Norpregnane glycosides from a Thai soft coral, Scleronephthya pallida.

Two new norpregnane glycosides, 19-norpregna-1,3,5(10), 20-tetraen-3-O-alpha-fucopyranoside (3) and 19-norpregna-1,3,5(10), 20-tetraen-3-O-beta-arabinopyranoside (4), were isolated from the soft coral Scleronephthya pallida, along with two known steroids, pregna-1,20-dien-3-one (1) and 19-norpregna-1,3,5(10), 20-tetraen-3-ol (2). 19-Norpregna-1,3,5(10), 20-tetraen-3-O-alpha-fucopyranoside (3) exhibits moderate antimalarial and cytotoxic activities. The chemical structures of 1-4 were elucidated from spectroscopic data.