Enantioselective hydrolysis of (R/S)-Naproxen methyl ester with sol–gel encapculated lipase in presence of calix[n]arene derivatives

Selcuk University, Department of Chemistry, 42031 Konya, Turkey
Applied Catalysis A: General 01/2009; 369:36-41. DOI: 10.1016/j.apcata.2009.08.030

ABSTRACT Lipases are enzymes that catalyses a variety of reactions, such esterifications, interesterification and hydrolysis. Several methods have been reported for the immobilization of lipases, such as deposition onto solid supports, covalent binding and encapsulation within a polymer matrix or silica glasses obtained by sol–gel techniques. In this study, the Candida rugosa lipase was encapsulated within a chemically inert sol–gel support prepared by polycondensation by tetraetoxysilane (TEOS) and octyltrietoxysilane (OTES) in the presence and absence of calix[n]arene, calix[n]-NH2 and calix[n]-COOH (n=4, 6, 8) compounds as additives. The catalytic activity of the encapsulated lipases was evaluated into model reactions, i.e. the hydrolysis of p-nitrophenylpalmitate (p-NPP), and the enantioselective hydrolysis of rasemic Naproxen methyl ester that was studied in aqueous buffer solution/isooctane reaction system.The results indicated that the particularly calix[4,6]-NH2 and calix[6]-COOH based encapsulated lipases had higher conversion and enantioselectivity compared to the sol–gel free lipase.

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