Field of the Invention

The invention relates to anionic pregnane derivatives and their production. Further, it concerns pharmaceuticals containing these anionic steroid compounds and their use as a neuroprotective against excitotoxic damage of the central nervous system (CNS), conditions associated with excessive activation of NMDA-subtype glutarnate receptors or, where this type of receptor is involved in the creation or during the certain mental and neurological diseases. This is essentially a traumatic and hypoxic damage of nervous tissue in the central nervous system diseases like Alzheimer's, Huntingdon's, and Parkinson's disease as well as in cognitive disorders arising in old age. Other indications could be tardive dyskinesia, amyotrophic lateral sclerosis, olivopontocerebellar degeneration, neurological problems associated with AIDS infection, allergic encephalomyelitis, and a medication for epilepsy, anxiety, depression, schizophrenia, chronic pain, and drug addiction.

Background of the Invention

Neurons are part of a system that adequately responds to various stimulations in order to protect the stability of the organism. An indispensable part of the activity of neurons is usually excitation, but under certain conditions may be excessive excitation of neurons harmful. Such a condition known as excitotoxicity, can lead to symptoms characteristic for severe diseases of nervous system, such as Alzheimer's, Huntington^ or Parkinson's disease. These diseases are becoming increasingly serious and growing problem especially for the aging population. Drugs for prevention and care for the sick are urgently needed. One of the goals, where you can intervene against the previously mentioned diseases, is NMDA receptor. It is an ion channel activated by glutamic acid, presented in all areas of the brain and spinal cord.

Medication for pathological conditions, such as craniocerebral injury, stroke and other neurological conditions associated with excitotoxicity, is currently the subject of intensive research. So far, there are no reliable drugs or unambiguously designated active substance that could be applied as a universal medicine. In 2006, the 3rd phase of clinical research for NXY- 059 was an unsuccessfully terminated (disodium άisufentone; Chacon M.R., Jensen M.B., Sattin J. A., Zivin J. A.: Neuroprotection in cerebral ischemia: emphasis of SAINT trial, Curr. Cardiol. Rep. 2008, 10, 37-42.). NXY was promising substance to improve chances of survival and reduce the consequences of stroke. For the treatment of early stages of Alzheimer's disease is used memantine with questionable therapeutic utility. The utilization of substances that have shown very good neuroprotective effects at excitotoxicity caused by excessive activation of NMDA receptors, both in vitro tests and in animal studies, such as drug is prevented by their side effects, in some cases serious mental disorders have been observed (psychosis are common). This group is represented by e.g. ketamine.

Neurosteroids are synthesized in the nervous tissue from cholesterol and/or modified to neuroactive compounds from circulating precursors (Baulieu EE. Neurosteroids: A novel function of the brain. Psychoneuroendocrinology 1998; 23, 963-87.). They act through neuronal membrane receptors for essential transmitters (e.g. γ-amino-butyric acid (GABA) an iV-methyl- D-aspartate (NMDA)). Such neurosteroids have been proposed to control neuronal excitability by modulating ligand and/or voltage-gated ion channels (Paul SM, Purdy RH. Neuroactive steroids. Faseb J 1992; 6, 2311r22; Biggio G, Concas A, Costa E. Steroid modulation of amino acid neurotransmitter receptors.' v: Farb DH, Gibbs TT, Wu FS, Gyenes M, Friedman L, Russek SJ. GABAergic Synaptic Transmission: Molecular, Pharmacological, and Clinical Aspects, New York: Raven Press; 1999, 119-131.) and this action has been shown to affect a lot of physiological processes e.g. learning (Tsien JZ, Huerta PT, Tonegawa S. The essential role of hippocampal CAl NMDA rece'ptor-dependent synaptic plasticity in spatial memory (Cell 1996; 87, 1327-38.), aging (Vallee M, Mayo W, Darnaudery M, Corpechot C, Young J, Koehl M, et al. Neurosteroids: deficient cognitive performance in aged rats depends on low pregnenolone sulfate levels in the hippocampus. Prόc Natl Acad Sci USA 1997; 94, 14865-70.), and stress (Grobin AC, Roth HR, Deutch AY. Regulation of the prefrontal cortical dopamine system by the neuroactive steroid 3α,21-dihydroxy-5α-pregnane-20-one. Brain Res 1992; 578, 351-56.) as well as certain neurological arid psychiatric disorders (Alzheimer's disease (Nasman B, Olsson T, Backstrom T, Eriksson S, Grankvist K, Viitanen M, et al. Serum dehydroepiandrosterone sulfate in Alzheimer's disease and in multi-infarct dementia. Biol Psychiatry 1991; 30, 684-90.), epilepsy (Gasior M, Carter RB, Witkin JM. Neuroactive steroids: potential therapeutic use in neurological and psychiatrical disorders. Trends in Pharmacol Sci 1999; 20, 107-112.) etc.). i

Defining a binding site of neurosteroids and the knowledge of the molecular mechanism present a molecular template ¹ for design and development of novel therapeutic entities. The molecular mechanism by which rieiirosteroids affect ligand-gated ion channels is still not clearly understood. In general, neurosterόids influence the frequency of single channel openings and the average channel open duration _: (Twyman RE, Macdonald RL. Neurosteroid regulation of GABA(A) receptor single-channel kinetic-properties of mouse spinal-cord neurons in culture. J Physiol 1992; 456, 215-45; Callachari H, Cottrell GA, Hather NY ₅ Lambert JJ, Nooney JM ₅ Peters JA. Modulation of the GA^BA- A. receptor by progesterone metabolites. Proc R Soc Lond B Biol Sci 1987; 231, 359-369. j ^'•

Similarly, much attention has been devoted to recognition of the corresponding binding sites and some of them were identified for the GABA _A receptor, but not for NMDA receptor. The results of current studies indicate that .neurosteroids have their specific binding sites, independent of particular agonists or other allosteric modulators (Park-Chung M, Wu FS, Purdy RH, Malayev AA, Gibbs TT, Farb DH. Distinct sites for inverse modulation of N-methyl-D-aspartate receptors by sulfated steroids. MoI Pharmacol 1997; 52, 1113-23; Akk G, Bracamontes JR, Covey DF, Evers A, Dao T ₅ Steinbach JH. Neuroactive steroids have multiple actions to potentiate GABAA receptors J Physiol 2004; 558, 59 ^j -74.>.

The knowledge of NMDA receptor's binding site is not as all-embracing as for the GABA receptor; nevertheless, the effect of neurosteroids on NMDA receptor seems to be mediated by independent binding sites located at the extracellular domain of the NMDA receptor (Park-Chung M, Wu FS, Farb DH. 3α-Hydroxy-5β-pregnan-20-one sulfate: a negative modulator of the NDMA-induced current in cultured neurons. MoI Pharmacol 1994; 46,1 46-50; Horak M ₅ Vlcek K, Chodounska H, Vyklicky L. Subtype-dependence of N-methyl-D-aspartate receptor modulation by pregnenolone sulfate. Neuroscience 2006; 137, 93-102.). The experiments with chimeric receptors have shown crucial role of an extracellular loop between the third and fourth transmembrane domains of the NR2 subunit in the mechanism of potentiating and inhibitory effects of 3β-hydroxy-pregn-5-en-20-one and 20-oxo-5β-pregnan-3α-yl sulfate (Horak M ₅ Vlcek K ₅ Chodounska H ₅ , Vyklicky L. Subtype-dependence of N-methyl-D-aspartate receptor modulation by pregnenolone sulfate. Neuroscience 2006; 137,93-102; Petrovic M ₅ Sedlacek M ₅ Horak, Chodounska H, Vyklicky L. 20-Oxo-5β-pregnan-3α-yl sulfate is a use- dependent NMDA receptor inhibitor. J Neurosci 2005; 25, 8439-50.).

