The mechanism whereby Escherichia coli K12 accumulates orotic acid in culture fluidwas studied. Pyrimidine compounds were incorporated effectively into cells of E. coli K12, stimulated the growth, and depressed the accumulation; while purine compounds were not so much consumed by the microorganism for its growth, and affected the accumulation to a lesser extent. On the other hand, E. coli B unable to accumulate orotic acid utilized less effectively pyrimidine compounds for its growth than strain K12.
It is supposed, therefore, that in the de novo pathway for pyrimidine synthesis in E. coli K12 the step from orotic acid to 5'-UMP is genetically depressed so that orotic acid is accumulated when pyrimidine compounds, that would cause a feedback inhibition of orotic acid synthesis upon incorporation, are not supplemented.

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The relationship of two factors in the cell membrane of an L-glutamic acid producing bacterium, the molar ratio of saturated fatty acid unsaturated fatty acid and the kinds and amounts of phospholipids, which have been reported to play important roles in the mecha-nism of extra-cellular accumulation of L-glutamate was investigated.
It was shown that the fatty acid composition of each phospholipid of the bacterium is almost unchangeable under any bacterial growth conditions, and that when a large amount of L-glutamic acid was accumulated extracellularly, the amount of saturated fatty acids rich-phospholipid such as cardiolipin increased and unsaturated fatty acids rich-phospholipid such as phosphatidic acid greatly decreased in the cell membrane.

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An uracil-requiring mutant (KY7122) of Arthrobacter paraffineus KY4303 (ATCC15591) was found to accumulate orotic acid and orotidine on n-paraffine as a sole carbon source.
Both substances were definitely indentified as orotic acid and orotidine, from the results on column and paper chromatography, UV and IR absorption spectra, elementary analysis and analyses of hydrolysate.
Cultural conditions for orotic acid and orotidine fermentation were then investigated. As the carbon source n-paraffines from C₁₄ to C₁₆ were the most suitable for the fermen-tation, and sorbitol, fructose and mannitol were best utilized for the growth, and orotidine produced from them were twice as much as those from hydrocarbon. The addition of 200mg of uracil and 2g of C. S. L to 1 liter of medium was most optimal for orotic acid and orotidine fermentation.
Orotic acid and orotidine accumulations were enhanced by the addition of either L-tyrosine, L-leusine, L-threonine, gluconate or meat extract.

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Preparation of an enzyme (H) specific for dephosphorylation of phosphorylated streptomycin, a precursor of streptomycin, was obtained from mycelium of Streptomyces griseus.
Previously, cell homogenate of the organism was employed as the source of H enzyme, but its purification was embarrassed by the proteinous contaminants in the homogenate. In the present investigation, it was found that 70 to 80% of H enzyme in mycelium could be extracted into medium merely by suspending the mycelium in 20% sucrose solution for several hours. The centrifuged supernatant of this suspension was much less contaminated with other proteinous materials, compared with other extraction methods. Column chr-matography of the supernatant on Sephadex A-50 gave a peak of H enzyme which had 50 times as much specific activity as that in cell homogenate, while purification of the enzyme from cell homogenate by an procedure including salting out, dialysis and column chromato-graphy on DEAE-Cellulose gave only 29 times increase in specific activity.
At the chromatography on Sephadex A-50, a peak of ordinary alkaline phosphatase other than H enzyme was also obtained. While H enzyme was eluted with 1% NaCl and showed high activity against phosphorylated streptomycin and some activity against p-nitrophenylphosphate, the ordinary alkaline phosphatase was eluted with 3 to 4% NaCl and showed very low activity against phosphorylated streptomycin but high activity against p-nitrophenylphosphate. H enzyme was more heat-stable than the ordinary alkaline phos-phatase, i. e., the former was stable below 50°C while the latter was inactivated above 35°C.

