Knowledges on chemical constituents and protein properties are fundamental prerequisites for the discussion of functional properties of food-grade soybean products. Chemical analysis was made on 43 commercial soybean products as well as on 3 gluten and 3 casein products. Principal component analysis was successfully applied for the classification of commercial products by their chemical constituents and protein properties. High correlation was observed between chemical composition and industrial processing method of soybean products. Correlation between water dispersible nitrogen and amount of native protein was unexpectedly low so that both should be taken independently as the indices for the discussion of functional properties.

View full abstract

Flavor profiles of commercial soybean products were studied organoleptically and results were analyzed by using principal component analysis. Flavor of soybean products could be represented by two mutually independent characteristics. They are the so-called “Soybean Flavor” and “Other Flavors.” Scatter diagram of commercial products was obtained on the basis of the above mentioned two characteristics, and results were discussed considering processing methods of the products. Correlations between flavor and chemical properties were also calculated and discussed.

View full abstract

Gel formation is one of the most important functional properties of the food-grade soybean products. In order to clarify the properties of heat-coagulated gels, correlations between gel properties and chemical composition and correlations between gel properties and protein properties of commercial soybean products, subjective and objective texture measurements were made on the gel samples from soybean products. Heat-coagulated gels from soybean products were classified into three categories, the “hard-gel, ” “soft-gel” and “paste” products. The “hard-gel” products have crude protein contents of more than 75% and form hard-gel samples. The “soft-gel” products have crude fiber contents of below 1% and form soft and “tofu”-like gel samples and most of the “paste” products have crude fiber contents of above 1% and form gels with textural properties like mashedpotatoes or “miso.”

View full abstract

Two water-soluble acidic polysaccharides were isolated and purified from soy sauce and their physico-chemical properties were investigated. The purified preparations seemed to be homogeneous on ultra-centrifugation and also on zone electrophoresis. Their sedimentation coefficients were 6.35S and 1.9S, and their intrinsic viscosities were 0.47 and 0.11dl/g, respectively. Molecular weights were estimated to be 320, 000 and 16, 000 by gel filtration technique. Consequently, it was proved that these acidic polysaccharides were close in their sugar compositions to those prepared from soybean cell wall by the enzymatic decomposition. Therefore, these acidic polysaccharides in soy sauce were presumed to be originated from soybean cell wall

View full abstract

When an aqueous solution of thymine glycol, a main radiolysis product from thymine, was gamma-irradiated in the absence of oxygen, a characteristic UV absorption which was absent before irradiation was found to be developed. From the chromatographical and spectrophotometrical investigations and microbiological assay, one of the main UV positive products was identified to be thymine. The initial G-values with 2mM thymine glycol solution were 1.1 and 0.4 for thymine glycol decomposition and thymine formation, respectively. The formation was suppressed by the presence of oxygen or nitrous oxide, while it was enhanced by potassium thiocyanate or sodium formate. Thus, the presence of a new reversible reaction between thymine and thymine glycol through radiolysis in an aqueous system was proposed.

View full abstract

Comparison of the effects of _??_ high fat and high protein diet on the capacity for glucose formation from pyruvate and glycerol was investigated in vivo and in vitro. Ratios of radioactivity incorporated from either pyruvate-3-¹⁴C or glycerol-1-¹⁴C into blood glucose to those into expired CO₂ were higher in both groups fed the high fat and the high protein diet than those in a group fed a high carbohydrate diet. Gluconeogenesis from pyruvate and glycerol by liver slices were both increased significantly in rats fed the high fat diet, while feeding the high protein diet caused increase of renal gluconeogenesis from pyruvate and glycerol. The activities of hepatic and renal glucose-6-phosphatase(s) were changed in a similar fashion to changes in hepatic and renal gluconeogenesis, respectively.
In addition, the response of the activity of hepatic glucose-6-phosphatase with high dietary fat was more rapid than that of the activity of renal glucose-6-phosphatase with high dietary protein. Furthermore, the intraperitoneal injection of actinomycin-D to rats resulted in decrease of the activities of renal glucose-6-phosphatase of both groups fed the high fat and the high protein diet, but no significant change of the activity of hepatic glucose-6-phosphatase was observed among dietary groups.
These findings suggested that the increases in the overall flow of metabolites towards glucose formation by feeding the high fat and the high protein diet might be based on the action of different mechanisms which regulate the activities of glucose-6-phosphatase(s) of the liver and kidney.