Without doubt, a lot of other aspects of the receptor structure will influence the nature and extent of the neurosteroid modulation: the stereochemistry of the neurosteroids should be mentioned. Previous structure-activity studies have reported several features which are important for activity of neurosteroids at NMDA receptors: the structure should include a sulfonyloxy group at the position 3 and a 20-oxo group as well (Cais O, Vyklicky L. Psychiatrie Suppl 2006; 10, 8-11.). The potentiating effect is* maintained if the sulfate group is replaced by another negatively charged group, e.g. hemioxylate, hemisuccinate or hemiglutarate (Park-Chung M, Wu FS, Purdy RH, Malayev AA, Gibbs TT, Farb DH. Distinct sites for inverse modulation of N- methyl-D-aspartate receptors by! sulfated steroids. MoI Pharmacol 1997; 52, 1113-23; Weaver CE, Land MB, Purdy RH, Richards KG, Gibbs TT, Farb DH. Geometry and charge determine pharmacological effects of steroids on N-methyl-D-aspartate receptor-induced Ca(2+) accumulation and cell death. J Pharmacol Exp Ther 2000; 293, 747-54.).

A number of preclinical studies demonstrate a significant ability of NMDA antagonists to prevent out flux of glutamate and thus limit the disturbance of function of CNS. However, their neuroprotective potential is small from a clinical point of view. Due to the fact that NMDA receptors are one of the most spre'ad type of receptors in CNS, medication with NMDA antagonists leads to a number of 'serious undesirable effects from the disruption of basic motoric up to the induction of schizophrenic psychosis. On the other hand, different subunit composition of NMDA receptors on presynaptic and postsynaptic elements, on different types of nerve cells and even in different parts of the brain offer the ability to selectively search for substances affecting only a certain subset ¹ of NMDA receptors, and thereby reduce the incidence of unexpected and undesirable effects while preserving neuroprotective action.

Steroid derivatives are not yet used in medical practice for medication, although their neuroactivity has been long known arid even alfaxolone was removed from medication. The aim of the authors of the present invention are neuroactive anionic compounds which have a high index of selectivity and efficiency, i.e. are less toxic but more effective than previously known analogues.

Therefore, the authors of present invention began development and testing of new NMDA antagonists that are derived from neurosteroids. During this study found that newly synthesized compounds show affinity for extrasynaptic NMDA receptors. What are even more important, electrophysiological studies have shown that this type of substance binds only to long-term open NMDA receptors. Consequently, blocking of excess calcium influx into the cell through long open-NMDA receptors was estimated as neuroprotective mechanism of action. During these studies were synthesized new pregnane derivatives, which inhibit the NMDA receptor and may therefore be useful for treating CNS diseases, such as cognitive disorders in aging, Alzheimer's disease, stroke, Parkinson's disease, Huntington's disease and other diseases and disorders resulting from excessive activation of NMDA receptors.

Summary of the Invention j

The object of the invention is new pregnane anionic compounds of general formula I

in which ^'

R ¹ is the ester group of general formula R ⁴ O-, which is able to form ion, where R ⁴ is

HSO ₃ -, pyridine-SO ₃ -, HOOC-(CH ₂ ) ₂ -CO- etc.,

R ² is hydrogen atom with the configuration of the alpha or beta and

R ³ is ester group of general formula R ⁵ COO-, where R ⁵ is CH ₃ - or CsH ₄ N-, such as acetoxy group, nicotinyloxy group etc., and their pharmaceutically acceptable salts.

of compounds of general formula I in which to which the compound of formula II

is transferred to 3,7-diprotected derivative, with the advantage of diacetate of formula III

that is then by partial hydrolysis, with the advantage of by alkali metal hydroxide, such as potassium, sodium, or lithium hydroxide, or acids such as hydrochloric or perchloric acid etc., in a suitable solvent such as alcohol, aqueous alcohol, or solvent mixtures, with the advantage of a mixture of methanol and benzene, converted to monoester formula IV

from which by the treatment with succinic anhydride in pyridine in the presence of DMAP can be prepared particular ester, with the advantage of hemisuccinate of formula I

in which R ¹ is hemisuccinate group, R ² means a hydrogen atom in the alpha position and R is acetoxy group, '

or by the reaction of pyridine-sulfur trioxide complex in an inert solvent, with the advantage in chloroform, can be prepared pyridiniurn sulfate of general formula I

in which R ¹ is pyridiniurn sulfate group, R ² means a hydrogen atom in the alpha position and R ³ is acetoxy group. Alternatively, the latter compound the formula I

in which R ¹ is pyridinium sulfate group, R ² means a hydrogen atom in the alpha position and R ³ is acetoxy group, can be converted by treatment with alkali metal hydroxide, with the advantage of sodium hydroxide, in alcohol, with the advantage in methanol, to the compound of general formula I

in which R ¹ is sodium salt of sulfate, R ² is hydrogen atom in the alpha position and R ³ is acetoxy group.

Compound of general formula I in which R ¹ is pyridinium sulfate, R ² is hydrogen atom in the alpha position and R is nicotinyloxy group, shall be synthesized so that the compound of general formula IV

is converted by a reaction with tert-butyldimethylsilyl chloride and imidazole in a suitable solvent, with the advantage in DMF, to the tert-butyldimethylsilyl derivative of formula V

which by the usual saponification of acetate group in position 7, with the advantage in potassium hydroxide in a mixture of ethanol and benzene at increased temperature, afforded a compound of formula VI . !

which can be esterified by treatment with nicotinoyl chloride in pyridine in the presence of DMAP to afford nicotinoyloxy derivative of formula VII

where R is TBDMS, and by the treatment with j?-toluenesulfonic acid in methanol provided the compound of general formula VII in which R means a hydrogen atom, which then by reaction with pyridine-sulfur trioxide complex in a suitable inert solvent, with the advantage in chloroform, afforded the compound of general formula I

in which R ¹ is sodium salt of pyridinium sulfate, R ² is hydrogen atom in the alpha position and R ³ is nicotinyloxy group. [

A similar sequence of reactions can produce compounds of general formula I in which R ² is hydrogen atom with the beta configuration, from compound of formula VIII

which differs from a compound of formula II only in configuration of the hydrogen atoms in position 5.

A similar sequence of reactions, as explained above, allows producing the following compounds of general formula I: i 20-Oxo-5α-pregnane-3α,7α-diyl 3-Hemisuccinate 7-Acetate,

20-Oxo-5α-pregnane-3α,7α-diyl 3-Sulfate 7-Acetate Pyridiniurn Salt, 20-Oxo-5α-pregnane-3α,7α-diyl 3-Sύlfate 7-Acetate Sodium Salt, 20-Oxo-5α-pregnane-3α,7α-diyl 3-Sulfate 7-Nicotinate Pyridinium Salt, 20-Oxo-5β-pregnane-3α,7α-diyl 3-Hemisuccinate 7-Acetate, 20-Oxo-5β-pregnane-3α,7α-diyl 3-Sulfate 7-Acetate Pyridinium Salt, 20-Oxo-5 β-pregnane-3α,7α-diyl 3-Sulfate 7-Acetate Sodium Salt, and 20-Oxo-5β-pregnane-3α,7α-diyl 3-Sulfate 7-Nicotinate Pyridinium Salt.

