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S B Mahato

Publications and source records attributed to S B Mahato.

At least 55 records · Page 3Linked to original sources
PubMed1986

Metabolism of 17-hydroxyprogesterone by a Bacillus species.

Fermentation of 17-hydroxyprogesterone with a Bacillus species (IICB-301) in a modified nutrient medium under aerobic conditions yielded androst-4-ene-3,17-dione and 15 alpha,17-dihydroxypregn-4-ene-3,20-dione in addition to a new pregnane analogue, 6 beta,17,20 alpha-trihydroxypregn-4-ene-3-one. Each microbial metabolite was characterized by the application of various spectroscopic techniques. The availability of the new metabolite, 6 beta,17,20 alpha-trihydroxypregn-4-ene-3-one, enabled complete elucidation of its 13C-n.m.r. spectrum.

17-alpha-Hydroxyprogesterone↗
PubMed1986

Metabolism of 11-deoxycortisol by a Bacillus species.

Microbial transformation by a Bacillus species was employed for the preparation of potentially important derivatives of 11-deoxycortisol. Each microbial metabolite was characterised by the application of various spectroscopic methods. The five metabolites of 11-deoxycortisol were characterised as 4-androstene-3,17-dione (2), 14-hydroxy-4-androstene-3,17-dione (3), 14,17 alpha,21-trihydroxy-4-pregnene-3,20-dione (4), 6 beta,17 alpha,21-trihydroxy-4-pregnene-3,20-dione (5) and 15 alpha,17 alpha,21-trihydroxy-4-pregnene-3,20-dione (6). The availability of the metabolites enabled complete elucidation of their [13C]NMR spectra.

17-Hydroxycorticosteroids↗
PubMed1984

Homogeneous enzyme immunoassay of diosgenin and its glycosides.

Homogeneous enzyme immunoassay has been used as a tool for the determination of diosgenin and its glycosides in plants. Diosgenin antisera was found to inhibit the activity of diosgenin hemisuccinate-horseradish peroxidase conjugate which was reversed by the addition of free diosgenin or its glycosides. The increase of enzyme activity was proportional to the quantity of the hapten over a certain range of hapten concentration. Thus, a minimum of 2.5 micrograms/ml of diosgenin and 11.5 micrograms/ml of diosgenin glycosides could be determined by this method. The results were comparable with those obtained by high-performance liquid chromatography and gravimetric methods.

Chromatography, High Pressure Liquid↗
PubMed1984

Metabolism of steroid acetates by Streptomyces albus.

Fermentation of 16-dehydropregnenolone acetate (1a) with Streptomyces albus yielded 16-dehydropregnenolone (1b) and 16-dehydroprogesterone (IIa). Similar incubation of pregnenolone acetate (Ic) with the strain afforded pregnenolone (Id), progesterone (IIb) and 20 alpha-hydroxy progesterone (IIc) while dehydroepiandrosterone acetate (IIIa) under the conditions was converted to dehydroepiandrosterone (IIIb), androstenedione (IVa) and testosterone (IVc). The strain was also capable of converting testosterone acetate (IVb) having the 17-acetoxy function in the 5-membered D-ring to testosterone (IVc) and androstenedione (IVa). All the products were identified by the application of various chemical and spectrometric techniques.

Androgens↗
PubMed1984

Microbial transformation of testosterone by Aspergillus fumigatus.

Microbial transformation has been employed for the preparation of the potentially important 15 beta-hydroxytestosterone which was obtained by fermentation of testosterone with a typical strain of Aspergillus fumigatus. The metabolite was characterized by employing 1H and 13C NMR, mass spectrometry and i.r. analysis. High performance liquid chromatography (HPLC) was used to examine the purity of the product and formation of other minor metabolites.

Aspergillus fumigatus↗
PubMed1984

Metabolism of progesterone and testosterone by a Bacillus sp.

Microbial transformations by a Bacillus sp. were employed as a means of preparing potentially important derivatives of progesterone and testosterone. Each microbial metabolite was subjected to structure elucidation employing 1H and 13C nmr, mass spectral and cd analysis. Hplc was used for the determination of the percentages of the metabolites formed. The progesterone metabolites were characterised as 14-hydroxy-4-pregnene-3,20-dione (II), 14-hydroxy-5 alpha -pregnane-3,6,20-trione (III), 11 alpha-hydroxy-5 alpha-pregnane-3, 6,20-trione (IV) and 11 alpha,14-dihydroxy-4-pregnene-3,20-dione (V). The testosterone analogs were identified as 4-androstene-3,17-dione (VII), 17 beta-hydroxy-5 alpha-androstane-3,6-dione (VIII), 14-hydroxy-4-androstene-3,17-dione (IX) and 14, 17 beta-dihydroxy-4-androsten-3-one (X). The availability of the metabolites enabled complete elucidation of their 13C nmr spectra.

Bacillus↗
PubMed1984

Mycoversilin, a new antifungal antibiotic. II. Structure elucidation.

The structure of a new antifungal antibiotic, mycoversilin, produced by Aspergillus versicolor (N5)17 was determined as I by various spectroscopic and chemical methods. Mycoversilin is a unique polynuclear aromatic compound having two methyl and six hydroxyl groups and two ether linkages. The acetyl derivative prepared was found to have no antifungal property.

Antifungal Agents↗
PubMed1981

Metabolism of sitosterol by a Pseudomonas species.

Fermentation of sitosterol by a Pseudomonas species (SK-25) resulted in the formation of 5-stigmastene-3 beta, 7 alpha-diol; 5,6 alpha-epoxy-5 alpha-stigmastan-3 beta-ol; 5,6 beta-epoxy-5 beta-stigmastan-3 beta-ol and 5 alpha-stigmastan-3 beta, 5,6 beta-triol. The metabolites were characterized by a variety of conventional chemical and spectrometric techniques.

Chemical Phenomena↗