View full abstract

To obtain (Z)-pyrethric acid, a geometrical isomer of pyrethric acid, the condensation between 1-methoxycarbonylethylphosphonate (II) and tert-butyl 2, 2-dimethyl-3-formylcyclopropane-1-carboxylate (I) was reinvestigated, the yield of the (Z)-isomer was increased to 61.5% in the reaction mixture. (Z)- and (E)-Isomers were separated effectively by recrystallization from acetonitrile after alkaline hydrolysis of the reaction product.
(Z)-Isomer of allethrin II was synthesized from (Z)-pyrethric acid and allethrolone. Toxicity of the (Z)-isomer to houseflies was compared with those of allethrin I and II.

View full abstract

Crystalline β-galactosidase was prepared from the cell extract of Saccharomyces fragilis KY5463, by procedures including protamine sulfate treatment and DEAE-cellulose, hydroxylapatite and DEAE-Sephadex column chromatographies. Crystals were formed when solid ammonium sulfate was added to solutions of the purified enzyme. This procedure resulted in a 55-fold purification with an over-all yield of 15.4%. The crystalline enzyme appeared to be homogeneous on ultracentrifugation and electrophoresis.
The sedimentation coefficient, s⁰_{20, w}, was determined to be 10.0 S. The molecular weight was estimated to be approximately 203, 000 by the sedimentation equilibrium method of Yphantis. Electrolysis with carrier ampholytes revealed that this enzyme has an isoelectric point at around pH 4.4.
The enzyme was activated by K⁺, in addition to bivalent cations, such as Mn²⁺, Mg^2- and Co²⁺. The Km values for o-NPG and lactose were 4.0×10^-3M and 21.0×10^-3M, respectively. The enzyme is sulfhydryl dependent and was completely inactivated by mercuric ions or p-chloromercuribenzoate.

View full abstract

The blood group B substance-degrading activity of Streptomyces 9917S₂ is induced by galactosides as α-galaetosidase activity is. Purification of the α-galactosidase was attempted by chromatography on DEAE-Sephadex and Sephadex. The purified preparation was shown to be free from α- and β-glucosiclases, β-galactosidase, α- and β-glucosaminidases, and α-and β-galactosaminidases activities. The blood group B substance-degrading activity was present only in this fraction. This enzyme preparation cleaves α-(1→3)- and α-(1→6)-galactosidic linkages. The activity is inhibited by D-galactose, melibiose, and raffinose and also by L-arabinose and D-xylose.

View full abstract

Isolation and determination of amino acid sequence of the bitter peptides formed in the digestion of cow milk casein with alkaline proteinase of Bacillus subtilis were investigated. The casein digest with the enzyme was extracted with butanol and the extracted bitter peptides were fractionally purified by treating with several other organic solvents followed by subjecting to chromatography and gel-filtration. The amino acid sequence of one of the bitter peptides was determined as follows: Arg•Gly•Pro•Pro•Phe•Ileu•Val. Liberation of N-terminal Arg with trypsin or bacterial aminopeptidase did not affect the bitterness. Also, splitting off of Val and Den or Ileu•Val at the C-terminus by carboxypeptidase, or a bacterial neutral proteinase gave no influence on the bitterness. However, liberation of Arg and Gly from the peptide with bacterial aminopeptidase gave rise to_??_non bitter peptide.

