Three New Steroid Biglycosides, Plancisides A, B, and C, from the Starfish Acanthaster planci

Abstract

Three new steroid biglycosides, plancisides A-C (1-3), were isolated from the ethanolic extract of the starfish Acanthaster planci. The structures of 1-3 were determined by extensive NMR and ESI-MS techniques, as (24 S)-28- O-[β-D-galactofuranosyl-(1→5)-α-L-arabinofuranosyl]-24-methyl-5α-cholestane-3β,4β,6α,8,15β,16β,28-heptol (1), (24 S)-28- O-[α-L-fucopyranosyl-(1→2)-3- O-methyl-β-D-xylopyranosyl]–24-methyl-5α-cholestane-3β,4β,6α,8,15β,16β,28-heptol (2) and (24 S)-28- O-[2,4-di- O-methyl-β-D-xylopyranosyl-(1→2)-α-L-arabinofuranosyl]-24-methyl-5α-cholestane-3β,4β,6α,8,15β,16β,28-heptol 6- O-sulfate (3), respectively. Compound 2 is the first steroid glycoside containing an α-fucopyranose unit found from starfish. Compound 1 slightly inhibits cell proliferation of HCT-116, T-47D, and RPMI-7951 cancer cell lines, but has no effect on colony formation of these cells in a soft agar clonogenic assay.