Separation of Positional Isomers by Combined Use of Enzymatic Hydrolysis and Extraction

Abstract

A number of industrially or physiologically important chemicals have isomers. These isomers, each of which has a different reactivity and physiological activity, are used for different purposes, and therefore must be manufactured with a sufficiently high level of purity. However, in general, it is very difficult to separate isomers efficiently by using conventional methods such as distillation, extraction or crystallization, because each isomer has quite similar physical properties. Therefore, an efficient separation process for isomers is needed. The present work was undertaken to develop an efficient enzymatic process for separating positional isomers. We developed two types of separators: (1) a flat-type separator with a membrane-bound enzyme [1, 3], (2) a hollow-fiber type separator in which an enzyme is confined in the shell-side of the ultrafiltration follow-fibers and in which the feed and sweep solutions flow. Separation of α — and β — naphthyl sulfates was demonstrated by use of the separators.