VITAMINS

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In this review, the transformation of vitamin B_6,the formation of pyridoxine glucoside, and the extracellular formation of vitamin B_6 in microorganisms are described. Pyridoxine (PIN) was oxidized to pyridoxal (PAL) by baker's yeast in the presence of semicarbazide. The yield of PAL semicarbozone formed from PIN was about 80%. A new phosphorylating reaction of vitamin B_6 which phosphorylated PIN through the transfer of a phosphoryl group from ρ-nitrophenylphosphate and other phosphate donors was found in various kinds of microorganisms. The enzyme catalyzing the transphosphorylation was purified to a crystalline from the cell extract of Escherichia freundii. It was recognized that the transphosphorylation might be catalyzed by the acid phosphatase. Pyridoxine phosphate (PINP) oxidase was purified from Alkaligenes faecalis and Azotobacter agilis and it was confirmed that PINP and pyridoxamine phosphate (PAMP) were oxidized to pyridoxal phosphate (PALP) by the same enzyme, requiring FMN as a coenzyme. It was suggested that the PINP oxidase might be used in the industrial production of PALP from PINP in the presence of some amino acids forming Schiff's compound of PALP. In some anaerobic bacteria, it was found that a new enzyme, PAMP-α-KGA aminotransferase, catalyzed the transamination between PAMP and α-KGA. The enzyme was purified from Clostridium kainantoi. Different enzyme systems in aerobic and anaerobic bacteria were suggested with regard to the formation of PALP. The formation of pyridoxine glucoside (PING) was found in the culture broth of Sarcina and Micrococcus, grown on medium containing sucrose and PIN. The enzyme which catalyzed the transglucosidation to form PING was purified from Micrococcus sp. and characterized. The extracellular formation of vitamin B_6 was searched in marine and terrestrial microorganisms. Marine microorganisms showed considerable formation of vitamin B_6 and the presence of vitamin B_6 in sea water was recognized.

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Since the previous reports from this laboratory suggest the possibility of clinical application of massive doses of myoinositol, the effect of massive doses of myoinositol on the liver and kidney of rat was studied morphologically. Male albino rats weighing about 100 g were injected with 3.0 g of myoinositol per kg body weight per day for 30 days. No appreciable change was detected in these organs by light microscopic observation. The same result was obtained when myoinositol was administered per os. These conclusions were also good in the cases of female rats.

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It was investigated using a flavinogenic and a non-flavinogenic strains of E. ashbyii whether the addition of caffeine into the non-growing cell medium brought about the accumulation of some compounds or not. The addition of glucose remarkably stimulated riboflavin production in the flavinogenic strain but the addition of caffeine restricted riboflavin production as described in the previous paper^<7)>. On the other hand, the marked effects of glucose or caffeine as found in the flavinogenic strain were not observed in the non-flavinogenic strain. The addition of caffeine in the absence of glucose resulted in the accumulation of unknown compound in mycelia of flavinogenic strain. But, there were no accumulations in the non-flavinogenic strain. This unknown compound was elucidated to be chromatographically single and to consist of adenine, guanine, ribose, phosphorus and glutathione by means of various qualitative and quantitative tests. Furthermore, this compound included adenine and guanine in the equimolar ratio. The role of this compound in the biosynthetic pathway of riboflavin was discussed in relation to the mode of action of glutathione.

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The rats were divided into three diet groups : the vitamin E deficient diet (1), the same diet supplemented with vitamin E (2) and supplemented with the multiple vitamins (3). After kept on these diets for 8 weeks, the animals were exposed to 100% oxygen at one atomosphere for given periods and were grouped into the A, B and C, according to the diet groups (1), (2) and (3), respectively, and the non-exposed rats correspondingly the groups AC, BC and CC. After the exposure to oxygen for 40 hours, a reduction in the sulfhydryl groups on the basis of tissue protein was observed in the sediment fraction of the lungs, in particular most markedly in the group A, rather than in the supernatant fraction. No significant differences were observed between the groups B and C. Electron microscopic studies were performed on the lungs exposed to oxygen for 36 and 48 hours, and it was found that pathological findings such as the alveolar hemorrhage, intra-alveolar exudation, intraseptal edema etc. were most prominent in the group A, and least apparent in the group C, the group B being in the middle. The measurement of thickness of the basement membrane between the alveolar epithelial cells and capillary endothelial cells was also made. The thickness of the basement membrane did not show any significant variation among the groups AC, BC and CC. However, if the thickness of the basement membrane was compared between the exposed and the non-exposed in each group, the basement membrane of the exposed was significantly thinner than that of the non-exposed in the groups A and B, in particular in the group A, while in the group C there was no significant difference in the thickness between the exposed and non-exposed.

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