Constituents of holothuroidea. 10. Isolation and structure of a biologically active ganglioside molecular species from the sea cucumber Holothuria leucospilota

Three ganglioside molecular species, HLG-1 (1), HLG-2 (2), and HLG-3 (3) have been obtained from the lipid fraction of the chloroform/methanol extract of the sea cucumber Holothuria leucospilota. The structures of these gangliosides have been determined, on the basis of chemical and spectroscopic evidence, as 1-O-[(N-gly colyl-α-D-neuraminosyl)-(2→6)-β-D-glucopyranosyl]-ceramide (1), 1-O-[(N-glycolyl-α-D-neuraminosyl)-(2→4) (N-acetyl-α-D-neuraminosyl)-(2→6)-β-D-glucopyranosyl] -ceramide (2) and 1-O-[α-L-fucopyranosyl-(1→11)-(N-glycolyl-α-D-neuraminosyl) -(2→4)-(N-acetyl-α-D-neuraminosyl)-(2→6) -β-D-glucopyranosyl]-ceramide (3). The ceramide moieties were composed of heterogeneous phytosphingosine, sphingosine and 2-hydroxy fatty acid units. Compounds 2 and 3 represent new ganglioside molecular species. These three ganglioside molecular species showed neuritogenic activity toward the rat pheochromocytoma cell line, PC-12 cell, in the presence of NGF (nerve growth factor).