5% to 99.0%) and one or more base components commonly employed in mouthwash formulations. Exemplary base components include (a) sorbitol; (b) polyethylene glycol (e.g. PEG 6) as a carrier and surfactant; (c) polysorbate (surfactant); (d) water (diluent); and (e) flavoring agents (e.g. sucralose). A preferred formulation comprises (a) from about 15% to about 25% of sorbitol, (b) from about 10% to about 20% of polyethylene glycol, (c) from about 2.5% to about 7.5% Polysorbate 20, (d) from about 2.5% to about 15% d-limonene, (e) from about 45% to about 65% water, (f) from about 0.2% to about 0.5% sucralose, and about 1.0% to 2.0% Belwood Wintergreen. Administration of the inventive mouthwash is similar to conventional mouthwashes (i.e., about 30 ml placed within the mouth and swished about therein for about 30 seconds prior to expectoration); however, the administrated dose and time within the mouth may be varied as desired. Foams (i.e., liquid oil-in-water emulsions packaged in aerosol form) can be administered from pressurised containers. Propellant gases include halogenated hydrocarbons, such as polyhalogenated alkanes such as dichlorofluoromethane and dichlorotetrafluoroethane, or, preferably, non-halogenated gaseous hydrocarbons, air, N ₂ O, or carbon dioxide. The oily phases used are, inter alia, those mentioned above for ointments and creams, and the additives mentioned there are likewise used. Tinctures and solutions usually comprise an aqueous-ethanolic base to which, humectants for reducing evaporation, such as polyalcohols (e.g., glycerol, glycols, polyethylene glycol) and re-oiling substances, such as fatty acid esters with lower polyethylene glycols (e.g., lipophilic substances soluble in the aqueous mixture) to substitute the fatty substances removed from the skin with the ethanol, and, if necessary or desired, other excipients and additives, are admixed. The present invention further provides veterinary compositions comprising at least one active ingredient as above defined together with a veterinary carrier therefor. Veterinary carriers are materials for administering the composition and may be solid, liquid, or gaseous materials, which are inert or acceptable in the veterinary art and are compatible with the active ingredient. These veterinary compositions may be administered orally, parenterally, or by any other desired route. The invention also relates to a process or method for treatment of the disease states mentioned above. The compounds can be administered prophylactically or therapeutically as such or in the form of pharmaceutical compositions, preferably in an amount, which is effective against the diseases mentioned. With a warm-blooded animal, for example, a human requiring such treatment, the compounds are used, in particular, in the form of pharmaceutical composition. A daily dose of about 0.1 to about 5 g, preferably 0.5 g to about 2 g, of a compound of the present invention is administered here for a body weight of about 70 kg. Examples of carrying out the Invention The following examples serve to illustrate the invention without limiting the scope thereof. Unless otherwise stated, all percentages and the like amounts are based on weight. The starting materials may be obtained from commercial sources (Sigma, Aldrich, Fluka, etc.) or can be prepared by known procedures. Thin-layer chromatography was carried out on Silica 60 F ₂₅₄ plates (Merck) using n-hexane/EtOAc as a developing system and the spots were detected by UV light (254 and 365 nm) and/or 6% vanilline in absolute EtOH containing 1 % of H ₂ SO ₄ . The column chromatography purification was carried out by silica Davisil 40-63 micron (Grace Davision). Elemental analysis was determined using Flash EA 1112 analyzer (Thermo Scientific). The chromatographic purity and mass of prepared compounds was determined using an Alliance 2695 separation module (Waters) linked simultaneously to a DAD detector PDA 996 (Waters) and a Q-Tof micro (Waters) benchtop quadrupole orthogonal acceleration time-of-flight tandem mass spectrometer. Samples were dissolved in DMSO and diluted to a concentration of 10 μg/ml in initial mobile phase. The samples (10 μl) were injected on a RP-column Symmetry C18 (150 mm x 2.1 mm x 3.5 μm, Waters) and separated at a flow rate of 0.2 ml/min with following binary gradient: 0 min, 10% B; 0-24 min, a linear gradient to 90% B, followed by 10 min isocratic elution of 90% B. At the end of the gradient, the column was re-equilibrated to initial conditions. 