Article ID Journal Published Year Pages File Type
153022 Chemical Engineering Journal 2008 4 Pages PDF
Abstract
Novozym 435-catalyzed regioselective acylation of 1-β-d-arabinofuranosylcytosine (ara-C) with vinyl caprylate for the preparation of its 5′-O-acyl derivative has been performed in six co-solvent mixtures and three pure polar solvents for the first time. Novozym 435 displayed low activity towards 1-β-d-arabinofuranosylcytosine in pure polar solvents, although those solvents can dissolve the nucleosides well. When a hexane-pyridine co-solvent system was adopted, both the initial rate and the substrate conversion were enhanced markedly. The most suitable co-solvent, initial water activity, reaction temperature and the molar ratio of vinyl caprylate to ara-C were hexane/pyridine (28/72, v/v), 0.03, 40 °C and 15, respectively. Under these conditions, the initial rate, the substrate conversion and the regioselectivity were as high as 99.0 mmol h−1, 98% and >99%, respectively. The product of the Novozym 435-catalyzed reaction was characterized by 13C NMR and confirmed to be 5′-O-octanoyl 1-β-d-arabinofuranosylcytosine.
Related Topics
Physical Sciences and Engineering Chemical Engineering Chemical Engineering (General)
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