Joseph T, Tsuge H, Suzuki Y, McCormick D B
Department of Biochemistry, Emory University, Atlanta, GA 30322-3050, USA.
J Nutr. 1996 Nov;126(11):2899-903. doi: 10.1093/jn/126.11.2899.
Uptake and metabolism of pyridoxine-4'-alpha-D-glucoside and pyridoxine-5'-alpha-D-glucoside by freshly isolated rat liver cells were studied using the membrane filtration method. The presence of the pyridoxine-alpha-glucosides at either 0.5 or 5.0 micromol/L had no inhibitory effect on the uptake of pyridoxine (0.5 micromol/L) by hepatocytes. The amount of pyridoxine-alpha-glucoside transported into the cells was only 10-12% of that of pyridoxine. The initial rates of uptake of the pyridoxine-alpha-glucosides were linear with concentrations up to 50 micromol/L. On entry into the cells, 78% of pyridoxine-5'-alpha-glucoside and 15% of the pyridoxine-4'-alpha-glucoside were hydrolyzed at the end of 60 min. Because pyridoxine-5'-alpha-glucoside is hydrolyzed readily and does not interfere with the transport of pyridoxine, the glucoside, if present in animal- or plant-derived foods, may be available as a source of vitamin B-6.