Stabilities of dilute solutions of n- and Ψ-TH2 in an alkaline solution and degradation by sulfite were investigated.
1. The stabilities of two isomers upon heating or standing at room temperature showed no difference; they were both unstable in a weakly acidic medium but relatively stable in a neutral medium. However, the n-form becomes labile in an alkaline medium, especially, it was readily degraded by heating, whereas the Ψ-form remained fairly stable upon heating.
2. Dilute solutions (final concentration, 17-33 μM) were quite unstable and the effect of sulfite was scarcely detectable, but at higher concentrations (final concentration, 3.7mM) both n- and Ψ-TH₂ were readily degraded (about 88% decomposed) by sulfite at pH 5.5-7.0 in the presence of 6 eqivalents of sulfite. In more acidic or alkaline solution, the degradation was decreased. Ψ-TH₂ was stable in an alkaline medium, being scarcely affected by sulfite, whereas n-TH₂ had a tendency to be degraded readily in the presence of sulfite.
3. These findings suggest that both n- and Ψ-TH₂ take the same, probably a quarternary form in a dilute aqueous solution, whereas in an alkaline solution, the Ψ-form takes a stable cyclic structure, and n-form is degraded gradually through a dihydro-form of thiamine and its labile thiol form.

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When thiamine derivatives were irradiated by a ultraviolet lamp with a maximum spectral energy at 365 mμ, the symmetric disulfides (thiamine disulfide, O-benzoylthiamine disulfide, O-benzenesulfonylthiamine disulfide, deoxythiamine disulfide, thiamine disulfide-O-methylether) and S-acylated thiamine (diacethylthiamine, O-acetyl-S-benzoylthiamine, O-benzoyl-S-acetylthiamine) were unstable, being remarkably decomposed, whereas the unsymmetric disulfides (thiamine propyl disulfide, thiamine tetrahydrofurfuryl disulfide) were somewhat resistant and S-carbethoxy-B₁, (S-carbethoxythiamine, dicarbethoxythiamine) and S-benzoylthiamine monophosphate were decomposed most slowly. On the other hand, thiamine, deoxythiamine or thiothiamine were hardly or not at all decomposed under the same condition. As a decomposition product of O-benzoylthiamine disulfide, 2-methyl-4-amino-5-aminomethyl pyrimidine was isolated and was identified as its picrate.

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Powdery polymers of vitamin A esters were synthesized by polymerizing acrylic and methacrylic ester of vitamin A under the presence of α, α′-azo-bis-isobutyronitrile as a catalyst at 70° or of n-butyl lithium in hexane at -10 to -20°. The polymer failed to be obtained when phenyl magnesium bromide was used as a catalyst. Crotonic and undecylenic esters of vitamin A were not polymerized by the above methods. Powdery copolymers of vitamin A esters with acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, styrene or 2-vinyl-5-ethyl-pyridine were also synthesized by the same methods.

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1. Thiamine-deficient poults operated to have artificial anus were used, and the thiamine levels in blood and urine of the birds were studied.
2. At first, a control test of determining the radioactivity excretion in the droppings after oral administration of thiamine-S³⁵ or TPD-S³⁵ was carried out in ordinary intact poults. The radioactivity excretion in the droppings was found to be greater in the case of thiamine-S³⁵ than in that of TPD-S³⁵.
3. S³⁵-Radioactivity excretion in the urine and feces after administration of thiamine-S³⁵ in the poults operated to have artificial anus was studied. Greater urinary excretion of the radioactivity was seen in the poults receiving thiamine-S³⁵, whereas it was very poor in the birds receiving TPD-S³⁵. Further, the proportion of the radioactivity excretion in urine and feces was determined. The more the intake of thiamine-S³⁵, the higher the fecal excretion of the radioactivity. In addition, the radioactivity distribution in various tissues was always higher in the poults receiving TPD-S³⁵ than those receiving thiamine-S³⁵.
4. The relative urinary excretion of thiamine-S³⁵ was extremely lower than that of S³⁵.
5. In the control tests for thiamine-S³⁵ excretion in the droppings of the thiamine-deficient poults without operation, total excretion of thiamine was rather low as compared with the radioactivity excreted in the droppings.
6. In the tests for relative thiamine-S³⁵ excretion to the total radioactivity in urine and feces in thiamine-defiicient poults having artificial anus showed that higher urinary excretion of the radioactivity was seen in the birds orally receiving thiamine-S³⁵, whereas the total excretion of thiamine in urine was extremely low in the poults receiving thiamine-S³⁵.
These findings suggest a marked decomposition of thiamine in the digestive tract of poults.

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During the investigations on the synthesis of glucose polymers by micro-organisms, it was found that strains of Leuconostoc mesenteroides produced a large amount of riboflavinylglucoside from sucrose in the presence of riboflavin in their growing cultures and under the same cultural conditions dextran was ascertained to be produced by the bacteria.

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Leuconostoc mesenteroides was found to produce a remarkable amount of riboflavinylglucoside when grown on a sucrose medium containing riboflavin, but not on any other kinds of sugar media. The formation of riboflavinylglucoside was observed to depend largely on the kinds of seed culture and on the temperature of fermentation and also on the concentration of sucrose. Riboflavin compounds of oligosaccharides were observed to be formed by successive transfers of D-glucosyl group of sucrose to riboflavin during the fermentation.

