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Chemo‐enzymatic synthesis of amino acid‐based surfactants
Author(s) -
Valivety Rao,
Jauregi Paula,
Gill Iqbal,
Vulfson Evgeny
Publication year - 1997
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-997-0232-8
Subject(s) - acylation , chemistry , amino acid , moiety , lysine , organic chemistry , yield (engineering) , fatty acid , acyl group , serine , catalysis , enzyme , biochemistry , group (periodic table) , materials science , metallurgy
The application of lipases to the synthesis of amino acid‐based surfactants was investigated. Low yields (2–9%) were obtained in the acylation of free amino acids, such as l ‐serine and l ‐lysine, as well as their ethyl esters and amides with fatty acids, owing in part to low miscibility of the reactants. When the N ‐carbobenzyloxy (Cbz)‐ l ‐amino acids were used in an effort to improve miscibility of the amino acid derivatives with the acyl donor, a dramatic improvement was observed for N ‐Cbz‐ l ‐serine (92% yield) but not for N α ‐Cbz‐ or N ζ ‐Cbz‐ l ‐lysine (7 and 2% yield, respectively). As an alternative, and efficient synthesis of N ζ ‐acyl‐ l ‐lysines was developed, based on the regiospecific chemical acylation of copper(II) lysinate. In pursuit of a general route to amino acid‐fatty acid surfactants, the utility of a polyol linker was investigated. Thus, the glycerol ester of N α′ N ζ ‐di‐Cbz‐ l ‐lysine was prepared and evaluated as a substrate for acylation. As expected, this and other glycer‐1‐yl esters of N ‐protected amino acids were excellent substrates for lipase‐catalyzed acylation. Their reaction with myristic acid in the presence of Novozyme resulted in the regioselective acylation of the primary hydroxyl group of the glycerol moiety to afford the corresponding 1‐ O ‐( N ‐Cbz‐ l ‐aminoacyl)‐3‐ O ‐myris‐toylglycerols with conversions of 50–90%. These were readily deprotected to give a range of 1‐ O ‐(aminoacyl)‐3‐ O ‐myristoyl‐glycerols with overall yields of 27–71%.