Neighboring group participation. Part 16. Stereoselective synthesis and receptor-binding examination of the four stereoisomers of 16-bromomethyl-3,17-estradiols

The four possible isomers of 3-benzyloxy-16-hydroxymethylestra-1,3,5(10)-trien-17-ol (1a-4a) with proven configurations were converted into the corresponding 3-benzyloxy-16-bromomethylestra-1,3,5(10)-triene-3,17-diols (5e-8e). Depending on the reaction conditions the cis isomers of 3-benzyloxy-16-hydroxymethylestra-1,3,5(10)-trien-17-ol (1a and 2a) were transformed into 3-benzyloxy-16-bromomethylestra-1,3,5(10)-trien-17-yl acetate (5b and 6b) or 16-bromomethyl-3-hydroxyestra-1,3,5(10)-trien-17-yl acetate (5c and 6c) on treatment with HBr and acetic acid. The mechanism of the process can be interpreted as involving front-side neighboring group participation. Under similar experimental conditions, the trans isomers (3a and 4a) yielded only 3-benzyloxy-16-acetoxymethylestra-1,3,5(10)-trien-17-yl acetates (3b and 4b) or 16-acetoxymethylestra-1,3,5(10)-triene-3,17-diyl diacetates (3d and 4d). Both the cis (1a and 2a) and the trans (3a, and 4a) isomers were transformed into 16-bromomethylestra-1,3,5(10)-trien-17-ol (5a-8a) by the Appel reaction on treatment with CBr4/Ph3P. Debenzylation of 5a-8a was carried out with HBr and acetic acid to yield 5e-8e. The debenzylation process in the presence of acetic anhydride produces the diacetates 5d-8d. The structures of the compounds were determined by means of MS, 1H NMR and 13C NMR spectroscopic methods. Compounds 5c-8c and 5e-8e were tested in a radioligand-binding assay. Except for the affinity of 7e for the estrogen receptor (Ki=2.55 nM), the affinities of the eight compounds (5c-8c and 5e-8e) for the estrogen, androgen and progesterone receptors are low (Ki > 0.55, 0.52 and 0.21 microM, respectively).     

Water-soluble metabolites of the estrogens. Quantitation of C-18 tetrols in rat feces.

Several radioactive estrogens possessing one, two and three hydroxyl groups were injected orally (and in the case of estrone sulfate also intraperitoneally) into adult male rats. The rats were either intact or had ligated or cannulated bile ducts. Two unconjugated estrogen tetrols together represented 21 - 87% of the total metabolites in the intact rat. One of the tetrols was 2-hydroxyestriol (estra-1,3,5(10)-triene-2,3,16alpha,17beta-tetrol); the other may be estra-1,3,5(10)-triene-2,3,6xi,17beta-tetrol but this was not confirmed. It is concluded that poly-hydroxylated estrogens represent a very large proportion of the previously unidentified water-soluble metabolites of the estrogens in the adult male rat.     

A short efficient synthesis of 16-oxygenated estratriene 3-sulfates

A novel synthesis of sodium 17-oxo-16 alpha-hydroxy-1,3,5(10)-estratrien-3-yl sulfate (4), sodium 16 alpha, 16 beta-dihydroxy-1,3,5(10)-estratrien-3-yl sulfate (5) and sodium 16-oxo-17 beta-hydroxy-1,3,5(10)-estratrien-3-yl sulfate (6) is described. 16 alpha-Bromo-3-hydroxy-1,3,5(10)-estratrien-17-one (1) was efficiently synthesized in one step with 70-97% yield by bromination of 3-hydroxy-1,3,5(10)-estratrien-17-one with cupric bromide. 3,16 alpha-Dihydroxy-1,3,5(10)-estratrien-17-one (3) was quantitatively obtained by controlled stereospecific hydrolysis of the bromoketone 1 with sodium hydroxide in aqueous pyridine. The bromoketone 1 was converted to the 16 alpha-hydroxy-17-ketone 3-sulfate 4 by sulfation with chlorosulfonic acid in pyridine and a subsequent controlled hydrolysis in a high yield without formation of the other ketols. Treatment of the sulfate 4 with sodium borohydride have the triol sulfate 5. The sulfate 4 was also rearranged to the 17 beta-hydroxy-16-ketone 6 with sodium hydroxide in water in a quantitative yield.     

The transfer of estrone glucuronide to bile in an isolated perfused rat liver system.

