Enzymatic syntheses of L-valyl,L-leucyl and L-isoleucyl esters of carbohydrates using Candida rugosa lipase

摘要

L-Valyl 1 L-leucyl 2 and L-isoleucyl 3 esters of carbohydrates 4-14 have been prepared through lipase catalysis using Candida rugosa lipase in organic media.This enzymatic esterification involving unprotected and unactivated L-amino acids 1-3 and carbohydrates,comprising,aldohexoses 4-6,ketohexose 7,pentoses 8-9,disaccharides 10-12 and carbohydrate alcohols 13-14,results in the formation of both monoesters(1-O-,2-O-,3-O-,4-0,5-O-,6-O-and 6'-O-)and diesters(1,6-di-O-,2,5-di-O-,2,6-di-O-,3,6-di-O-,4,6-di-O-and 6,6'-di-O-)with conversion yields in the range 21-68%.Among 70 esters synthesized on the whole,65 esters are reported here for the first time.