Identification of sixteen new galactocerebrosides from the starfish Protoreaster nodosus.

Twenty-one galactocerebrosides (1-21), including sixteen new compounds (3-7, 9-17, 19, 21), were identified from a cerebroside molecular species obtained from the chloroform/methanol extract of pyloric caeca dissected from the starfish Protoreaster nodosus. The structures of these galactocerebrosides were determined on the basis of chemical and spectroscopic evidences. Especially, one-pot GC-MS analysis following methanolysis and periodate oxidation of these galactocerebrosides gave efficient structural information of ceramide moiety rapidly in minute amounts.