Three new pyridoxine-glycosides were isolated from rice bran (10kg) as colorless powder by various chromatographic techniques: compound A, 53mg; compound B, 7.8mg; compound C, 5.8mg. Compound A was shown to consist of pyridoxine and glucose in a 1:2 molar ratio by β-glucosidase hydrolysis, and by 1H-NMR and secondaryion 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-(β-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-(β-D-glucosyl)-5'-0-(β-cellobiosyl) pyridoxine, and compound C to be 5'-O-(β-glucotriosyl) pyridoxine in which a glucose molecule was bound to the cellobiosyl moiety of compound A through β-glycosidic linkage.
The absorption of pyridoxine from the intestine of the mouse was studied in whole animals. [3H] Pyridoxine was orally adminis-tered and the distribution of isotope between the six recognized forms of vitamin B6 was determined in portal and peripheral blood after the administration. When small doses (1.4 or 14 nmol) were administered, labeled pyridoxine could hardly be found in the portal blood as well as in the peripheral blood, although labeled pyridoxal and pyridoxal phosphate were found both in the portal and peripheral blood. However, when a large amount (46 or 140 nmol) was given, a significant amount of labeled pyridoxine was found with labeled pyridoxal and pyridoxal phosphate both in the portal and peripheral blood. These results suggest that a physiological dose of pyridoxine is transformed to pyridoxal in the intestinal tissues and then is released in the form of pyridoxal into the portal blood.
Either α-tocopherol (vitamin E) or one of its model com-pounds having side chains of different length at the 2-position of α-to-copherol, forms complexes with an unsaturated fatty acid in methanol. For complex formation, the isoprenoid side chain and hydroxy group of α-tocopherol are unessential and, rather, the methyl groups attached to the aromatic ring of the chromanol moiety seems to be responsible. For better interaction, more than three methylene-interrupted Z double bonds of a fatty acid are necessary. These findings are incompatible with the hy-pothesis of Diplock and Lucy (l) on the interaction of vitamin E with each polyunsaturated fatty acid.
We estimated the utilization of calcium in spinach and calcium-oxalate to calcium-deficient rats, and the effect of oxalic acid on absorption of dietary calcium by using calcium-deficient rats. The body weight gain of the calcium-deficient rats for 8 days receiving a calcium-deficient diet supplemented with raw-powdered spinach (R-sp), boiled-powdered spinach (B-sp), or calcium-oxalate (Ca-ox), and a control diet supplemented with oxalic acid (OX-C) were 4.8, 2.8, 4.9, and 5.1g, respectively. The calcium content in the liver and kidney of the rats receiving R-sp, B-sp, Ca-ox, and OX-C diets significantly increased as compared with the calcium-deficient rats. Significant differences in the liver calcium levels were not observed among the rats receiving various additional diets, though the content in the kidneys of the rats receiving R-sp, B-sp, Ca-ox, and OX-C diets were 28.0, 21.5, 0.11, and 0.59mg, respectively. An especially large amount of calcium was accumulated in the kidneys of the rats receiving R-sp and B-sp diets. The calcium concentration in the serum of the rats receiving Ca-ox and OX-C diets was higher than the calcium concentration in the serum of the R-sp, B-sp, and calcium-deficient rats. The calcium content in the left tibiae of the rats receiving Ca-ox and OX-C diets was higher than that of the rats receiving R-sp and B-sp diets. The breaking force of the right tibiae of the rats was highest in the OX-C group, and higher in the R-sp and Ca-ox groups than the breaking force of the right tibiae of the rats fed on B-sp diet. The alkaline phosphatase activity in the small intestines of the rats rose in the order of the R-sp, B-sp, and Ca-ox groups, although significant differences of the activity were not observed between the Ca-ox and the OX-C groups. The calcium retention of the rats receiving the calcium-deficient, R-sp, B-sp, Ca-ox, and OX-C diets was -18.5, 35.2, 25.6, 41.6, and 45.8%, respectively. About 35% of the calcium in the spinach was absorbed by the calcium-deficient rats, and oxalic acid depressed the calcium absorption in the rats.
