The inactivation of papain brought about by low concentration of urea or guanidine hydrochloride was found to be a non-competitive type and that of cyanate ion to be a mixed type. The results are presented as Lineweaver-Burk plots.
These inactivations are not due to a change in the secondary structure of papain molecule as a result of the measurements of optical rotatory dispersion, circular dichroism, and UV-difference spectra.

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Effects of the substrate and the coenzyme on the crystalline yeast phosphoglyceric acid mutase activity have been investigated. Lineweaver-Burk plots at different concentrations of the substrate (D-3-phosphoglyceric acid: 3×10^-4 to 8×10^-3M) and the coenzyme (D-2, 3-diphosphoglyceric acid: 8×10^-7 to 10^-5M) change in such a way to indicate the involvement of an enzyme-substrate-coenzyme ternary complex as an active intermediate in the enzymic reaction process. It is concluded that the reaction catalyzed by the yeast enzyme follows the sequential pathway and that a phosphorylated enzyme does not participate as an obligatory intermediate in the reaction mechanism, if it occurs. Kinetic studies indicate Km values of 6×10^-4M for D-3-phosphoglyceric acid and 8×10^-7M for D-2, 3-diphosphoglyceric acid. The substrate is a competitive inhibitor of the coenzyme with a Ksi (inhibition constant) of 3.2×10^-3M. The coenzyme inhibition is not observed at concentration tested. A kinetic treatment to determine the mechanism of the enzyme reaction from the experimental data which are obtaind in the range of inhibitory substrate concentrations is presented.

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An antibacterial substance isolated from the mycelical extract of a stract of Penicillium crustosum Thom was identified as viridicatin, 3-hydroxy-4-phenylcarbostyril. To study the physiological and structural function of viridicatin, 3-(4-phenylcarbostyriloxy) acetic acid was synthesized from viridicatin and monochloroacetic acid, and its physiological activity on microorganisms and plants was compared with that of viridicatin. It was found that although viridicatin has a fairly strong antimicrobial activity on some gram positive bacteria and inhibits the growth of rice seedlings, the carboxymethylene derivative has a very weak activity on microorganisms but has stimulatory effect on the growth of rice seedlings. The physiological significance of the substituting group in carbostyril structure of these compounds was discussed.

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The present report describes the successful isolation procedure and some physico-chemical properties of an unknown blue-violet fluorescent substance existing in spinach leaves. Through the isolation steps of water extraction of leaves (200kg), active carbon adsorption, extraction by organic solvents, and column chromatographies with various adsorbents and ion exchange resins, a purified compound was obtained in colorless planeary crystal of long parallelogram (40mg; mp. 195°C; C₁₃H₁₇O₉N₁). The UV-, IR- and NMR-spectra, the results of organic tests, and behaviors on chromatographies and electrophoreses are presented.

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The blue-violet fluorescent compound of spinach, reported in the preceeding paper, was found to be the monoammonium salt of an unknown acid. The structure of the acid was determined as mono-p-coumaryl-meso-tartaric acid by the results of spectral analyses and hydrolysis experiments, and finally by chemical synthesis.

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Kori-tofu was stored under RH 95% at 60°C and the changes of its nitrogenous compounds in the course of browning were examined. The water-soluble and 10% TCA-soluble fractions prepared from the ether extraction residue of Kori-tofu were analyzed. The nitrogen content of water-soluble fraction temporarily decreased and then increased gradually in the course of browning, while that of 10% TCA-soluble fraction increased gradually during the browning process. Amino acid analyses of 10% TCA-soluble fraction and its hydrolyzate revealed that no free amino acid was detected in unbrowned Kori-tofu, whereas in browned Kori-tofu occurred peptides, ammonia and free amino acids such as aspartic acid, serine, glutamic acid, glycine and alanine.
Free amino acids similar to those detected in browned Kori-tofu occurred in the model system consisting of lysozyme and methyl linoleate, crotonaldehyde, glyoxal, methyl-glyoxal and also the brown substance prepared from glycine and methyl linoleate during storage. The formation mechanism of free amino acids from proteins was discussed.