15 mM formic acid adjusted to pH 4.0 by ammonium hydroxide was used as solvent (A) and methanol as the organic modifier (solvent B). The eluent was introduced into the DAD (scanning range 210-400 nm, with 1.2 nm resolution) and an ESI source (source temperature 110 °C, capillary voltage +3.0 kV, cone voltage +20 V, desolvation temperature 250 °C). Nitrogen was used both as desolvation gas (500 l/h) as well as cone gas (50 l/h). The data was obtained in positive (ESI+) ionization mode in the 50-1000 m/z range. ¹ H and ¹³ C NMR spectra were recorded on Jeol ECA-500 operating at a frequency of 500 MHz ( ¹ H) and 126 MHz ( ¹³ C) or on Jeol ECA400II operating at a frequency of 400 MHz ( ¹ H) and 101 MHz ( ¹³ C), respectively. Samples were prepared by dissolving substances in Chloroform-d or DMSO-d ₆ . Chemical shifts are reported in ppm and their calibration was performed (a) in case of ¹ H NMR experiments on residual peak of non-deuterated solvent δ (CHCl ₃ ) = 7.26 ppm; δ (DMSO) = 2.50 ppm, and (b) in case of ¹³ C NMR experiments on the middle peak of the ¹³ C signal in deuterated solvent δ (CDCl ₃ ) = 77.2 ppm; δ (DMSO-d ₆ ) = 39.5 ppm. All microwave irradiation experiments were carried out in a dedicated CEM-Discover mono-mode microwave apparatus. The reactor was used in the standard configuration as delivered, including proprietary software. The reactions were carried out in 30 mL glass vials sealed with an Silicone/PTFE Vial caps top, which can be exposed to a maximum of 250 °C and 20 bar internal pressure. The temperature was measured with an IR sensor on the outer surface of the process vial. After the irradiation period, the reaction vessel was cooled to ambient temperature by gas jet cooling. General method for aldehyde synthesis This protocol was applied if a commercially unavailable aldehyde was used to prepare targeted structures of formula I. (E)-3-(3,4-dimethoxyphenyl)acrylaldehyde synthesis A solution of methyl (E)-3-(3,4-dimethoxyphenyl)acrylate (3.3g, 13.49 mmol, 1.0 equiv) in dry CH ₂ Cl ₂ (27 mL, 0.5M) was cooled to 0°C and DIBAL-H (33.7 mL, 33.7 mmol, 2.5 equiv; 1.0M solution in CH ₂ Cl ₂ ) was added dropwise. The resulting mixture was stirred at 0 °C for 30 min prior the cooling bath removal. After 1 h at RT, the reaction mixture was again cooled to 0 °C and stirred for 15 min at 0 °C. Aqueous saturated solution of Rochel salt (10 mL) was added dropwise to quench the reaction and the resulting mixture was stirred at RT for next 13 h (milky suspension turned into the clear biphasic solution). Resulting phases were separated and the aqueous layer was extracted with CH ₂ Cl ₂ (3x75 mL). Combined organic layers were washed with brine (50 mL), dried over Na ₂ SO ₄ , filtered and evaporated under reduced pressure. The residue was purified by column chromatography (SIO ₂ ; n-hexane:EtOAc = 2:1) yielding the desired (E)-3-(3,4-dimethoxyphenyl)prop-2-en-1-ol (2.60g, 98%) as colorless solid. M.p. = 76-77 °C ¹ H NMR (500 MHz, CDCl ₃ ) δ (ppm): 6.97 – 6.91 (m, 2H), 6.83 (d, J = 8.3 Hz, 1H), 6.56 (d, J = 15.9 Hz, 1H), 6.26 (dt, J = 15.9, 6.1 Hz, 1H), 4.32 (dd, J = 6.1, 1.5 Hz, 2H), 3.91 (s, 3H), 3.89 (s, 3H). ¹³ C NMR (126 MHz, CDCl3) δ (ppm): 149.2, 149.1, 131.4, 129.9, 126.7, 119.9, 111.3, 109.0, 64.1, 56.1, 56.0. 3,4-dimethoxycinnamyl alcohol (1.00 g, 5.1 mmol) in CH ₂ Cl ₂ (10mL) was slowly added via syringe to a mixture of pyridinium dichromate (PDC, 3.86g, 10.3 mmol, 2.0 equiv) in CH ₂ CI ₂ (20 mL). Resulting mixture was stirred for 2 h at RT prior 0.5 mL of methanol was added. The whole mixture was passed through silica gel (filtration) and filter cake was washed with EtOAc (300 mL). Organic solvents were removed under reduced pressure and the crude aldehyde was purified by column chromatography (SiO ₂ ; n-hexane:EtOAc = 4:1) yielding a desired (E)-3-(3,4-dimethoxyphenyl)akrylaldehyde (690mg, 70%) as a viscose oil. ESI ⁺ -MS m/z (rel. int. %, ion): 193 (100) [M+H] ⁺ , 210 (26) [M+NH ₄ ] ⁺ . ¹ H NMR (500 MHz, CDCl ₃ ) δ (ppm): 9.66 (d, J = 7.9 Hz, 1H), 7.42 (d, J = 15.9 Hz, 1H), 7.17 (dd, J = 8.4, 2.0 Hz, 1H), 7.08 (d, J = 2.1 Hz, 1H), 6.91 (d, J = 8.3 Hz, 1H), 6.61 (dd, J = 15.9, 7.6 Hz, 1H), 3.94 (s, 3H), 3.93 (s, 3H). ¹³ C NMR (126 MHz, CDCl ₃ ) δ (ppm): 193.8, 153.1, 152.1, 149.5, 127.2, 126.9, 123.6, 111.3, 110.0, 56.2, 56.1. General method for dialkyl (S)-2-hydroxysuccinate synthesis Dimethyl (S)-2-hydroxysuccinate A solution of malic acid (10.0 g, 74.6 mmol, 1.0 equiv) was dissolved in MeOH (250 mL) and the resulting mixture was cooled to 0°C. Acetyl chloride (13.3 mL, 0.186 mol, 2.5 equiv) was added dropwise over a period of 1h and the resulting mixture was stirred at RT for 48h. The vollatiles were removed under reduced pressure and the resulting residue was purified by column chromatography (SiO ₂ ; n-hexane:EtOAc = 2:1) yielding a desired dimethyl (S)-2-hydroxysuccinate (11.4 g, 94%) as a colorless oil. [α] _D ^23,1 = - 10.2 (c = 2.1, EtOH); ESI ⁺ -MS m/z (rel. int. %, ion): 163 (45) [M+H] ⁺ , 180 (12) [M+NH ₄ ] ⁺ ; ¹ H NMR (500 MHz, CDCl ₃ ) δ (ppm): 4.54 – 4.45 (m, 1H), 3.79 (s, 3H), 3.70 (s, 3H), 2.82 (qd, J = 16.5, 5.2 Hz, 2H); ¹³ C NMR (126 MHz, CDCl ₃ ) δ (ppm): 173.8, 171.1, 67.3, 52.9, 52.1, 38.4. Diethyl (S)-2-hydroxysuccinate A solution of malic acid (10.0 g, 74.6 mmol, 1.0 equiv) in EtOH (250 mL) was stirred at RT and SOCl2 (100 µL, 0.75 mmol, 0.01 equiv) was added. The whole mixture was refluxed for 23 h before it was cooled to RT and solvents were removed under reduced pressure. The residue was purified by purified by column chromatography (SiO ₂ ; n-hexane : EtOAc = 2:1) yielding a desired diethyl (S)-2- hydroxysuccinate (13.0 g, 92%) as a colorless oil. [α] _D ^23.0 = - 14.2 (c = 4.8, acetone); ESI ⁺ -MS m/z (rel. int. %, ion): 191 (39) [M+H] ⁺ , 208 (23) [M+NH ₄ ] ⁺ ; ¹ H NMR (500 MHz, CDCl ₃ ) δ (ppm): 4.46 (dd, J = 6.0, 4.5 Hz, 2H), 4.32 – 4.19 (m, 4H), 3.19 (s, 1H), 2.80 (qd, J = 16.3, 5.2 Hz, 4H), 1.30 – 1.23 (m, 6H); ¹³ C NMR (126 MHz, CDCl ₃ ) δ (ppm): 173.4, 170.6, 67.3 , 62.1 , 61.0 , 38.7, 15.1, 14.2. Diisopropyl (S)-2-hydroxysuccinate A solution of malic acid (10.0 g, 74.6 mmol, 1.0 equiv) in iPrOH (250 mL) was stirred at RT and SOCl ₂ (100 µL, 0.75 mmol, 0.01 equiv) was added. The whole mixture was refluxed for 24 h before it was cooled to RT and solvents were removed under reduced pressure. The residue was purified by purified by column chromatography (SiO2; n-hexane : EtOAc = 2:1) yielding a desired diisopropyl (S)-2-hydroxysuccinate (16.3 g, 87%) as a colorless oil. [α] _D ^23.0 = - 10.5 (c = 2.5, MeOH); ESI ⁺ -MS m/z (rel. int. %, ion): 219 (61) [M+H] ⁺ , 236 (36) [M+NH ₄ ] ⁺ ; ¹ H NMR (500 MHz, CDCl ₃ ) δ (ppm): 5.14 – 4.97 (m, 2H), 4.44 – 4.40 (m, 1H), 2.84 – 2.68 (m, 2H), 1.42 – 1.05 (m, 12H); ¹³ C NMR (126 MHz, CDCl ₃ ) δ (ppm): 173.1, 170.0, 69.9, 68.3, 67.4, 39.0, 21.2. Example 1 Methyl (2E,4E)-5-(4-hydroxyphenyl)penta-2,4-dienoate (compound 5 in Table 1) Method A: A suspension of (E)-3-(4-hydroxyphenyl)acrylaldehyde (0.741 g, 5.00 mmol, 1.0 equiv) and stabilized Wittig ylide (1.84 g, 5.5 mmol, 1.1 equiv) in toluene (5.0 mL, 1.0 M to aldehyde) was placed in a microwave vial (35 mL) equipped with a magnetic stirring bar. The vial was sealed an Silicone/PTFE Vial cap and placed in a CEM Discover reactor. The resulting mixture was then irradiated (300 W) for 10 minutes (fixed time) at 150°C. The reaction mixture was allowed to cool down, transferred to a round-bottom flask and the toluene was removed under vacuum. Residue (2.0 g) was purified on by flash column chromatography (SiO ₂ ; hexane:EtOAc = 4:1->2:1) and yielded 0.92 g (90%; purity 98+%). Pale yellow solid, chemical formula: C ₁₂ H ₁₂ O ₃ , yield (%): 90, E,E/E,Z = 95:1. Method B: A solution of (E)-3-(4-hydroxyphenyl)acrylaldehyde (5.0 g, 33.7 mmol, 1.0 equiv) and malonic acid (5.27 g, 50.6 mmol, 1.5 equiv) in pyridine (10 mL, 3.5M to aldehyde) was stirred at RT for 5 min. Piperidine (0.58 mL, 5.1 mmol, 0.15 equiv) was added and the resulting mixture was stirred at 85°C in Schlenck tube for 8.5h. The resulting mixture was cooled to RT and the Schlenck tube was carefully opened and its contain was poured into ice/water bath (100g/150 mL placed in 500mL beaker). The resulting mixture was vigorously stirred and generated carboxylic acid started to precipitate. When the ice melted, the resulting precipitate was filtered and dried under the vacuum at 30°C yielding corresponging acid (3.97 g, 62%) in form of yellowish crystals. Acid (3.97 g, 20.9 mmol, 1.0 equiv) was dissolved in methanol (21 mL, 1.0M) and the whole mixture was cooled to 0°C. Acetyl chloride (1.22 mL, 17.24 mmol, 0.8 equiv) was added and the whole mixture was allowed to warm to RT and stirred at RT for additional 12h. The whole mixture was evaporated under reduced pressure and the residue was purified by column chromatography on silica gel (hexane:EtOAc = 4:1- >2:1) yielding the desired compound 1 as slightly yellow solid (4.6 g, 56% over two steps). Pale yellow solid, chemical formula: C ₁₂ H ₁₂ O ₃ , yield over two steps (%): 56, E,E/E,Z = 90:1. M.p. = 170- 171 °C; HPLC-UV/VIS retention time, purity (min., %): 18.2, 99.2; ESI ⁺ -MS m/z (rel. int. %, ion): 205 (100, M+H] ⁺ ); ¹ H NMR (400 MHz, Chloroform-d) δ (ppm): 3.81 (s, 3H, OCH ₃ ), 5.93 (d, J = 15.1 Hz, 1H), 6.74 (dd, J = 10.9, 15.4 Hz, 1H), 6.84 (d, J = 15.4 Hz, 1H), 6.87 (d, J = 8.8 Hz, 2H), 7.40 (d, J = 8.8 Hz, 2H), 7.43 (dd, J = 10.9, 15.1 Hz, 1H); ¹³ C NMR (101 MHz, Chloroform-d) δ (ppm): 53.5 (OCH ₃ ), 114.2 (2xC), 120.0, 124.1, 128.6 (2xC), 128.8, 140.0, 144.9, 159.3, 167.2. Example 2 Methyl (2E,4E)-5-phenylpenta-2,4-dienoate (compound 1 in Table 1) Prepared according to Example 1. Yellow solid, chemical formula: C ₁₂ H ₁₂ O ₂ , yield (%): Method A: 93, E,E/E,Z = 88:1; Method B: 39, E,E/E,Z = 90:1. M.p. = 69-70 °C; HPLC-UV/VIS retention time, purity (min., %): 29.6, 98.8; ESI ⁺ - MS m/z (rel. int. %, ion): 189 (100, [M+H] ⁺ ); HRMS (FAB): calculated (for C ₁₂ H ₁₂ NaO ₂ ⁺ ) 211.0730, found 211.0728; ¹ H NMR (400 MHz, CDCl ₃ ) δ (ppm): 7.49–7.42 (m, 3H), 7.37–7.30 (m, 3H), 6.93– 6.83 (m, 2H), 6.00; (d, J = 15.3 Hz, 1H), 3.77 (s, 3H); ¹³ C NMR (101 MHz, CDCl ₃ ) δ (ppm): 167.5, 144.8, 140.6, 136.0, 129.1, 128.8, 127.2, 126.2, 120.8, 51.6. Example 3 Dimethyl (S)-2-(((2E,4E)-5-phenylpenta-2,4-dienoyl)oxy)succinate (compound 2 in Table 1) A solution of (E)-cinnamaldehyde (3.44 g, 26 mmol, 1.0 equiv) and malonic acid (4.06 g, 39 mmol, 1.5 equiv) in pyridine (7.5 mL, 3.5M to aldehyde) was stirred at RT for 5 min. Piperidine (0.44 mL, 3.9 mmol, 0.15 equiv) was added and the resulting mixture was stirred at 85°C in Schlenck tube for 8.5h. The resulting mixture was cooled to RT and the Schlenck tube was carefully opened and its contain was poured into ice/water bath (100g/150 mL placed in 500mL beaker). The resulting mixture was vigorously stirred and generated