An isolated rat liver perfusion system has been utilized in a study of the biliary excretion of estrone glucuronide. The estrogen was initially shown to be excreted without prior metabolism. Disappearance from the medium was rapid and biliary concentrations exceeded that in the medium by more than a thousand-fold. Disappearance rates were decreased when medium estrone glucuronide concentrations exceeded 0.29 mM. Inhibition by other steroidal conjugates, testosterone glucuronide, 2-methoxyestrone (3-hydroxy-2-methoxy-estra-1,3,5(10)-trien-17-one glucuronide and 2-hydroxyestrone (2,3-dihydroxyestra-1,3,5(10)-trien-17-one) glutathione, was also demonstrated. Phenolphthalein glucuronide, at 10 times the molar concentration of estrone glucuronide, did not affect the medium clearance of the latter compound. These findings indicate the possibility of utilizing this system for further studies of possible interactions by other organic compounds for excretion via the biliary route.     

Synthesis of C-2 and C-4 deuterium-labeled estradiol-17 beta

Estradiol-17 beta labeled with deuterium in the positions 2 or 4 can be prepared from 2-chloromercurio-1,3,5(10)-estratriene-3,17 beta-diol 3-methyl ether 17-acetate or 4-chloromercurio-1,3,5(10)-estratriene-3,17 beta-diol, respectively, in refluxing CH3COO(2)H/(2)H2O. The same reaction performed on 4-acetoxymercurio-1,3,5(10)-estratriene-3,17 beta-diol afforded 2,4-dideuterio-estradiol-17 beta in good yields.     

Lumi-mestranol and epi-lumi-mestranol.

Treatment of lumi-estrone 3-methyl ether (I) with acetylene gave the C-17-epimeric compounds lumi-mestranol (3-methoxy-17 alpha-ethynyl-13 alpha-estra-1,3,5(10)-trien-17 beta-ol, III ) and epi-lumi-mestranol (3-methoxy-17 beta-ethynyl-13 alpha-estra-1,3,5(10)-trien-17 alpha-ol, IV). The structures of the two isomers were assigned on the basis of their molecular rotations and shift-reagent experiments in the NMR. The irradiation of estrone 3-methyl ether (II) to provide compound I was investigated in two solvent systems. Minor products of these reactions were the seco-steroids VII, VIII and X.     

Microbiologic oxidation of estratrienes and estratetraenes by Streptomyces roseochromogenes ATCC 13400

Incubation of estrone (1a) with Streptomyces roseochromogenes ATCC 13400 yielded a mixture of 3,16 alpha-dihydroxyestra-1,3,5(10)-trien-17-one (3a) and 3,17 beta-dihydroxyestra-1,3,5(10)-trien-16-one (4a). Transformation of 3-methoxyestra-1,3,5(10)-trien-17-one (1b), 3-hydroxyestra-1,3,5(10),9(11)-tetraen-17-one (2a), and 3-methoxyestra-1,3,5(10),9(11)-tetraen-17-one (2b) with the same microorganism gave the corresponding mixtures of 16 alpha-hydroxy-17-ketones and 17 beta-hydroxy-16-ketones (3b and 4b, 6a and 7a, 6b and 7b, respectively). In addition, in these three last experiments, the 16 beta-17 beta-dihydroxy derivatives 5b, 8a, and 8b, respectively, were also isolated. The complete assignments of the 13C nuclear magnetic resonance spectra of these compounds are given.     

Precursor role of 15alpha-hydroxyestradiol and 15alpha-hydroxyandrostenedione in the formation of estetrol

Studies were designed to elucidate the origin of estetrol (15alpha-hydroxyestriol (estra-1,3,5(10)triene-3,15alpha,17beta-tetrol) or E4) during late human pregnancy. 3H-Labelled 15alpha-hydroxyestradiol (3,15alpha-dihydroxyestra-1,3,5(10)-trien-17-one or 15E2) and 14C-labelled 17beta-estradiol (estra-1,3,5(10)-triene-3,17beta-diol or E2) were infused into the fetus during transfusion in utero for erythroblastosis fetalis, and in another study the same substrates were injected intravenously into the maternal circulation. In a third study, 3H-labelled 15alpha-hydroxyandrostenedion (15alpha-hydroxyandrost-4-ene-3,17-dione or 15delta4) and 14C-labelled E2 were infused into the fetus. Maternal urine was collected for 5--6 days, and after Glusulase hydrolysis, the following metabolites were isolated: estriol (estra-1,3,5(10)-triene-3,16alpha,17beta-triol or E3) containing 14C only and 15alpha-hydroxyestrone (3,15alpha-dihydroxyestra-1,3,5(10)-trien-17-one or 15E1), 15E2, and E4, all containing both labels. From the isotope content of these metabolites, it was concluded that E4 was derived from both fetal E2 and 15delta4 and only partially via 15E2. When administered to the fetus E2 and 15delta4 contributed approximately equal amounts to urinary E4. The yield of 15alpha-hydroxylated estrogens from E2 injected into the mother was very low indicating the predominantly fetal origin of the 15alpha-hydroxylase. 15delta4 was a better precursor than E2 for urinary 15E2.     

