An endo-1, 5-α-L-arabinase [EC 3.2.1.99] has been highly purified from the culture fluid of Bacillus subtilis IFO 3022 grown on a medium containing beet pulp extract. The molecular weight of the enzyme was 33, 000 by SDS polyacrylamide gel electrophoresis. The purified enzyme was active on 1, 5-arabinan, and inactive on p-nitrophenyl α-L-arabinofuranoside. The optimum pH was 6.0. The enzyme was inhibited by Hg²⁺, but not by L-arabonic-γ-lactone. The purified enzyme was able to loosen potato tissue.

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The effects of detergents on the lysozyme-catalyzed hydrolysis of Micrococcus lysodeikticus cells were investigated by changing the concentration of Na-phosphate buffer and pH in the presence or absence of sucrose. Also, a parallel study of the hydrolysis of glycolchitin by lysozyme was conducted and compared to the lytic reaction. Electron microscopy was utilized to follow the changes in cell morphology during the various treatments.
None of the detergents changed turbidity of the cell suspension. However, they did affect the change in turbidity during lysis in unique ways. SDS, which is an anionic detergent, inhibited lysozyme activity and its addition to the reaction mixture caused a rapid and large decrease in the turbidity. Brij 35 and Triton X-100, which are non-ionic detergents, did not inhibit lysozyme activity, but their presence in the reaction mixture changed the rate of turbidity change. Apparently non-ionic detergents disrupt only the protoplast, while anionic detergents disrupt both the protoplast and the damaged cell. The lytic mechanism of M. lysodeikticus by lysozyme was discussed in detail.

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Several species of fungi were tested for their abilities to degrade (S)-nicotine, of which Pellicularia filamentosa JTS-208, the pathogen of tobacco damping off disease, and Cunninghamella echinulata IFO-4444, a saprophyte, were found to be able to degrade nicotine. P. filamentosa JTS-208 accumulated nornicotine only in the nicotine medium. C. echinulata IFO-4444 accumulated nornicotine and N-methylmyosmine, the first fungal metabolite, and three unidentified compounds.

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During the formation of radical A (2) and its precursor (tris (2-deoxy-2-L-ascorbyl) amine, 1) by the reaction of dehydroascorbic acid (DHA) with amino acid, ascorbic acid (AsA) and the reduced red pigment (3) were newly identified, in addition to scorbamic acid (SCA) and the red pigment (4), as intermediate products. The addition of AsA to the DHA-amino acid reaction, as well as to the DHA-SCA reaction, greatly increased the formation of 3 and 1. The reaction of AsA with 4 gave rapidly 3, followed by the gradual production of 1. From these results, a reaction pathway is proposed that 3 formed by the reduction of 4 with AsA is a key intermediate and its condensation with DHA followed by reduction with AsA might produce 2 and 1.

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A novel aspartate aminotransferase inhibitor named gostatin was isolated as crystals from the culture filtrate of Streptomyces sumanensis NK-23. The structure has been established to be 5-amino-2-carboxy-4-oxo- 1, 4, 5, 6-tetrahydropyridine-3-acetic acid by X-ray crystallographic analysis (K. Ibata et al., manuscript in preparation). The results of chemical and instrumental analyses of the inhibitor are described in this paper.
Gostatin showed time-dependent inhibitory action against aspartate aminotransferases and alanine aminotransferase. Both pyridoxal phosphate- and pyridoxamine phosphate-linked enzymes were sensitive to the inhibitor.

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When arachin (S₂₀, w, 9S) was heated in 0.01 m sodium phosphate buffer, pH 7.9, at 70°C, the 9S protein decreased, accompanied by an increase of the 3S component and precipitate. The 3S component was not precipitated by prolonged heating. The precipitate contained six arachin subunits (S₁ to S₆) in a molar ratio of 3/4:3/4:3/4:1:1:1, but the 3S component comprised S₁, S₂ and S₃ as dissociated forms in an equimolar ratio. The molar ratio of S₁, S₂ and S₃ in the 3S component to those in the precipitate was 1:3 at each time of heating. On the other hand, arachin was neither dissociated nor precipitated by heating in 0.3 M sodium phosphate buffer, pH 7.9. The fluorescence intensity of 1-anilino-8-naphtalene sulfonate (ANS) conjugated with the heated arachin in 0.3 M buffer, however, was stronger than that of ANS conjugated with the intact arachin. These results suggest that two different pathways leading to insolubilization are involved in the thermal denaturation of arachin.

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The irradiation effects on histamine in fish meals and fish solubles for animal feeds and in aqueous solution were investigated. The amount of histamine in fish meal (0.4mg/100 g) was not changed by up to 5.0 Mrad (50 kGy), while the histamine content in fish soluble (45.7 mg/100 g) decreased ca. 16% at 5.0 Mrad. There occurred no accumulation of histamine by irradiation or during storage.
The G values of histamine formation from histidine solution and histamine decomposition by irradiation in deoxygenated neutral solutions were 0.077 and 1.90, respectively. Oxygen inhibited the formation of histamine from histidine but it had little effect on histamine decomposition. Nitrous oxide accelerated the decomposition of histamine and inhibited the accumulation of histamine in histidine solution by irradiation. These results show that there is no problem of histamine accumulation in feedstuffs caused by irradiation since the decomposition of histamine is preferred to its formation.

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A mutagenic fraction was separated by gas chromatography (GC) from the gaseous phase of protein pyrolyzate and a compound in the fraction was identified as hydrogen cyanide (HCN). Authentic HCN shows mutagenicity. It is proposed that most of the mutagenic activity in the gaseous phase of protein pyrolyzate is due to HCN.

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The structures of substances A and C have been elucidated by chemical and spectroscopic analyses. Both compounds gave stearic acid on catalytic hydrogenation. Based on the analysis of 400MHz¹H-NMR spectral data, substance A was determined as 13-hydroxy-cis-9, trans-11, cis-15-octadecatrienoic acid and substance C as 9-hydroxy-trans-10, cis-12, cis-15-octadecatrienoic acid.
Substance A was identical with a reduction product of 13-hydroperoxylinolenic acid prepared by treatment of α-linolenic acid with soybean lipoxygenase.

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Denitrifying bacteria, strain 220A and G59, belonging to the genus Pseudomonas, were isolated from soils percolated anaerobically with nitrate sewage. In denitrifying cultivation in the presence of 0.05atm oxygen, strain 220A accumulated N₂O, whereas strain G59 did not. Both strains produced dinitrogen alone in the absence of added oxygen. In resting cell suspension experiments, 0.1-0.2atm oxygen inhibited the reduction of N₂O to N₂ in strain 220A but not in strain G59. Production of N₂O from NO₂^- in the presence of 0.1atm C₂H₂ was not influenced by 0.1-0.2atm oxygen in either strain. Production of N₂ from NO₂^- in the absence of C₂H₂ by strain G59 was not inhibited by the amounts of added oxygen. From these results, accumulation of N₂O in denitrifying cultivation of strain 220A in the presence of oxygen could be due to the inhibition of N₂O reduction prior to any depression in NO₂^- reduction to N₂O by oxygen.

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2-Deuterio-2-cyclohexen-1-one, 3-deuterio-2-cyclohexen-1-one and 2-methyl-2-cyclohexen-1-
one were reduced by Clostridium La 1 giving a single bioconversion product resulting from reduction of the carbon-carbon double bond. Stereochemistry of the reaction was studied.

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The peroxide-decomposing activities of phospholipid fractions obtained from krill, egg yolk, soybean, rice bran, and sunflower seed were compared. The peroxide-decomposing activities of the total lipids depended upon the phospholipid contents. The phospholipid fractions from krill, egg yolk, and soybean did not show any antioxidative activities, but the peroxide-decomposing properties which varied somewhat among the sources were clearly observed. The most peroxide-decomposing activity was demonstrated by the phospholipid fraction of krill, followed by that of egg yolk. The existence of oxidation products of phospholipids were presumed to be responsible for the decomposition of lipid peroxides.

