Synthesis of glycero amino acid-based surfactants. Part 2.1 Lipase-catalysed synthesis of 1-O-lauroyl-rac-glycero-3-O-(Nα-acetyl-L-amino acid) and 1,2-di-O-lauroyl-rac-glycero-3-O-(Nα-acetyl-L-amino acid) derivatives
Synthesis of glycero amino acid-based surfactants. Part 1. Enzymatic preparation of rac-1-O-(Nα-acetyl-l-aminoacyl)glycerol derivatives
作者:Carmen Morán、María Rosa Infante、Pere Clapés
DOI:10.1039/b103132p
日期:——
controlled synthesis). The best yields (61–89%) are obtained at 50 °C in glycerol containing a range of aqueous buffer from 0 to 10% (v/v). Readily available industrial proteases and lipases are used as catalysts. The method allowed us to selectively acylate one of the primary hydroxy groups of the glycerol with the carboxylate groups of the amino acid. In the case of aspartic acid and glutamic acid, selective
Synthesis of glycero amino acid-based surfactants. Part 2.1 Lipase-catalysed synthesis of 1-O-lauroyl-rac-glycero-3-O-(Nα-acetyl-L-amino acid) and 1,2-di-O-lauroyl-rac-glycero-3-O-(Nα-acetyl-L-amino acid) derivatives
作者:Carmen Morán、María Rosa Infante、Pere Clapés
DOI:10.1039/b200577h
日期:2002.4.9
An enzymatic procedure for the synthesis of mono- and dilauroylated amino acid glyceride conjugates is presented. The reaction consisted of the lipase-catalysed esterification of one or two hydroxy groups of the amino acid glyceryl ester derivatives by lauric acid. Solvent-free media with continuous removal of the water produced at atmospheric pressure were the reaction systems of choice. It is found that the mono- and dilauroylation yields and enzymatic activity depended crucially on the reaction temperature, the molar ratio of lauric acid to amino acid glyceryl ester, and concentration of phosphate salts using Candida antarctica (Novozym® 435) and Rhizomucor miehei (Lipozyme® IM) lipases as catalysts. These reaction variables are identified and studied systematically using BocâArgâOGl as a model substrate and modulated accordingly for the target amino acid-based compounds. As in conventional glycerides, spontaneous
intramolecular acyl-migration reactions are observed for the lauroyl and aminoacyl moieties of the glycerol backbone. This reaction led to a number of regioisomers, which are identified and quantified by mono- and bidimensional NMR techniques. The method developed allowed us to prepare glycero conjugates of arginine, aspartic acid, glutamic acid, asparagine, glutamine and tyrosine in isolated yields of the regioisomeric mixtures ranging from 22 to 69%.