Regioselective synthesis of cytarabine monopropionate by using a fungal whole-cell biocatalyst in nonaqueous medium

Efficient acylation of gastrodin by Aspergillus oryzae whole-cells in non-aqueous media

Gastrodin, a bioactive compound extracted from the plant source of Gastrodia elata Blume, has a wide range of therapeutic effects on central nervous system (CNS) diseases, but suffers from poor brain permeability and short half-life in plasma. In this study, fatty acid esters of gastrodin were successfully synthesized by a whole cell-based biocatalytic method. Aspergillus oryzae cells showed different catalytic activities in the organic solvent systems tested. Tetrahydrofuran was confirmed as the most suitable pure organic solvent, with the highest substrate conversion of 98.0%. Addition of ionic liquids (ILs) into pyridine dramatically accelerated the reaction with conversion increased from 5.9% to 84.2%, and also changed the selectivity of the cells, mainly due to the use of IL-containing systems altering cell permeability and contact of the enzymes with solvent molecules possessing different polarities. The ester products were characterized by 13C-NMR and ESI-MS as gastrodin monoester and diester.

Highly efficient synthesis of arbutin esters catalyzed by whole cells ofCandida parapsilosis

Acylation modification of phenol glycosides is currently of great interest due to the improved bioavailability and multiple functions.

Biocatalytic approaches applied to the synthesis of nucleoside prodrugs

Nucleosides are valuable bioactive molecules, which display antiviral and antitumour activities. Diverse types of prodrugs are designed to enhance their therapeutic efficacy, however this strategy faces the troublesome selectivity issues of nucleoside chemistry. In this context, the aim of this review is to give an overview of the opportunities provided by biocatalytic procedures in the preparation of nucleoside prodrugs. The potential of biocatalysis in this research area will be presented through examples covering the different types of nucleoside prodrugs: nucleoside analogues as prodrugs, nucleoside lipophilic prodrugs and nucleoside hydrophilic prodrugs.