摘要:
A new ceramide, 2,3-dihydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxyicosan-2-yl[tetracosanamide (1) along with four known compounds: 2-(4 '-hydroxyphenyl)-ethyl lignocerate (2), docosyl-3,4-dihydroxy-trans-cinnamate (3), beta-sitosterol (4) and beta-sitosterol glycoside (5) were isolated from Tinospora oblongifolia (Menispermaceae). Their structures were determined on the basis of spectroscopic methods, mass spectrometry analysis as well as chemical transformation and by comparing their physical and spectral data with those reported in the literature. Compound 1 exhibited strong cytotoxic activity against KB cells with IC50=3.4 mu M although less than that of camptothecin IC50=0.3 mu M (positive control).