STARFISH SAPONINS .40. STRUCTURES OF 2 NEW ASTEROSAPONINS FROM THE STARFISH PATIRIA-MINIATA - PATIRIOSIDE-A AND PATIRIOSIDE-B

An investigation of the extracts from the starfish Patiria miniata has led to the isolation of four 'astero-saponins.' Two are new compounds designated as patirioside A (1) and patirioside B (2). They are hexaglycosides with two branches and have been characterized as sodium (20R,22R,23S,24S)-6α-O- {α-L-arabinopyranosyl-(1→2)-[(β-D-fucopyranosyl-(1→4)] -β-o-glucopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1-»2)] -ß-D-xylopyranosyl-(1-»3)-ß-D-quinovopyranosyl}-22. 23-epoxy-20-hydroxy-24-methyl-5α-cholest-9(11)-en-3β-yl sulphate (1) and sodium (20S)-6α-O-{β-D-fucopyranosyl-(1→2)-[β-D- galactopyranosyl-(1→4)]-β-D-glucopyranosyl-(1→4) -[β-o-quinovopyranosyl(1→2)]-β-D-quinovopyranosyl-(1→3) -β-D-quinovopyranosyl}-20-hydroxy-23-oxo-5α-cholest9(11) -en-3β-yl sulphate (2). The spectral data of the two remaining asterosaponins agree with those of pectinioside G (3), an hexaglycoside recently described from Asterina pectinifera, and with those of acanthaglycoside C (4), a pentaglycoside first isolated from Acanthaster planci.