抄録
One of the bound forms of vitamin B6 occurring in rice bran was isolated in a faintly yellowish syrup by repeating ion-exchange and paper-partition chromatographic techniques. The behaviors of the isolate on thin-layer and Aminex A-5 column chromatograms were coincident with those of synthetic pyridoxine-β-D-glucoside which was obtained by Königs-Knorr condensation of α4, 3-O-isopropylidene pyridoxine and 2, 3, 4, 6-tetra-O-acetyl-α-D-glucopyranosyl bromide. On acid hydrolysis, the isolate gave pyridoxine and glucose. Glucose was proved to bind to the 5-hydroxymethyl group of pyridoxine, because the isolate did not react with 2, 6-dichloroquinone chlorimide in the presence of boric acid. An equimolar amount of pyridoxine and D-glucose was produced with an equivalent consumption of the isolate by the action of β-glucosidase. No essential difference between the isolated and synthetic preparations could be detected in UV- and NMR-spectral features. Thus, the chemical structure of the isolate was identified as 5'-O-(β-D-glucopyranosyl) pyridoxine.