carboxylic acid started to precipitate. When the ice melted, the resulting precipitate was filtered and dried under the vacuum at 30°C yielding corresponging acid (3.58 g, 79%) in form of yellowish crystals. Acid (3.58 g, 20.5 mmol, 1.0 equiv) and dimethyl (S)-2- hydroxysuccinate (3.33 g, 20.5 mmol, 1.0 equiv) were added to the reaction flask. To this mixture, 1- ethyl-3-(3-dimethylaminopropyl)carbodiimide (7.95 g, 51.25 mmol, 2.5 equiv) and 1- hydroxybenzotriazole (6.92 g, 51.25 mmol, 2.5 equiv) dissolved in THF (250 mL) were added and the whole mixture was vigorously stirred at RT for 72h. The solvent was evaporated to dryness under reduced pressure, and then the whole slurry was partitioned between CH ₂ Cl ₂ (500 mL) and 1.0 m aq. HCl (300 mL). The resulting layers were separated and the organic layer was washed with sat. aq. NaHCO ₃ (250 mL), brine (250 mL), dried over anhydrous sodium sulfate, filtered and solvents were evaporated to dryness under reduced pressure. The residue was purified by column chromatography (SiO ₂ ; n-hexane:EtOAc = 10:1->4:1) to yield desired dimethyl (S)-2-(((2E,4E)-5-phenylpenta-2,4- dienoyl)oxy)succinate 2 as viscose oil (3.15 g, 38% over 2 steps). Viscose oil, chemical formula: C ₁₇ H ₁₈ O ₆ , yield (%): 38, E,E/E,Z = 93:1. HPLC-UV/VIS retention time, purity (min., %): 29.8, 98.3; ESI ⁺ -MS m/z (rel. int. %, ion): 319 (100, M+H] ⁺ ); HRMS (FAB): calculated (for C ₁₇ H ₁₈ NNaO ₆ ⁺ ) 341.0996, found 341.0999; [α] _D ^23,1 = + 8.7° (c = 1.05, CH ₂ Cl ₂ ); ¹ H NMR (400 MHz, CDCl3) δ (ppm): 7.49–7.42 (m, 3H), 7.37–7.30 (m, 3H), 6.93–6.83 (m, 2H), 6.01 (d, J = 16.0 Hz, 1H), 5.62 (dd, J = 7.0, 5.1 Hz, 1H), 3.79 (s, 3H), 3.73 (s, 3H); ¹³ C NMR (101 MHz, CDCl3) δ (ppm): 169.8, 169.5, 165.9, 149.8, 146.6, 134.2, 130.7, 129.0, 128.4, 116.8, 111.2, 68.4, 52.9, 52.3, 36.2. Example 4 Diethyl (S)-2-(((2E,4E)-5-phenylpenta-2,4-dienoyl)oxy)succinate (compound 3 in Table 1) Prepared according to Example 3. Viscose oil, chemical formula: C ₁₉ H ₂₂ O ₆ , yield (%): 41, E,E/E,Z = 89:1; HPLC-UV/VIS retention time, purity (min., %): 30.1, 98.4; ESI ⁺ -MS m/z (rel. int. %, ion): 347 (100, M+H] ⁺ ); HRMS (FAB): calculated (for C ₁₉ H ₂₂ NNaO ₆ ⁺ ) 369.1309, found 369.1315; [α] _D ^23°C = + 9.1° (c = 1.11, CH ₂ Cl ₂ ); ¹ H NMR (400 MHz, CDCl ₃ ) δ (ppm): 7.49–7.42 (m, 3H), 7.37–7.29 (m, 3H), 6.93–6.81 (m, 2H), 6.23 (d, J = 15.0 Hz, 1H), 5.59 (dd, J = 6.9, 5.4 Hz, 1H), 4.26 (qd, J = 7.1, 1.1 Hz, 2H), 4.13 (qd, J = 7.1, 1.0 Hz, 2H), 3.00 – 2.90 (m, 2H), 1.29 (t, J = 7.1 Hz, 3H), 1.21 (t, J = 7.1 Hz, 3H); ¹³ C NMR (101 MHz, CDCl ₃ ) δ (ppm): 169.9, 169.3, 165.8, 149.7, 146.1, 134.3, 130.8, 129.1, 128.2, 116.7, 111.6, 68.6, 68.4, 68.1, 36.3, 15.2, 15.1. Example 5 Diisopropyl (S)-2-(((2E,4E)-5-phenylpenta-2,4-dienoyl)oxy)succinate (compound 4 in Table 1) Prepared according to Example 3. Viscose oil, chemical formula: C ₂₁ H ₂₆ O ₆ , yield (%): 26, E,E/E,Z = 90:1. HPLC-UV/VIS retention time, purity (min., %): 33.2, 99.0; ESI ⁺ -MS m/z (rel. int. %, ion): 375 (100, M+H] ⁺ ); HRMS (FAB): calculated (for C ₂₁ H ₂₆ NNaO ₆ ⁺ ) 397.1622, found 397.1622; [α] _D ^23°C = + 1.9° (c = 1.01, CH ₂ Cl ₂ ); ¹ H NMR (400 MHz, CDCl ₃ ) δ (ppm): 7.68–7.48 (m, 3H), 7.39–7.29 (m, 3H), 6.93–6.81 (m, 2H), 6.48 (d, J = 15.3 Hz, 1H), 5.54 (dd, J = 6.7, 5.9 Hz, 1H), 5.10 – 5.04 (m, 2H), 2.93 – 2.86 (m, 2H), 1.24 (dd, J = 11.5, 5.3 Hz, 12H); ¹³ C NMR (101 MHz, CDCl ₃ ) δ (ppm): 168.8, 168.6, 165.9, 146.2, 134.3, 130.6, 129.1, 128.3, 117.0, 116.7, 112.6, 69.7, 68.8, 68.5, 36.8, 21.6, 21.3. Example 6 Methyl (2E,4E)-5-(3,4-dimethoxyphenyl)penta-2,4-dienoate (compound 11 in Table 1) Prepared according to Example 1. Yellow solid, chemical formula: C ₁₄ H ₁₆ O ₄ , yield (%): Method A: 89, E,E/E,Z = 89:1; Method B: 42, E,E/E,Z = 92:1. M.p. = 73-74 °C; HPLC-UV/VIS retention time, purity (min., %): 25.7, 98.9; ESI ⁺ - MS m/z (rel. int. %, ion): 249 (100, [M+H] ⁺ ); HRMS (FAB): calculated (for C ₁₄ H ₁₆ NaO ₄ ⁺ ) 271.0941, found 271.0941; ¹ H NMR (400 MHz, CDCl ₃ ) δ (ppm): 7.60-7.15 (m, 2H), 7.10-6.60 (m, 4H), 5.94 (d, 1H, J = 15.0 Hz), 3.91 (s, 3H), 3.89 (s, 3H), 3.82 (s, 3H); ¹³ C NMR (101 MHz, CDCl ₃ ) δ (ppm): 167.2, 149.1, 144.8, 140.3, 129.1, 124.3, 121.2, 120.1, 111.0, 108.9, 55.8, 55.7, 53.2. Example 7 Ethyl (2E,4E)-5-(3,4,5-trimethoxyphenyl)penta-2,4-dienoate (compound 17 in Table 1) Prepared according to Example 1. Orange solid, chemical formula: C ₁₆ H ₂₀ O ₅ , yield (%): Method A: 78, E,E/E,Z = 90:1; Method B: 39, E,E/E,Z = 91:1. M.p. = 121-122 °C; HPLC-UV/VIS retention time, purity (min., %): 27.3, 98.5; ESI ⁺ - MS m/z (rel. int. %, ion): 293 (100, [M+H] ⁺ ); HRMS (FAB): calculated (for C ₁₆ H ₂₀ NaO ₅ ⁺ ) 315.1208, found 315.1209; ¹ H NMR (400 MHz, CDCl ₃ ) δ (ppm): 7.43 (ddd, 1H, J = 15.2, 8.6, 1.7 Hz), 6.85-6.72 (m, 2H), 6.68 (s, 2H), 5.98 (d, 1H, J = 15.1 Hz), 4.23 (q, 2H, J = 7.2 Hz), 3.90 (s, 6H), 3.87 (s, 3H), 1.32 (t, 3H, J = 7.2 Hz); ¹³ C NMR (101 MHz, CDCl ₃ ) δ (ppm): 167.1, 153.4, 144.4, 140.3, 139.2, 131.7, 125.7, 121.0, 104.3, 61.0, 60.3, 56.1, 14.3. Example 8 methyl (2E,4E,6E)-7-(4-methoxyphenyl)hepta-2,4,6-trienoate (compound 20 in Table 1) Prepared according