Enzymatic Synthesis of a Novel Pterostilbene α-Glucoside by the Combination of Cyclodextrin Glucanotransferase and Amyloglucosidase.

The synthesis of a novel α-glucosylated derivative of pterostilbene was performed by a transglycosylation reaction using starch as glucosyl donor, catalyzed by cyclodextrin glucanotransferase (CGTase) from sp. The reaction was carried out in a buffer containing 20% (/) DMSO to enhance the solubility of pterostilbene. Due to the formation of several polyglucosylated products with CGTase, the yield of monoglucoside was increased by the treatment with a recombinant amyloglucosidase (STA1) from var.

Purification, characterization, and primary structure of a novel N-acyl-D-amino acid amidohydrolase from Microbacterium natoriense TNJL143-2.

A novel N-acyl-D-amino acid amidohydrolase (DAA) was purified from the cells of a novel species of the genus Microbacterium. The purified enzyme, termed AcyM, was a monomeric protein with an apparent molecular weight of 56,000. It acted on N-acylated hydrophobic D-amino acids with the highest preference for N-acetyl-D-phenylalanine (NADF).

Increased enantioselectivity and remarkable acceleration of lipase-catalyzed transesterification by using an imidazolium PEG-alkyl sulfate ionic liquid.

Several types of imidazolium salt ionic liquids were prepared derived from poly(oxyethylene)alkyl sulfate and used as an additive or coating material for lipase-catalyzed transesterification in an organic solvent. A remarkably increased enantioselectivity was obtained when the salt was added at 3-10 mol % versus substrate in the Burkholderia cepacia lipase (lipase PS-C)-catalyzed transesterification of 1-phenylethanol by using vinyl acetate in diisopropyl ether or a hexane solvent system. In particular, a remarkable acceleration was accomplished by the ionic liquid coating with lipase PS in an iPr(2)O solvent system while maintaining excellent enantioselectivity; it reached approximately 500- to 1000-fold acceleration for some substrates with excellent enantioselectivity.

Formation and stability of alternate-stranded triplex formed with alpha,beta-chimeric oligoDNA.

Chimeric oligoDNAs composed of alpha-anomeric oligonucleotide and beta-anomeric oligonucleotide with modified nucleobases and/or phosphodiester backbone are synthesized and their ability to form alternate-stranded triple helix with dsDNA was examined. Substitution of normal phosphodiester linkages with phosphorothioate linkages resulted in the prominent destabilization of the alternate-stranded triplex. Meanwhile, the introduction of cationic molecule or intercalative molecule at certain positions of the modified DNA was effective to increase the stability of the triplexes.