The influence of tea catechins on the absorption of starch or sucrose was investigated in vivo. Tea catechins were administered orally to rats before soluble starch or sucrose administration. Saccharide-dosed rats were killed and the blood and the contents of the intestine were collected at intervals over two hours. Catechins of certain concentrations suppressed the increase of plasma glucose levels, thus concurrently suppressing insulin activity. Increased activity of intestinal α-amylase by starch dosing was inhibited markedly in the catechin-administered rats. Sucrase on the brush border membrane was also inhibited by prior catechin administration. From these results it was assumed that orally administered catechins will inhibit intestinal α-amylase or sucrase, thereby deterring the digestion of certain amounts of starch or sucrose and eventually reducing the plasma glucose levels.

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The scaling law derived from the percolation theory was applied to the concentration dependence of mechanical properties of polyacrylamide measured near the sol-gel transition point. The critical concentration of the sol-gel transition, φ_g, was estimated from the plot of concentration (φ) vs. the reciprocal of viscosity (η) by extrapolating 1/η to zero. The critical exponent for the sol viscosity, s, which was estimated from the slope of the log(φ_g-φ) vs. log η plot was about 0.7. The estimated value of s was similar to the value predicted by the percolation theory based on the superconductor-normal conductor mixture model. The critical exponent for the gel elasticity, t, was estimated from the slope of the log(φ-φ_g) vs. log G' plot, where G' was the dynamic shear modulus of the gel at a frequency of 2Hz. The value of t was about 2, which was also similar to the value predicted by the percolation theory. These results indicated that the concentration dependences of η and G' of polyacrylamide near the sol-gel transition point were described by the percolation theory.

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The concentration dependence of mechanical properties for gelatin near the sol-gel transition point was analyzed by the scaling law derived from the percolation theory, and compared with the results previously obtained for polyacrylamide. The critical concentration at the sol-gel transition point, φ_g, was estimated from the concentration (φ) vs. the reciprocal of viscosity (η) plots by extrapolating 1/η to zero. The critical exponent for sol viscosity, s, was estimated from the slope of a log(φ_g-φ) vs. log η plot. The critical exponent s was about 1.1, being larger than the value predicted by the percolation theory assuming the superconductor model. The critical exponent for gel elasticity, t, was estimated from the slope of a log(φ-φ_g) vs. log G' plot, where G' is the dynamic shear modulus at a frequency of 2 Hz. The critical exponent t was about 2, being similar to the value predicted by the percolation theory.

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Secondary structure, microstructure, and mechanical properties of heat induced 11S globulin gel were studied to discover their relationships. Heat-induced 11S globulin gel at 80, 90, and 95°C were comprised of 7.2, 16.6, and 23.8% of α-helix ; 19.4, 19.5, and 27.5% of β-sheet, and 73.5, 64.5, and 48.6% of random coil, respectively. This indicated the gel formed at higher temperatures contained more α-helix and less random coil structures. Micrographs of gels heated at 90 and 95°C had a more extended and integral matrix. Gel strength of heat-induced gels at 90 and 95°C were significantly greater than that of 80°C. These data indicated that the increase in α-helix of heat-induced 11S globulin gel have facilitated the establishment of a good gel matrix.

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The effect of soybean grinding temperature on the firmness of tofu was investigated. The firmness of tofu decreased with increasing grinding temperature between 0°C and 50°C, this being related to the content of sulfhydryl (SH) groups in soymilk. It could, therefore, be presumed that the decrease in firmness depended upon the decrease in SH content, which was of enzymatic nature and closely correlated with the peroxide value. These facts suggested that the decrease in SH content was caused by a lipid oxidative reaction of lipoxygenases in soybean. When the soybean was ground at a low temperature and in a nitrogen atmosphere to inhibit the action of lipoxygenase, the soymilk was rich in SH content and formed firmer tofu.

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The composition and the structures of native "group B saponin" in soybean seeds were reinvestigated. Five kinds of saponins named soyasaponins αg, βg, βa, γg, and γa, according to elution order from HPLC, were isolated and the structures were characterized as 2, 3-dihydro-2, 5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) attaching through an acetal linkage to the C-22 hydroxyl of the aglycones of soyasaponins V, I, II, III, and IV, respectively, by UV, IR, MS, and NMR. DDMP-conjugated saponins were detected as major saponin constituents by extraction under mild conditions, and soyasaponins I-V were not detected. Therefore it was strongly suggested that these DDMP-conjugated saponins were genuine saponins in the intact soybeans.

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Enterococcus faecium-100, screened from 120 strains of lactic acid bacteria, produced an antibacterial substance. From the narrow inhibitory spectrum, proteineous nature, and bactericidal mode of action, this antibacterial substance was concluded to be a bacteriocin and designated enterocin-100. E. faecium-100 produced bacteriocin during its log phase and in a narrow pH range of the culture broth around pH 6.3. Enterocin-100 was most active at neutral pH between 6 and 8, and was stable below pH 5.0. From the scanning electron microscopic observation, enterocin-100 caused morphorogical changes especially in highly sensitive bacteria at log and stationary phase.