to Example 1. Viscose oil, chemical formula: C ₁₅ H ₁₆ O ₃ , yield (%): Method A: 54, E,E,E/E,E,Z = 78:1; Method B: 21, E,E,E/E,E,Z = 90:1. HPLC-UV/VIS retention time, purity (min., %): 26.4, 98.1; ESI ⁺ -MS m/z (rel. int. %, ion): 245 (100, [M+H] ⁺ ); HRMS (FAB): calculated (for C ₁₅ H ₁₆ NaO ₃ ⁺ ) 267.0997, found 267.0996; ¹ H NMR (400 MHz, CDCl ₃ ) δ (ppm): 7.40 – 7.34 (m, 2H), 7.37 (dd, J = 15.3, 11.5 Hz, 1H), 6.91 – 6.84 (m, 2H), 6.82 – 6.62 (m, 3H), 6.48 – 6.32 (m, 1H), 5.89 (d, J = 15.3 Hz, 1H), 3.82 (s, 3H), 3.76 (s, 3H); ¹³ C NMR (101 MHz, CDCl ₃ ) δ (ppm): 167.7, 160.0, 144.9, 141.4, 136.5, 129.5, 129.1, 128.2 (2xC), 125.9, 119.7, 114.3 (2xC), 55.3, 51.5. Example 9 (2E,4E)-5-(3,4-dimethoxyphenyl)-1-(piperidin-1-yl)penta-2,4- dien-1-one (compound 25 in Table 1) A solution of (E)-3-(3,4-dimethoxyphenyl)acrylaldehyde (5.0 g, 26 mmol, 1.0 equiv) and malonic acid (4.06 g, 39 mmol, 1.5 equiv) in pyridine (7.5 mL, 3.5M to aldehyde) was stirred at RT for 5 min. Piperidine (0.44 mL, 3.9 mmol, 0.15 equiv) was added and the resulting mixture was stirred at 85°C in Schlenck tube for 8.5h. The resulting mixture was cooled to RT and the Schlenck tube was carefully opened and its contain was poured into ice/water bath (100g/150 mL placed in 500mL beaker). The resulting mixture was vigorously stirred and generated carboxylic acid started to precipitate. When the ice melted, the resulting precipitate was filtered and dried under the vacuum at 30°C yielding corresponging acid (3.59 g, 59%) in form of yellowish crystals. Acid (3.59 g, 15.3 mmol, 1.0 equiv) and diethylamine (1.52 mL, 15.3 mmol, 1.0 equiv) were added to the reaction flask. To this mixture, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (5.94 g, 38.3 mmol, 2.5 equiv) and 1- hydroxybenzotriazole (5.17 g, 38.3 mmol, 2.5 equiv) dissolved in THF (160 mL) were added and the whole mixture was vigorously stirred at RT for 48h. The solvent was evaporated to dryness under reduced pressure, and then the whole slurry was partitioned between CH ₂ Cl ₂ (500 mL) and 1.0 m aq. HCl (250 mL). The resulting layers were separated and the organic layer was washed with sat. aq. NaHCO ₃ (200 mL), brine (200 mL), dried over anhydrous sodium sulfate, filtered and solvents were evaporated to dryness under reduced pressure. The residue was purified by column chromatography (SiO ₂ ; CHCl ₃ /MeOH = 100:1->50:1) to yield desired (2E,4E)-5-(3,4-dimethoxyphenyl)-1-(piperidin- 1-yl)penta-2,4-dien-1-one 21 as yellow solid (4.25 g, 54% over 2 steps). Yellow solid, chemical formula: C ₁₈ H ₂₃ NO ₃ , yield (%): 54, E,E/E,Z = 91:1. M.p. = 115-116 °C; HPLC-UV/VIS retention time, purity (min., %): 21.3, 98.6; ESI ⁺ -MS m/z (rel. int. %, ion): 302 (100, M+H] ⁺ ); HRMS (FAB): calculated (for C ₁₈ H ₂₃ NNaO ₃ ⁺ ) 324.1576, found 324.1577; ¹ H NMR (500 MHz, Chloroform-d) δ (ppm): 1.57-1.65 (m, 6H), 3.57(broad s, 4H), 3.87 (s, 3H), 3.89 (s, 3H), 6.43 (d, 1H, J = 15.2 Hz), 6.71-6.82 (m, 2H), 6.81-6.83 (m, 1H), 6.96-7.00 (m, 2H), 7.39-7.44 (m, 1H); ¹³ C NMR (126 MHz, Chloroform-d) δ (ppm): 24.7, 26.3, 55.9, 56.0, 109.1, 111.2, 119.8, 120.8, 125.2, 129.7, 138.5, 142.7, 149.1, 149.8, 165.5. Example 10 (2E,4E)-1-(piperidin-1-yl)-5-(3,4,5-trimethoxyphenyl)penta-2 ,4-dien-1-one (compound 26 in Table 1) Prepared according to Example 9. Slightly yellow solid, chemical formula: C ₁₉ H ₂₅ NO ₄ , yield (%): 42, E,E/E,Z = 88:1. M.p. = 157-159 °C; ESI ⁺ -MS m/z (rel. int. %, ion): 332 (100, M+H] ⁺ ); HRMS (FAB): calculated (for C ₁₉ H ₂₅ NNaO ₄ ⁺ ) 354.1681, found 354.1680; ¹ H NMR (500 MHz, Chloroform-d) δ (ppm): 1.56-1.68 (m, 6H), 3.58 (broad s, 4H), 3.85 (s, 3H), 3.87 (s, 6H), 6.48 (d, 1H, J = 15.2 Hz), 6.62 (s, 2H), 6.74-6.84 (m, 2H), 7.39-7.44 (m, 1H); ¹³ C NMR (126 MHz, Chloroform-d) δ (ppm): 24.7, 26.3, 56.2, 61.0, 104.1, 120.7, 126.6, 132.2, 138.5, 138.8, 142.4, 153.5, 165.4. Example 11 (2E,4E,6E)-7-(4-methoxyphenyl)-1-(piperidin-1-yl)hepta-2,4,6 -trien-1-one (compound 33 in Table 1) Prepared according to Example 9. Slightly yellow solid, chemical formula: C ₁₉ H ₂₃ NO ₂ , yield (%): 19, E,E,E/E,E,Z = 78:1. M.p. = 130- 132 °C; ESI ⁺ -MS m/z (rel. int. %, ion): 298 (100, M+H] ⁺ ); HRMS (FAB): calculated (for C ₁₉ H ₂₃ NNaO ₂ ⁺ ) 320.1626, found 320.1627; ¹ H NMR (500 MHz, Chloroform-d) δ (ppm): 1.56-1.65 (m, 6H), 3.55 (broad s, 4H), 3.80 (s, 3H), 6.34-6.42 (m, 2H), 6.61 -6.74 (m, 3H), 6.85 (d, 2H, J =10.2 Hz), 7.29-741 (m, 3H); ¹³ C NMR (126 MHz, Chloroform-d) δ (ppm): 24.8, 26.2, 43.5, 46.8, 55.4, 114.2, 119.8, 126.3, 128.1, 129.8, 130.1, 135.3, 139.6, 142.6, 159.8, 165.5.