Identification of radioactive 17beta-estradiol-17-beta-D-glucuronide and 17alpha-estradiol-17-beta-D-glucuronide in the urine of the domestic fowl after intramuscular injection of [4-14C]estrone.

Two previously uncharacterized radioactive estrogen conjugates, 17beta-estradiol-17-beta-D-glucuronide (3-hydroxyestra-1,3,5(10)-trien-17beta-D-glucopyranosiduronate) and 17alpha-estradiol-17beta-D-glucuronide (3-hydroxyestra-1,3,5(10)-trien-17alpha-yl-beta-D-glucopyranosiduronate), have been identified in small but significant amounts in avian urine and in a ratio of approximately 2:1 after intramuscular injection of [4-14C]estrone.     

Biliary metabolites of estriol in the rat

Following the subcutaneous administration of estriol-6,7-³H to rats, biliary metabolites were identified and quantitated. Approximately 70% of the metabolites were excreted in the form of “glucosiduronate” conjugates. 3, 17β-Dihydroxy-2-methoxy-1,3,5(10)-estratrien-16-one was the major metabolite in this conjugate fraction. Significant amounts of 3,17β-dihydroxy-1,3,5(10)-estratrien-16-one and 2,3,17β-trihydroxy-1,3,5(10)-estratrien-16-one, as well as smaller quantities of 1,3,5(10)-estratriene-2,3,16α,17β-tetrol and 2-methoxy-1,3,5(10)-estratriene-3,16α, 17β-triol, were also found. In 17α-ethinylestradiol - treated animals, the rate of excretion of radioactivity and the proportion of 16-oxo-17β-ol metabolites found in the “glucosiduronate” fraction were reduced.     

Reduction of aromatic steroidal A rings by lithium in ethyl amine.

The reduction of 3-methoxy-estra-1,3,5(10)-trien-17beta-ol (6) and 13-ethyl-3-ethoxy-gona-1,3,5(10)-triene-11alpha,17beta-diol (2) by lithium in ethyl amine in the absence of a proton source is described. Both reductions, contrary to the reports of previous investigators, which indicated the 4-ene to be the main reaction product, gave a complex mixture of products. In the case of the reduction of 2, which is an intermediate in the synthesis of the progestagen desogestrel (1), we obtained the expected known 13-ethyl-gona-4-ene-11alpha,17beta-diol (4) in small amounts and three new steroidal monoenes, 13-ethyl-gona-5(10)-ene-11alpha,17beta-diol (11), 13-ethyl-gona-5(6)-ene-11alpha,17beta-diol (12), and 13-ethyl-gona-1(10)-ene-11alpha,17beta-diol (13). These compounds were characterized as the 11,17-diacetates with the 5(10)-ene 11 being the major compound.     

Properties of hydroxysteroid oxidoreductase isolated from yeast.

Yeasts can advantageously be utilized for the production of the 17beta-hydroxy-derivative, from 3-methoxy-8,14-seco-1,3,5(10),9(11)-estratetraene-14,17-dione (14,17-dione) while 14alpha-hydroxy and 14alpha,17beta-dihydroxy-derivatives are also formed. The biochemical properties of yeasts' enzymes responsible for the formation of the two monohydroxy-derivatives have been studied in detail. In the cell-free extract of Saccharomyces the presence of two hydroxysteroid oxidoreductases could be detected. The first enzyme forms 3beta,17beta-dihydroxy-derivative from 5alpha-androstane-317-dione. This enzyme is responsible for the formation of 17beta-hydroxy-derivative from 14,17-dione. The second enzyme forms 3alpha-hydroxy-derivative from 5beta-androstanedione as well as 14alpha-hydroxy-derivative from its 14,17-dione. The cofactor of both enzymes is pyridine nucleotide. The two enzymes possessing different properties can selectively be inhibited.     

