The cytoplasmic reduction-oxidation state of some NAD-linked reactions has been investigated in the liver in vivo under normal and diabetic conditions with or without CoQ₇ administration.
1. In the liver, the close relationships among lactate/pyruvate, malate/oxaloacetate and glycerol-1-phosphate/dihydroxyacetone phosphate ratios were found in all the metabolic conditions studied. In diabetic rats, these systems were found to be more reduced.
2. CoQ₇ administration to diabetic rats for four days intramuscularly tended to restore these ratios to normal. This effect was followed by a significant drop in malate concentration.
Present findings would indicate that the effect of CoQ₇ on the reduced state in diabetic rats seems to be mediated via malate removal.

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The administration of a fat free, low protein diet with no B vitamin supplement to albino rats for 3 weeks resulted in marked fatty livers. When these depleted rats suffering from fatty liver were treated with B vitamins for a week, livers were abnormally swelled and their fats and cholesterols were greatly increased. Such a type of fatty liver, however, was partly cured by administering, besides B vitamins, either myoinositol or choline, and almost completely by administering both of them for a week.
A considerable delay was found in the movement of cholesterol from fatty livers to adipose tissues, when compared with that from the livers cured by administration of myoinositol. This may be ascribed to an occurrence of an inhibitory mechanism on cholesterol transport in fatty livers, which is eliminated by the administration of myoinositol.

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Some comments to the earlier reports on the preparations, spectral characteristics, and stabilities of 5, 6- and 5, 8-monoepoxyretinyl acetates were described.
1. The 5, 6-monoepoxide was obtained from the acetate and perphthalic acid, followed by a preparative thin layer chromatography on activated alumina using 10-15% acetone in hexane as a developer and 20% ether in hexane as an eluant.
2. The 5, 6-monoepoxide indicated a distinct fine structure in its UV spectrum at 326, 312, and 298mμ in hexane and its extent was similar to that of β-carotene 5, 6-monoepoxide and less than β-carotene 5, 6, 5′, 6′-diepoxide.
3. The IR spectrum of the 5, 6-monoepoxide showed a medium peak at 9.58μ. From the accumulated data on β-carotene epoxides, this peak was assigned to the 5, 6-epoxy group in the molecules of epoxypolyene hydrocarbons.
4. The 5, 8-monoepoxide showed a degraded structure in its UV spectrum and λ_max was located at 280.5mμ in hexane accompanied by two shoulders at 291.5-292 and 268-270mμ.
5. The 5, 6-monoepoxide was easily transformed to its 5, 8-monoepoxide with CHCI₃-HCI or ethanolic 0.05N HCI. The former epoxide was also decomposed rapidly on irradiation with UV light in the presence of l₂. On the contrary, the 5, 8-epoxide was far stable under the same circumstances.

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The action of thiamine and its derivatives on the contraction of glycerinated muscle fiber was investigated.
Neither TMP, TDP, TTP, DCET nor thiamine-HCI induce the contraction in the absence of ATP.
TDP or TTP, especially TDP, enhance ATP-induced contraction. This enhancing action could not be due to the contaminant calcium but to the change of physicochemical property of contractile protein caused by the binding of thiamine phosphate to it in the same way as ADP.

