Isolation and structural elucidation of three new pyridoxine-glycosides in rice bran.

Publisher Website
Google Scholar
Abstract
Three new pyridoxine-glycosides were isolated from rice bran (10 kg) as colorless powder by various chromatographic techniques: compound A, 53 mg; compound B, 7.8 mg; compound C, 5.8 mg. Compound A was shown to consist of pyridoxine and glucose in a 1:2 molar ratio by .beta.-glucosidase hydrolysis, and by 1H-NMR and secondary ion mass spectrometry (SI-MS) data. On partial acid hydrolysis of the compound, cellobiose was liberated. Compound A showed the positive Gibbs color reaction, but the reaction was negative in the presence of boric acid. Thus, compound A was identified as 5''-O-(.beta.-cellobiosyl)pyridoxine. The 13C-NMR spectral data were compatible with this structure. Compounds B and C were proven to be triglucosides of pyridoxine by enzymic hydrolysis and SI-MS data. From the results of the Gibbs color reaction and partial hydrolyses which yielded compound A, compound B was concluded to be 4''-O-(.beta.-D-glucosyl)-5''-O-(.beta.-cellobiosyl)pyridoxine, and compound C to be 5''-O-(.beta.-glucotriosyl)pyridoxine in which a glucose molecule was bound to the cellobiosyl moiety of compound A through .beta.-glycosidic linkage.

This publication has 2 references indexed in Scilit: