Regioselective resolution of 1,n-diols catalysed by lipases: a rational explanation of the enzymayic selectivity

The regioselective acylation of different phenylalkanediols catalysed by porcine pancreatic lipase (PPL) was used for modelling the enzymatic substrate recognition. Thus, different racemic or prochiral (1,n)-diols, with n ranging from 2 to 6, were resolved via transesterification with vinyl acetate, and the results obtained (yield, reaction rate, enantioselectivity) were explained according to the microcrystalline enzyme structure. A logical model for explaining the enzyme regio-and stereoselectivity is proposed, based on literature data reporting similar recognition patterns for some other lipases; our model is built on three residues of the active site (Ser153, Phe216 and His264), which turned out to be crucial for the substrate binding and transformation. Furthermore, some other tentative models proposed for PPL recognition are explained with our criterion.