Yoichi Hiraguri

Selective enzymatic preparation of vinyl sugar esters using DMSO as a denaturing co-solvent

The protease-catalyzed transesterifications between hexoses and divinyladipate were examined. In dimethylformamide hexoses such as d-glucose, d-mannose, d-galactose and α-methyl d-galactoside were esterified with divinyladipate by alkaline protease from Streptomyces sp. to give corresponding 6-O-vinyl adipoyl sugars. When the denaturing cosolvent, DMSO, was added to the solvent, galactose was selectively esterified at only the C-2 position.

Synthesis of vinyl arabinose ester catalyzed by protease from Streptomyces sp.

The transesterification of 0.5 M divinyladipate with 0.25 M arabinose in dimethylformamide for 7 days was catalyzed by Streptomyces sp. alkaline protease to give 5-O-vinyladipoyl-d-arabinofuranose at ca. 50% yield. Only enzymatic transesterification of primary hydroxyl group of arabinofuranose proceeded without esterification of arabinopyranose.

Regio-selective preparation of vinyl adenosine ester catalyzed by alkaline protease

The transesterification of divinyladipate with adenosine in DMF containing 20% (v/v) DMSO was catalyzed by Streptomyces sp. alkaline protease and esterification occurred exclusively at the 3′-position of hydroxyl group of ribofuranose in adenosine to give 3′-O-vinyladipoyl adenosine without other products.

Biodegradation of copolymer having ester-ether group in backbone and isopropylidene group in side-chain

A copolymer having ester-ether group in the backbone and isopropylidene group in the side-chain could be synthesized by copolymerization of 2-methylene-1,3,6-trioxocane (MTC) with 1,2 : 5,6-di-O-isopropylidene-3-O-vinyladipoyl glucofuranose in the presence of a radical initiator. The copolymer was found to be biodegradable as measured by biochemical oxygen demand (BOD).