Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
153022 | Chemical Engineering Journal | 2008 | 4 Pages |
Abstract
Novozym 435-catalyzed regioselective acylation of 1-β-d-arabinofuranosylcytosine (ara-C) with vinyl caprylate for the preparation of its 5â²-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 hâ1, 98% and >99%, respectively. The product of the Novozym 435-catalyzed reaction was characterized by 13C NMR and confirmed to be 5â²-O-octanoyl 1-β-d-arabinofuranosylcytosine.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Min-Hua Zong, Hong Wu, Zi-yang Tan,