The object of this invention is the utilization of compounds of general formula I as neuroprotective agents in traumatic brain injury, spinal cord, stroke, in the central nervous system diseases such as Alzheimer's, Huntington's and Parkinson's disease, also in the prevention of CNS disease, and for medication of conditions associated with excitotoxicity. Indications could be the prevention or deceleration of onset of neurodegeneration in Alzheimer's disease, the consequences of stroke, traumatic brain damage, Parkinson's disease, tardive dyskinesia, Huntington's disease, amyotrophic lateral sclerosis, olivopontocerebellar degeneration, AIDS, allergic encephalomyelitis, and for medication of epilepsy, anxiety, depression, schizophrenia, chronic pain and drug addiction.

The objects of the invention are also pharmaceuticals which as active ingredients include the above compounds of general formula I, in the R ¹ , R ² and R ³ represent, as seen above, or their substituted analogues, either alone or in combination with any pharmaceutically acceptable carrier, diluents or adjuvant. ^•

Pregnanolone sulfate and its homologs show a positive role in different models of human diseases, such as NMDA-induced epileptic seizures, formalin induced pain and neuroprotective effect, both in vitro and in vivo models _* Based on our findings (see details in the example 20), we believe that homologies of pregnanolone sulfate may have therapeutic value in the treatment of the central nervous system diseases of a human.

The following examples serve only to illustrate the objects referred in the invention, without thereby in any way limiting this invention, which is given only to the extent of accompanying patent claims.

EXAMPLES

Example 1

20-Oxo-5α-pregnane-3α,7α-diyl Diacetate

I

To a solution of 20-oxo-5α-pregnane-3α,7α-diol (100 mg, 0.3 mmol) in pyridine (5 mL), acetic anhydride (0.42 mL, 4.4 mmol) was added and the mixture was heated for 6 h at 50 ⁰ C. After standing at room temperature for 2 days, the reaction mixture was poured into ice-water and extracted with ethyl acetate (50 mL). Extract was washed with solution of potassium hydrogen carbonate, water, and dried. Solvents were evaporated and the oily residue purified by preparative thin layer chromatography in a mixture of acetone/petroleum ether (1:1) to give title diacetate (67 mg, 54%): m.p. 11J2-114 °C, [α] _D +21.8 (c 0.363, CHCl ₃ ). IR spectrum (CHCl ₃ ): 1726 (C=O, acetate); 1702 (C=O, ketone); 1259, 1241, 1030 (C-O). ¹ H NMR (200 MHz): 0.60 (s, 3 H, 3 x H-18); 0.80 (s, 3 H -3 x H-19); 2.05 (s, 3 H, C(3)-OAc); 2.08 (s, 3 H, C(7)-OAc); 2.12 (s, 3 H, 3 x H-21); 2.54 (t, 1 H, J = 8.8, H-17); 4.92 (q, 1 H, J = 2.9, H-7); 5.03 (m, 1 H, H- 3). FAB MS: 399 (12%, M + Na), 359 (8%, M + 1 - H ₂ O), 299 (80%, M + 1 - H ₂ O, AcOH). C ₂₅ H ₃₈ O ₅ : Calculated C, 71.74; H, 9.15. Found C, 72.44; H, 9.22. Example 2

3α-Hydroxy-20-oxo-5α-pregnan-7α-yϊ Acetate

A solution of diacetate from Example 1 (90 mg, 0.22 mmol) in benzene (10 mL) was treated with a solution of potassium hydroxide (15.4 mg, 0.27 mmol) in methanol (1 mL). After standing overnight at room temperature, the mixture was poured into water and extracted with ethyl acetate (50 mL). The extract was washed with water, dried and the solvent was evaporated. The residue was purified by preparative thin layer chromatography in a mixture of acetone/petroleum ether (1:1) to give title compound (69 mg, 85%): m.p. 148-150 ⁰ C (ether/petroleum ether), [α] _D +64.5 (c 0.346, CHCl ₃ ). IR spectrum (CHCl ₃ ): 3616 (OH); 1717 (C=O ₅ acetate); 1701 (C=O, ketone); 1256 (C-O). ¹ H NMR (200 MHz): 0.59 (s, 3 H, 3 x H-18); 0.78 (s, 3 H ₅ 3 x H-19); 2.07 (s, 3 H, OAc); 2.11 (s, 3 H, 3 x H-21); 2.55 (t, 1 H, J = 8.8, H-17); 4.06 (quintet, 1 H, J = 2.4, H- 3); 4.91 (q, I HJ = 2.9, H-7). FAB MS: 399 (17%, M + Na), 317 (8%, M + 1 - AcOH), 299 (9%, M + 1 - AcOH, H ₂ O). C ₂₃ H ₃₆ O ₄ : Calculated C, 73.37; H, 9.64. Found C, 74.12; H, 9.87.

Example 3

20-Oxo-5α-pregnane-3α,7α-diyl 3-Hemisuccinate 7-Acetate

A mixture of compound prepared according to Example 2 (100 mg, 0.27 mmol) and succinic anhydride (100 mg, 2 mmol) was dried in vacuo (25 ⁰ C, 100 Pa) for 30 min. Dry pyridine. (10 mL) and 4-dimethylaminopyridme (20 mg, 0.17 mmol) were added. The mixture was heated for 6 h at 140 ⁰ C. Additional succinic anhydride (200 mg, 4 mmol) and 4-dimethylaminopyridine (20 mg, 0.17 mmol) were added and the mixture was heated for 1O h at 140 ⁰ C. The reaction mixture was poured into water and extracted with ethyl acetate (50 mL). Aqueous phase was extracted again with ethyl acetate (50 mL), and the collected organic extracts were extracted with water and dried. The solvent was evaporated and the residue crystallized from hot ethyl acetate to give title hemisuccinate (71 mg, 35%): m.p. 193-195 ⁰ C, [α] _D +43.3 (c 0.246, CHCl ₃ ). IR spectrum (CHCl ₃ ): 3516, 3100 broad (COOH); 1717 (C=O ₅ acetate); 1701 (C=O, ketone); 1379 (CH ₃ ); 1257, 1248 (C-O, acetate). ¹ H NMR (200 MHz): 0.60 (s, 3 H, 3 x H-18); 0.80 (s, 3 H ₅ 3 x H-19); 2.08 (s, 3 H, OAc); 2.12 (s, 3 H, 3 x H-21); 2.54 (t, 3 HJ = 8.8, H-17); 2.60-2.71 (m, 4 H ₅ 0OCCH ₂ CH ₂ COO); 4.92 (m, ¹ 1 H ₅ H-3); 5.06 (q ₅ 1 H ₅ J = 2.4, H-7). FAB MS: 499 (100%, M + Na), 417 (13%, M + 1 - AcOH), 2S>9 (55%, M - AcOH, C ₄ H ₅ O ₄ ). HR-MS (+ESI) Calculated for C ₂₇ H ₄₀ O ₇ Na [M ⁺ ] 499.2666, found 499.2662. C ₂₇ H ₄₀ O ₇ : Calculated C, 68.04; H, 8.46. Found C ₅ 67.83; H, 8.46.

