John F. Templeton

Opiate receptor binding activity of 17-Alpha estrogenic steroids☆

A large number of steroids of the estrane, androstane, pregnane and, etianic acid series, including their sulfate and glucuronide conjugates, were inactive in an opiate radioreceptor assay (> 10% displacement of 3H-naloxone at 10−4M). Only certain estrogens were active, the most potent being 17α-hydroxy-estrogens. The displacement curves for the active steroids were parallel to those of known opiate drugs. SC 22,000, a semisynthetic steroid with opiate effects, was a potent agonist in the assay. The sodium effect indicated the active estrane steroids to be of mixed agonist-antogonist character. IC50 for 17α-dihydroequilin, 17α-dihydroequilenin, and 17α-estradiol was 1.0, 1.8, and 3.0 μm, respectively. Sulfation or acetylation of the 3-OH or 17-OH abolished binding activity.

Ion-pairs of ibuprofen: increased membrane diffusion

The purpose of the present study was to determine the influence of pH and ion‐pairing on the permeation of ibuprofen across polydimethylsiloxane (PDMS) membrane. The solubility of ibuprofen sodium was determined at a range of pH values. Saturated solutions were then used to determine the influence of pH on diffusion across PDMS as a model membrane. The apparent partition coefficient of ibuprofen sodium between n‐octanol and phosphate buffer at various pH values was also investigated. Organic salts of ibuprofen using ethylamine, diethylamine, triethylamine and ethylene diamine as counter‐ions were synthesized and the influence of these counter‐ionson the permeation of ibuprofen was studied. The presence of ion‐pairing was confirmed using 1H NMR and 13C NMR. Diffusion studies at different pH values (4.0, 5.0, 6.0, 7.0 and 8.0) indicated that ibuprofen sodium flux increased significantly with increasing pH from 4.0 to 7.0. Above pH 7.0 a decrease in diffusion was observed. The permeability coefficient increased with an increase in the amount of unionized acid. The apparent partition coefficient was directly related to the steady‐state flux. The steady‐state flux of ibuprofen increased up to 16‐fold using different counter‐ions. The highest flux was measured from ibuprofen triethylamine. The flux of ibuprofen salts across a lipophilic membrane can be increased by formation of ion‐pairs. The extent of enhancement is associated with the lipophilicity, extent of ion‐pairing and reduction in charge over the drug molecule.

Synthesis of 20α- and 20β-acetamido, amino, nitro and hydroxy derivatives of 14-hydroxy-5β,14β-pregnane 3β-glycosides: pregnanes that bind to the digitalis receptor

Synthesis of 20α- and 20β-acetamido-, amino-, nitro- and hydroxy-3β-glycoside (α-L-rhamnopyranoside and tris-β-D-digitoxoside) and genin derivatives of 14-hydroxy-5β,14β-pregnane together with the C-20 oxime, hydrazone and amidinohydrazone is described from digitoxin. Ortho esters were also isolated. Structures were established by NMR measurements. These compounds have been shown to bind to the digitalis receptor of heart muscle. The 20β derivatives were consistently more potent than are the corresponding 20α compounds. The 20β-nitro α-L-rhamnoside derivative proved to be the most potent. Receptor binding data are given and structure-activity relationships are presented.

Synthesis of 3β,14-dihydroxy-5β,14β-pregnan-20-one C-3 derivatives: ozonolysis of digitoxin and digitoxigenin and their derivatives followed by zinc–acetic acid reduction to the C-21 methyl ketone

Ozonolysis of digitoxin, digitoxin tetraacetate, digitoxin tetrakis-(2,2,2-trichloroethyl carbonate), digitoxigenin, digitoxigenin acetate, digitoxigenin hemisuccinate and digitoxigenin 2,2,2-trichloroethyl carbonate followed by treatment with excess of zinc in acetic acid gave either the corresponding 21-hydroxy ester after 5 min or the 21-methyl ketone after 20 h. This procedure is more efficient than methods previously reported for the conversion of the α,β-unsaturated γ-lactone into an acetyl group and is applicable to the cardiac glycosides directly to give 14β-hydroxypregnan-20-one derivatives. Acidic hydrolysis of 14,21-dihydroxy-and 14-hydroxy-3β-tris(digitoxosyloxy)-5β,14β-pregnan-20-one is reported. Structures are based on 1H and 12C NMR assignments.

Sterically crowded trialkylsilyl ether derivatives for the analysis of steroid metabolites.

The applications of sterically crowed trialkyksilyl ether derivatives to the analysis and characterization by thin-layer chromatography, gas chromatography and mass spectrometry, of metabolites of 2alpha, 3alpha-cyclopropano-5alpha-androstan-17beta-ol in the rabbit are described. These derivatives are complementary to the familiar trimethysilyl ether derivatives, but have greater hydrolytic stability (an advantage for TLC), generally give better GC separations, and have characteristic mass spectra. Isomer differentiation by GC and MS is also more readily achieved than via the TMSi ether derivatives. These properties should make SCTASi ethers useful derivatives for studies of steroid metabolism.