Twenty-five healthy female college students were studied for the gustatory function tests for salt (NaCI) and some selected biochemical parameters including plasma retinol and plasma retinol-binding protein (PRBP). Plasma zinc (PZn) and retinol levels were comparable with those of good responders in tests of discrimination between two levels of NaCl in the previous report, but PRBP was lower in the present subjects. From the results of correlation analysis and stepwise multiple regression ana-lysis, the individual students' discriminability of NaCI concentrations was related to the parameters regarding metabolic status of calcium (Ca), magnesium (Mg), sodium (Na), and selenium (Se). The detection thresh-old of NaCI concentration ranged from 1 to 60mmol/liter and was related to PRBP. Plasma Zn was significantly positively correlated with both plasma retinol and PRBP, but significantly negatively correlated only for the detection threshold of NaCI concentration. On the basis of these results, the importance of vitamin-A nutrition and the relation of minerals such as Na, Ca, Mg, and Zn to the gustatory functions of NaCI was confirmed and a possible participation of Se to the functions was suggested.
β-Alanine-oxoglutarate aminotransferase (β-Ala-T I) was found to be distributed mainly in liver, brain, kidney, and testis (decreas-ing order of enzyme activity in the rat). D-3-Aminoisobutyrate aminotrans-ferase (β-Ala-T II) was distributed in kidney and liver. Both β-AIa-TI and β-Ala-T II were localized in the mitochondrial fraction in rat kidney. β-Ala-TI in the liver of rats fed on pyridoxine-deficient or control diets was induced by injecting with prednisolone, while β-Ala-T II in the liver of these rats was unaffected by prednisolone injection. The activities of β-Ala-TI and β-AIa-T II in the liver of rats fed on pyridoxine deficient diet did not change. However, in kidney, pyridoxine deficiency suppressed both enzyme activities, while treatment with prednisolone did not induce either enzyme. The ratios of the apo- to holo-enzyme for β-AIa-TI and β-Ala-T II in control rat kidney were 1.04 and 0.11, respectively. The values increased to 2.69 and 1.53, respectively, in pyridoxine-deficient rat kidney. These experiments indicate that pyridoxine deficiency and prednisolone affect the activities of β-alanine degrading enzymes, but that the degree is different between liver and kidney.
Male young rats were fed 8% corn oil diets supplemented either with 2% phosphatidylinositol (PI) from safflower seeds or soybean lecithin (SL) for 22 days. Other groups of rats were fed 10% corn oil diets with or without (control) 0.3% inositol (IN, equivalent to the inositol moiety of the PI diet). The plasma cholesterol level was low in the SL group whereas liver triglyceride was low in all supplemented groups. The aortic production of prostacyclin tended to be high in rats fed the control diet and low in rats fed the SL diet, the PI and IN groups being intermediate. The concentration of plasma thromboxane B2 was compara-ble among various groups. In plasma and liver phosphatidylcholine, the ratio of arachidonate/linoleate was low in rats fed SL and high in rats fed PI or IN diets. The results indicate that, in addition to SL, the inositol moiety of PI may have a significant role in the regulation of lipid metabolism.
The amino acid requirement has been investigated by many laboratories since 1931. Authors considered that the requirement was influenced by the protein level of the basal diet and also by the experimental method. In light of those earlier studies, the present study investigated the effect on lysine and methionine requirements by modify-ing total nitrogen level or essential amino acid level. The result of our study confirmed that when the amino acid requirement for maximum growth was expressed as the dietary percentage, amino acid to total amino acid ratio, and amino acid to total nitrogen ratio, the requirement had changed according to not only essential amino acids but also to non-essential amino acids. Furthermore, we investigated the relationship between amino acid intake and body protein gain, and found that 6.2mg lysine and 9.0 mg methionine were required for the maintenance of a rat weighing 80g and 71.6mg of lysine and 48.8mg of methionine were required for one gram of body protein gain. The lysine and methionine intakes required for one gram of protein gain were equivalent to 100% and 124% of amino acid contents of body protein, respectively.