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A glucomannan isolated from konjac flour was hydrolyzed with commercially available crude and purified cellulases. The following oligosaccharides were isolated from the hydrolyzate and identified: (a) 4-O-β-D-mannopyranosyl-D-monnose (b) 4-O-β-D-mannopyranosyl-D-glucose (c) O-β-D-mannopyranosyl-(1→4)-O-beta;-D-mannopyranosyl-(1→4)-D-mannose (d) O-β-D-mannopyranosyl-(1→4)-O-β-D-mannopyranosyl-(1→4)-D-glucose (e) O-β-D-mannopyranosyl-(1→4)-O-β-D-mannopyranosyl-(1→4)-O-β-D-mannopyranosyl-(1→4)-D-mannose (f) O-β-D-mannopyranosyl-(1→4)-O-β-D-mannopyranosyl-(1→4)-O-β-D-mannopyranosyl-(1→4)-D-glucose (g) O-β-D-mannopyranosyl-(1→4)-O-β-D-mannopyranosyl-(1→4)-O-β-D-mannopyranosyl-(1→4)-O-β-D-mannopyranosyl-(1→4)-D-glucose (h) 4-O-β-D-glucopyranosyl-D-glucose(cellobiose) (i) 4-O-β-D-glucopyranosyl-D-mannose (epicellobiose) (j) O-β-D-glucopyranosyl-(1→4)-O-β-D-mannopyranosyl-(l→4)-D-mannose. Of these saccharides, (h), (i) and (j) were isolated from the hydrolyzate by purified cellulase, while (g) was isolated from the hydrolyzate by crude cellulase. The others were all present in the hydrolyzates both by crude and by purified cellulases.

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Leaf oil samples of four Japanese citrus species were analysed by gas chromatography to determine the detailed composition of each leaf oil. The following components were identified: α-pinene, α-thujene, camphene, β-pinene, sabinene, β-myrcene, α-terpinene, limonene, β-phellandrene, trans-2-hexen-1-al, γ-terpinene, p-cymene, terpinolene, cis-2-penten-1-ol, n-hexyl alcohol, cis-3-hexen-1-ol, trans-2-hexen-1-ol, p-α-dimethylstyrene, linalool, linalyl acetate, β-elemene, terpinen-4-ol, caryophyllene, humulene, β-terpineol, neryl acetate, geranyl acetate, β-selinene, geraniol and thymol. Most components were contained in common in leaf oils of the four citrus species, but relative contents of some of the components; such as γ-terpinene, linalyl acetate, and thymol differed from species to species. For example, γ-terpinene was the major component (33.8%) of Hassaku, whereas it was only a minor component in Daidai. Daidai is characterized by a very high content of linalyl acetate (35%) which is only a trace in the other three species. Kishu-mikan is characterized by a high content of thymol (15%).

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Reaction rates of the extracts from foods and biological tissues with hydrated electrons were measured by using competition with N₂O. Water and 3% Na₂SO₄ aqueous extracts of pork and water extract of onion gave results which conformed to the simple relationship of competition. An addition test of the onion with acetone and nitrate suggested that their reactivities were simply additive, but the additive effect of cysteine was complicated.

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The chemical constituents of the cell wall of Piricularia oryzae, the pathogenic fungus of rice blast disease, were studied with the aids of chemical analysis, X-ray diffraction, infra-red absorption and enzymatic degradation. The sugar constituents were identified by chromatography as glucose (62%), mannose (4%), galactose (0.5%), and hexosamine (13%). The acidic amino acid rich protein was comprised 4.6% in the cell wall. The cell wall consists of at least three different polysaccharide complexes: a) α-Heteropolysaccharide protein complex containing mannose, glucose and galactose. b) β-1, 3-Glucan containing β-1, 6-linked branch. c) Chitin like substance.