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The effect of sucrose esters of fatty acids with carbon numbers from 8 to 16 on soybean lipoxygenase-1 (L-1) was investigated. The sucrose esters inhibited L-1 and the inhibitory effect increased with an increase in the carbon number of the fatty acid up to 12, being constant above 12. Kinetic studies showed that two molecules of the sucrose ester bound to L-1 and inhibited it competitively. Based on the behavior of pK_i dependence on the carbon chain length of the sucrose esters, the dodecyl group appeared to be optimum to bind L-1. The results suggest that sucrose esters bind to the catalytic site of L-1 by hydrophobic interaction of the fatty acid and lead to the loss of activity. Sucrose esters, which are widely used as an emulsifier, can be an effective inhibitor of enzymatic lipid peroxidation in food processing.

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The behavior of 2-O-α-D-glucopyranosyl-L-ascorbic acid (AA-2G) in a whole wheat flour suspension was investigated. AA-2G was hydrolyzed by a non-dialyzable and heat-labile component in flour and liberated L-ascorbic acid (AA). The pH profile for the hydrolysis is similar to that of rice α-glucosidase. However, the hydrolysis of AA-2G was inhibited completely by endogenous sugars, mainly maltose, which were produced rapidly during the hydration of flours. In the presence of Saccharomyces cerevisiae strain with a strong maltose-utilizing capability, the hydrolysis of AA-2G proceeded in a flour suspension, and was followed by the formation of dehydro-L-ascorbic acid. The hydrolysis of AA-2G also proceeded in yeasted dough, concomitant with increases in the resistance on an extensigram and in the loaf volume of the bread. These effects of AA-2G on dough were less than those of equimolar AA because of the imperfect liberation of AA. The results show that AA-2G could be useful as a highly stable dough improver.

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The fusion (F) and hemagglutinin-neuraminidase (HN) glycoproteins of Sendai virus were expressed using a baculovirus expression vector to examine the structures and functions of these proteins. Both proteins were detected in Spodoptera frugiperda (Sf) cells infected with the recombinant viruses on immunoprecipitation and indirect immunofluorescence staining. The molecular weights of the expressed F and NH proteins were 66 kDa and 70-72 kDa, respectively, suggesting that both proteins were glycosylated, and the F protein was not cleaved into F₁ and F₂ even when the F and HN proteins were coexpressed.

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Muscle proteases from mackerel and milkfish were purified to electrophoretical homogeneity by concanavalin A-Sepharose and Sephadex G-100 chromatographies. Both proteases appear to be an aspartic protease, cathepsin D (EC 3.4.23.5). The molecular weights of the purified cathepsin D's from mackerel and milkfish were 51, 000 and 54, 000, estimated by Sephadex G-100, and 59, 000 and 61, 000 by SDS-PAGE, respectively. Both cathepsin D's were completely inhibited by pepstatin, but not affected by leupeptin, N-ethylmaleimide, dithiothreitol, or glutathione. β-Mercaptoethanol, iodoacetic acid, p-chloromercuri-benzoate, phenylmethylsulfonyl fluoride, and sodium dodecyl sulfate partially or completely inhibited both cathepsin D's. Na⁺ and K⁺ partially activated the cathepsin D from milkfish. Both cathepsin D's were inhibited by Mg²⁺, Sr²⁺, Fe²⁺, and Hg²⁺, but activated by Ca²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, and Cd²⁺. The pI and optimal temperature of the cathepsin D's from mackerel and milkfish were 5.04 and 4.91, 45°, and 50°C, respectively. The temperatures for inactivating 50% activity of the cathepsin D's from mackerel and milkfish during 20 min of incubation were 53° and 48°C, respectively. Both cathepsin D's had similar optimal pHs near 3. The activity of that from milkfish markedly decreased when the pH was higher than 4, and was almost completely lost at pH above 6, while that from mackerel still had at least 40% activity at pH 6.

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After heat treatment at 55°C for 15s, Escherichia coli cells were incubated at 37°C in a chemically defined medium for cell recovery from heat injury. During this period, four heat-inducible proteins with similar molecular masses of 15kDa or so but different isoelectric points were found to appear and to be sedimented by ultracentrifugation. This subset of proteins were σ³²-dependent and two of them were C14.7 and G13.5 proteins, which have been known as heat shock proteins (HSPs), but the other two, which were designated here as B and F proteins, are unknown. The 15-kDa proteins were solubilized by the treatment of the sediment with 6M urea. The result obtained by peptide mapping of these proteins suggests that B and F proteins may be modified forms of C14.7 and/or G13.5 proteins and that these proteins have a homologous structure.