Example 4

20-Oxo-5α-pregnane-3α,7α-diyl 3-Sulfate 7-Acetate Pyridinium Salt

The mixture of compound prepared according to Example 2 (200 mg, 0.53 mmol) and a sulfur trioxide pyridine complex (400 mg, 2.5 mmol), dried in vacuo (25 ⁰ C, 100 Pa) for 1 h, was dissolved in dry chloroform (10 mL). The reaction mixture was stirred for 4 h at room temperature under argon. After standing overnight at -20 ⁰ C, the undissolved sulfur trioxide pyridine complex was filtered off. Trie solvent was evaporated and the residue was dissolved in absolute methanol (1 mL) with diethylether (15 mL). The mixture was concentrated to almost one-half. After standing overnight at -20 ⁰ C, the crystals were collected, filtered off and dried in a desiccator (over potassium hydroxide) to afford compound 6 (230 mg, 82%): m.p. 156-160 ⁰ C, [α] _D +29.3 (c 0.288, CHCl ₃ ). IR spectrum (CHCl ₃ ): 3072 (pyridinium); 1716 (C=O, acetate); 1702 (C=O, ketone); 1258, 1220 ;(C-O, acetate); 1258 (S-O). ¹ H NMR (400 MHz): 0.59 (s, 3 H, 3 x H-18); 0.80 (s, 3 H, 3 x H-1S>); 2.06 (s, 3 H, OAc); 2.12 (s, 3 H, 3 x H-21); 2.56 (t, I HJ = 9.2, H-17); 4.78 (quintet, 1 H, J = 2.6, H-3); 4.89 (q, 1 H, J = 2.9, H-7); 7.98 (m, 2 H, H-3 and H- 5, pyridinium); 8.48 (tt, 1 H, J ₁ = 7.8, J ₂ =1.5, H-4, pyridinium); 8.94 (m, 2 H, H-2 and H-6, pyridinium). ESI MS: 574 (17%, M + K), 494 (14%, M + K - pyridinium), 478 (21%, M + Na - pyridinium), 412 (15%, M - CH ₃ CO, pyridinium), 341 (47%, M + Na - OSO ₃ C ₅ H ₆ N, CH ₃ CO). HR-MS (+ESI) Calculated for C ₂₈ H ₄₁ O ₇ NNaS [M ⁺ + Na] 558.2496, found 558.2502. C ₂₈ H ₄₁ NO ₇ S: Calculated C, 62.78; H, 7.71; N, 2.61; S, 5.99. Found C, 62.38; H, 7.62; N, 2.70; S, 6.73.

Example 5

20-Oxo-5α-pregnan-3α,7α-diyl 3-Sulfate 7-Acetate Sodium Salt

The compound prepared according to Example 4 (140 mg, 16.1 mmol) was dissolved in absolute methanol (2 mL) and solution of sodium hydroxide in methanol (0.9 mL, 0.373 M) was added dropwise during 1 h to pH 8. The solution was concentrated to one-half and absolute ether (10 mL) was added. After standing overnight at -20 ⁰ C, the obtained crystals were filtered off and dried in a desiccator (over potassium hydroxide) to yield title sodium salt (86 mg, 68%): m.p. 162-163 ⁰ C, [α] _D +29.6 (C 0.215, CHCl ₃ ). IR spectrum (CHCl ₃ ): 1733, 1717 (C=O, acetate); 1703 (C=O, ketone); 1257, 1245, 1198 (C-O, acetate). ¹ H NMR (200 MHz): 0.61 (s, 3 H, 3 x H- 18); 0.79 (s, 3 H, 3 x H-19); 2.10, (s, 3 H, OAc); 2.11 (s, 3 H, 3 x H-21); 2.54 (t, 1 H ₅ J = 8.8, H- 17); 4.69 (m, 1 H, H-3); 4.85 (m, 1 H, H-7). ESI MS: 501 (12%, M + Na), 381 (100%, M + Na - OSO ₃ Na). C ₂₃ H ₃₅ NaO ₇ S + 2H ₂ O: Calculated C, 53.68; H, 7.63; S, 6.23. Found C, 53.52; H, 7.64; S, 6.11.

Example 6 !

3α-(tert-Butyldimethylsilyloxy)-20-oxo-5α-pregnan-7α-y l Acetate

Hydroxy derivative prepared in Example 2 (528 mg, 1.4 mmol) and imidazole (570 mg, 8.37 mmol) were dissolved in N,N-dimethylformamide (11 mL) and the mixture was cooled to 0 ⁰ C. Then, /ert-butyldimethylsilyl chloride was added (528 mg, 3.5 mmol). The reaction mixture was allowed to attain room temperature and stirred. After 2 h, the reaction was diluted with ethyl acetate (150 mL), organic phase was washed with solution of citric acid, potassium hydrogen carbonate, and water. The organic layer was dried and evaporated in vacuo. Crystallization from ethyl acetate gave 687 mg (99%) of title compound: m.p. 120-121 ⁰ C, [α] _D +29.0 (c 0.369, CHCl ₃ ). IR spectrum (CHCl ₃ ): 2897 ((CH ₃ ) ₂ Si); 1715 (C=O, acetate); 1701 (C=O, ketone); 1472, 1463 ((CH ₃ ) ₃ C); 1258 (C-O, acetate); 1053 (C-OSi). ¹ H NMR (200 MHz): 0.02 (s, 6 H, 6 x (CH ₃ ) ₂ Si); 0.59 (s, 3 H, 3 x H-I8); 0.76 (s, 3 H, 3 x H-19); 0.89 (s, 9 H, (CH ₃ ) ₃ C); 2.03 (s, 3 H, OAc); 2.12 (s, 3 H, 3 x H-21); 2.54 (t, 1 H, J = 8.7, H-17); 3.97 (quintet, 1 H, J = 2.9, H-3); 4.89 (q, 1 H, J = 2.4, H-7). ESI MS: 513 ^; (83%, M + Na), 457 (20%, M + Na - (CH ₃ ) ₃ C), 353 (42%, M + Na - (CH ₃ ) ₃ C(CH ₃ ) ₂ Si0, CH ₃ CO, AcOH). C ₂₉ H ₅₀ O ₄ Si: Calculated C, 70.97; H, 10.27. Found C, 70.49; H, 10.39. ^{" ;}

Example 7

3α-(tert-Butyldimethylsilyloxy)-7α-hydroxy-5α-pregnan- 20-one

The solution of acetate prepared; in Example 6 (650 mg, 1.32 mmol) in benzene (50 mL) and potassium hydroxide in ethanol (0.89 M, 60 niL) were heated at 60 ⁰ C for 16 h. The mixture was poured into water and extracted with ethyl acetate (80 mL). The organic layer was washed with water, dried and the solvents were evaporated in vacuo. The residue was crystallized from hot ethyl acetate to give title compound (527 mg, 88%): m.p. 135-140 ⁰ C (ethyl acetate), [α] _D +63.3 (c 0.232, CHCl ₃ ). IR spectrum (CHCl ₃ ): 3615 (O-H); 1699 (C=O, ketone); 1472, 1463 ((CHs) ₃ C); 1253 ((CHs) ₂ Si); 1052 (C-OSi). ¹ H NMR (200 MHz): 0.02 (s, 6 H, (CH ₃ ) ₂ Si); 0.59 (s, 3 H, 3 x H-18); 0.88 (s, 12 H, 3 k H-19 and (CH ₃ ) ₃ C); 2.11 (s, 3 H, 3 x H-21); 2.56 (t, 1 H, J = 8.8, H-17); 3.83 (m, 1 H, H-7); 3.98 (m, 1 H, H-3). ESI MS: 919 (100%, 2M + Na), 471 (50%, M + Na). C ₂₇ H ₄₈ O ₃ Si: Calculated C, 72.26; H, 10.70. Found C, 72.25; H, 11.11.