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Sulfur-containing compounds, fatty acids and neutral non-carbonyl oxygenated compounds in the volatiles from roasted barley were investigated.
The sulfur-containing compounds were separated as mercuric chloride complexes, regenerated, and then gas-chromatographed. Fatty acids and the neutral non-carbonyl oxygenated fraction were separated by the usual methods and also analyzed by gas chromatography. By the retention times with the aid of authentic compounds on two kinds of columns, the following compounds were tentatively identified: dimethyl disulfide, acetic acid, propionic acid, n-butyric acid, isovaleric acid, n-valeric acid, isocaproic acid, n-caproic acid, ethanol, n-propanol, n-butanol, isobutanol, n-pentanol, n-hexanol, furfuryl alcohol, γ-octalactone, γ-nonalactone and γ-decalactone. The odors and origins concerned with these compounds were briefly discussed.

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The crystal structure of γ-cyclodextrin complexes with several organic compounds have been investigated by X-ray powder method. A two-dimensional tetragonal unit cell having a=b=27.2Å and a two-dimensional hexagonal unit cell having a=b=32.7Å, were reasonably proposed for hydrated and anhydrous γ-dextrin complexes, respectively. The change of the crystal structure caused by dehydration seemed to be resulted from the change of the packing arrangement of circular cylinders that are made by coaxial alignment of the dextrin molecules. Results obtained were tentatively applied to consider the 8₁-helical configuration of amylose.

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Chicken feather powder was solubilized by Schweitzer's reagent with shaking in the presence of air and the soluble feather keratin was prepared by dialyzing this extract against running water. Cystine residues in the starting feather keratin was converted to cysteic acid residues in the solubilized derivatives by air oxygen. Copper was bound fairly tightly to the solubilized protein and this copper-protein complex was separated into four fractions by CM- and DEAE-cellulose column chromatography. Each fraction had varied amount of bound copper, having a broad distribution of the molecular weight between 10, 000 and 60, 000 Sephadex column chromatographically. Although the amino acid composition of all separated feather keratin fractions were quite similar, the different electrophoretic patterns were observed among them by DISC electrophoresis.

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Effects of the change of dietary protein on serine dehydrase activity in rat liver have been studied, using egg albumin, casein, rice protein, and wheat gluten as protein source. At 35% of dietary protein level, the activity induced by egg albumin and casein diets were higher than those by rice protein and wheat gluten diets. Parallel relation was observed between the enzyme activity and the protein intake. These results suggest that the dietary induction of this enzyme are based on the protein intake, which reflects the nutritional quality of dietary protein, rather than merely on the dietary protein level.
The contribution of individual amino acid for the enzyme induction by the egg albumin diet at 35% level was investigated, and it was concluded that this enzyme induction is dependent not on a specific amino acid but on the combined effect of each amino acid.

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The nature of aromatic amino acid residues in Japanese-radish peroxidase a and the apoprotein was investigated by means of spectrophotometry and fluorospectrophotometry. The tyrosine residues in the holoenzyme were masked in the alkali-titration, giving an abnormally high pK_H⁺ value of 12.6, while they were exposed in the apoenzyme, exhibiting a pK_H⁺ value of 10.8. The difference spectra in the ultraviolet region between the holo- and apo-enzyme showed characteristic bands of tryptophan and phenylalanine as well as tyrosine. The perturbation of the aromatic amino acid residues by 50 % ethyleneglycol was observed in the apoenzyme but not in the holoenzyme. The fluorophotometric experiments also revealed that the aromatic amino acid residues were in different environments in the holo- and apoenzyme. The difference between the conformation of peroxidase and that of the apoprotein was discussed.

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Intermediate and high boiling compounds in green tea flavor (pan-firing process) have been isolated by distillation, silica-gel column chromatography and gas chromatography. Identification of these compounds was carried out using gas chromatography, mass spec-trometry and infrared spectrometry.
4-Ethylguaiacol, cadinenol, nerolidol, 3, 7-dimethyl-1, 5, 7-octatriene-3-ol, 3, 5-octadiene-2-one α- and β-ionone, indole, and dibutylphthalate have been newly identified as the constituents in green tea flavor.
The fraction which contributed most to the green tea flavor was composed of the former six compounds together with linalool, acetophenone and three important but unidentified compounds.