The genes encoding the hydroxylase of 3-hydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione in steroid degradation in Comamonas testosteroni TA441

Steroid degradation genes of Comamonas testosteroni TA441 are encoded in at least two gene clusters: one containing the meta-cleavage enzyme gene tesB; and another consisting of ORF18, 17, tesI, H, ORF11, 12, and tesDEFG. TesH and I are, respectively, the Delta(1)- and Delta(4)(5alpha)-dehydrogenase of the 3-ketosteroid, TesD is the hydrolase for the product of meta-cleavage reaction, and TesEFG degrade one of the product of TesD. In this report, we describe the identification of the function of ORF11 (tesA2) and 12 (tesA1). The TesA1- and TesA2-disrupted mutant accumulated two characteristic intermediate compounds, which were identified as 3-hydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione (3-HSA) and its hydroxylated derivative, 3,17-dihydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione by MS and NMR analysis. A complementation experiment using a broad-host range plasmid showed that both TesA1 and A2 are necessary for hydroxylation of 3-HSA to 3,4-dihydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione (3,4-DHSA).     

Regulation of chloride transport in parotid secretory granules by membrane fluidity.

Zymogen granule membranes contain Cl- conductance and Cl/anion exchange activities that become important for primary fluid production after fusion with the apical plasma membrane of the acinar cell. We have used steady-state fluorescence anisotropy of diphenylhexatriene derivatives and measurements of Cl- transport in isolated secretory granules to determine the contribution of membrane fluidity to the regulation of transport across the granule membrane. Secretory granules from several unstimulated glands (rat pancreas and parotid, rabbit gastric glands) were shown to have low membrane fluidity compared to plasma membranes. In addition, Cl- transport activity in different granule preparations showed a strong correlation to the membrane fluidity when measured with 1-[4-(trimethylammonio)phenyl]-6-phenyl-1,3,5-hexatriene p-toluenesulfonate (TMA-DPH), but not with 3-[p-(6-phenyl)-1,3,5-hexatrienyl)-phenyl]propionic acid (PA-DPH). These data suggest that TMA-DPH preferentially partitions into a specific lipid environment associated with, or which exerts an influence on, the Cl- transport proteins and that increases in the fluidity of this environment are associated with higher transport rates. Data from other types of plasma membranes indicate that TMA-DPH partitions much more than PA-DPH into the cytoplasmic leaflet, suggesting that this part of the granule membrane is involved in the observed fluidity changes. Furthermore, increasing the bulk membrane fluidity with the local anesthetics benzyl alcohol and n-alkanols increased the Cl- transport rates up to 10-fold. This increase was apparently through specific transporters as anion selectivity was maintained in spite of the higher absolute rates.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hydroxysteroid dehydrogenases of Pseudomonas testosteroni. Separation of a 17 beta-hydroxysteroid dehydrogenase from the 3(17) beta-hydroxysteroid dehydrogenase and comparison of the two enzymes.

When a crude extract of Pseudomonas testosteroni induced with testosterone was subjected to polyacrylamide gel electrophoresis, six bands that stained for 17 beta-hydroxysteroid dehydrogenase activity was observed. A protein fraction containing the enzyme corresponding to the fastest migrating band and devoid of the other hydroxysteroid dehydrogenase activities has been obtained. This preparation appears to be distinct from the previously isolated 3(17) beta-hydroxysteroid dehydrogenase (EC 1.1.1.51) in its chromatography properties on DEAE-cellulose, substrate and cofactor specificity, immunological properties and heat stability. The preparation appears devoid of 3alpha-, 3beta-, 11beta-, 17alpha-, 20alpha-, and 20beta-hydroxysteroid dehydrogenase activities. The enzyme transfers th 4-pro-S-hydrogen of NADH from estradiol-17beta (1,3,5(10)estratriene-3,17beta-diol) to estrone (3-hydroxy-1,3,5(10)-estratriene-17-one).     

