New Efficient Route for Synthesis of Lipid A by using Affinity Separation

New efficient synthesis of lipid A, an immunostimulating glycoconjugate of bacteria, was achieved for the construction of lipid A library by using synthesis based on affinity separation (SAS), where the compounds possessing a barbituric acid (BA)-tag are selectively and rapidly purified by interaction with an artificial receptor for BA. Glycosylation of a glycosyl acceptor possessing the BA-tag with a 4′-phosphorylated N-Troc glucosaminyl trichloroacetimidate gave the disaccharide 4′-phosphate, which was purified by the affinity separation. Successive removal of protective groups and introduction of acyl groups were then effected and the synthetic intermediate at each step was purified by the affinity separation. Cleavage of the tag and subsequent deprotection afforded Escherichia coli lipid A. SAS enabled the rapid preparation of lipid A, therefore, proved to be a promising method for synthesis of other complex glycoconjugates.

lipid A - high throughput synthesis - affinity separation - barbituric acid - library