M. Maeno et al., FEEDING EXPERIMENTS OF PYRIDOXINE DERIVATIVES AS VITAMIN-B-6, International journal for vitamin and nutrition research, 67(6), 1997, pp. 444-449
In order to compare the nutritional effect of vitamin B-6 derivatives,
long-term feeding experiments with rats were carried out using pyrido
xine-alpha-D-glucoside (PN-alpha-Glc), pyridoxine-beta-D-glucoside (PN
-beta-Glc) or epsilon- (N-phosphopyridoxyl)lysine (PNP-Lys) with test
diets consisting of basically the AIN-76 composition, except for the a
ddition of 0.1 mg pyridoxine equivalent (PN eq.)/100 g diet. During 21
days of pair-feeding against the vitamin B-6-deficient diet group, bo
dy weight gain, urinary excretion of xanthurenic acid and pyridoxic ac
id were measured. After the feeding experiment, rats were killed and e
xamined in terms of liver kynureninase activity (EC 3.7.1.3) with and
without adding exogenous pyridoxal 5'-phosphate (PLP), erythrocyte asp
artate aminotransferase activity (EC 2.6.1.1), as well as PLP concentr
ation in blood. Rats fed with PN-alpha-Glc grew well, relative to the
PN group. On the contrary, PN-beta-Glc poorly served as vitamin B-6 so
urce, because average bioavailability was only about 22% in comparison
to that of PN (100%). From this long-term feeding experiment, we have
shown that PN-alpha-Glc (average bioavailability about 84%) is a good
source of vitamin B-6 similar to PN.