H. Tsuge et al., COMPARATIVE-STUDY OF PYRIDOXINE-ALPHA,BETA-GLUCOSIDES, AND PHOSPHOPYRIDOXYL-LYSINE AS A VITAMIN-B-6 NUTRIENT, Journal of nutritional science and vitaminology, 42(5), 1996, pp. 377-386
The nutritional effects of pyridoxine-alpha-glucoside (PN-alpha-Glc),
pyridoxine-5'beta-glucoside (PN-5'beta-Glc) and epsilon-N-(phosphopyri
doxyl)-lysine (PNP-Lys) were examined by means of: 1) transport across
the intestinal wall using everted rat intestine, 2) metabolic convers
ion by liver or kidney homogenate, and 3) oral administration of the c
ompound to B-6-deficient rats and the subsequent analysis of B-6 deriv
atives found in plasma. Using everted sacs prepared from rat small int
estine, PN-alpha-Glc was transported into the serosal side in its inta
ct form. On the other hand, a part of PN-5'beta-Glc was found as PN on
the serosal side (PN-5'beta-Glc: PN=2:1). When PN-alpha-Glc, PN-5'bet
a-Glc or PNP-Lys was incubated with liver or kidney homogenate for 3 h
at pH 6.0, PN-alpha-Glc was hydrolyzed to PN (6%), while there was no
hydrolysis of PN-5'beta-Glc. After 30 min of administration of each B
-6 derivative to B-6-deficient rats, blood was collected from the hear
t, and the B-6-derivatives found in plasma were analyzed. It was ascer
tained that PN-alpha-Glc served as well as PN as a B-6 nutrient, while
PN-5'beta-Glc and PNP-Lys were not easily metabolized to the coenzyme
form, pyridoxal 5'-phosphate.