ABSTRACT
Porcine liver esterase-catalyzed hydrolysis of 3,5,7,3',4'-pentaacetylated catechin was studied. The selectivity of the enzyme in hydrolyzing the acetate moiety is time dependent. Careful control of the duration of hydrolysis makes it possible to isolate the differentially protected catechins. Similar result was also obtained in the epicatechin series. These results are important for elaboration of epicatechin or catechin into different derivatives with defined regiochemistry. These include novel dimeric and trimeric architectures.
Subject(s)
Catechin/analogs & derivatives , Catechin/metabolism , Esterases/metabolism , Liver/enzymology , Animals , Catalysis , Catechin/chemical synthesis , Catechin/chemistry , Dimerization , Esterases/chemistry , Hydrolysis , Liver/metabolism , Liver Extracts/metabolism , SwineABSTRACT
Two regioisomeric isoxazoline monoacetates 1 and 2 were synthesized from the corresponding diacetate 3 via PPL or PLE catalyzed hydrolysis. With both the enzymes, the initial regioselectivity (approximately 3-4:1) was offset by an intramolecular acyl transfer. In addition to a non-enzymatic catalysis for the acyl transfer, preliminary experiments do suggest a definite but minor role of enzyme for this intramolecular acyl transfer. Compounds 1 and 2 may serve as intermediates for nucleoside analogues.