Species differences in biotransformation of 17α-cyanomethylestradiol 3-methyl ether

Following oral administration of 9,11- ³H-17α-cyano-methylestra-1,3,5(10)-triene-3,17-diol 3-methyl ether, urinary metabolites were studied in man, baboon, beagle dog, minipig and rat. The metabolite pattern revealed remarkable species differences, especially in quantitative respects. 17α-Cyanomethylestra-1,3,5(10)-triene-3,17-diol, 17α-cyanomethylestra-1,3,5(10)-triene-2,3,17-triol 2-methyl ether, 17α-hydroxymethylestra-1,3,5(10)-triene-3,17-diol and 17α-cyanomethylestra-1,3,5(10)-triene-3,16$\text{6}\text{5}$,17-triol were isolated as principal metabolites. In rat bile, a metabolite was tentatively identified as aγ-lactone of a 17α-carbozymethyl-16α-hydroxy compound.     

Radioimmunoassay of contraceptive steroids. I. Synthesis of 6-oxomestranol 6-(O-carboxymethyl) oxime

A synthesis of 6-(O-carboxymethyl) oxime of 6-oxo-mestranol (3-methoxy-17-ethinyl-17β -hydroxy-1,3,5 (10)-estratrien-6-one) which was required for coupling with bovine serum albumin in order to produce a specific anti-sera for mestranol (3-methoxy-17-ethinyl-1,3,5 (10)-estratrien-17β-ol) has been described. 6-Oxoestradiol-17β 3-methyl ether was prepared from estradiol-17β 3,17-diacetate by chromic acid oxidation, followed by hydrolysis and methylation. It was converted to its O-carboxymethyloxime derivative which was smoothly oxidized by Jones reagent to the corresponding es estrone derivative. This was easily ethinylated with lithium acetylide-ethylenediamine complex to the desired compound. In an alternate approach to the desired compound, it was found that 6-oxoestradiol-17β 3- methyl ether could not be converted to its ketal under any of a variety of conditions. Ethinylation of 6-oxoestrone 3-methyl ether with limited amount of lithium acetylide reagent probably gave the 17α -ethinyl derivative as was indicated from IR and UV spectra, but its identity could not be further confirmed due to its extremely poor yield.     

Microbial degradation of 19-hydroxy-sterol side chains

Experimental evidence is herein presented to show that C₂₂ acids are key intermediates in the microbial degradation of cholesterol and campesterol (β-sitosterol) side chains. Exposure of 19-hydroxy-sterols to Rhodococcus mutant K-3 gave four new steroid carboxylic acids in addition to that known as estrone (P1); the chemical structures of these metabolites were characterized as 2(3-hydroxy-1,3,5(10)-estratrien-17-yl)-propionic acid (P2), 2-methyl-6(3-hydroxy-1,3,5(10)-estratrien-17-yl)-heptanoic acid (P3), 2,3-dimethyl-6(3-hydroxy-1,3,5(10)-estratrien-17-yl)-heptanoic acid (P4), and 2(3-hydroxy-1,3,5(10), 17-estratetraen-17-yl)-propionic acid (P5). We propose a degradation pathway of 19-hydroxy-cholesterol and campesterol (β-sitosterol) side chains.     

Synthesis and photochemical reactions of nitroestrogens: possible photoaffinity labels of zero length

The syntheses of 3,4-dimethoxy-1,3,5(10)-estratrien-17-one and 4-bromo-3-methoxy-2-nitro-1,3,5(10)-estratrein-17-one are described and their photoreactions with amines and hydroxide ion studied. The possible usefulness of these new steroids as photoaffinity labels of zero length is discussed.     

Omega-pyridiniumalkylethers of steroidal phenols: new compounds with potent antibacterial and antiproliferative activities

Novel omega-pyridiniumalkylethers of two steroidal phenols were synthesized as compounds with potential antimicrobial activity. 3-Hydroxy-estra-1,3,5(10)-triene-17-one and 1-hydroxy-4-methyl-estra-1,3,5(10)-triene-17-one were reacted with omega,omega'-dibromoalkanes to omega-bromoalkoxy-estra-1,3,5(10)-trienes followed by reaction with pyridine to obtain the desired steroidal omega-pyridiniumalkoxy compounds as bromides. Their antimicrobial activity against strains of multiresistant Staphylococcus aureus (MRSA), a vancomycin resistant Enterococcus faecalis and fast growing mycobacteria depends clearly on the length of the alkyl chain. A strong broadband activity has been found for the compounds with eight or 10 C-atoms; in some cases better than ciprofloxacin or cetylpyridinium salts. In addition, the antiproliferative and cytotoxic activity depends on the chain length, too. The differentiation between antibacterial and cytotoxic activity is better for the steroid hybrid molecules than the cetylpyridinium salts. These new compounds can serve as lead compounds for further optimization.