Substrate specificity of maize β-glucosidase

The effect of germination on the free and glycosylated B6 vitamers (pyridoxine, pyridoxal, pyridoxamine and glycosylated pyridoxine), thiamin and riboflavin content in pea seed (Pisum sativum L, var Esla) was investigated. In raw peas, the total vitamin B6 content (sum of all vitamers expressed as pyridoxine) was 2.183 mg kg−1 DM. Pyridoxine was found to be the predominant B6 vitamer, while only a little amount of glycosylated pyridoxine, the vitamer with the lowest boiavailability, was observed. Thiamin and riboflavin content in raw peas was found to be 7.614 and 2.110 mg kg −1 DM, respectively. After 6 days of germination, carried out at 20°C, in the dark and with daily rinsing, a significant increase of the total vitamin B6 content, mainly due to the increase of glycosylated pyridoxine, was observed. The content of pyridoxal and riboflavin increased in peas 7.5 and 2 times, respectively, whereas pyridoxine, pyridoxamine and thiamin decreased by 83, 24 and 25%, respectively, at the end of the experiment. Results obtained for these vitamins during pea germination were fitted to modelling curves in order to predict vitamin content for different germination periods.



© 1999 Society of Chemical Industry

Kinetics of free and glycosylated B6 vitamers, thiamin and riboflavin during germination of pea seeds

Disclosed is a compound represented by the following general formula (I): (I) (wherein R1 represent a glycosyl group, a phosphoric acid group , or a cyclic phosphoric acid group bonded with R2; R2 represents -CH2OH, -CHO, -CH2NH2, -CH2-amino acid residue or -CH2-OPO2H; and R3 represents a hydrogen atom or -PO3H2) or a salt thereof. Also disclosed is a composition for cosmetics, drugs, foods and/or animal feed which contains such a compound or a salt thereof.

Stable vitamin b6 derivative

Publisher Summary This chapter examines the biological synthesis based on the germination of peas and alfalfa for preparation of pyridoxine 5'- β -D-glucoside. The preparative methods discussed involve biological syntheses using germinating alfalfa seeds. These methods are advantageous in comparison to other potential methods of biosynthesis or chemical synthesis in terms of simplicity, convenience, and suitability for the preparation of nonlabeled, tritiated, and deuterated forms of pyridoxine 5'- β -D-glucoside. These synthetic methods and purifications provide various forms of pyridoxine 5'- β -D-glucoside in high purity and sufficient quantity for use in nutritional and biochemical studies. The partial availability of pyridoxine 5'- β -D-glucoside as a source of vitamin B 6 for mammals provides evidence of the existence of enzyme activity capable of hydrolyzing the β -glycosidic bond. Supernatant fractions of mammalian jejunal mucosa exhibit the ability to hydrolyze pyridoxine 5'- β -D-glucoside. In rats, jejunal pyridoxine-5'- β -D-glucoside hydrolase activity increases during vitamin B 6 deficiency. The microflora of rat jejunum also exhibits pyridoxine-5'- β -D-glucoside hydrolase activity, although this decreases during vitamin B 6 deficiency.

Preparation of nonlabeled, tritiated, and deuterated pyridoxine 5'-beta-D-glucoside and assay of pyridoxine-5'-beta-D-glucoside hydrolase.

A new derivative of pyridoxine was formed from PN in seedlings of podded pea, Pisum sativum L. cv. Kinusaya, together with 5'-O-(beta-D-glucopyranosyl)pyridoxine and 5'-O-[6-O-(3-hydroxy-3-methyl-4-carboxybutanoyl)-beta-D-glucopyran osyl] pyridoxine. The compound was isolated and identified as 5'-O-(6-O-malonyl-beta-D-glucopyranosyl)pyridoxine.

Isolation and structure of a minor metabolite of pyridoxine in seedlings of Pisum sativum L.

A particulate glucosyltransferase catalyzing the formation of 5'-O-(beta D glucopyranosyl)pyridoxine from pyridoxine: The occurrence in the seedlings of Pisum sativum L.

Mahomi Nakamura

Papers

A particulate glucosyltransferase catalyzing the formation of 5'-O-(beta D glucopyranosyl)pyridoxine from pyridoxine: The occurrence in the seedlings of Pisum sativum L.