Asterosaponins from the tropical starfish Acanthaster planci and their cytotoxic and anticancer activities in vitro

New asterosaponin, acanthaglycoside G (1), along with three previously known steroidal oligoglycosides (2-4), were isolated from the ethanolic extract of the starfish Acanthaster planci, collected off the coast of Vietnam. The structure of 1 was mainly elucidated by extensive NMR and ESIMS techniques as sodium 6-O-{beta-D-fucopyranosyl-(1 -> 2)-beta-D-quinovopyranosyl-(1 -> 4)-[beta-D-quinovopyranosyl-(1 -> 2)]-beta-D-quinovopyranosyl-(1 -> 3)-beta-D-quinovopyranosyl}-6 alpha-hydroxy-5 alpha-pregn-9(11)-en-20-one-3 beta-yl sulfate. Compounds 3 and 4 showed slight cytotoxic activities against cancer RPMI-7951, HT-29, and MDA-MB-231 cell lines, but effectively inhibited in non-toxic concentrations colony formation of HT-29 and MDA-MB-231 cells and cell migration of MDA-MB-231 cells. Compounds 1 and 2 were inactive or less active, respectively. [GRAPHICS] .

Automated summary

A new asterosaponin, acanthaglycoside G, was isolated from the starfish Acanthaster planci collected off the coast of Vietnam, along with three known steroidal oligoglycosides. Compounds 3 and 4 showed cytotoxic activities against certain cancer cell lines, while compounds 1 and 2 were less active or inactive. The structure of compound 1 was elucidated using NMR and ESIMS techniques.