The low activity of enzymes in organic solvents limits their impressive synthetic potential. 1 It is not unusual to see processes employing more enzyme than substrate by weight. 2 In the case of lipases, this low efficiency can be explained, at least in part, by the low purity of commercial preparations. For example, the commercial preparations of two of the most synthetically useful lipasessfrom Candida rugosa (CRL) and Pseudomonas cepacia (LPS) scontain less than 5-6% and 1% of the lipase, respectively. The large amount of impurities makes the downstream processing difficult and expensive, and complicates our understanding of the mechanistic aspects of enzymatic catalysis in organic solvents.

One would think that by using lipases in purified form much higher activity could be achieved. In addition, recent pulbications have indicated that purified lipases exhibit higher enantioselectivity in hydrolytic resolutions, simply by eliminating contaminating enzymes with opposite enantioselectivity. 3, 4 Surprisingly, the potential synthetic benefits of purified lipases in organic solvents have not been realized to date. 5, 6 Not only is the cost of purified lipases higher, but their stability and activity in organic solvents are lower than those of their crude