Metabolism of 17α-methyltestosterone in the rabbit: C-6 and C-16 hydroxylated metabolites

17 alpha-Methyltestosterone and the reduced metabolites, 17 alpha-methyl-5 alpha-androstane-3 alpha, 17 beta-diol, 17 alpha-methyl-5 alpha-androstane-3 beta, 17 beta-diol and 17 alpha-methyl-5 beta-androstane-3 alpha, 17 beta-diol, together with three hydroxylated metabolites, 17 alpha-methyl-5 beta-androstane-3 alpha, 16 alpha, 17 beta-triol, 17 alpha-methyl-5 beta-androstane-3 alpha, 16 beta, 17 beta-triol and a new metabolite, 17 alpha-methyl-5 alpha-androstane-3 beta, 6 alpha, 17 beta-triol, were isolated and identified in the urine of rabbits dosed with 17 alpha-methyltestosterone. No hydroxylated 5 alpha-metabolite of 17 alpha-methyltestosterone has been identified previously. No of 17 alpha-methyltestosterone has been identified previously. No evidence for epimerization at the C-17 position was observed.

Metabolism of 17β-hydroxy-2α,3α-cyclopropano-5α-androstane in the rabbit

Abstract The neutral urinary excretion products of 17β-hydroxy-2α,3α-cyclopropano-5α-androstane from the rabbit, dosed orally, were investigated. Column chromatography yielded five crystalline metabolites which were identified by GLC and spectroscopic measurements. Three of these substances were hydroxylated in the 4α-position and one in the 6a-position with the cyclopropane ring intact. The fifth substance, 17β-hydroxy-3β-methyl-5α-androstan-2-one, can be derived from initial hydroxylation of the cyclopropane ring at C-2 followed by ring opening. The dosed substance and triol material was shown to be present by GLC and m.s. measurements. GLC determinations show that hydroxylation has occurred at C-4≫C-6>C-2.

Synthesis and structure-activity relationships of 14β-hydroxy-5α-pregnanes: pregnanes that bind to the cardiac glycoside receptor

Abstract 5α-pregnane-3β,14β,20β-triol 3-α- l -rhamnopyranoside (8) and 3β-(α- l -rhamnopyranosyloxy)-5α-pregn-14-en-20-one (14) were prepared from uzarigenin by ozonolysis followed by zinc and acetic acid reduction and glycosidation. During the glycosidation reaction leading to (8) the corresponding ortho ester (9) was also obtained. Uzarigenin α- l -rhamnopyranoside (15) also was prepared. Synthesis of 5α-pregnane-3β,14β,20β-triol (20) is described. Structures were established by analysis of their NMR spectra. The binding affinity of 5α and 5β cardenolide and pregnane derivatives as a measured in a radioligand binding assay was determined and their structure-activity relationships compared. The receptor binding affinity of the 5α derivatives is les than that of the corresponding 5β derivatives.

Proton magnetic resonance spectra of 17ξ-hydroxy-17ξ-methyl-5ξ-androstane C-3 ketone and C-3ξ alcohol isomers in chloroform-d and pyridine-d5

Abstract 17α-Hydroxy-17β-methyl-5β-androstan-3-one, 17μ-methyl-5α-androstane-3α, 17α-diol, 17β-methyl-5α-androstane-3β, 17α-diol, 17α-methyl-5β-androstane-3β, 17β-diol, 17β-methyl-5β-androstane-3α, 17α-diol and 17β-methy1–5β-androstane-3β, 17α-diol were synthesized for the first time. 1 H NMR spectra of all four 17ξ-hydroxy/17ξ-methyl C-3 ketones and all eight C-3 alcohols were recorded in chloroform-d and pyridine-d 5 . Pyridine-induced chemical shifts are discussed. Thin-layer Chromatographic data are given.

Metabolism of 17α-methyl-5β-dihydrotestosterone in the rabbit

Abstract 17α-Methy1-5β-androstane-3α, 17β-diol together with the hydroxylated metabolites 17α-methyl-5β-androstane-1β, 3α, 17β-triol, 17α-methyl-5β-androstane-3α, 12β, 17β-triol, 17α-methyl-5β-androstane-3α, 16α, 17β-triol and 17α-methyl-5β-androstane-3α, 16β, 17β-triol were isolated and identified in the urine of rabbits orally dosed with 17α-methyl-5β-dihydrotestosterone. Biotransformations differ from the 5α-series where hydroxylation occurred at C-6 and C-15. In both series, the C-3 equatorial epimer was the major urinary excretion product among the non-hydroxylated metabolites. The 5β-compound was more resistant to metabolic hydroxylation than the 5α-compound. No evidence for epimerization at the C-17 position was observed.