Sarasinoside A1: A Saponin Containing Amino Sugars Isolated from a Sponge

Article abstract of DOI:10.1021/jo00260a025

A new saponin designated sarasinoside A₁, 1, has been isolated from a sponge, Asteropus sp., collected from Guam Island and also from Truk Lagoon.Acid hydrolysis of sarasinoside A₁ afforded the aglycon 2, identified as 3β-hydroxy-4,4-dimethylcholesta-8,24-dien-23-one by spectral analysis.Methanolysis of 1 yielded the methyl glycosides of xylose, glucose, N-acetyl-2-amino-2-deoxygalactose, and N-acetyl-2-amino-2-deoxyglucose.Glycosidic connections were established by a combination of chemical degradations and spectroscopic methods. 1H and 13C NMR assignments were made with the aid of 1H/13C NMR correlations, relayed coherence transfer, and ROESY experiments.This appears to be the first saponin isolated from a sponge.