Intact pyridoxine glucoside showed about 20% of microbiological activity of equivalent mole of pyridoxine for Saccharomyces carlsbergensis 4228 ATCC 9080. The activity was gradually increased accompanied with the prolonged incubation. It seems that pyridoxine glucoside is hydrolyzed to pyridoxine and glucose by α-glucosidase of Saccharomyces carlsbergensis 4228 ATCC 9080 and can be bioassayed as pyridoxine. Hydrolysis of pyridoxine glucoside by autoclaving in 0.055 N sulfuric acid yielded pyridoxine quantitatively. Pyridoxine glucoside was found to be as stable as pyridoxine-borate complex against irradiation of ultraviolet light and heating, while pyridoxine was less stable.

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The effect of feeding katha to rats at a level of 0.5 per cent of diet on the ‘in vitro’ and ‘in vivo’ biosynthesis of niacin and the niacin requirement of rats was studied.
Katha feeding does not affect the biosynthesis of niacin in rats. However, the minimum daily requirement of niacin of rats fed katha is increased considerably.

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It was found that highly purified crystalline yeast alcohol dehydrogenase (YADH) was still contaminated with a small amount of thiolesterase. Separation of these two enzymes from each other was performed by DEAE-cellulose column chromatography. YADH preparation resulted from this treatment was found to be homogeneous by disc electrophoresis and chromatography on hydroxylapatite column.
Treatment of pure YADH with O, S-diacetylthiamine (DAT) in 0.05M phosphate buffer at pH 6.0 and 30° resulted in 50% inactivation of the enzyme with concomitant loss of two SH groups per mole of the protein. Reaction of the DAT-inactivated YADH with hydroxylamine resulted in full reactivation accompanied by restoration of SH groups to the level of the native enzyme.
These results supply evidence that the change in enzymatic activity that occurs upon treatment of YADH with DAT is the consequence of acetylation of two SH groups essential for activity per molecule of the enzyme.

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It was found that acetyl groups combined with SH groups in yeast alcohol dehydrogenase (YADH) were easily released and transferred to SH group of coenzyme A (CoA) in contrast with acetyl group bound to SH group of glutathione. Stabilization of thiolester bonds in S-acetyl-YADH was observed upon denaturation of the protein in the presence of urea.
These findings appeared to open new approach to a problem about mechanism of storage and supply of active acetyl groups in living cells.

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An analytical method for the determination of vitamin D in the presence of vitamin A and α-tocopherol was investigated. After saponifying preparations, extracting the unsaponifiable matters and dissolving in iso-propanol, the solution was subjected to the column chromatography using Amberlyst A-26 as a strongly basic anion exchange resin. Vitamin A alcohol and vitamin D were eluted with iso-propanol, whereas α-tocopherol was remained in the column. After evaporating solvent from the eluate, the residue was dissolved in chloroform and then treated with gel filtration through a Sephadex LH-20 column to eliminate vitamin A alcohol and α-tocopherol degradation products accompanied with vitamin D. The vitamin A degradation products still accompanied with vitamin D were removed by means of the adsorption chromatography through a Florex XXS column. Then, vitamin D was determined by Nield's antimony trichloride color reaction applying Wilkie's color inhibitor method. When this proposed method was applied to the model preparations made by mixing vitamin D₂, vitamin A palmitate and α-tocopheryl acetate, satisfactory results were obtained. It was also confirmed that this method was available for the determination of vitamin D in pharmaceutical preparations.

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Upon the addition of adenine, the remarkable enhancement of the riboflavinsensitized photoinactivation of yeast
alcohol dehydrogenase [EC 1.1.1.1] was observed, and the inactivation of the enzyme was found to be a first-order reaction. The extent of the enhancement calculated from the apparent rate constants was about five times. An attempt to analyse the action spectra revealed that quantum efficiency increased approximately three times. Adenine had no effect on the photodynamic inactivation of the enzyme in the case where methylene blue, eosin yellowish or fluorescein was used as a sensitizer in place of riboflavin. The ability of adenine to enhance the inactivation was exhibited only when flavin, such as riboflavin, FMN or FAD, was employed as a sensitizer. The accelerative effect similar to that of adenine was also observed with several purine derivatives such as guanine. Of the amino acids susceptible to the riboflavin-sensitized photooxidation, only cysteine was photooxidized increasingly by the addition of adenine.
The mechanism through which adenine causes the enhancement of the riboflavin-sensitized photoinactivation of the enzyme is discussed in correlation with the ability of adenine to form a molecular complex with riboflavin.

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The new simple technique for determination of administered labeled thiamine in biological materials was described.
Outline of this method is based on the thiamine determination procedure of Fujiwara and Matsui. Tissue samples containing labeled thiamine were extracted with H₂SO₄, protein was precipitated and removed. The extract was adsorbed on Permutit column and labeled thiamine was eluted using hot KCI in 0.1 N HCI. To the eluate, cyanogen bromide in sodium hydroxide was added, the resulting labeled thiochrome was extracted into n-butanol.
In case of determination using the gas flow counter the butanol layer was transferred into a counting dish, dried under an infrared lamp and counted. When determining by liquid scintillation the butanol was added directly to the counting solution in the vial.
This method is simple, rapid and accurate. Moreover, it is possible to determine differentially free and esterified labeled thiamine.

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The incorporation of ³H-myoinositol into the phospholipid fraction of the normal and dietary fatty livers of rats was compared. ³H-Myoinositol was found only in phosphatidyl-inositol. The rate of incorporation of ³H-myoinositol into phosphatidyl-inositol of the fatty livers was higher than into the normal livers. This observation supports the view that the administered myoinositol promotes the synthesis of phosphatidyl-inositol which appears to increase the synthesis and secretion of β-lipoprotein of the liver, thus explaining the lipotropic action of myoinositol.

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