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The main object of this investigation was an attempt to elucidate the steps and intermediates comprising biosynthetic pathway of dihydropteroic acid in a higher plant, Brassica pekinensis Rupr. The inhibition tests with three types of inhibitors specific to affect the respective different processes were projected for this purpose. The results gained as itemized in the followings offered a powereful support for the suggestion that the pathway originating in GMP might proceed through the three steps blocked by the inhibitors, including as intermediary precursors 2-amino-4-hydroxy-6-(D-erythro-trihydroxypropyl) dihydropteridine, 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine and the pyrophosphate ester of the latter pteridine. The cell-free system of the plant was able to catalyze the formation of dihydropteroic acid not only from GMP but also from these pteridine derivatives. These conversions required ATP, Mg²⁺ and p-aminobenzoic acid, except the case of the pyrophosphate compound that could be immediately transformed to the final product without ATP.
1. When 2-amino-4-hydroxy-6-(D-erythro-trihydroxypropyl) dihydropteridine, 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine and the pyrophosphate ester of the latter pteridine were tested as substrates, the formation of dihydropteroic acid from these pteridines was inhibited by p-aminosalicylic acid, sulfanilic acid and sulfanilamide, These findings suggested that the donors are metabolized to dihydropteroic acid by coupling of the phosphate ester with p-aminobenzoic acid.
2. The existence of 2-amino-4-hydroxy-6-carboxydihydropteridine, 2-amino-4-hydroxydihydropteridine and dihydrobiopterin caused significant inhibition of dihydropteroic acid formation derived from both 2-amino-4-hydroxy-6-(D-erythro-trihydroxypropyl) dihydropteridine and 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine, but not from the pyrophosphorylated derivative of the latter substance. The most powerful inhibition was shown by the carboxydihydropteridine and reversed by increasing the concentration of the hydroxymethyldihydropteridine supplied in the media. These data indicated a possibility that the inhibitors might affect the pyrophosphorylation of the hydroxymethyldihydropteridine by action of ATP and the transformation of the trihydroxypropyldihydropteridine to the final product might involve this step.
3. When 2-amino-4-hydroxy-6-(D-erythro-trihydroxypropyl) dihydropteridine was examined together with one of the corresponding L-erythro, D-threo and L-threo isomers, the yield of dihydropteroic acid was reduced, while no inhibition resulted by the combination of the isomers with either 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine or this pyrophosphorylated pteridine. L-Erythro form was most effective as inhibitor and the inhibition induced by this isomer was partially released by increasing the amount of the D-erythro derivative applied. From these evidence, it was assumed that the isomer could act on the conversion process of the D-erythro compound to the hydroxymethyldihydropteridine.
4. Sulfanilic acid, 2-amino-4-hydroxy-6-carboxydihydropteridine and 2-amino-4-hydroxy-6-(L-erythro-trihydroxypropyl) dihydropteridine blocked the production of dihydropteroic acid from GMP. This finding provides a reasonable basis for an assumption that the pathway of GMP metabolized to the final product might involve the three steps suggested above.
5. The present findings are discussed in relation to other recent works on pteridine biosynthesis.

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1. About 400-fold purification was achieved from the crude heat-treated extract of M. butyricum.
2. The purified enzyme has a broad pH optimum and the Km value for NAD is 1.6×10^-3M. This enzyme is quite insensitive to nicotinamide and isonicotinic acid hydrazide. PCMB shows no effect on the enzyme.
3. M. butyricum NADase cannot catalyze the transfer of isonicotinic acid hydrazide to the adenosine diphosphate ribose moiety of NAD.
4. A molecular weight of the purified enzyme was shown to be about 70, 000, while, for its protein inhibitor, about 20, 000 was obtained by Sephadex G-200 gel filtration.
5. The complex of NADase and its inhibitor was shown by Sephadex G-200 column.

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In the present investigation, the difference in sensitivity to ω-methylpantothenic acid among various species of plants was studied in connection with their patterns of respiratory function, and the following results were obtained.
1. The levels of oxygen consumption of rice plant and Japanese millet (belonging to Panicoideae subfamily) were lower as compared with those of barley (belonging to Festucoideae subfamily) and cucumber (belonging to dicotyledonous plant) in the buffer solution.
2. The addition of ω-methylpantothenic acid brought about the increase of oxygen consumption of all the tested seedlings temporally in the early period such as first 24 hours with treatment of ω-methylpantothenic acid. After 48 hours, however, the consumption began to decrease in two species of barley (Festucoideae subfamily) and cucumber (dicotyledonous plant), which were recognized to be inhibited by this antagonist at this concentration. On the contrary, the former two species showed continuously a resistance to this inhibitory action.
3. The results of 1 and 2 show that the stronger inhibitory action of ω-methylpantothenic acid appears with those species, barley and cucumber, which had high level of oxygen consumption in the germination.
4. From a consideration of present data and Taylor's suggestion that the ability to germinate and grow in very low oxygen concentration depends upon the possession of high functional fermentation system, it seems reasonable to assume that ω-methylpantothenic acid inhibits the oxidative respiration rather than the fermentation on the germination process.
5. The mechanism of the action of ω-methylpantothenic acid upon the germination of higher plant was discussed in connection with their patterns of respiratory function.

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Turnover of thiamine in various organs was investigated by giving TPD-³⁵S (inner) or thiamine-³⁵S by mouth or by subcutaneous injection to white rats and the following results were obtained:
1. The turnover ratio of thiamine in the organs was increased day by day after daily oral administration or subcutaneous injection of TPD-³⁵S (inner) or thiamine-³⁵S.
2. The turnover ratio of thiamine in the organs was distinctly higher after administration of TPD-³⁵S (inner) by either route than in the case of thiamine-³⁵S.
3. No marked difference in the turnover ratio due to difference in the route of administration, oral or subcutaneous, of both TPD and thiamine was noted.

