Thermomyces lanuginosus lipase-catalyzed regioselective acylation of nucleosides: Enzyme substrate recognition.

Substrate recognition of Thermomyces lanuginosus lipase in the acylation of nucleosides was revealed through rational substrate engineering for the first time. T. lanuginosus lipase displayed higher catalytic activities and excellent 5'-regioselectivities (94->99%) in the acylation of ribonucleosides 1f-1j as compared to those in the acylation of 2'-deoxynucleosides 1a-1e. The higher reaction rates and excellent 5'-regioselectivities might derive from a favorable hydrogen bonding between the 2'-hydroxyl group of 1f-1j and phenolic hydroxyl group of Tyr21 present in the hydrophilic region of the lipase.