Structural determination of cerebrosides isolated from Asterias amurensis starfish eggs using high‐energy collision‐induced dissociation of sodium‐adducted molecules

Abstract

Six cerebrosides were isolated from the eggs of the starfish Asterias amurensis using solvent extraction, silica gel column chromatography, and reversed-phase high-performance liquid chromatography. This study demonstrated that the structures of cerebrosides could be completely characterized, based on their sodium-adducted molecules, using fast atom bombardment (FAB) tandem mass spectrometry. The high-energy collision-induced dissociation of the sodium-adducted molecule, [M + Na](+), of each cerebroside molecular species generated abundant ions, providing information on the compositions of the 2-hydroxy fatty acids and long-chain sphingoid bases, as well as the sugar moiety polar head group. Each homologous ion series along the fatty acid and aliphatic chain of the sphingoid base was useful for locating the double-bond positions of both chains and the methyl branching position of the long-chain base. The N-fatty acyl portions were primarily long-chain saturated or monoenoic acids (C16 to C24) with an α-hydroxy group. The sphingoid long-chain base portions were aliphatic chains (C18 or C22) with two or three degrees of unsaturation and with or without methyl branching.

High‐energy collision‐induced dissociation of [M+Na]+ ions desorbed by fast atom bombardment of ceramides isolated from the starfish Distolasterias nipon

“…The CID of the monosodiated ion, m / z 792.6 of DNC‐B3, produced abundant ions at m/z 185 (B), 203 (C), 244 (E), 320 (T), 538 (O), 498 (S), 630 (Y), 658 ( 1,5 X) and 672 ( 0,2 X), which are characteristic ions observed in the CID spectra of cerebrosides. This spectral pattern was the same as that of cerebroside AA‐1 observed in a previous study . Therefore, the structure of DNC‐B3 was revealed to 1‐( β ‐ d ‐glucopyranosyloxy)‐3‐hydroxy‐2‐[2’‐hydroxyhexadecanoyl]amino‐4,13‐docosadiene.…”

“…Because the abundant product ion peaks of DNC‐C2 were observed at m/z 185 (B), 203 (C), 244 (E), 430 (T), 480 (O), 608 (S), 682 (Y), 710 ( 1,5 X) and 724 ( 0,2 X), and its CRF pattern in the high‐mass region was same to that of cerebroside AA‐6, which its structure was also confirmed by NMR study, the structure of DNC‐C2 was determined to be 1‐( β ‐ d ‐glucopyranosyloxy)‐3‐hydroxy‐2‐[2’‐hydroxy‐15’‐tetracosenoyl]amino‐4,8,10‐octadecatriene. In Fig.…”

“…Recently, five glucosylceramides were isolated from marine sponges and characterized using FAB‐linked scanning at a constant B/E . The structures of six cerebrosides were also determined using high‐energy CID tandem mass analyses, with a four sector tandem mass spectrometer in our previous work . In the present study, the structures of ten ceramides (DNC‐A1, A2 with two position isomers, DNC‐B1, B2, DNC‐C1, C3, C4 and DNC‐D1, D2; Fig.…”

“…To reduce these problems, the structural identification of ceramide species in the fractions, in which were separated by the solvent extraction and chromatography techniques, using fast atom bombardment (FAB)‐MS/MS has been conducted. FAB‐MS/MS is regarded as a useful tool because it can provide important structural information for compounds that have a repetitive similar moiety . Ann and Adams contributed significantly to the characterization of ceramides and neutral glycosphingolipid structures by using high‐energy collision‐induced dissociation (CID) of [M+Li] + ions desorbed by FAB .…”

Effects of <i>Asterias amurensis</i>-derived Sphingoid Bases on the <i>de novo</i> Ceramide Synthesis in Cultured Normal Human Epidermal Keratinocytes

“…Humans produce sphingosine d18:1 , sphinganine d18:0 , and phytosphingosine t18:0 16 . Asterias amurensis GlcCers comprise relatively long-carbon-chain sphingoid bases, such as C22 sphingosine d22:1 , C22 sphingadienine d22:2 , and C18 sphingatrienine d18:3 , in addition to 9-methyl-sphingatrienine 9-Me-d18:3 13,17 .…”