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The whole-body burdens and concentrations of ΣDDT(the sum of p, p'-DDE and p, p'-DDT) and PCBs in the Weddell seal, Leptonychotes weddelli, caught near Syowa Station, Antarctica, were determined by detailed biometric measurements of their organs and tissues and analyses of ΣDDT and PCBs in them. The concentration levels of ΣDDT and PCBs in Weddell seals were much lower than those in various species of marine mammals from other oceans. The low levels may be attributable to the low concentration of these chemicals in the food of Weddell seals and in the sea water under antarctic fast ice. However, the concentration ratio of ΣDDT between the food organisms of seals and sea water under antarctic fast ice was higher than those of other ocean ecosystems.

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Screening by using high alkaline media was carried out to detect new antibiotics produced by alkalophilic and alkali-resistant microorganisms. Three thousand strains of microorganisms, mainly fungi and streptomycetes, were isolated on high alkaline media (pH 10.3). The microorganisms consisted of 1206 strains of streptomycetes, 1511 strains of fungi and 283 strains of bacteria. Among these strains, 151 strains of streptomycetes, 148 strains of fungi and 36 strains of bacteria showed antimicrobial activities. One strain of alkalophilic streptomycetes, Streptomyces sp. No. 1543, produced antimycin A. An alkali-resistant fungi, strain No. 401, identified as Verticillium lecanii, produced helvolic acid. An alkalophilic fungi, strain No. 1907, identified as Paecilomyces lilacinus, produced a group of homologous new peptide antibiotics, Nos. 1907-II to VIII, in a broth fermented under the high alkaline conditions.

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Two chromones isolated from the methanol extract of glasswort (Salicornia europaea L.) were elucidated to be 7-hydroxy-6-methoxychromoneand 7 O-β-D-glucopyranosyl-6-methoxychromone on the basis of chemical and spectral analyses and synthetic studies. These two are natural products hitherto unknown.

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Autoxidation products of linoleic acid (LA) were analyzed, when the weight became 1.14-fold under the autoxidation conditions of satisfactory atmospheric oxygen, at 37°C, in the dark, for 7 days. The LA absorbed 2.8mol of oxygen to form secondary degradation products. This autoxidized LA consisted of 45% intact substance, 22% a mixture of polymers and endoperoxides, 18% LA hydroperoxides, 3% polar products, 1.7% azelaldehydeic acid, 1.3% hexanal, 0.9% azelaic acid, 0.6% octanoic acid, 0.3% suberaldehydeic acid, and so on. Thus, unstable 2, 4-dienoic carbonyls were the main intermediate products of autoxidation of LA. Therefore, malonaldehyde was not a main product nor a major thiobarbituric acid reactive substance.

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The origin of the amino acids in the precursor pool for hepatic protein synthesis has been studied by following the distribution of administered [³H]Asp and [³H]Val to the tRNA-charged, the extracellular (EC) and the intracellular (IC) amino acid pools of rat liver under two physiological states (fed and starved). Our results indicated that both the EC and IC amino acids contributed to the precursor pool for hepatic protein synthesis. Asp was mainly derived from the IC pool for protein synthesis, but in Val, the contribution of the IC and EC pools was not differentiated in fed rats, because the specific radioactivities of the three Val pools were very close. In starved rats, the difference in the contributions of IC and EC Val was relatively small. The difference in the specific radioactivities between tRNA-charged and hepatic EC or IC free amino acids depended on the kind of amino acids and the physiological states of the animals.