Example 8

3α-(tert-Butyldimethylsilyloxy)-2θ-oxό-5α-pregnan-7α -yl Nicotinate

Compound prepared in previous Example 7 (450 mg, 1.0 mmol) and 4-dimethylaminopyridine (10 mg, 0.09 mmol) were dissolved in pyridine (15 mL) and the solution was cooled to 0 ⁰ C. Nicotinoyl chloride hydrochloride (900 mg, 5.0 mmol) was added to a stirred mixture in small portions. The reaction mixture was stirred at room temperature for 3 h. Then, it was poured into water (50 mL) and, after standing 15 h at 5 ⁰ C, the precipitate of title product was separated by suction and subsequently dried in a desiccator (over potassium hydroxide) overnight to yield title compound (498 mg, 89%): m.p. 147-151 ⁰ C, [α] _D +14.5 (c 0.391, CHCl ₃ ). IR spectrum (CHCl ₃ ): 2897 ((CHs) ₂ Si); 1714 (C=O, nicotinate); 1703 (C=O, ketone); 1286 (C-O, nicotinate); 1053 (C- OSi). ¹ H NMR (400 MHz): 0.05 (s, 6 H, (CH ₃ ) ₂ Si); 0.64 (s, 3 H, 3 x H-18); 0.72 (s, 9 H, (CHs) ₃ C); 0.83 (s, 3 H, 3 x H-19); 2.11 (s, 3 H, 3 x H-21); 2.51 (t, I H ₁ J = 8.8, H-17); 3.96 (quintet, J = 2.4, 1 H, H-3); 5.22 (q, 1 H, J = 2.6, H-7); 7.40 (ddd, 1 H ₅ J ₁ = 7.8, J ₂ = 4.8, J ₃ = 0.7, H-5, nicotinate); 8.29 (dt, 1 H, J ₁ = 8, J ₂ = 2, H-4, nicotinate); 8.79 (dd, 1 H, J ₁ = 4.8, J ₂ = 1.8, H- 6, nicotinate); 9.25 (m, 1 H, H÷2, nicotinate). FAB MS: 554 (36%, M + 1), 496 (8%, M - (CHs) ₃ C), 299 (4%, M - (CH ₃ ) ₃ C(CH ₃ ) ₂ Si0, OCOC ₅ H ₄ N), 255 (79%, M - (CH ₃ ) ₃ (CH ₃ ) ₂ Si0, OCOC ₅ H ₄ N, CH ₃ CO). C ₃₃ H _5I NO ₄ Si: Calculated C, 71.56; H, 9.28; N, 2.53. Found C, 71.40; H, 9.41; N, 2.25. Example 9

3α-Hydroxy-20-oxo-5α-pregnan-7α-yl Nicotinate

Compound prepared in previous Example 8 (120 mg, 0.21 mmol) was dissolved in methanolic solution of jo-toluenesulfonic acid (0.005 M, 72 niL). After standing at room temperature for 10 days, the mixture was neutralized with 10% potassium carbonate solution, extracted with ethyl acetate (100 mL), organic layer was washed with water and dried. The solvents were evaporated and the product was purified by preparative thin layer chromatography in a mixture of petroleum ether/acetone (8:2) to give title compound (83 mg, 87%): m.p. 183-187°C (acetone/heptane), [α] _D +15.0 (c 0.169, CHCl ₃ ). IR spectrum (CHCl ₃ ): 3615 (O-H); 1715 (C=O, nicotinate); 1703 (C=O, ketone); 1287 (C-O, nicotinate); 1002 (C-OH). ¹ H NMR (200 MHz): 0.72 (s, 3 H, 3 x H- 18); 0.86 (s, 3 H, 3 x H-19); 2.25 (s, 3 H, 3 x H-21); 2.53 (t, I HJ = 8.8, H-17); 4.05 (quintet, 1 H, J = 2.4, H-3); 5.25 (q, 1 H, J = 2.8, H-7); 7.44 (m, 1 H, H-5, nicotinate); 8.30 (dt, 1 H, Jj = 7.8, J ₂ = 1.9, H-4, nicotinate); 8.78 (dd, I H ₁ J ₁ = 4.8, J ₂ = 1.4, H-6, nicotinate); 9.26 (m, 1 H, H- 2, nicotinate). ESI MS: 901 (100%, 2M + Na), 462 (93%, M + Na), 440 (24%). C ₂₇ H ₃₇ NO ₄ : Calculated C ₅ 73.77; H, 8.48; N, 3.19, Found C, 73.75; H, 9.24; N, 2.53.

Example 10

20-Oxo-5α-pregnane-3α,7α-diyl 3-Sulfate 7-Nicotinate Pyridinium Salt

The mixture of compound prepared in previous Example 9 (60 mg, 0.13 mmol) and a sulfur trioxide pyridine complex (120 mg, 0.75 mmol), dried in vacuo (25 °C, 100 Pa) for 1 h, was dissolved in dry chloroform (5 mL). The reaction mixture was stirred for 4 h at room temperature under argon. After standing overnight at -20 ⁰ C, the undissolved sulfur trioxide pyridine complex was filtered off. The solvents were evaporated and the residue was dissolved in absolute methanol (1 ml) with added diethyl ether (5 ml). The mixture was evaporated to almost one-half. After standing overnight at -20 ⁰ C, the solvents were evaporated to afford title product (71 mg, 87%) as a foam: [α] _D +6.0 (c 0.204, CHCl ₃ ). IR spectrum (CHCl ₃ ): 3457, 3139 (pyridinium); 1715 (C=O, nicotinate); 1702 (C=O, ketone); 1289 (C-O, nicotinate); 1243, 1046 (SO ₃ ). ¹ H NMR (400 MHz): 0.63 (s, 3 H, 3 x H-18); 0.87 (s, 3 H, 3 x H-19); 2.11 (s, 3 H, 3 x H-21); 2.54 (t, 1 H, J = 8.7, H-17); 4.79 (quintet, J = 2.7, 1 H, H-3); 5.25 (q, 1 H, J = 2.5, H-7); 7.74 (dd, 1 H, J ₁ = 7.8, J ₂ = 5.5, H-5, nicotinate); 7.83 (m, 2 H, H-3 and H-5, pyridinium); 8.30 (tt, 1 H, J ₁ = 7.8, J ₂ = 1.5, H-4, pyridinium); 8.62 (dt, 1 H, J ₁ = 7.8, J ₂ = 1.5, H-4, nicotinate); 8.84 (m, 2 H, H-

2 and H-6, pyridinium); 8.93 (mj 1 H, H-6, nicotinate); 9.29 (m, 1 H, H-2, nicotinate). FAB MS: 554 (3%, M - CH ₃ CO), 440 (0.5%, M - 2 x C ₅ H ₆ N), 422 (10%, M + 1 - OSO ₃ C ₅ H ₆ N). HR-MS (+ESI) Calculated for C ₃₂ H ₄₂ O ₇ N ₂ NaS [M ⁺ + Na] 621.2605, found 621.2609. C ₃₂ H ₄₂ N ₂ O ₇ S: Calculated C, 64.19; H, 7.07; N, 4.68; S, 5.36. Found C, 60.87; H, 7.33; N, 3.55; S, 5.37.

