A New Ceramide from Cissus Aralioides Baker (Vitaceae) and its Antimicrobial Activity.

Purification through repeated column chromatography over silica gel and Sephadex LH-20 of the ethanol extract of the stems of Cissus aralioides (Baker) Planch. resulted in the isolation of a new ceramide, aralioidamide A (1), along with five known compounds (2-6). Their structures were determined by the extensive analyses of their spectroscopic (1D and 2D NMR) and spectrometric data, and comparison with those reported in the literature. Aralioidamide A (1) displayed weak antibacterial activity (MIC=256 µg/mL) against Bacillus subtilis, Staphylococcus aureus and Shigella flexneri and was inactive (MIC>256 µg/mL) against the tested fungi.

Two new flavone glycosides from the leaves of Ochna afzelii Oliv. (Ochnaceae).

Two new glycosylflavones, 6''-O-acetyl-8-C-ß-D-galactopyranosylchrysoeriol (1) and 8-C-ß-D-galactopyranosylchrysoeriol (2) were isolated from the methanol extract of the leaves of Ochna afzelii Oliv., along with four known compounds namely 8-C-ß-D-galactopyranosylapigenin (3), ochnaflavone (4), sitosterol-3-O-ß-D-glucopyranoside (5) and D-mannitol (6). Isolation was performed chromatographically and the structures of the purified compounds were elucidated by analyzing their spectroscopic and mass spectrometric data. The antibacterial activity of extract, fractions, and compounds 1 - 4 was evaluated using broth microdilution method against Gram-positive and Gram-negative bacteria while the antioxidant capacity was performed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the ferric reducing antioxidant power (FRAP) methods. The new flavones (1 and 2) displayed moderate antibacterial activities (MIC = 32 - 64 µg/mL) and weak antioxidant properties.