View full abstract

To confirm the possibility of conversion of Tyr to Phe as one of the reasons why the adult rooster is capable of maintaining its positive nitrogen balance on a Phe-free diet for a long period, U-¹⁴C-L-Tyr and 2-¹⁴C-DL-Tyr were injected to the roosters and, for reference, U-¹⁴C-L- Tyr to the rats fed a Phe-free diet.
In the case of fowls, hydrolyzates of liver, blood and muscle protein contained radioactivities only in Phe and Tyr fractions.
It was confirmed that radioactivity of Phe was not due to contamination of radioactive Tyr and transmission of ¹⁴C from Tyr to Phe was not due to transcarboxylation, because ¹⁴C was found in the benzoic acid derived from Phe when U-¹⁴C-Tyr was injected and it was not found in CO₂ derived from carboxyl group of Phe when 2-¹⁴C-Tyr was injected.
But the amount of Phe converted from Tyr was too little to meet the amount of Phe used for synthesis of body protein both in fowls and rats.

View full abstract

Sclerin (SCL) enhanced the formation of aminoacyl-tRNA by mouse liver enzyme both in _??_ heterologous reaction with yeast tRNA and in a homologous reaction with mouse liver “pH 5 fraction” to which was added CTP. The effect of SCL has been found to involve the following two points of action; one is the stimulation of the formation of aminoacyl-AMP accompanied with the activation of inorganic pyrophosphatase activity in “pH 5 fraction, ” and the other is an increase in the incorporation of AMP and CMP into the tRNA fraction. On the other hand, 2, 4-dinitrophenol (DNP) rather inhibited the pyrophosphatase activity, though its effect on aminoacyl-tRNA formation varied depending on the kind of amino acids and the reaction condition. It is assumed that SCL stimulates amino acid incorporation into the protein and cold TCA soluble fractions of liver tissue through the above-mentioned mechanism of action.

View full abstract

Seventeen peroxidase isoenzymes have been detected in the crude extract of rice embryos by polyacrylamide gel electrophoresis. Four isoenzymes out of 17 peroxidases were isolated and purified in a preparative scale by procedures involving ammonium sulfate fractionation, calcium phosphate gel treatment, ion exchange chromatography on DEAE- and CM-Sephadex, and gel filtration on Sephadex G-75 and G-100. The four isoenzymes were those as follows; isoenzyme 15 (peroxidase 556) as the major component of basic nature, two neutral isoenzymes 6 and 7, and isoenzyme 2 as an acidic peroxidase. All of the isolated peroxidases exhibited absorption spectra of high-spin type with minor differences from each other. The individual isoenzymes differed not only in enzymatic activity toward guaiacol as a hydrogen donor but also in molecular dimensions. It has been suggested that each isoenzyme may require specific hydrogen donor substance in the cellular metabolism.

View full abstract

Yeast pro-proteinase C was transformed to active form by brief exposure to a lower concentration of protein denaturants: urea, guanidine hydrochloride, acid and various solvents including dimethylformamide, 2-chloroethanol, dioxane, formamide, ethanol and n-propanol. Dioxane 30_??_35% or 4M urea were most effective in obtaining high activity.
In respect to catalytic properties, the reagent-activated enzymes were identical with proteinase C which was obtained from yeast autolysate. The characteristic participation of cysteine and serine residues in the catalytic process was also suggested in the aforementioned enzymes.
The proenzyme was composed of two subunit proteins. However their dissociation was not involved in the denaturant-activation process, as determined from the sedimentation and gel-filtration analyses. Changes in the reactivity of an unessential cysteine residue of the proenzyme, however, suggested that the structural alteration would be accompanied in the process.
From these results, it was concluded that the denaturants rearrange the quartenary structure of the proenzyme and lead to demasking of the active site.