Example 11

3α-Hydroxy-20-oxo-5 β-pregnan-7α-yl Acetate

A solution of 20-oxo-5β-pfegnane-3α,7α-diyl diacetate (100 mg, 0.24 mmol) known from previous art in methanol (8 mL) was treated with a solution of potassium hydrogen carbonate in water (0.7 mL, 0.2 M) at 70 ⁰ C. After 5 h, the mixture was poured into water and extracted with ethyl acetate (70 mL). The organic layer was washed with water, dried and the solvents were evaporated. Crystallization afforded ^' title compound (40 mg, 45%): m.p. 143-145 ⁰ C, [α] _D +40.3 (c 0.303, CHCl ₃ ). IR spectrum (CHCl ₃ ): 3610, 3527 (O-H); 1726 (C=O, acetate); 1703 (C=O, ketone); 1252 (C-O, acetate); 1047 (C-O). ¹ H NMR (200 MHz): 0.61 (s, 3 H, 3 x H-18); 0.93 (s,

3 H, 3 x H-19); 2.06 (s, 3 H, OAc); 2.12 (s, 3 H, 3 x H-21); 2.55 (t, 1 H, J = 8.8, H-17); 3.52 (m, 1 H, W = 32.7, H-3); 4.89 (q, I H ₁ J = 2.4, H-7). FAB MS: 377 (5%, M + 1), 317 (12%, M + 1 - AcOH), 299 (40%, M + 1 - AcOH, H ₂ O), 283 (32%, M - AcOH, H ₂ O, CH ₃ ), 255 (17%, M - AcOH, H ₂ O, CH ₃ CO), 159 (30%), 145 (34%), 131 (33%), 119 (37%). C ₂₃ H ₃₆ O ₄ : Calculated C, 73.37; H, 9.64. Found C, 73.49; H, 9.93.

Example 12

20-Oxo-5β-pregnane-3α,7α-diyl 3-Hemisuccinate 7-Acetate

A mixture of title compound prepared in previous Example 11 (100 mg, 0.27 mmol) and succinic anhydride (200 mg, 2 mmol) wa's dried in vacuo (25 ⁰ C, 100 Pa) for 30 min. Dry pyridine (20 mL) and 4-dimethylarninopyridine (20 mg, 0.17 mmol) were added. The mixture was heated for

4 h at 140 ⁰ C. The reaction mixture was poured into water and extracted with ethyl acetate (50 mL). Aqueous phase was extracted again with ethyl acetate (50 mL), washed with water and dried. The residue by preparative thin layer chromatography in a mixture of petroleum ether/acetone (9:1) afforded the title compound (44 mg, 35%): m.p. 131-134 ⁰ C ₅ [α] _D +50.3 (c 0.218, CHCl ₃ ). JJR. spectrum (CHCl ₃ ): 3517, 2676 broad (COOH); 1756 (C=O, COOH); 1726 (C=O, acetate); 1720 (C=O, hemisuccinate); 1703 (C=O, ketone); 1252 (C-O, acetate); 1173 (C- O, hemisuccinate). ¹ H NMR (200 MHz): 0.61 (s, 3 H, 3 x H-18); 0.94 (s, 3 H, 3 x H-19); 2.06 (s, 3 H, OAc); 2.12 (s, 3 H, 3 x H-21); 2.54-2.69 (m, 5 H ₅ H-17 and 0OCCH ₂ CH ₂ COO); 4.62 (m, 1 H ₅ W = 31.8, H-3); 4.89 (q, 1 H, J = 2.7, H-7). FAB MS: 499 (69%, M + Na), 417 (18%, M + 1 - AcOH), 299 (28%, M - AcOH ₅ C ₄ H ₅ O ₄ ). HR-MS (+ESI) Calculated for C ₂₇ H ₄₀ O ₇ Na [M ⁺ + Na] 499.2666, found 499.2664. C ₂₇ H ₄₀ O ₇ : Calculated C ₅ 68.04; H, 8.46. Found C, 69.20; H ₅ 8.59.

Example 13 ,

20-Oxo-5β-pregnan-3α,7α-diyl 3-Sulfate 7-Acetate Pyridinium Salt

The mixture of compound prepared in. Example 11 (110 mg, 0.3 mmol) and a sulfur trioxide pyridine complex (220 mg, 1.4 mmol), dried in vacuo (25 ⁰ C, 100 Pa) for 1 h, was dissolved in dry chloroform (4 mL). The reaptiori mixture was stirred under argon at room temperature for 4 h. After standing overnight at -20 °C, the undissolved sulfur trioxide pyridine complex was filtered off. The solvent was evaporated and the residue was dissolved in absolute methanol (1 mL) and absolute ether (7 mL) was added. The mixture was concentrated to almost one-half of volume. After standing overnight at -20 °C, the crystals of title compound were collected and dried in a desiccator (over potassium ¹ hydroxide) (155 mg, 99%): m.p. 155-158 ⁰ C ₅ [α]o + 45.7 (c 0.285, CHCl ₃ ). IR spectrum (CHCl ₃ ): 3140 (pyridinium); 1725 (C=O, acetate); 1702 (C=O, ketone); 1253 (C-O); 1363, 1171, 960 (0-SO ₃ ). ¹ H NMR (200 MHz): 0.60 (s, 3 H, 3 x H-18); 0.92 (s, 3 H, 3 x H-19); 2.04 (s, 3 ^' H ₅ OAc); 2.56 (t, 1 H ₅ J = 8.7, H-17); 4.34 (m, 1 H ₅ W = 31, H- 3); 4.88 (q, 1 H ₅ J = 2.9, H-7); 7.97!(m ₅ 2 H, H-3 and H-5, pyridinium); 8.48 (tt, 1 H, J ₁ = 7.8, J ₂ = 1.5, H-4, pyridinium); 8.95 (m, 2 H ₅ H-2 and H-6, pyridinium). EI MS: 558 (0.5 %, M + Na), 455 (0.5%, M - pyridinium), 256 (0.5%, M - pyridinium, OSO ₃ , CH ₃ CO, AcOH) ₅ 230 (3%), 80 (100%). HR-MS (+ESI) Calculated for C ₂₈ H ₄₁ O ₇ NNaS [M ⁺ + Na] 558.2496, found 558.2501. C ₂₈ H _4I NO ₇ S Calculated C, 62.78; H, 7.71; N, 2.61; S, 5.99. Found C, 59.99; H ₅ 7.71; N, 2.61; S, 6.25. Example 14

20-Oxo-5β-pregnane-3α,7α-diyl 3-Sulfate 7-Acetate Sodium Salt

Pyridinium salt prepared in Example 13 (90 mg, 0.17 mmol) was dissolved in absolute methanol (2 mL) and a solution of sodium hydroxide in methanol (0.45 mL, 0.373 M) was added dropwise during 1 h up to pH 8. The solution was concentrated to one-half and absolute ether (6 mL) was added. After standing overnight at -20 °C, the obtained crystals were collected and dried in a desiccator (over potassium hydroxide) to give title compound (54 mg, 67%): m.p. 187-191 ⁰ C, [α] _D + 35.0 (c 0.248, CHCl ₃ ). IR spectrum (CHCl ₃ ): 1726 (C=O, acetate); 1703 (C=O, ketone); 1251, 1236 (C-O); 1262, 1236, 1198 (0-SO ₃ ). ¹ H NMR (200 MHz): 0.61 (s, 3 H, 3 x H-18); 0.93 (s, 3 H, 3 x H-19); 2.07 (s, 3 H, OAc); 2.12 (s, 3 H, 3 x H-21); 2.54 (t, I HJ = 8.8, H-17);. 4.23 (m, 1 H, W = 32, H-3); 4.84 (m, 1 H, H-T). FAB MS: 449 (3%), 427 (2.5%), 405 (2.5%),

381 (5%), 307 (10%), 285 (10%), 263 (10%), 143 (100%). C ₂₃ H ₃₅ NaO ₇ S: Calculated C, 57.72; H, 7.37; S ₅ 6.70. Found C, 50.66; H,, 6.85; S, 4.57.

