Asterosaponins and glycosylated polyhydroxysteroids from the starfish Culcita novaeguineae and their cytotoxic activities.

Using combined chromatographic methods, two asterosaponins (compounds1and2), including a new compound novaeguinoside E (compound1), and six glycosylated polyhydroxysteroids (compounds3–8) were isolated from a methanol extract of the starfishCulcita novaeguineae. Their structures were determined on the basis of spectroscopic data (1H and13C NMR, HSQC, HMBC,1H–1H COSY, ROESY, and HRESI-MS) and by comparison with the literature values. The new compound1represents the third example of asterosaponins containing the 5α-cholesta-9(1l)-en-3β,6α,20,22-tetraol aglycone. Among isolated compounds,4–7exhibited moderate to weak cytotoxic activities against five human cancer cell lines such as Hep-G2 (hepatoma), KB (epidermoid carcinoma), LNCaP (prostate cancer), MCF7 (breast cancer), and SK-Mel2 (melanoma). [ABSTRACT FROM AUTHOR]