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In connection with flavor deterioration accompanied by food irradiation, the effect of γ-irradiation on sulfoxide amino acids in air free aqueous system was investigated. The major radiolysis products from S-n-propyl-L-cysteine sulfoxide (PCSO) were alanine, cysteic acid, dipropyl disulfide, etc.., and from S-allyl-L-cysteine sulfoxide (ACSO) were S-allyl-L-cysteine, cystine, cysteic acid, etc., which were isolated chromatographycally and identified by using IR and mass spectrometry. The sulfoxide in ACSO was more easily reduced to sulfide than that of in PCSO, and the bond of S-C (β-carbon in alanine moiety) in ACSO was difficult to cleave. These differences observed between PCSO and ACSO in the radiolysis products and their yields indicate that the radiolysis degradation is considerably influenced by the structure of alkyl group. From the experiments with N₂0 or KBr addition during irradiation, principal roles of the active species in irradiated water in the degradation processes were partly elucidated.

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1. Suitable agar plate media were selected for isolation of nucleotide producing strains, by salvage synthesis, from natural sources. Since this agar medium contains a high con-centration of phosphates, manganese and glucose, it is specific for these bacteria.
2. With this plate medium, 113 bacterial strains accumulating 5'inosinic acid (IMP) or IMP-like substances were isolated effectively from feces of a variety of birds and mammals and from soils.
Some of the strains isolated were recognized to accumulate other nucleotides, purine bases and sugars, such as guanine nucleotides, XMP, xanthine, ribulose or xylnlose, with or without hypoxanthine in the media.
3. Five strains of IMP accumulating bacteria were identified; two were classified as Brevibacterium, two as Corynebacterium and one as Arthrobacterium species by taxonomical studies. But their characteristics did not completely coincide with those of bacteria described in Bergey's manual.
4. One of the IMP producing bacteria isolated, culture No. 21-26, actually consisted of two separate strains, namely No. 21-26-101 and No. 21-26-102. The highest production of IMP or guanine nucleotides was obtained, when each strain was inoculated together to the fermentation medium from each seed culture in the same inoculum size.
5. The nucleotide productions by No. 21-26-101 or No. 21-26-102 with authentic strains were examined by the mixed culture technique. It was found that production of IMP or guanine nucleotides by Brevibacterium ammoniagenes ATCC 6871 was stimulated remarkably in the presence of No. 21-26-102.

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Some enzymatic properties of purified alkaline proteinase from Aspergillus sojae were investigated. The optimum pH for casein digestion was 11.0. The enzyme activity was almost completely lost at 60°C within ten minutes. At low temperature, the enzyme was highly stable at the range of pH 4.5 to 10.0. At 50°C, the most stable pH was around 6.0. None of metallic ions tested promoted the activity, but Hg²⁺ showed a remarkable inhibition. The Hg²⁺-treatment seemed to cause a large unfolding of the enzyme molecule. The enzyme was inhibited by potato inhibitor and a number of animal sera. Metal chelating reagents and sulfhydryl reagents tested had no effect on the activity, but DFP caused a marked inhibition. The sensitivity to DFP of the enzyme was about 1/300 of that of α-chymotrypsin. The enzyme was inhibited neither by TPCK nor by TLCK. As the result it was assumed that the structure of the active site of the enzyme is fairly different from that of trypsin, or of chymotrypsin.

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Some new N-p-chlorophenyl-N'-2-(substituted) benzothiazolyl-N''-alkyl guanidines have been synthesized. Several of these including some N p-chlorophenyl-N'-2-(substituted) benzothiazolyl guanidines and N-p-chlorophenyl-N'-2-(substituted) benzothiazolyl-N'-methyl guanidines^* have been tested for their antibacterial activities against B. subtilis, S. aureus, S. typhi., E. coli and A. tumefaciens, and also for their antitubercular activity against M. tuberculosis (H37Rv).

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