Example 15 i

3α-(tert-Butyldimethylsilyloxy)-5β-pregnan-7α-yl Acetate i

Hydroxyderivative prepared in Example 14 (70 mg, 0.18 mmol) and imidazole (76 mg, 1.1 mmol) were dissolved in N,N-dimethylformamide (1.4 mL). The mixture was cooled to 0 °C, then tert-butyldimethylsilyl chloride was added (84 mg, 0.56 mmol). The reaction mixture was stirred at room temperature. After 2 h, the reaction was diluted with ethyl acetate (50 mL) and washed with solution of citric acid, potassium hydrogen carbonate, and water. The organic layer was dried and evaporated in vacuo: Crystallization form ethyl acetate afforded title compound (50 mg, 55%): m.p. 110-112 ⁰ C, [αj _D +30.5 (c 0.333, CHCl ₃ ). IR spectrum (CHCl ₃ ): 2955, 2906 ((CH ₃ ) ₃ C); 1725 (C=O, acetate); 1702 (C=O, ketone); 1254, 1021 (C-O, acetate); 1090, 1076 (C- OSi); 853, 837 ((CH ₃ ) ₂ Si). ¹ H NMR (200 MHz): 0.05 (s, 6 H, (CH ₃ ) ₂ Si); 0.6 (s, 3 H, 3 x H-18); 0.88 (s, 9 H, (CHs) ₃ C); 0.91 (s, 3 H, 3 x H-19); 2.04 (s, 3 H, OAc); 2.12 (s, 3 H, 3 x H-21); 2.54 (t, 1 H, J = 8.7, H-17); 3.45 (m, 1 H, W = 32, H-3); 3.87 (q, I H ₁ J = 2.4, H-T). FAB MS: 433 (2%, M - 57, (CHs) ₃ C), 373 (18%, M - (CH ₃ ) ₃ C, AcOH), 299 (100%, M - (CH ₃ ) ₃ (CH ₃ ) ₂ Si, AcOH), 255 (12%, M- (CH ₃ ) ₃ (CH ₃ ) ₂ SiO, AcOH, CH ₃ CO). C ₂₉ H ₅₀ O ₄ Si: Calculated C, 70.97; H, 10.27. Found C, 70.03; H ₅ 10.44.,

Example 16

3α-(tert-Butyldimethylsilyloxy)-7α-hydroxy-5β-pregnan- 20-one

A solution of acetate prepared in Example 15 (40 mg, 0.08 mniol) in benzene (5 mL) was refluxed with a solution of potassium hydroxide in ethanol (4 mL, 0.89 M) for 3 h. The mixture was poured into water and extracted with ether (40 mL). The organic layer was washed with water, dried and the solvents were evaporated in vacuo. Preparative thin layer chromatography in a mixture of petroleum ether/acetone (8:2) afforded the title compound (20 mg, ,55%): m.p. 131 — 136 ⁰ C, [α] _D +47.6 (c 0.29, CHClJ ₃ ). IR spectrum (CHCl ₃ ): 3621 (O-H); 1699 (C=O); 1472, 1463, 1385 ((CKb) ₃ C); 1361 (Ac, (CH ₃ ) ₃ C); 1254 ((CHb) ₂ Si); 1098,1082 (C-OSi). ¹ H NMR (200 MHz): 0.05 (s, 6 H, (CHs) ₂ Si); Q.60 (s, 3 H, 3 x H-18); 0.88 (s, 12 H, 3 x H-19 and (CH ₃ ) ₃ C);

2.12 (s, 3 H, 3 x H-21); 2.53 (t, J ₁ H ₉ J = 9, H-17); 3.41 (m, 1 H, W = 32.7, H-3); 3.86 (m, 1 H, H-7). FAB MS: 449 (11%, M 4- I)V 317 (10%, M - (CH ₃ ) ₃ (CH ₃ ) ₂ Si0), 299 (26%, M + 1 - (CH ₃ ) ₃ (CH ₃ ) ₂ SiO, H ₂ O), 283 (13%, M + 1 - (CH ₃ ) ₃ (CH ₃ ) ₂ SiO, H ₂ O, O), 255 (14%, M - (CH ₃ ) ₃ (CH ₃ ) ₂ SiO, H ₂ O, CH ₃ CO) ¹ . C ₂₇ H ₄₈ O ₃ Si: Calculated C, 72.26; H, 10.70. Found C, 72.20; H, 10.84. ■ ^{• "}

Example 17 i ^•

3 α-(tert-Butyldimethylsilyloxy)-20-oxo-5 β-pregnan-7α-yl Nicotinate

Compound from previous Example 16 (240 mg, 0.53 mmol) and 4-dimethylaminopyridine (10 mg, 0.09 mmol) were dissolved in pyridine (10 mL) and the solution was cooled to 0 °C.

Nicotinoyl chloride hydrochloride (720 mg, 4.0 mmol) was slowly added. The reaction mixture

! was stirred at room temperature. After 1O h, it was poured into water and extracted with ethyl acetate (100 mL). Aqueous phase was extracted again with ethyl acetate (100 mL), and the combined organic phases were dried and evaporated. Preparative thin layer chromatography in a mixture of petroleum ether/acetone (9:1) afforded title compound (208 mg, 70%): m.p. 57-59 °C, [α] _D +54.9 (c 0.387, CHCl ₃ ). IR spectrum (CHCl ₃ ): 2907 (CH ₃ , (CH ₃ ) ₃ (CH ₃ ) ₂ SiO); 1714 (C=O, nicotinate); 1703 (C=O, ketone); 1286, 1108 (C-O, nicotinate); 1092 (C-OSi). ¹ H NMR (400 MHz): 0.05 (s, 6 H, (CH ₃ ) ₂ Si); 0,63 (s, 3 H, 3 x H-18); 0.77 (s, 9 H, (CH ₃ ) ₃ C); 0.96 (s, 3 H, 3 x H-19); 2.11 (s, 3 H, 3 x H-21); 2.52 (t, I H ₅ J = 9.1, U-U); 3 A3 (m, 1 H, W = 32, H-3); 5.21 (q, 1 H, J = 2.8, H-7); 7.44 (ddd, 1 H,- J ₁ = 7.8, J ₂ = 7.8, J ₃ = 0.7, H-5, nicotinate); 8.30 (dt, 1 H, J ₁ = 8.3, J ₂ = 2, H-4, nicotinate); 8.78 (dd, I HJi = 4.8, J ₂ = 1.7, H-6, nicotinate); 9.27 (dd, 1 H, J ₁ = 2, J ₂ = 0.7, H-2, nicotinate)! FAB MS: 579 (6%, M + Na), 554 (22%, M + 1), 496 (7%, M - (CH ₃ ) ₃ C), 299 (4%, M - (CH ₃ ) ₃ (CH ₃ ) ₂ Si0, OCOC ₆ H ₄ N), 255 (79%, M - (CH ₃ ) ₃ C(CH ₃ ) ₂ SiO, OCOC ₆ H ₄ N, CH ₃ CO). C ₃₃ H ₅₁ O ₄ Si: Calculated C, 71.56; H, 9.28; N, 2.53. Found C, 70.77; H, 9.32; N ₅ 2.23.

