ISOLATION AND STRUCTURE OF 3 NEW CERAMIDES FROM THE STARFISH ACANTHASTER-PLANCI

Three new phytosphingosine-type ceramides, AC-1-6, AC-1-10 and AC-1-11 , were isolated from the ceramide molecular species AC-1, obtained fro m the less polar fraction of the CHCl3/MeOH extract of the starfish Ac anthaster planci. The structures of these ceramides were determined on the basis of chemical and spectroscopic evidence as 2-hydroxyhexadeca noylamino)-9-docosene-1,3,4-triol (AC-1-6), (2S,2'R,3S,4R)-2-(2-hydrox ytricosanoylamino) hexadecane-1,3,4-triol (AC-1-10) and (2S,2'R,3S,4R) -2(2-hydroxytetracosanoylamino) hexadecane-1,3,4-triol (AC-1-11). Posi tive ion FABMS/MS of each ceramide gave important information for thei r structure elucidation. Mass spectrometry of the dimethyl disulfide d erivatives of ceramide was also useful for the determination of the do uble bond position in the long-chain base.