Subcellular fractions were obtained from the liver, kidney, heart and femoral muscles, and the small intestinal mucosa of mice according to Strittmatter et al. and the distribution of NADH-diaphorase activity and the specific activity of the enzyme were examined.
1. The method was suitable for fractionating the liver and kidney tissues, but the microsomal fractions of the heart and femoral muscles and small intestinal mucosa were contaminated with mitochondria.
2. Distribution of the NADH-diaphorase activity in the subcellular fractions was corrected for the contamination of mitochondria. It was found that the liver, kidney, and small intestinal mucosa contained the enzyme activity both in mitochondria and microsomes whereas the heart and femoral muscles contained mainly in mitochondria.
3. In the liver, kidney, heart and femoral muscle, the specific activity of the NADH-diaphorase was higher in mitochondria than in microsomes, whereas it was higher in microsomes than in mitochondria in the small intestinal mucosa.
4. The NADH-diaphorase activity in small intestinal mucosa was as a whole lower than that in liver and kidney, but relatively higher in microsomes than in mitochondria. It was taken as a favorable support of the assumption of the authors that the NADH-diaphorase activity of microsomes was involved in cell proliferation.

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1. Microbiological assay of pantethine was investigated, using Lactobacillus bulgaricus B₁. Although the bacillus responds to pantothenic acid with about 1/25 sensibility, the pantethine level may be determined by substructing the pantothenic acid value obtained by Lactobacillus fermenti ATCC 9338.
2. Pantethine was never recognized in the urine of normal adults.
3. Pantethine was neither eliminated in the urine when pantothenic acid had been given intramusculary in healthy adults. Urinary elimination of pantethine was very low even when pantethine had been loaded. The sum of pantethine and pantothenic acid in the urine was only about one half of the case of pantothenic acid loading.
4. It is assumed that pantethine has higher reabsorbability in uriniferous tubules and higher tissue affinity than pantothenic acid.

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1. Cell-free extracts of Brassica pekinensis Rupr (Hakusai) catalyzed the formation of dihydropteroic acid from guanosine compounds and p-aminobenzoic acid. This reaction required ATP, Mg²⁺ and phosphate.
2. GTP and GDP were more active in dihydropteroic acid synthesis than GMP and guanosine. When GTP was used as substrate, the synthesis was absolutely dependent on ATP and Mg²⁺.
3. 2-Amino-4-hydroxy-6-(D-erythro-1′, 2′, 3′-trihydroxypropyl) dihydropteridine was the most active as a pteridine donor for the formation of dihydropteroic acid. This enzyme reaction needed ATP and Mg²⁺. The L-erythro, D-threo and L-threo isomers of 2-amino-4-hydroxy-6-(D-erythro-trihydroxypropyl) dihydropteridine, 2-amino-4-hydroxy-6-(L-arabo-1′, 2′, 3′-trihydroxy-4′-deoxybutyl) dihydropteridine, 2-amino-4-hydroxy-6-(D-arabo-1′, 2′, 3′, 4′-tetrahydroxybutyl) dihydropteridine and 2-amino-4-hydroxy-6-(D-lyxo-1′, 2′, 3′, 4′-tetrahydroxybutyl) dihydropteridine were tested in the ability of enzymatic transformation to dihydropteroic acid.
4. 2-Amino-4-hydroxy-6-(D-erythro-1′, 2′, 3′-trihydroxypropyl) dihydropteridine seemed to convert to 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine without ATP and Mg²⁺.
5. 2-Amino-4-hydroxydihydropteridine and 2, 4, 5-triamino-6-hydroxypyrimidine were not involved in the synthesis of dihydropteroic acid.
6. 2-Amino-4-hydroxy-6-hydroxymethyldihydropteridine pyrophosphate could be converted into dihydropteroic acid only in the presence of Mg²⁺. The monophosphate ester was not utilized in the conversion.

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Based on inhibition tests of yeast alcohol dehydrogenase and nuclear magnetic resonance studies, the 7, 8-dihydro structure of 2-amino-4-hydroxy-6-substituted-pteridines was shown to be the one prepared by reduction with hydrosulfite.

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Reduction of glyoxylate by lactate dehydrogenase was confirmed through the demonstration of the formation of reaction products, mode of inhibition by trypsin and urea, and the mode of distribution among different organs. In crystalline lactate dehydrogenase, the difference in Km and pH was clearly demonstrated between glyoxylate and pyruvate.

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In order to reevaluate the effects of thiamine and its derivatives in large dosis on heart muscle, the following experiments on the isolated toad heart were performed.
1. Using Yagi's apparatus of recycling, the action on the contractile power was observed. It was confirmed that thiamine-HCl, thiamine propyl disulfide (TPD), thiamine tetrahydrofurfuryl disulfide (TTFD), thiamine disulfide and oxythiamine increased the contractile power. Especially, in the concentration of 1.4mM, the action of TPD and TTFD was so pronounced that approximately doubled values of the contractile deflection, cardiac output and aortic pressure were recorded. However, thiamine diphosphate showed no action during the period of time tested. Thiaminic acid showed even the inhibitory action.
2. In the concentration of 1.4mM, TPD caused the prolongation of latent period and repolarization phase of transmembrane action potential.
3. The oxygen consumption of recycling toad heart was measured manometrically with a modified Warburg chamber. When the contractile power increased on the administration of TPD, the cardiac efficiency did not diminish in spite of the increase of oxygen consumption.

