Triterpene constituents from the fruits of Cyclocarya paliurus and their anti-HIV-1(IIIB) activity

Four new norceanothane-type triterpenes, cyclopalin A-D (1-4), and sixteen known compounds (5-20) were obtained from the fruits of Cyclocarya paliurus. Their structures were determined by spectroscopic data, experimental electronic circular dichroism (ECD) and X-ray single crystal analyses. All isolated compounds were assayed for their anti-HIV-1(IIIB) activity. Compound 18 exhibited potent anti-HIV-1(IIIB) activity with an EC50 value of 1.32 mu M (SI = 151.52).