Table 1. Examples of phenylrpopanoid derivatives Phenylpropanoid derivatives CHN MS Example 12 In vitro cytotoxic activity of novel compounds on normaland cancer human cells Low cytotoxicity of the compounds to normal cells is important factor affecting their possible cosmetic use. One of the parameters used, as the basis for cytotoxicity assays, is the metabolic activity of viable cells. For example, a microtiter assay, which uses the Calcein AM, is now widely used to quantitate cell proliferation and cytotoxicity. For instance, this assay is used in drug screening programs and in chemosensitivity testing. Because only metabolically active cells cleave Calcein AM, these assays detect viable cells exclusively. The quantity of reduced Calcein AM corresponds to the number of vital cells in the culture. BJ (human foreskin fibroblasts), G361 (human malignant melanoma), MCF7 (human breast cancer) and CEM (human T cell leukemia) were used for routine screening of compounds. The cells were maintained in Nunc/Corning 80 cm ² plastic tissue culture flasks and cultured in cell culture medium (DMEM with 5 g/l glucose, 2 mM glutamine, 100 U/ml penicillin, 100 µg/ml streptomycin, 10% fetal calf serum and sodium bicarbonate). The cell suspensions that were prepared and diluted according to the particular cell type and the expected target cell density (2.500-30.000 cells per well based on cell growth characteristics) were added by pipette (80 µl) into 96/well microtiter plates. Inoculates were allowed a pre-incubation period of 24 hours at 37 °C and 5% CO ₂ for stabilisation. Four-fold dilutions of the intended test concentration were added at time zero in 20 µl aliquots to the microtiter plate wells. Usually, the compound tested was evaluated at six 4-fold dilutions. In routine testing, the highest well concentration was 66.7 µM, but it can be the matter of change dependent on the agent. All compound concentrations were examined in duplicates. Incubations of cells with the tested compounds lasted for 72 hours at 37 °C, in 5% CO ₂ atmosphere and 100% humidity. At the end of the incubation period, the cells were assayed by using Calcein AM. Ten microliters of the stock solution were pipetted into each well and incubated for 1 hour. Fluorescence (FD) was measured with the Labsystem FIA Reader Fluoroscan Ascent (UK). The tumour cell survival (IC ₅₀ ) was calculated using the following equitation: TCS=(FD _{drug exposed well} / mean FD _{control wells} ) x 100%. The IC ₅₀ value, the compound concentration lethal to 50 % of the cells, was calculated from the obtained dose response curves (Table 2). Zero cytotoxicity of the novel compounds is the basic prerequisite for cosmetical and pharmaceutical applications. The cytoxicity of the novel compounds was tested on a panel of cell lines of different histogenetic and species origin (Table 2). We show herein that equal activities were found in all tumour cell lines tested as well as the non-malignant cells, e.g. BJ fibroblasts. As demonstrated in Table 2, IC ₅₀ for cancer cell lines as well as BJ fibroblasts was always higher than 50 µM. The novel derivatives show no toxicity to normal and tumour cells in concentrations of about 50 µM and thus are very suitable for pharmaceutical and cosmetical applications. Table 2: Cytotoxicity of novel compounds for different normal and cancer cell lines tested / IC ₅₀ (µmol/L)

Example 13 Antiinflammatory activity One of the most important parameters of specific cellular immunity is proliferative response of lymphocytes to antigens or polyclonal mitogens. The majority of normal mammalian peripheral lymphocytes comprise resting cells. Antigens or nonspecific polyclonal mitogens have the capacity to activate lymphoid cells and this is accompanied by dramatic changes of intracellular metabolism (mitochondrial activity, protein synthesis, nucleic acids synthesis, formation of blastic cells and cellular proliferation). Compounds with ability to selectively inhibit lymphocyte proliferation are potent immunosuppressants. Variety of in vitro assays was developed to measure proliferative response of lymphocytes. The most commonly used is ³ H-thymidine incorporation method. During cell proliferation, DNA has to be replicated before the cell is divided into two daughter cells. This close association between cell doublings and DNA synthesis is very attractive for assessing cell proliferation. If labelled DNA precursors are added to the cell culture, cells that are about to divide incorporate the labelled nucleotide into their DNA. Traditionally, those assays usually involve the use of radiolabelled nucleosides, particularly tritiated thymidine ([ ³ H]-TdR). The amount of [ ³ H]-TdR incorporated into the cellular DNA is quantified by liquid scintillation counting. Human heparinized peripheral blood was obtained from healthy volunteers by cubital vein punction. The blood was diluted in PBS (1:3) and mononuclear cells were separated by centrifugation in Ficoll- Hypaque density gradient (Pharmacia, 1.077 g/ml) at 2200 rpm for 30 minutes. Following centrifugation, lymphocytes were washed in PBS and resuspended in cell culture medium (RMPI 1640, 2mM glutamine, 100 U/ml penicillin, 100 µg/ml streptomycin, 10% fetal calf serum and sodium bicarbonate). The cells were diluted at target density of 1.100.000 cells/ml were added by pipette (180 µl) into 96/well microtiter plates. Four-fold dilutions of the intended test concentration were added at time zero in 20 µl aliquots to the microtiter plate wells. Usually, test compound was evaluated at six 4-fold dilutions. In routine testing, the highest well concentration was 266.7 µM. All drug concentrations were examined in