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Various O-acyl thiamine disulfides were parenterally given in rabbits, the retentivity in the blood was compared, and the following findings were obtained.
1. The proximate elimination rate constant and the biological half-life were calculated by treating reaction-kinetically the decreasing process of the blood total thiamine level to estimate the retentivity of each compound in the body by exact numerical values.
2. It was clarified that the retentivity obtained by this procedure had a correlation with the uptake by erythrocytes, determined in vitro.
3. Among the derivatives examined, O-butyrylthiamine disulfide was proved to be of value as a new thiamine derivative, in respect to the maintenance of the high blood level, stability, solubility and safty.

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Thiochrome, its mono- and diphosphate were synthesized and their physicochemical properties such as paper chromatography, ultraviolet absorption, infrared absorption and fluorescnce spectra were investigated. It was found that the ultraviolet absorption and fluorescence maxima of these compounds were shifted to longer wavelengths with decreasing pH values. In alkaline solutions, the ultraviolet absorption and fluorescence maxima are located at 370 and 450 mμ, respectively. It is of interest to note that the phosphorylation induces no changes in the absorption and the appearance of emission spectra but induces an appreciable decrease in the fluorescence intensity. The ratio of the fluorescence intensity, thiochrome: thiochrome monophosphate: thiochrome diphosphate, is 10:8:9 in the alkaline solution (pH 9 to 12).
The concentration of thiamine, thiamine monophosphate, and thiamine diphosphate were determined fluorometrically without dephosphorylation. A reasonable results was obtained when cyanogen bromide was used as an oxidizing agent, whereas an unreasonable result was obtained when potassium ferricyanide was used because of its quenching effect.

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1. The main part of “nothing” dehydrogenase in liver, heart, kidney of man, rat and rabbit is placed by lactate dehydrogenase as pointed out by Barnett.
2. In the liver of man and rabbit alcohol dehydrogenase also appears to be partially responsible.
3. In the zymogram without phenazine methosulphate, participation of lactate dehydrogenase, reduced NAD dehydrogenase, and pyridine nucleotide transhydrogenase is also suggested.
4. Appearance of “nothing” dehydrogenase in the serum following experimental liver damage in rats was found.

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1. A reaction of β-lipoic acid with acetic anhydride under mild conditions yielded an unknown product which liberated acetic acid by hydrolysis with NaOH. The product showed almost the same microbiological activity for Streptococcus faecalis 10 C1 and Corynebacterium bovis as α-lipoic acid and β-lipoic acid.
2. The results of ultraviolet and infrared spectrophotometry and other tests confirmed the identity of the acetylated product with an acetoxy derivative of α-lipoic acid.
3. Deuterium exchange studies revealed the possibility of a proton attracted to the carbon adjacent to the sulfoxide group in β-lipoic acid. A possible steric hindrance caused by the bulky side chain suggests that the acetylated product is 8-C-acetoxy-lipoic acid, the formation mechanism of which is thought to be analogous to that of the Pummerer reaction.
4. Associated with the competitive inhibitory effect of 8-C-methyllipoic acid, the results obtained in this experiment would suggest the possible reactivity at carbon 8 of β-lipoic acid which may play an unknown interesting role in biological systems.

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1. There were little differences between BP 1960 and BP 1963 methods on the values of the all-trans vitamin A acetate solution.
2. The values of the mixed sample solutions containing both pure all-trans vitamin A acetate and pure neovitamin A acetate estimated by BP 1963 method were a little higher than those by BP 1960 method, the latters being closer to the calculated biological potencies.
3. The values of vitamin A oil standard containing all-trans vitamin A only estimated by JP VII revised method and USP XVI method were 1 to 1.5% lower than those by BP 1960 and BP 1963 methods because of the loss of vitamin A in the preparation of unsaponifiable matters.
4. The values of the samples containing all-trans vitamin A and neovitamin A (oleovitamin A and fish liver oils) estimated by BP 1963 method were 1 to 4% higher than those by JP VII revised method, USP XVI and BP 1960 methods. This might be due to the influence of neovitamin A.
5. According to the results of this and the previous reports, it may be concluded that JP VII revised method is the most desirable one for the determination of all-trans vitamin A and of a mixture of all-trans vitamin A and neovitamin A, followed by USP XVI and BP 1960 methods.

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From the comparison of the values of twenty-two long stored samples before and after alumina column chromatography, the following results were obtained.
1. Nine samples (two vitamin preparations and seven fish liver oils) were decided to be in need of purification by chromatography.
2. However, the increase in vitamin A value was very small. When these observations and the complicated procedure of alumina column chromatography were considered, it might be concluded that the application of chromatography was not always necessary for vitamin A determination of these samples.
3. The Brunius regulation might be available to decide the necessity of chromatographic purification.

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