Starfish saponins VII. Structure of luzonicoside, a further steroidal cyclic glycoside from the pacific starfish Echinaster luzonicus

On the basis of comparative chemical and spectral data, the structure of the major saponin, luzonicoside, from the starfish Echinaster luzonicus has been elucidated as 2. This is a further example of a novel class of steroidal cyclic glycoside from starfish of the genus Echinaster. Its structure includes a Δ7, 3β,6β-dioxygenated-23-oxosteroidal moiety, already found in the saponins of Echinaster sepositus, and a trisaccharide moiety, β-D-galactopyranosyl-(1→2) α-L-arabinopyranosyl-(1→2)-β-D-glucuronopyranosyl, bridging C-3 and C-6 of the steroid. © 1982 Birkhäuser Verlag.