Bacopasaponin C: critical evaluation of anti-leishmanial properties in various delivery modes.

Bacopasaponin C, an indigenous glycoside, was isolated from Indian medicinal plant Bacopa monniera (b. brahmi) and was tested for antileishmanial properties both in free and in various delivery modes, e.g., niosomes, microspheres, and nanoparticles that are used now as alternatives to more commonly used liposomes. The different vesicles were prepared by published protocols. The percent intercalation of Bacopasaponin C in liposomes, niosomes, and micropspheres determined at its absorption maximal (lambda(max) = 238 nm, epsilon = 8.6 x 10(3) M(-1) x cm(-1)) was found to be 30; for nanoparticles it was 50. At equivalent dose of 1.75 mg/kg body weight, every third day for a total of 6 doses in 15 days, Bacopasaponin C in all the vesicular forms was found to be very active. An inverse linear relationship between the efficacy and the size of the vesicles was established. As analyzed from tissue histology, blood pathology, and specific tests related to normal liver and kidney functions, Bacopasaponin C in each of the four vesicular forms was found to be without any side effects. Thus, because of its indigenous origin and non-toxic nature, Bacopasaponin C could very well be considered for application in the clinic through these alternative delivery modes.

Bacopasaponins E and F: two jujubogenin bisdesmosides from Bacopa monniera.

Two new dammarane-type jujubogenin bisdesmosides, bacopasaponins E and F of biological interest have been isolated from the reputed Indian medicinal plant Bacopa monniera and defined as 3-O-[beta-D-glucopyranosyl(1 --> 3)[alpha-L-arabinofuranosyl(1 --> 2)]alpha-L-arabinopyranosyl]-20-O-(alpha-L-arabinopyranosyl) jujubogenin and 3-O-[beta-D-glucopyranosyl(1 --> 3)[alpha-L-arabinofuranosyl(1 --> 2)]beta-D-glucopyranosyl]-20-O-alpha-L-arabinopyranosyl) jujubogenin respectively by spectroscopic methods and some chemical transformations.

Advances in microbial steroid biotransformation.

Microbial biotransformations of various steroids are reviewed. Developmental studies on hydroxylation, carbon-carbon bond cleavage, enzymatic catalysis in nonaqueous solvents, use of cyclodextrin medium, cell immobilization, and new microbial reactions are highlighted. Various steroid substrates, their metabolites and the microorganisms used for the transformations are compiled covering the literature for the period 1992-1995.

Novel reduction and hydroxylation products formed by Aspergillus fumigatus from Reichstein's substance S.

Fermentation of Reichstein's Substance S with Aspergillus fumigatus (AM-21) under aerobic conditions yielded 17 alpha, 21-dihydroxy-5 alpha-pregn-l-ene-3.20-dione. 17 alpha,20 alpha, 21-trihydroxy-5 alpha-pregn-l-en-3-one. 6 beta,17 alpha, 21-trihydroxypregn-4-en-3,20-dione. 15 beta,17 alpha,21-trihydroxy-5 alpha-pregnane-3,20-dione, and 15 beta, 17 alpha,20 alpha,21-tetrahydroxy-5 alpha-pregn-l-en-3-one. Each microbial metabolite was characterized by spectroscopic methods, including 13C NMR chemical shifts.

Isolation and structure elucidation of three triterpenoid saponins from Acacia auriculiformis.

Three new triterpenoid saponins, proacaciaside-I, proacaciaside-II and acaciamine isolated from the fruits of Acacia auriculiformis, were identified as acacic acid lactone-3-O-beta-D-glucopyranosyl (1 --> 6)-beta-D-glucopyranoside, acacic acid lactone-3-O-alpha-L-arabinopyranosyl (1 --> 2)-beta-D-glucopyranoside and acacic acid lactone-3-O-alpha-L-arabinopyranosyl (1 --> 6)-2-acetamide-2-deoxy-beta-D-glucopyranoside based on their spectral properties and some chemical transformations.

Bacopasaponin D--a pseudojujubogenin glycoside from Bacopa monniera.

A new dammarane-type pseudojujubogenin glycoside, bacopasaponin D, has been isolated from the reputed Indian medicinal plant Bacopa monniera and defined as 3-O-[alpha-L-arabinofuranosyl(I-->2)beta-D-glucopyranosyl]pseudojujub ogenin by spectroscopic methods and some chemical transformations. The 13C signals of the saponin were assigned by DEPT, 1H-1H COSY and HSQC techniques.

Dammarane-type triterpenoid saponins from Bacopa monniera.

Three new dammarane-type triterpenoid saponins, bacopasaponins A, B and C, of biological interest have been isolated from the reputed Indian medicinal plant Bacopa monniera and identified as 3-O-alpha-L-arabinopyranosyl-20-O-alpha-L-arabinopyranosyl-+ ++jujubogenin, 3-O-[alpha-L-arabinofuranosyl (1--> 2)alpha-L-arabinopyranosyl]pseudojujubogenin and 3-O-[beta-D-glucopyranosyl (1 -->3)[alpha-L-arabinofuranosyl (1--> 2)]alpha-L-arabinopyranosyl]pseudojujubogenin by spectroscopic methods and some chemical transformations. The hitherto undetermined configurations at C-20 and C-22 of pseudojujubogenin were elucidated by phase-sensitive ROESY, and 1H and 13C signals of the saponins were assigned by DEPT, 1H-1H COSY, HSQC and HMBC techniques.