PREPARATION OF DEFINED MOLECULAR-SPECIES OF LACTOSYLCERAMIDE BY CHEMICAL DEACYLATION AND REACYLATION WITH N-SUCCINIMIDYL FATTY-ACID ESTERS

A procedure for the preparation of specific molecular species of D-ery thro-lactosylceramide involving deacylation and reacylation of lactosy lceramide prepared from bovine brain gangliosides is described. Lactos ylceramide was N-deacylated by alkaline hydrolysis and the resulting f our lysolactosylceramides, which contained d18:1, d20:1, d18:0 and d20 :0 long-chain bases, were simultaneously re-hr-acylated with the N-suc cinimidyl ester of either 16:0, 18:0, 20:0, 22:0, 24:0, 20:1, 22:1 or 24:1 fatty acid. The resulting lactosylceramide contained four molecul ar species of lactosylceramides, i.e., d18:1, d20:1, d18:0 and d20:0 l ong-chain bases coupled with the fatty acid that was introduced. Lacto sylceramides prepared in this manner were separated into four individu al molecular species by high-performance liquid chromatography (HPLC). Each of the purified molecular species of lactosylceramide was quanti tated by HPLC after derivatization with benzoylchloride and was charac terized by mass spectrometry. The yields of reacylated lactosylceramid e were 38-58% relative to the starting lactosylceramide; the purity of each of the molecular species of lactosylceramide was greater than 95 %.