β-Glucosidase Catalyzed Syntheses of Pyridoxine Glycosides
作者:Rajachristu Einstein CHARLES、Soundar DIVAKAR
DOI:10.1271/bbb.80463
日期:2009.1.23
Enzymatic syntheses of pyridoxine glycosides were carried out in di-isopropyl ether organic medium using β-glucosidase isolated from sweet almond. Optimum conditions determined for the reaction with d-glucose were 40% (w/w d-glucose) β-glucosidase at 0.18 mm (1.8 ml) of pH 5 acetate buffer over a 72 h incubation period. Of 11 carbohydrates employed, β-glucosidase gave 7-O-(α-d-glucopyranosyl)pyridoxine 5a, 7-O-(β-d-glucopyranosyl)pyridoxine 5b, 6-O-(α-d-glucopyranosyl)pyridoxine 5c, 7-O-(α-d-galactopyranosyl)pyridoxine 6a, 7-O-(β-d-galactopyranosyl)pyridoxine 6b, 6-O-(α-d-galactopyranosyl)pyridoxine 6c, 7-O-(α-d-mannopyranosyl)pyridoxine 7a, 7-O-(β-d-mannopyranosyl)pyridoxine 7b, and 6-O-(α-d-mannopyranosyl)pyridoxine 7c in yields ranging from 23 to 40%.
Regioselective Glucosylation of Pyridoxine by Microorganisms
作者:Yasuhisa ASANO、Koichi WADA
DOI:10.1271/bbb.67.499
日期:2003.1
Microorganisms from culture collections and isolates from nature were screened for the ability to catalyze the regioselective glucosylation of pyridoxine (PN) to produce pyridoxine 5′-α-D-glucoside (PN-5′-α-G) or pyridoxine 4′-α-D-glucoside (PN-4′-α-G). Transglucosylation activity specific to 5′-position of PN was found in fungi belonging to genera such as Coriolus and Verticillium, and activity at the 4′-position of PN was found in bacteria belonging to genera such as Bacillus and Serratia. From 100 mM PN, intact cells of Verticillium dahliae TPU 4900 produced 42 mM (13.9 mg/mL) PN-5′-α-G after 70 h of reaction. Intact cells of Bacillus cereus TPU 5504 produced 33 mM (10.9 mg/mL) PN-4′-α-G after 19 h of reaction. The selectivities for 5′- and 4′-positions were 80% and 90%, respectively.