View full abstract

Activation of pro-proteinase C by yeast proteinase A was examined under controlled conditions. Maximum activation occurred at pH 3.5 and 0°C, releasing a cationic protein. The active enzyme and the protein was separated and chemically analyzed.
The same N-terminal amino acid, lysine, was found in both the active enzyme and proenzyme. Amino acid analysis revealed that the released protein is a protein of small molecular weight about 19, 000 containing one SH-group and one disulfide bond. These results strongly suggested that the protein would correspond to the cationic subunit of the proenzyme. In both activation processes by denaturant and proteinase A, a decrease of β-structure was found as determined from ORD and CD measurements.
All of these results supported the idea that activation of the proenzyme occurred by denaturant- or enzyme-modification of the inhibitor protein, followed by demasking of the active site.

View full abstract

Rate-constants of β-D-mannosidic and β-D-glucosidic linkages for acid hydrolysis were determined. And from these results, statistical analysis of acid hydrolysis of the main chain of the mannan was made whereby the yields of the fragmental disaccharides could be calculated for any degree of hydrolysis. The symmetry of the result of these calculations with those observed experimentally may support the proposed chemical structure of the mannan. Moreover, from the result of action of cellulase on the manno-oligosaccharides, the main process of the reaction, “hydrolysis of the mannan by cellulase” was discussed.

View full abstract

Sixteen phosphate or phosphorothioate esters related to neurotoxic tri-p-ethylphenyl phosphate and its active metabolites were synthesized and their biological activities including inhibitory activity against cholinesterases, insecticidal activity, toxicity to mammals and neurotoxicity were examined. Dialkyl p-ethylphenyl phoshates, p-acetylphenyl phosphates and their thiono analogs showed insecticidal activity, but did not show the ataxic sign by any sublethal doses in hens. When a methyl group was introduced on p-acetylphenyl ring, the biological activity changed remarkably by its position. The introduction of a methyl group into o-position made the ester inactive, while the introduction into m-position made it active to insects selectively.

View full abstract

The molecular weight of γ₃ globulin was determined to be 120, 000 daltons by means of both sedimentation equilibrium and gel filtration methods. The protein was composed of 3 identical major and 1 minor subunits, and the molecular weights of them were found to be 35, 000 and 13, 000 daltons, respectively, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The major subunit has an arginyl residue as the amino terminal amino acid. The amino acid and carbohydrate composition of γ₃ globulin was determined as follows: Lys₃₇His₃₇Arg₉₂Asp₆₀Glu₁₃₉Gly₁₂₀Ala₈₃Val₇₆Leu₇₀Ile₃₁Pro₅₄Ser₇₇Thr₃₃ Cys₁₁Met₉Phe₅₁Tyr₂₆Trp₈ (Amide NH₃)₆₉Hexose₁₅Pentose₄Hexosamine₄. The structure of γ₃ globulin was discussed with comparing that of γ₁ globulin.

View full abstract

A minor component of cigar tobacco (+)-3-isopropyl-5-hydroxypentanoic acid lactone (I) was isolated. Synthesis of (+)-I from (+)-limonene established the absolute R-configuration. Stereochemistry of (+)-I is also described.

View full abstract

Volatile basic compounds from a heated D-glucose/L-alanine mixture were analyzed by gas chromatography and coupled gas chromatography-mass spectrometry. By comparison of mass spectra with corresponding reference spectra, the following compounds were identified: pyrrolidine, β-picoline, pyrazine, 2-methylpyrazine, 2, 5-dimethylpyrazine, 2, 3-dimethylpyrazine, 2-ethyl-5-methylpyrazine, 2, 3, 5-trimethylpyrazine and 2, 5-dimethyl-3-ethylpyrazine. 2-Methyl-3, 5-diethylpyrazine, 2-methyl-5, 6-diethylpyrazine and two alkylpyrazines with M. W. 164 and 178 were also tentatively identified.
No evidence for the presence of N-nitrosamine with low molecular weight was found.

View full abstract