Polar steroid compounds from the Arctic starfishAsterias microdiscusand their cytotoxic properties against normal and tumor cellsin vitro

Two new natural compounds, sulfated polyhydroxysteroid, microdiscusol G (1), and polyhydroxysteroid bioside, microdiscusoside A (2), along with eight previously known polar steroid substances3-10, were isolated from the Arctic starfishAsterias microdiscus. The structures of1and2have been elucidated by extensive 1D and 2D NMR spectroscopy and HRESIMS techniques. The 28-sulfooxy-24-methylcholestane side chain in1has been found among starfish steroid metabolites for the first time. Steroid saponins9and10exhibited cytotoxic effects against normal cells JB6 Cl41 and cancer cells HT-29, MDA-MB-231, THP-1, and Raji and effectively suppressed cell proliferation and colony formation of cancer cells HT-29 and MDA-MB-231 in non-toxic concentrations. Compounds5,7, and8were inactive or less active in the same experiments.

Automated summary

Two new natural compounds, sulfated polyhydroxysteroid microdiscusol G (1) and polyhydroxysteroid bioside microdiscusoside A (2), along with eight previously known polar steroid substances, were isolated from the Arctic starfish Asterias microdiscus. Compounds 9 and 10 showed cytotoxic effects against normal and cancer cells, while compounds 5, 7, and 8 were inactive or less active in the same experiments.