17 Enzymatic Synthesis and Modification
of Glycolipids
Siegmund Lang, Christoph Syldatk and Udo Rau
17.1 Enzymatic synthesis of glycolipids
The biochemical transfer of sugars or sugar alcohols on lipids such as fatty acids or
fatty alcohols may have considerable impact in the industrial production of surfac-
tants, sweeteners, food ingredients (e.g., emulsifiers), and chemical and pharmaceu-
tical intermediates. For instance, sucrose laurates with different degrees of esterifi-
cation are currently being used in food and personal care formulations. In addition,
their antitumoral, antibacterial and insecticidal properties have also been reported,
thus indicating their great versatility (Kato and Arima, 1971; Nishikawa et al., 1976;
Chortyk et al., 1996).
In the future, enzymatically derived glycolipids should be able to compete with
well-known alkyl polyglucosides (APGs; Henkel, Du ̈sseldorf, Germany) which are
produced from renewable resources using chemical methods (Hill et al., 1997; von
Rybinsky and Hill, 1998). Especially when the production conditions would be non-
toxic, despite of higher-priced, biosurfactants could surpass conventional products in
more high-value goods.
The use of single enzymes, lipases, proteases and glycosidases, permits the pre-
paration of a wide range of glycolipids which can be designed to possess the desired
physico-chemical properties in the final product. In addition, mild reaction condi-
tions and the regioselectivity of sugar acylation or alkylation are advantageous to the
biocatalysts. Reviews on this topic have been published by Vulfson (1993), Coulon
and Ghoul (1998) and Bevinakatti and Mishra (1999), as well as by Lang and Fischer
(1999).
The aim of this chapter is to describe these results in more detail, and to update our
most recent findings which have been published during the past two years.
17.2 Lipase- and protease-catalyzed esterification of
lipids with sugars and sugar alcohols
Using aqueous buffer systems, lipases (EC 3.1.1.3) are commonly known to hydro-
lyze triacylglycerols and other fatty acid esters at the lipid–water interface. The
reversal reaction, acyl transfer, can be rendered possible through carrying out the
biocatalysis in ‘enzyme-friendly’ organic solvents. In particular, those with logP
values>3 (cyclohexane,n-hexane,n-octane) favor the formation of ester lin-
kages, minimize enzyme inactivation and enable efficient re-use of the biocata-
lyst. Another important feature is the water activity (aw) of the entire reaction sys-
Enzymesin LipidModification.Editedby UweT. Bornscheuer
Copyright 2000 Wiley-VCHVerlagGmbH& Co. KGaA,Weinheim.ISBN:3-527-30176-3