duplicates. All wells with exception of unstimulated controls were activated with 50 µl of concanavalin A (25 µg/ml). Incubations of cells with test compounds lasted for 72 hours at 37 °C, in 5% CO ₂ atmosphere and 100% humidity. At the end of incubation period, the cells were assayed by using the [ ³ H]TdR: Cell cultures were incubated with 0.5 µCi (20 µl of stock solution 500 µCi/ml) per well for 6 hours at 37 °C and 5% CO ₂ . The automated cell harvester was used to lyse cells in water and adsorb the DNA onto glass-fiber filters in the format of microtiter plate. The DNA incorporated [ ³ H]TdR was retained on the filter while unincorporated material passes through. The filters were dried at room temperature overnight, sealed into a sample bag with 10-12 ml of scintillant. The amount of [ ³ H]TdR present in each filter (in cpm) was determined by scintillation counting in a Betaplate liquid scintillation counter. The effective dose of immunosuppressant (ED) was calculated using the following equation: ED = (CCPMdrug exposed well / mean CCPMcontrol wells) x 100%. The ED ₅₀ value, the drug concentration inhibiting proliferation of 50% of lymphocytes, was calculated from the obtained dose response curves. To evaluate antiinlammatory activity of novel phenolic derivatives, their ability to inhibit polyclonal mitogen induced proliferation of normal human lymphocytes was analyzed (Tab. 3). Our data demonstrate that these compounds have only marginal activity on ³ H-thymidine incorporation, nonetheless, they efficiently inhibit proliferation of activated lymphocytes. Effective antiinflammatory dose of new derivatives under in vitro conditions was close to 1-20 µM. Table 3: Antiinflammatory activity of novel derivatives Example 14 Radical scavenging activity determined by ORAC The ability of compounds to scavenge free radicals in vitro was determined by Oxygen Radical Absorbance Capacity (ORAC) method. In brief, fluorescein (100 µl, 500 mM) and 25 µl of compound solution were added into each working well in a 96-well microplate preincubated at 37 °C. Thereafter, 25 µL of 250 mM AAPH was quickly added, microplate was shaken for 5 s and the fluorescence (Ex. 485 nm, Em. 510 nm) was read every 3 min over 90 min by using microplate reader Infinite 200 (TECAN, Switzerland). The net area under the curve was used to express antioxidant activity relative to trolox which was used as a standard. Compounds with ORAC value higher than 1 are more effective than trolox, the hydrophilic equivalent of vitamin E. *Mean ± SD (n=3) Example 15 Activation of transcription factor Nrf2 The ability of compounds to activate Nrf2-dependent expression was determined by EpRE-LUX reporter cell line. In brief, compounds at 100, 10, 1 and 0.1 µM concentrations were incubated for 24 h with cells. After cells lysis (10 mM Tris, 2 mM DTT), a buffer containing 0.2 mM luciferin was added to start luminescent reaction. The increase in luminescence was measured with microplate reader Infinite M200 (TECAN). Compounds with Nrf2 value higher than 1 are more effective than dimethylfumarate (DMF), a strong Nrf2 activator approved for the treatment of psoriasis and multiple sclerosis. *Mean ± SD (n=3) Example 16 Antimicrobial activity Antimicrobial activities of the synthesized compounds were assessed using the standard dilution micromethod. Disposable microtitration plates were used for the tests. The compounds (10mM) were diluted 50times with Breath heart infusion broth (3.675μL) for diluting the concentration of DMSO below 5%, which does not affect the growth of bacteria and then 2–128times with an additional Breath heart infusion broth (50 μL) inoculated with the tested bacteria/yeast/mould at a concentration of 105–106CFUmL ⁻¹ . Tested concentrations of compounds were 1.56µM–200µM. The minimum inhibitory concentration (MIC) of aerobic bacteria was read after 24h of incubation at 37°C as the minimum inhibitory concentration (MIC) of the tested substance that inhibited the growth of the bacterial strain. The MIC of anaerobic bacteria, yeast and mould was read after 48h of incubation at 30°C. Table 4: Antimicrobial activity of novel compounds against different dental pathogens expressed as MIC (µM) Example 17 Ames test The test substances was (1, 2, 12, 21) assayed for the mutagenicity by the Bacterial Reverse Mutation Test. The performed test was based on EU method B.13/14 Mutagenicity – Reverse mutation test using bacteria, which is analogous to the OECD Test Guideline No. 471. Four indicator Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537 and one indicator Escherichia coli WP2 uvrA strain were used. The test substance was dissolved in dimethylsulfoxide (DMSO) and assayed in doses of 10-1000 µg per plate, which were applied to plates in volume of 0.1 mL. Experiments were performed without as well as with metabolic activation with a supernatant of rat liver and a mixture of cofactors. The working procedure described is in accordance with the documents Method B.13/14, Mutagenicity: Reverse Mutation Test Using Bacteria, Council Regulation (EC) No.440/2008. Published in O.J. L 142, 2008 and OECD Test Guideline 471, Bacterial Reverse Mutation Test. Adopted July 21, 1997. In the arrangement given above, the test substance was non-mutagenic for all the used tester strains without as well as with metabolic activation. Example 18 Mouthwash formulation A mouthwash formulation was manufactured by combining the following components (amounts in wt.