A new pregnane glycoside from Gomphocarpus fruticosus growing in Egypt.

Phytochemical investigation of Gomphocarpus fruticosus (L.) Ait. of Egyptian origin afforded the new pregnane glycoside lineolon-3-O-[ß-D-oleandropyranosyl-(1-4)-ß-D-cymaropyranosyl-(1-4)-ß-D-cymaropyranoside], along with six known compounds. The structures of the isolated compounds were elucidated on the basis of extensive spectroscopic evidences derived from 1D, 2D NMR experiments, mass spectrometry and by comparing their physical and spectroscopic data to literature. These included the triterpenoids 3ß-taraxerol, 3ß-taraxerol acetate and betulinic acid, which are identified for the first time in G. fruticosus and the cardenolides uzarigenin, gomphoside and calotropin.

A new lanostane-type triterpene and sesquiterpene lactones from Vernonia leopoldii and their in vitro cytotoxicity.

Investigation of the aerial parts of Vernonia leopoldii (Sch. Bip.) Vatke afforded a new lanostane-type triterpene along with known hirsutinolide-type sesquiterpene lactones and flavonoid glycosides, all are identified for the first time in this species. The new compound was identified as lanost-3ß, 23S-dihydroxy-22(31)-ene. The structures of the isolated compounds were elucidated based on spectroscopic evidence. The hirsutinolides and the triterpene were evaluated for their cytotoxicity against four human cancer cell lines using MTT assay.

The genus Machaerium (Fabaceae): taxonomy, phytochemistry, traditional uses and biological activities.

Machaerium, in the family Fabaceae, predominantly is a genus of a Neotropical distribution of trees, shrubs, and lianas occurring from southern Mexico to Brazil and northern Argentina and as far as South America. Several Machaerium species are widely used in traditional medicine and are considered to have multiple medicinal properties. This review aims to provide up-to-date and comprehensive information on the taxonomy, phytochemistry, traditional uses and biological activities of plants in the genus Machaerium.

Corncobs as a potential source of functional chemicals.

Phytochemical examination of corncob extracts led to the isolation of a new lignan identified as 7,7'-dihydroxy-3'-O-demethyl-4-methoxymatairesinol, together with seven known compounds, identified as ß-sitosterol, ß-sitosteryl-ß-D-glucoside, 6ß-hydroxy-campest-4-en-3-one, 5α,8α-epidioxyergosta-6,22-dien-3ß-ol, tricin, kaempferol and p-coumaric acid. The isolated compounds were identified by one and two-dimensional NMR spectroscopies and mass spectrometry.

Bioactive microbial metabolites from glycyrrhetinic acid.

Biotransformation of 18beta-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. 15alpha-hydroxy-18alpha-glycyrrhetinic acid, 13beta-hydroxy-7alpha,27-oxy-12-dihydro-18beta-glycyrrhetinic acid and 1alpha-hydroxy-18beta-glycyrrhetinic acid are new. The 13C NMR data and full assignment for the known metabolite 7beta, 15alpha-dihydroxy-18beta-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.