Various dyes were tested in order to compare photosensitizing ability based on relative quantum yield for photosensitized oxidation of histidine. Each dye belongs to such u class as thiazine, xanthene, acridine, thiazole, phenylmethane, monoazo, azine, oxazine, porphylline and flavin. The heterocyclic structure was essential to the development of photosensitizing ability, but this ability was remarkably influenced by introduction of substituents on aromatic rings. Fluorescence was not always accompanied with photosensi-tization.
Except for fluoresceine, each dye had a common feature as to pH dependence of photosensitized oxidation of histidine, and this reaction was dependent on electrical charge of imidazole group of histidine. Each dye also showed a common behaviour on Line-weaver-Burk's plots. Using various dyes, the photosensitized oxidation of histidine was compared with that of tryptophan, and it was found that the ratio of raction rates of both amino acids was varied with the kinds of dye. For example, the reaction rate of tryptophan was only one forth of that of histidine in the case of thionine, while in eosine no difference was shown between the reaction rate of both amino acids.

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Tannase was found in the mycelium of Aspergillus flavus grown on the medium con-taining tannic acid as a sole carbon source. The enzyme formation might be inducible and was dominant at the initial stage of growth.
Tannase was purified about 30-fold from the mycelial extract of Aspergillus flavus grown on the tannic acid medium by a procedure involving ammonium sulfate and tannic acid precipitation, DEAE-cellulose column chromatography, Sephadex G-200 gel filtration and acetone fractionation. The final enzyme preparation showed single symmetric peak upon ultracentrifugation and electrophoresis.
The enzyme was stable up to 60°C and showed optimum activity at 50 to 60°C. The optimal and stable pH ranges were found to be at 5.0 to 5.5 for methylgallate. The tannase of Aspergillus flaeus hydrolyzed the ester linkages of tannic acid. The substrate-enzyme dissociation constants for substrates were found to be 0.5×10^-4M, 1.4×10^-4M and 8.6×l0^-4M for tannic acid, glucose-l-gallate and methylgallate, respectively.

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With the purified perparation of the tannase of Aspergillus fiavus, some physicochemical properties were investigated. The purified enzyme was homogeneous when examined in the ultracentrifuge and electrophoresis. The molecular weight determined by the sedimen. tation-diffusion method, was found to be 194, 000. The Archibald approach-to-equilibrium method gave a molecular weight of 192, 000. The enzyme was a glycoprotein containing 25.4% hexose and showed an isoelectric point in the vicinity of pH 4.0.
The nitrogen content of the enzyme was determined to be 12.9% by the micro-Kjeldahl method. The amino terminal amino acids were composed of approximately l mole each of alanine and arginine per mole of enzyme by the DNP-method. Evidence is presented to show that the enzyme undergoes dissociation into inactive subunits of equal size by the treatment with guanidine hydrochloride.

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With swine fed on the died containing polyethyleneglycol (mol. wt. 4, 000) and chromic oxide at the constant rate, excretion variation has been observed for 5 consecutive days, and digestibility estimated by polyethyleneglycol-ratio method compared with that by chromic oxide-ratio method.
There was little difference in excretion variation and in variation of estimated digestibility between both these methods. However, the estimate of crude protein digesti-bility by the former method was significantly lower than that by the latter or by the conventional feces-collection method due to incomplete recovery of polyethyleneglycol in feces, the reasons for which remained to be elucidated. The digestibility estimated by polyethyleneglycol-ratio method is considered to need appropriate correction.

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Studies were made on the influence of phenolic compounds on the nutritive value of casein by the nitrogen-balance technique with rats and by the chemical measurement of available lysine.
It was found that caseins allowed to react with caffeic, isochlorogenic acids and phenolic compounds of red clover leaves in the presence of o-diphenol oxidase were inferior to control casein in biological value, digestibility and available lysine content. In the absence of o-diphenol oxidase, caffeic acid showed none of these effects. p-Coumaric acid lowered the biological value of casein in the presence of o-diphenol oxidase but did not lowered its digestibility.

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6-Hydroxydehydroabietinol and hinokiol were isolated from the non-steam-volatile frac-tion of the leaves of Torreya nucifera Sieb. et Zucc. (Taxaceae) (Japanese name “Kaya”). The former was also isolated from the immature fruits of the same plant. This is the first report of the isolation of 6-hydroxydehydroabietinol from a natural source. This compound was prepared previously and reported to show marked estrogenic activity.

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Absolute configurations of C-2 and C-3 in “Acid III” (IIa), a degradation product of piericidin A diacetate, was determined as R and S, respectively. Consequently both C-9 and C-l0 in piericidin A were confirmed to have S configurations. On the basis of UV and NMR specta, configurations of the double bonds in piericidin A were assigned as shown in Ia.

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Piericidin B was isolated from mycellia of Streptomyces mobaraensis besides piericidin A. On the basis of IR, NMR and mass spectral studies together with chemical evidences, its structure was assigned as Id. Its physiological activities are also deescribd.