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1. Abnormal excretion of thiamine and riboflavin from the patients with pulmonary tuberculosis was not ascertained in this study.
2. More reduction of urinary thiamine and riboflavin by administration of UDCA was observed after loading the vitamins to the patients than without loading.
3. Administration of UDCA for a long period of time did not improve the liver function of the patients with tuberculosis to absorb the vitamins.
4. Reduction of the amounts of excreted thiamine and riboflavin after administration of UDCA was supposed to be due to the increase of phosphorylation and absorption of both vitamins.

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An attempt was made to elucidate the natural forms of the cobamides synthesized in Propionibacterium shermanii grown in the culture medium containing both a cobinamide-like compound (X factor) and 5, 6-dimethylbenzimidazole as precursors. The cells were homogenized in alcohol and the extract was examined by paper electrophoresis, whereby at least 4 forms of cobamide, including Barker's coenzyme and a protein-bound form were observed.

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When Propionibacterium shermanii is cultured in the presence of OH-form or CN-form of cobinamide-like compound (X factor) together with 5, 6-dimethylbenzi-midaxole or in the presence of OH-B₁₂ or CN-B₁₂ alone, a large quantity of E. coli-active substance accumulated in the cells. In order to know the forms and the amounts of the active substance, an alcoholic extract of the cells was prepared and subjected to paper electrophoresis. The paper was cut into pieces and after extraction of each piece the extract was determined by the tube assay.
At least 4 forms were found to be present. There was no great difference between OH- and CN-form, but the yield was greater after addition of cobamide than after addition of both cobinamide and 5, 6-dimethylbenzimidazole.

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The effects of various nitrogen and carbon sources alone or in combination on the growth of Propionibacterium shermanii were examind for the purpose of enhancing the production of DBCC. It was found that the addition of bonito extract to the Bernhauer medium from which Casamino acid and Tryptose had been omitted, resulted in a 20% increase in bacterial growth. When OH-B₁₂ was added to the improved medium, about 80% of the active substance was found to have been transfered to the cells and moreover, the active substance was found to be mostly 5, 6-dimethylbezimidazolylcobamide coenzyme.

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Thiamine disulfide produced from thiamine in an alkaline medium immediately after adding ferricyanide solution or after allowing to stand for some time was determined by adsorption on and elution from Amberlite IRC-50. The formation was maximal at pH around 11.6, decreasing at other pH levels. Addition of ferricyanide after the solution was left standing for some time in an alkaline medium, resulted in production of less thiochrome and more thiamine disulfide with the lapse of minutes. The oxidation of thiamine with ferricyanide produces both thiochrome and thiamine disulfide simultaneously, but at pH 11 to 12, thiamine disulfide was predominantly produced and the reaction can be used as a practical synthetic method of the disulfide.

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1. 10^-7 M 2-methyl-4-amino-5-hydroxymethylpyrimidine (OMPm) or 2-methyl-4-amino-5-aminomethylpyrimidine (AMPm) together with 4-methyl-5-β-hydroxyethyl-thiazole (MHT) was added to the homogenates of sprouting peas, sprouting beans, clovers, potatoes, onions, scallions and germinating radishes, and the pH was adjusted to 5.0, followed by incubation for 3 hours at 37° and the thiamine production was determined.
In the germinating radishes 0.4-1.6mg thiamine per 10g samples was produced after addition of OMPm and MHT, corresponding to 26-77% increase of thiamine content.
2. Sand culture of germinating radishes after addition of OMPm, AMPm, 2-methyl-4-amino-5-formylpyrimidine (FP) or 2-methyl-4-amino-5-carboxylic acid-pyrimidine (CAP) to MHT showed that OMPm was most effective for producing thiamine, more than twice as much being produced as the controls, followed by FP and AMPm.
3. The same experiment using cysteine or methionine instead of MHT in the presence of OMPm resulted in less production of thiamine than that of MHT. MHT, therefore could not be replaced by cysteine or methionine.
4. Thiamine production in germinating radishes in sand culture was further compared in 4 groups, i.e., addition of OMPm alone, addition of both OMPm and MHT, addition of MHT alone, and without any addition. As for the weight, dry matter, length, and nitrogen content of the sprout, no marked difference was found among the 4 groups, but the amount of thiamine was about 3 times as great in the presence of OMPm and MHT, somewhat greater in the presence of OMPm, and about the same in the presence of MHT as the controls.

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Crystals melting at 172-173° were obtained as the main metabolite of thiamine anhydride in rats, and they agreed with thiamine anhydride sulfoxide in regard to R_F values and elementary analyses.
2-Methyl-4-amino-5-aminomethylpyrimidine was also obtained as a crystalline form, but it remains unsettled whether it is a true metabolite or not.

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Thiamine anhydride sulfoxide (mp 131-132°) and thiamine anhydride sulfone (mp 131°) were obtained as pure crystals by oxidation of thiamine anhydyde with hydrogen peroxide. Both the compounds showed higher melting-points of 177° and 155°, respectively, after careful drying and returned to the former melting range by recrystallization. Both compounds can be distinguished either by infrared spectra or by PbO₂ oxidation. The urinary metabolite of thiamine anhydride, melting at 172-173°, was proved to be thiamine anhydride sulfoxide.

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