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1. When TPD-³⁵S (inner) or thiamine-³⁵S was given daily to rats, ³⁵S was found in the largest amount in the supernatant fraction, followed by the mitochondrial and nuclear fractions and it was least in the microsome fraction in both liver and heart.
2. It was shown that the uptake of thiamine was prominent in the mitochondrial fraction of heart when TPD-³⁵S (inner) was given daily.
3. It was found that the turnover ratio of thiamine in the mitochondrial, microsomal and supernatant fractions of both liver and heart was obviously higher in the case of TPD-³⁵S (inner) administration than in the case of thiamine-³⁵S administration.

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By spraying ¹⁴C-labeled α-tocopheryl acetate on the surface of the skin, and by conducting microradiographic investigations on the condition of its absorption in seven cases and 14 samples, the following observation have been acquired, and at the same time, some discussion have been made.
1. α-Tocopheryl acetate is absorbed well through the healthy hartless skin.
2. There are two routes of absorption from the surface of the skin to the dermis. The first one leads through the horny layer, the epidermis and the borderline between the epidermis and the dermis. The second one goes through the pilo-sebaceous canal, the interior of hair follicles, inner and outer root sheaths and connective-tissue sheaths. No route through the sebaceous gland and sweat ducts has been detected.
3. The material has proven to have a high affinity for small blood vessels everywhere.
4. Hesitation in the absorption of the material has been observed in line with the lower part of the horny layer, the borderline between the epidermis and dermis, the borderline of inner and outer root sheaths, and the borderline between epidermal and connective-tissue hair follicles.
5. Noticeable observations on the study of microdistribution are as follows:
(a) In a comparatively short period of time, a large quantity of the material has appeared in hair papillae.
(b) Although a large quantity of the material is seen in the sebaceous gland and excretory ducts, it is scarcely detected in the environment of those systems.
(c) The material has not been seen in the sweat gland and sweat ducts. However, a large quantity of the agent has been witnessed in the environment of these systems and also in the blood vessels around them.
(d) Although the agent has not been observed in the fatty cell, it was seen in the fatty intercellular septum in large quantities.

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Cell-free extracts of pea seedlings contain the enzyme system which catalyzes the formation of folate compounds from 2-amino-4-hydroxy-6-substituted pteridines and p-aminobenzoic acid or p-aminobenzoylglutamic acid. Active pteridines were 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine and its pyrophosphate ester, i.e., 2-amino-4-hydroxy-6-pyrophosphorylmethyldihydropteridine, and a considerable amount of folate compound was formed enzymatically from the latter compound in the presence of Mg²⁺ as a cofactor, whereas the less amount was formed from the former in the presence of both ATP and Mg²⁺. The products were characterized, by a bioautographic technique, as dihydropteroic acid and dihydrofolic acid from p-aminobenzoic acid and p-aminobenzoylglutamic acid, respectively, in the presence of pyrophosphorylmethyldihydropteridine. In the enzymatic reaction, p-aminobenzoic acid was more active as substrate than p-aminobenzoylglutamic acid. When p-aminobenzoic acid and L-glutamic acid were used in place of p-aminobenzoic acid in the enzyme system, dihydropteroic acid and dihydrofolic acid were formed in the presence of the pteridine, ATP and Mg²⁺. From these results presented, the following pathway for the biosynthesis of folate compounds in plants was proposed:

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Dihydropteroate-synthesizing enzyme was found in 25 to 45% saturated fraction with ammonium sulfate of the extracts from pea seedlings, and some properties of the enzyme were investigated. The optimum pH for the enzyme activity was found to be 8.5 to 9.0 under the experimental conditions. In the enzyme reaction, Mg²⁺ was the most effective as cofactor, and the effect could partially be replaced by Mn²⁺, whereas divalent heavy metal ions inhibited the enzyme activity. This enzyme was also inhibited by p-chloromercuribenzoate. The Michaelis constant for 2-amino-4-hydroxy-6-pyrophosphorylmethyldihydropteridine was found to be 7.1×10^-5 M. It has been suggested that the enzyme reaction proceeds stoichiometrically as shown in Reaction (a), and the reaction is reversible.

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