THE ENANTIOSELECTIVITY OF LIPASE PS IN CHLORINATED SOLVENTS INCREASESAS A FUNCTION OF SUBSTRATE CONVERSION

The enantiomeric ratio E of lipase from Pseudomonas cepacia increased markedly as a function of substrate conversion in the resolution of (/-)-6-methyl-5-hepten-2-ol (sulcatol) when methylene chloride was used as reaction medium. Such behavior was observed, even though less pron ounced, also in dichloroethane. Instead, when cyclohexane and toluene were used as reaction medium or when 3-methyl-2-cyclohexen-1-ol was em ployed as substrate, enzyme enantioselectivity remained constant. No e xplanation for the phenomenon, which can have practical implications f or resolutions carried out in organic solvents, has been found yet. (C ) 1997 Elsevier Science Ltd.