Bioactive microbial metabolites from glycyrrhetinic acid

Biotransformation of 18β-glycyrrhetinic acid, using Absidia pseudocylinderospora ATCC 24169, Gliocladium viride ATCC 10097 and Cunninghamella echinulata ATCC 8688a afforded seven metabolites, which were identified by different spectroscopic techniques (1H, 13C NMR, DEPT, 1H-1H COSY, HMBC and HMQC). Three of these metabolites, viz. 15α-hydroxy-18α-glycyrrhetinic acid, 13β-hydroxy-7α,27-oxy-12-dihydro-18β-glycyrrhetinic acid and 1α-hydroxy-18β-glycyrrhetinic acid are new. The 13C NMR data and full assignment for the known metabolite 7β, 15α-dihydroxy-18β-glycyrrhetinic acid are described here for the first time. The major metabolites were evaluated for their hepatoprotective activity using different in vitro and in vivo models. These included protection against FeCl3/ascorbic acid-induced lipid peroxidation of normal mice liver homogenate, induction of nitric oxide (NO) production in rat macrophages and in vivo hepatoprotection against CCl4-induced hepatotoxicity in albino mice

Production of a New Cyclic Depsipeptide by the Culture Broth of Staphylococcus sp. Isolated from Corallina officinalis L.

A new cyclic depsipeptide (1) has been isolated from culture broth of Staphylococcus sp. (No. P-100826-4-6) derived from Corallina officinalis L., together with the known compounds indol-3-carboxylic acid (2), 1,5-dideoxy-3-C-methyl arabinitol (3), thymine (4), uracil (5), cyclo (L-pro-L-omet) (6) and macrolactin B (7). The structure of (1) was established to be cyclo (2α, 3-diaminopropoinc acid-L-Asn-3-β-hydroxy-5-methyl-tetradecanoic acid-L-Leu1-L-Asp-L-Val-L-Leu2-L-Leu3) by extensive spectroscopic techniques including1 H NMR,13 C NMR,1 H-1 H COSY, HMBC, HSQC, NOESY, and HRFABMS. The antimicrobial activities of compounds 1?7 were evaluated. Compounds 1?5, and 7 showed moderate antimicrobial activity while compound 6 exhibited a potent antimicrobial and antifungal activities

Production of a New Cyclic Depsipeptide by the Culture Broth of Staphylococcus sp. Isolated from Corallina officinalis L.

A new cyclic depsipeptide (1) has been isolated from culture broth of Staphylococcus sp. (No. P-100826-4-6) derived from Corallina officinalis L., together with the known compounds indol-3-carboxylic acid (2), 1,5-dideoxy-3-C-methyl arabinitol (3), thymine (4), uracil (5), cyclo (L-pro-L-omet) (6) and macrolactin B (7). The structure of (1) was established to be cyclo (2α, 3-diaminopropoinc acid-L-Asn-3-β-hydroxy-5-methyl-tetradecanoic acid-L-Leu1-L-Asp-L-Val-L-Leu2-L-Leu3) by extensive spectroscopic techniques including1 H NMR,13 C NMR,1 H-1 H COSY, HMBC, HSQC, NOESY, and HRFABMS. The antimicrobial activities of compounds 1–7 were evaluated. Compounds 1–5, and 7 showed moderate antimicrobial activity while compound 6 exhibited a potent antimicrobial and antifungal activities