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Twenty-seven substituted ethyl β-phenoxyacrylates were prepared to clarify the relationship between chemical structure and inhibition of the shoot elongation of barnyard-grass. ortho-Halo-substitution greatly enhanced the inhibitory activity, the order of which was Cl>F_??_Br>I.
The cis/trans ratio of each preparation was approximately 1:4 on the basis of the NMR spectrum, and the activity of trans isomers was about 100 times higher than that of cis isomers in the case of the 2-chloro- and 2, 4-dichloro-derivatives. Among the compounds tested, ethyl trans- β-(2, 4-dichlorophenoxy) acrylate was found to be the most effective in inhibiting shoot elongation.

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The effect of conventional antioxidants on soybean lipoxygenase reaction was examined. Inhibitory activities of o-diphenols such as pyrocatechol, homocatechol, propyl gallate and NDGA were higher than those of m- and p-diphenols. The mode of inhibition by NDGA, one of the most effective inhibitors among the phenolic antioxidants tested, conformed to a competitive type and not to an induction period type. Under certain conditions, NDGA could be an irreversible inactivator for the enzyme. The effect of NDGA on the enzyme reaction could not be completely explained by the coupled oxidation theory. The inactivation by NDGA were effectively prevented by either of adding catalase, of incubating under anaerobic condition or in low pH medium or of adding borate. These facts showed that the inactivation of lipoxygenase took place in consonance with the autoxidation of NDGA. of Studies on Soybean Lipoxygenase.

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One of the lipoxygenase isozymes whose activity was dependent on calcium ion (lipoxygenase b) was isolated from soybean meal, and its protein and catalytic natures were compared with those of relatively well-defined one (lipoxygenase a). Lipoxygenase b was found different from lipoxygenase a in electrophoretic mobility on polyacrylamide gel, pH-activity profile and sensitivity to added calcium ion. The isozymes were separated from each other by fractional precipitation with ammonium sulfate and following ion exchange chromatography. Added calcium ion was found to stimulate significantly the enzymic activity of lipoxygenase b while to be rather inhibitory for that of lipoxygenase a. Hemoproteins were also stimulated by calcium ion in catalyzing the oxidation of colloidal linoleate.

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Substances which acted on the behavior of planarian were searched for, and two active components were isolated from culture broth of Streptomyces sp. 340. They were identified as trans-3-methylthioacrylic acid (MTAA) and 3-methylthiopropionic acid (MTPA).
It was found that many Streptomyces and some fungi accumulated MTAA, and many Streptomyces, fungi, bacteria and yeasts accumulated MTPA when the microorganisms were grown in the medium containing methionine.

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Photosensitized oxygenation of dehydro-β-ionylidene-ethanol afforded 1'-hydroxy-4'keto-α-ionylidene-ethanol, which was oxidized with active MnO₂ to give 1'-hydroxy-4'-keto-α-ionylidene-acetaldenhyde. The Wittig reaction of α-ionylideneacetaldehyde with carbethoxy-methylenetriphenylphosphorane or the phosphorane prepared from ethyl γ-bromosenecioate gave ethyl α-ionylidene-crotonate or ethyl α-ionylidenesenecioate. Vitamin A₂ acid ethyl ester was converted to the hydroxy-keto-exter by photosensitized oxygenation. About the above synthesized compounds were examined growth inhibitory activities on rice seedlings.

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Japanese-radish root contained eighteen isoenzymes of peroxidase distinguishable on polyacrylamide gel electropherograms. The isoenzymes were found to be quite similar to those of horseradish peroxidase, although their quantities were different between two plants. The acidic components were the major isoenzyme in Japanese-radish peroxidase, while the neutral ones were the major one in horseradish. The chromatographic purification of the isoenzymes was performed on CM- and DEAE-Sephadex columns to characterize the components. The components in the preparations purified by the previously reported procedures of Morita et al. were also identified.

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A total synthesis of racemic 4-epipimaric and 4-episandaracopimaric acids is described.

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A total synthesis of the title compound, a sesquiterpene ester with high juvenile hormone ativity, is described.