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Conversion products of 2-(2', 3'-dihydroxypropyl)-3-hydroxymethylquinoxaline under alkaline and acidic refluxed conditions were characterized using GLC, GC-MS, HPLC, and NMR measurements.
In an alkaline solution (pH 10, carbonate buffer), 2-(2', 3'-dihydroxypropyl)-3-methylquinoxaline (GA-I) and 2-(2', 3'dihydroxypropyl)quinoxaline were produced in yields of 16% and 19%, respectively, whereas in an acidic solution (MeOH-AcOH-H₂O=4:5:2), a large amount (65%) of 3, 4-dihydro-1H-pyrano[3, 4-b]quinoxalin-3-yl methanol and a small amount (5%) of GA-I were obtained. These results suggest that the C-C linkage of the side chain in the quinoxaline readily splits in alkaline solutions, whereas in acidic solutions no such splitting can be observed, but condensation or dehydration occurs between hydroxyl groups of the side chains, or the hydroxymethyl group is reduced to a methyl group.

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Activities of various known antifungal antibiotics known to induce morphological abnormalities of fungi and yeasts were examined. The observations seemed to provide a standard for detecting new antifungal antibiotics with a selective mode of action. Three new antibiotics, AC549, ATS1287 (leptomycin) and AM630 (fosfazinomycin), were found according to their activities to induce characteristic morphological changes of test organisms. AC549 seemed to be a compound related to gougeroxymycin.

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The interaction of allyl isothiocyanate (1) with L-cystine and polypeptides under mild conditions was studied in detail. The reaction mixtures composed of isothiocyanate and cystine were incubated at 40, 60 and 80°C, in which cystine completely decomposed after 120, 6 and 2hr, respectively. Degradation products were isolated and identified as 2-allylamino-2-thiazoline-4-carboxylic acid (2), 2-amino-2-thiazoline-4-carboxylic acid (3) and 3(3H)-allyl-5, 6-dihydro-5-amino-2(2H)-thioxo-1, 3-thiazin-4-one (4). These products were formed through an oxidative scission of the disulfide bond in cystine by the electrophilic attack of allyl isothiocyanate; the products 2 and 4 seemed to be derived through alanyl N-allyldithiocarbamate and the product 3 through β-thiocyanoalanine. In addition, it was confirmed that a part of the disulfide bond in oxidized glutathione and insulin was also cleaved by isothiocyanate.

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The flavor constituents of the highest quality Longjing tea parched on a pan while the leaves were turned over by hand were identified by GC-MS, and compared with those of Japanese kamairi-cha. Seventy-six components were characterized in Longjing tea. Nine compounds were newly identified related to tea aroma ; six from both Longjing and Japanese kamairi-cha, two from Longjing only and one from Japanese kamairi-cha only. The amount of pyrazines, linalool oxides, carboxylic acids, lactones, geraniol, 2-phenylethanol and ionone compounds was larger, while the amount of cis-3-hexenol, cis-jasmone, nerolidol, indole and benzyl cyanide was much smaller in Longjing tea than in Japanese kamairi-cha. The former seven compounds seemed to contribute to its characteristically strong pan-fired aroma as well as its floral and sweet aroma.

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β-N-Acetylhexosaminidase (NAHase) was purified from egg white and the lysosomal and microsomal fractions of hen oviduct. The purification procedure included affinity chromatography using Sepharose 4B coupled with IgG specific for NAHase of hen oviduct. The isoelectric points of the three enzymes were different, but their antigen determinants were identical. In sodium dodecyl sulfate polyacrylamide gel electrophoresis, both the egg white and lysosomal enzyme gave only one protein band each, corresponding to a MW of 68000 and 53000, respectively, but the microsomal enzyme gave two protein bands, corresponding to those of the lysosomal and egg white enzymes.

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The structural properties of Brazil nut 11S globulin, excelsin, were examined by polyacrylamide gel electrophoresis, circular dichroism, electron microscopy and X-ray diffraction.
Excelsin was separated into five fractions by SDS-gel electrophoresis, and the molecular weight of the largest subunit was 51, 000. The contents of helical, β-form and unordered structure were 14, 27 and 59%, respectively. The molecular shape was a double-layer polygon with a hole at the centre, and the molecular dimensions were 72×69×62Å. The space group of the crystal was R3.

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