%): Polyol 20.0% PEG 6/Ultra PEG 300 15.0% Polysorbate 20 5.0% Compound of formula I 5.0% Water 52.7% Sucralose 0.30% Belwood Wintergreen 2.0% Example 19 Toothpaste formulations A preferred toothpaste formulation comprises from about 15% to about 35% of sorbitol; from about 15% to about 30% of a silica agent (e.g. ZEODENT 113 and ZEODENT 165), from about 10% to about 20% water; from about 5% to about 15% glycerin, from about 2% to about 7% of surfactant (e.g. Polysorbate 20), from about 1% to about 2% flavoring agent (including sodium saccharin), from about 0.5% to about 1.5% of titanium dioxide, from about 0.5% to about 1.5% of binder (e.g. CEKOL 2000 gum), from about 0.05% to about 0.15% of a preservative (e.g. sodium benzoate), from about 0.25% to about 1.75% of pure calcium, and from about 0.10% to about 1.75% of magnesium phosphate; and may further comprise from about 10% to about 40% d-limonene (98.0% or higher purity, more preferably 98.5%-99.0%). Amounts are in wt.%. A) An example toothpaste formulation was manufactured by combining the following components: 25.00% polyol (sorbitol) 20.00% Zeodent 113 (silica abasive) 2.00% phenolic derivative (compound 1, at least 99.5% purity) 13.39% water 10.00% Glycerin Natural 5.00% Polysorbate 20 2.70% Zeodent 165 (silica abrasive) 1.00% Flavor 484 (Walmart brand) 1.00% titanium dioxide 1.00% CMC 9M31XF/Cekol 2000 (binder gum) 0.45% pure calcium 0.25% saccharin 0.11% magnesium phosphate 0.10% sodium benzoate The foregoing components were combined as follows: the sodium saccharin and sodium benzoate were dissolved in the water and set aside. The Cekol and glycerin were combined, and, while mixing these two components together, the polyol was added. The solution of sodium saccharin and sodium benzoate were then added to the Cekol/glycerin, and polyol mixture. Next, Zeodent 165 was added to the mixture and blended in well, followed by the Zeodent 113, which in turn was blended in well until the mixture was free of lumps. Titanium dioxide, Polysorbate 20, and d-limonene were combined with the mixture and blended until the mixture was smooth. Finally, the calcium and magnesium phosphate was added, followed by the flavoring agent (i.e. Flavor 484). Example 20 Gel formulation An ointment formulation was tested during a pilot clinical study with 4 volunteers with psoriatic skin disorders. The components are given in grams per 100 g. The gel consistence may be additionally modified by addition of silica colloidalis anhydrica. It is again expected that the transdermal Transcutol P/Lauroglycol FCC system will increase the efficiency of compound 1. Silica colloidalis anhydrica will probably slow down the penetration of the active substance. Example 22 Preparation procedure of a skin ointment The formulation components are given in grams per 200 g: Recommended procedure Phase A: 2 grams of phenylpropanoid derivative 1 was dissolved in 20 g of Transcutol P while stirring continuously at room temperature in a separate glass or stainless-steel container. The dissolution process may be accelerated by heating the solution to a maximal temperature of 40°C. Phase B: 0.4 grams of Nipanox BHT and 0.4 g of Nipabutyl were dissolved while stirring continuously in 133.2 g of Lauroglycol FCC at a temperature of approximately 70°C in another separate glass or stainless-steel container. The clear oily solution is heated to a temperature of approximately 80°C and 44 g of Compritol 888 ATO are melted in it while stirring continuously. The clear oily solution is cooled down to approximately 60°C and during continuous stirring and cooling down is mixed with phase A. The resulting whitish ointment-like substance is divided into approximately 15 gram portions and filled into prearranged plastic containers. Example 23 Formulation of a composition for topical application to the skin A composition for topical application to the skin contains the following ingredients by weight%: Active ingredient: Compound 1 0.1 % Oil phase: Cetyl alcohol 5.0 % Glyceryl monostearate 15.0 % Sorbitan monooleate 0.3 % Polysorbate 80 USP 0.3 % Aqueous phase: Methylcellulose 100 cps 1.0 % Methyl paraben 0.25 % Propyl paraben 0.15 % Purified water q.s. to 100 % Methyl paraben and propyl paraben were dissolved in hot water and subsequently methylcellulose was dispersed in the hot water. The mixture was chilled at 6°C until the methylcellulose dissolved. The mixture was then heated to 72°C and added to the oil phase which was heated to 70°C while stirring continuously. The phenylpropanid derivative 1 was added at a temperature of 35°C and the resulting mixture was stirred continuously until dispersed. This composition is applied to the skin on at least a daily basis until the desired skin-ameliorating effect is reached.