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This experiment made clear the effect of the small intestinal fistulae fixation on the excretion pattern of hard feces and soft feces, apparent digestibility of crude fiber, and the recovery rate of manganese dioxide in the experimental pellet diet. The filter stick method for crude fiber determination and the wet-ashing method for manganese were approved to be useful. Radioactivity measurements of both duodenum and ileum digesta, collected after the oral administration of radioactive manganese dioxide prepared by the neutron irradiation method, resulted in a considerably rapid passage rate of manganese dioxide through the small intestinal tract.

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Relationship between the chemical constituents of tobacco leaves and the gaseous constituents of cigarette smoke from which K value¹⁾ was computed was discussed and the following presuppositions were demonstrated to be correct.
1. Fibrous substances in tobacco leaves are the main precursors of acetaldehyde, propionaldehyde, acrolein, acetone, methylethylketone, diacetyl, methanol, furan, an unknown compound, No. 6 and an unknown compound, No. 16 in cigarette smoke.
2. Sugars in tobacco leaves are the main precursors of 2-methylfuran and 2, 5-dimethyl-furan in cigarette smoke.
3. Resinous substances in tobacco leaves are the main precursors of isoprene and an unknown compound, No. 2 in cigarette smoke.

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In the previous papers we reported that the antibiotic Polyoxin D induced the characteristic swelling of the mycelia of fungi, ^{1, 2)} and strongly inhibited the incorporation of ¹⁴C-glucosamine into the fungal cell wall chitin.³⁾ The present work has been conducted to further investigate the influence of this antibiotic on the fungal cell wall biosynthesis.
Polyoxin D did not inhibit the incorporation of ¹⁴C-glucose, ¹⁴C-amino acids and ¹⁴C-sodium acetate into the cell wall. In addition, UDP-N-acetylglucosamine, a precurcor of chitin biosynthesis of cell wall, was accumulated in the Polyoxin D-treated mycelia of Cochliobolus miyabeanus more than 150 to 160% of that accumulated in the untreated one.
Chitin synthetase prepared from Piricularia oryzae which is not treated with Polyoxin D was completely inhibited by the addition of 0.1ppm of Polyoxin D. The fungitoxicity of Polyoxins A to G was positively related to their inhibition of ¹⁴C-glucosamine incorporation into the cell wall chitin of C. miyabeanus. From above results, it became evident that the antibiotic Polyoxin complex inhibited the biosynthesis of fungal cell wall chitin.

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Bitter peptides were isolated from the tryptic hydrolysate of casein. Fractionation and isolation were carried out using n-butanol extraction, acidic precipitation at pH 5.4, gel filtration with Sephadex G-25, ion exchange chromatography with Dowex 50W and paper chromatography. Three kinds of bitter peptides were purified. The primary structures of these peptides were proposed as follows; BP-I, Gly-Pro-Phe-Pro-Val-Ileu; BP-II, Phe-Phe-Val-Ala-Pro-Phe-Pro-Glu-Val-Phe-Gly-Lys; BP-III, Phe-Ala-Leu-Pro-Gln-Tyr-Leu-Lys. These peptides were very bitter in a 0.1% solution.
L-Tyrosine, L-phenylalanine and their derivatives were also tasted. The importance of the position of bitter amino acids in the peptide in the development and strengthening of its bitter taste is discussed.

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The condensation of ambreinolal (III), prepared by LiAlH₂(OC₂H₅)₂ reduction of ambreinolide (II), with 2-carbethoxyethylidenetriphenylphosphorane gave the α-methyl-cis-α, β-unsaturated ester (IV), which was converted to the allylalcohol (V) by reduction with Li-AlH4. And then the reaction of the hemiacetal (III) with isopropylidenetriphenylphosphorane afforded the isopropenyl derivative (VII) with the same olefinic methyl group as those of ambrein (I). By assignment of the NMR spectra of the above compounds structurally related to ambrein (I), it was confirmed that the configuration of I is the trans form (VIII).

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