New glycosphingolipids from the marine sponge Aplysinella rhax and their potential as nitric oxide release inhibitors

Several new glycosphingolipids were isolated by means of reversed-phase HPLC from the less-polar fraction of the methanol extract of the sponge Aplysinella rhax. Their structures, showing very close similarity, were elucidated by extensive NMR experiments and chemical evidence. The molecular masses of the glycosphingolipids were determined by negative-ion fast-atom bombardment mass spectrometry, while HREIMS and HRFABMS provided important information for the identification of the fatty acids and sphingoid bases. The mixture of glycosphingolipids exhibited a good inhibitory activity on LPS-induced NOE release by J774 A.1 macrophages.