Example 18

3α-Hydroxy-20-oxo-5β-pregnan-7α-yl Nicotinate

A solution of compound prepared in Example 17 (100 mg, 0.18 mmol) in dry THF (10 mL) was cooled to 0 ⁰ C and solution of tetrabutylammonium fluoride (1 M in THF, 0.3 mL, 0.3 mmol) was added. The mixture was stirred at room temperature. After 2 days, further tetrabutylammonium fluoride solution (1 M in THF, 0.1 mL, 0.1 mmol) was added and the mixture was stirred for another 3 days. The mixture was extracted with ethyl acetate (100 mL), organic layer was washed solution of citric acid, potassium hydrogen carbonate, water, and dried. Preparative thin layer chromatography (2 plates) in a mixture of petroleum ether/acetone (9:1) afforded title compound (58 mg, 74%): m.p. 70-73 °C (acetone/heptane), [α] _D +29.2 (c 0.279, CHCl ₃ ). JR spectrum (CHCl ₃ ): 3613; 3451 (O-H); 1715 (C=O, nicotinate); 1705 (C=O, ketone); 1287 (C-O, nicotinate); 1034, 1026 (C-OH); 1592, 1421 (nicotinate). ¹ H NMR (400 MHz): 0.64 (s, 3 H, 3 x H-18); 0.98 (s, 3 H, 3 x H-19); 2.12 (s, 3 H, 3 x H-21); 2.54 (t, 1 H ₅ J = 9.2, H-17); 3.49 (m, 1 H, W = 3Ϊ, H-3); 5.20 (q, 1 H ₅ J = 2.7, H-7); 7.45 (ddd, 1 H, J ₁ = 7.8, J ₂ = 4.8, J ₃ = 0.7, H-5, nicotinate); 8 -31 (dt, 1 H, J ₁ = 7.8, J ₂ = 1.7, H-4, nicotinate); 8.80 (dd, 1 H, J ₁ = 4.8, J ₂ = 1.7, H-6, nicotinate); ^: 9.26 (dd, 1 H, J ₁ = 2, J ₂ = 0.7, H-2, nicotinate). FAB MS: 440 (12%, M + 1), 145 (7%), 124 (100%), 105 (35%). C ₂₇ H ₃₇ NO ₄ : Calculated C, 73.77; H, 8.48; N, 3.19. Found C, 73.71; H, 8.95; N, 2/67.

Example 19

20-Oxo-5β-pregnane-3α,7α-diyl 3-Sulfate 7-Nicotinate Pyridinium Salt

The mixture of compound prepared, in Example 18 (45 mg, 0.1 mmol) and a sulfur trioxide pyridine complex (90 mg, 0.56 mmol), dried in vacuo (25 °C, 100 Pa) for 1 h, was dissolved in dry chloroform (5 mL) and under argon stirred for 4 h. After standing at -20 ⁰ C overnight, the undissolved sulfur trioxide pyridine complex was filtered off and evaporated, the residue was dissolved in methanol (1 mL) and diethylether (4 mL). The mixture was let to stand overnight at -20 ⁰ C. The solvents were evaporated to afford title compound (40 mg, 74%) as a foam: [α]o +42.0 (c 0.321, CHCl ₃ ). IR spectrum (CHCl ₃ ): 3139, 2652 (pyridinium); 1714 (C=O, nicotinate); 1703 (C=O, ketone); 1287 (C-O, nicotinate); 1175, 978, 958 (0-SO ₃ ). ¹ H NMR (400 MHz): 0.63 (s, 3 H, 3 x H-18); 0.98 (s, 3 H, 3 x H-19); 2.11 (s, 3 H, 3 x H-21); 2.56 (t, I H ₁ J = 8.7, H-IT); 4.32 (m, 1 H, W = 32, H-3); 5.26 (m, 1 H, H-T); 7.74 (dd, 1 H, J ₁ = 7.6, J ₂ = 5.3, H-5, nicotinate); 7.82 (m, 2 H, H-3 and H-5, pyridinium); 8.33 (t, 2 H, J =7.8, H-4, pyridinium); 8.60 (d, 1 H, J = 7.6, H-4, nicotinate); 8.8.8 (m, 2 H, H-2 and H-6, pyridinium); 8.93 (d, 1 H, J = 5, H- 6, nicotinate); 9.33 (m, 1 H, H-2, nicotinate). FAB MS: 564 (10%), 542 (20%), 519 (12%, M + 1 - pyridinium), 444 (18%), 422 ^: (10%, M + 1 - OSO ₃ C ₅ H ₆ N). HR-MS (+ESI) Calculated for C ₃₂ H ₄₂ O ₇ N ₂ NaS [M ⁺ + Na] 621.2605, found 621.2608. C ₃₂ H ₄₂ N ₂ O ₇ S: Calculated C, 64.19; H, 7.07; N, 4.68; S, 5.36. Found C, 58.39; H, 6.88; N, 3.70; S, 6.99.

Example 20

Biological Activity Assay

Cell Culture

Primary dissociated hippocampal cultures were prepared from 1- to 2-day-old postnatal rats. Animals were decapitated and ⁴ the hippocampi dissected. Trypsin digestion, followed by mechanical dissociation, was used to _. prepare cell suspension. Single cells were plated at a density of 500,000 cells/cm ² on 31 mm or 12 mm polylysine-coated glass cover slips. Neuronal cultures were maintained in Neurobasal™-A (Invitrogen, Carlsbad, USA) medium supplemented with glutamine (0.5 mM) and B-27 Serum-Free Supplement (Invitrogen) at 37 ⁰ C and 5% CO ₂ .

Electrophysiology

For the electrophysiological experiments, neurons cultured for 5-10 days were used. Whole-cell voltage-clamp recordings were made with a patch-clamp amplifier (Axopatch ID; Axon Instruments, Inc., Foster City; USA) after capacitance and series resistance (<10 MΩ) compensation of 80 - 90%. Agonist-induced responses were low-pass filtered at 1 kHz with an 8-pole Bessel filter (Frequency Devices, Haverhill, USA), digitally sampled at 5 kHz and analyzed using pClamp software version 9 (Axon Instruments). Patch pipettes (3-6 MΩ) pulled from borosilicate glass were filled with Cs ⁺ based intracellular solution containing (in mM): 125 gluconic acid, 15 CsCl, 5 EGTA, 10 HEPES, 3 MgCl ₂ , 0.5 CaCl ₂ , and 2 ATP-Mg salt (pH- adjusted to 7.2 with CsOH). Extracellular solution (ECS) contained (in mM): 160 NaCl, 2.5 KCl, 10 HEPES, 10 D-glucose, 0.2 EDTA and 0.7 CaCl ₂ (pH-adjusted to 7.3 with NaOH). Glycine (10 μM) and TTX (0.5 μM) were present in the control and test solutions. Steroids were dissolved in dimethyl sulfoxide (DMSO) to make a fresh stock solution (20 mM) before each experiment. The same concentration of DMSO was maintained in all extracellular solutions. A microprocessor-controlled multibarrel fast perfusion system, with a time constant of solution exchange around cells of ~10 ms, was used to apply test and control solutions.

Biological Activity

Responses (currents) elicited by 100 μM NMDA were recorded in cultured hippocampal neurons voltage-clamped at a holding potential of - 60 mV. In accordance with previous results, pregnenolone sulfate diminished the amplitude of NMDA-induced currents (Fig. 1). At lOOμM pregnanolone sulfate, the mean inhibitory effect was 71.3 ± 5.0% (n = 5). Synthetic analogs of pregnenolone sulfate had also negative-modulatory effect on NMDA-induced responses with the mean inhibition induced by lOOμM steroid that ranged from 17% (compound from Example 5) to 71% (5β-pregnenolone sulfate). The relative degree of steroid-induced inhibition was used to estimate IC ₅₀ . IC ₅₀ was calculated from the logistic equation RI = 1 - (1 / (1 + ([steroid] / IC ₅₀ ) ^h ); where RI is relative degree of steroid induced inhibition and h is the apparent Hill coefficient (1.2). The values of relative inhibition and estimated IC ₅₀ values of steroids are listed in following table. Table

Inhibition of NMDA-induced response in cultured hippocampal neurons by pregnenolone sulfate and its synthetic analogs.

The second column shows relative degree of steroid (100 μM) inhibition of current responses induced in cultured hippocampal ; neurons by fast application of 100 μM NMDA and co- application of 1 OOμM of pregnenolone sulfate.