ENANTIOSELECTIVE CONVERSIONS OF THE RACEMIC C-3-ALCOHOL SYNTHONS, GLYCIDOL (2,3-EPOXY-1-PROPANOL), AND SOLKETAL (2,2-DIMETHYL-4-(HYDROXYMETHYL)-1,3-DIOXOLANE) BY QUINOHEMOPROTEIN ALCOHOL DEHYDROGENASES AND BACTERIA CONTAINING SUCH ENZYMES

Several purified or commercially available alcohol oxidoreductases of different kinds were tested for their ability to convert the racemic, glycerol-based C-3-synthons glycidol (2,3-epoxy-1-propanol) and solket al (2,2-dimethyl-4-(hydroxymethyl)-1,3-dioxolane), with adequate activ ity and enantioselectivity. Quinohaemoprotein alcohol dehydrogenases ( enzymes containing haem c as well as pyrroloquinoline quinone (PQQ) as cofactors) appeared to be excellently suited for such use. The bacter ia from which the enzymes were purified had the same enantiomer prefer ence and had an efficient respiratory chain for reoxidation of these d ehydrogenases. In some cases, however, H hole cells gave a lower enant iomer ratio (E) than the pure enzyme. NAD-dependent alcohol dehydrogen ases also are present in these bacteria, but their presence may not ex plain the lower ratio because they oxidized the C-3-synthons little if at all. It seems, therefore, that different kinetic mechanisms are re sponsible for the discrepancy between the effects of whole cells and p urified enzymes.