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The four kinds of aminoglycosides of 2-deoxystreptamine (DSTA)* including kano-saminide were synthesized by a modified Königs-Knorr reaction using a benzylhalogeno derivative of the corresponding aminosugar. Each of the glycosides was isolated as its crystalline N-acetate and proved to have α-configuration. The possible intermediates of this versatile a-glucosylation reaction are discussed.

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Kanamycin A (Ia) and its isomer (IVa) were first synthesized by a modified Konigs-Knorr reaction of 3-acetamido-2, 4, 6-tri-O-benzyl-3-deoxy-α-D-giucopyranosyl chloride²⁾ with 4-O-(6-acetamido-2, 3, 4-tri-O-benzyl-6-deoxy-α-D-glucopyranosyl)-N, N'-dicarbobenzoxy-2-deoxystreptamine (IIIa).²⁾ They were isolated as their crystalline N-acetate (Ic and IVc). From the diastereomer of IIIa, ²⁾ the diastereomer (VIa) of kanamycin A was also synthesized.

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A new gibberellin, tentatively called Lupinus gibberellin I, was isolated from young yellow lupin seeds. It has been shown Lo have structure (X), and now named gibberellin A₁₈.

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A leaf protease of tobacco whose activity was enhanced during curing was purified about 60 times with ammonium sulfate fractionation, ethanol precipitation, calcium phosphate gel treatment and Sephadex G-200 column chromatography, and some properties of the protease were examined. The purified enzyme showed the optimum pH at 5.5 and the optimum temperature at 60°C. The protease activity was stable between pH 4.5 and 5.5 at 50°C or at pH 5.5 below 40°C for 1hr, but completely destroyed at 70°C during 1 hr. The protease activity was greatly activated by reducing agents such as cysteine, glutathione or mercaptoethanol and inhibited by p-chloromercuribenzoate, phenyl-mercuric acetate or silver ions. Metal ions except for silver ion and ethylenediamine tetraacetic acid did not affect the protease activity so far examined.

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1. The incorporation of mevalonate-2-¹⁴C into ipomeamarone in sweet potato root tissue infected by Ceratocystis fimbriata was demonstrated, but the rate was low when compared with acetate-2-¹⁴C. No dilution effect of mevalonate was noted during the incorporation of acetate-2-¹⁴C into ipomeamarone. This is very likely to result from the passive transfer of mevalonate into the cells.
2. No dilution effect of acetate during the incorporation of mevalonate-2-¹⁴C into ipomeamarone was noted. This indicates that mevalonate is not incorporated into ipomeamarone after its conversion to acetate.
3. Evidence for incorporation of acetate-2-¹⁴C into mevalonate was shown by the fact that the specific radioactivity of mevalonic acid benzhydrylamide was not lowered throughout repetitive crystallizations. These data also support the participation of mevalonate in ipomeamarone synthesis as an intermediate.

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Attempts were made with success to develop a chemically defined medium for 5'-purine ribonucleotide production by Brevibacterium ammoniagenes ATCC 6872 and its adenine auxotroph KY 7208.
The results demonstrated that the presence of pantothenate and thiamine and a limiting level of manganese in the medium are essential for IMP production from hypoxanthine. These conditions were likewise indispensable for GMP, GDP and GTP productions and AMP, ADP and ATP productions from corresponding bases by ATCC 6872 and for direct IMP fermentation with KY 7208 strain.
It was further shown that R 5 P accumulation by ATCC 6872 culture, in the absence of bases, was affected by the two vitamins and Mn²⁺ exactly in the same way as the nucleotide synthesis. Morphogenetic alterations were induced under such conditions as two vitamins added and Mn²⁺ kept deficient.

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More than ninety phenylphenol derivatives were tested for fungistatic activity toward ten species of agriculturally important fungi. One of N-methylcarbamates and some nitro- or chloro-substituted derivatives were highly toxic against Piricularia oryzae. From the relationship between the chemical structure and the activity, it is supposed that the reactivity, the permeability, the steric effect and the metabolic activation of the compound are the responsible factors for the fungistatic activity.

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The ability of Hansenula miso IFO 0146 to utilize various alcohols and acidic salts as sole sources of carbon and the ability of resting cells to oxidize various alcohols and glucose were studied. Growing cells could utilize only ethanol, glycerol, acetate and lactate, while resting cells grown on ethanol medium could oxidize various alcohols such as 1, 2-ethanediol, DL-1, 2-propanediol, 1, 3-propanediol, meso-2, 3-butanediol, DL-1, 3-butane-diol, and 1, 4-butanediol. From 2g of 1, 2-ethanediol and DL-1, 3-butanediol, 1.3g of glycolic acid and 0.5 g of β-hydroxybutyric acid respectively were produced. The organism formed D-arabinitol from glycerol and glucose, respectively. From 100ml of culture in medium containing 6ml of ethanol and 3.0g of (NH₄)₂HP0₄ as carbon and nitrogen sources 3.40g of dried cells were obtained.

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Biotin derivatives with biotin activity for some biotin-requiring microorganisms have been isolated in crystalline form from the culture filtrate of strain 194, identified as Rhodotorula fiava. The crystalline vitamer was identified as d-biotinamide.

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