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To delineate the mosquitocidal regions of the ISRH3 (CryIVB) and ISRH4 (CryIVA) proteins, which are two of the mosquitocidal 130-kDa proteins contained in the crystalline protein bodies (CPBs) of Bacillus thuringiensis var. israelensis (BTI), a deletion analysis of these protein genes has been done. Based on the evidence that each 130-kDa protein had two mosquitocidal regions, N-terminal and C-terminal ones, and these two regions shared a common part in the center of the 130-kDa proteins, deleted genes on this region were constructed. As the protein products which lacked the central region had reduced activities, the central region could be important for the mosquitocidal activity. The mosquitocidal and non-mosquitocidal truncated gene products of 130-kDa protein genes were also applied to a cultured lepidopteran cell line, TN-368. The mosquitocidal proteins caused the swelling and disruption of the cells in spite of the insecticidal specificity of CPBs of BTI, but the non-mosquitocidal proteins did not. Therefore, TN-368 cells were sensitive to the mosquitocidal fragments of 130-kDa proteins of BTI under the assay conditions used.

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An analysis of the aroma components of Asakura-sanshoo leaves was conducted by using head-space gas chromatography. It shows that a greater part of the shoot-tip culture lines of Asakura-sanshoo preserved the same characteristics as those of the parent plant with respect to aroma productivity in the secondary metabolites, apart from a few variant strains. It was found, however, that the level of total aroma components of selected variant culture lines gradually increased during five subcultures, although that of the control culture lines remained low. Thus, the combination of shoot-tip culture and selection was found to be very effective for improving Asakura-sanshoo with high aroma emanation.

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An esterase with excellent stereoselectivity for (+)-trans-ethyl chrysanthemate was purified to homogeneity from Arthrobacter globiformis SC-6-98-28. The purified enzyme hydrolyzed a mixture of ethyl chrysanthemate isomers stereoselectively to produce (+)-trans-acid with 100% stereoisomeric purity. The apparent molecular weight of the purified enzyme was 43, 000 on SDS-polyacrylamide gel electrophoresis, and 94, 000 on gel filtration chromatography. The optimum conditions for the ester hydrolysis were pH 10.0 at 45°C. The purified esterase hydrolyzed short-chain fatty acid esters, but did not have detectable activity on long-chain water-insoluble fatty acid esters. The enzyme activity was inhibited by diisopropyl fluorophosphate and phenylmethylsulfonyl fluoride.

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To study the carcinogenic activity of bile acids, we examined the mutagenic activity of bile acids by Rec-assay using B. subtilis H17 and M45 strains. Cholic, chenodeoxycholic, lithocholic, and glycolithocholic acids exerted much weaker mutagenicity than mitomicin C (MMC), and deoxycholic and glycodeoxycholic acids showed toxicity toward the bacteria. Most of the conjugated bile acids (glycocholic, taurocholic, and taurodexycholic acids). and their amino acid components (glycine and taurine) were neither toxic nor mutagenic. No bile acids enhanced the mutagenicity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), but glycine enhanced both toxicity and mutagenicity of MNNG in a dose-dependent manner. On the other hand, taurine decreased the mutagenicity of MNNG, and most of the bile acids decreased the mutagenicity of MMC. Furthermore, taurocholic acids decreased toxicity and/or mutagenicity of other bile acids. These results suggested that the mutagenic and comutagenic activities of bile acids can be disregarded, but they are antimutagenic in some situations.

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The ice nucleation-active protein of Erwinia ananas IN-10 (inaA protein) was over-expressed as inclusion bodies in Escherichia coli in a yield of 15.3mg of inaA protein from 60mg of bacterial cells on a dry-matter basis. The inaA protein was purified from the inclusion bodies by solubilization with detergents to obtain a protein preparation free from sugar and lipid. This preparation had a distinct ice nucleation activity, indicating that the inaA protein per se is able to act as a nucleus.

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To study how much the side chains of the corrin ring of vitamin B₁₂ are involved in the physiological roles of the vitamin, five vitamin B₁₂ analogues (cyanocobalamin-b-monocarboxylate, cyanocobalamin-d-monocarboxylate, cyanocobalamin-e-monocarboxylate, cyano-13-epicobalamin, and cyanocobalamin(c-lactam)) with alternations in the side chains were synthesized chemically and then administered orally and intravenously to vitamin B₁₂-deficient rats. Male rats fed a vitamin B₁₂-deficient diet for 11 wk developed a severe vitamin B₁₂ deficiency with a high urinary methylmalonate excretion (223.8 ± 136.2 μmol/d) and ∼97% (1.2±0.7ng/g tissue) lower hepatic vitamin B₁₂ content. Oral and intravenous administration of cyanocobalamin-b-, -d-, and -e-monocarboxylates and cyano-13-epicobalamin could not improve the severe vitamin B₁₂-deficient status of the rats, indicating that the b-, d-, and e-propionamide side chains of the corrin ring of vitamin B₁₂ are important in the absorption, transport, and function of the vitamin in rats. Urinary methylmalonate excretion of the rats that were intravenously administered cyanocobalamin(c-lactam) increased twice as much as those of the other analogue-supplemented rats, suggesting that cyanocobalamin(c-lactam) act as a powerful Cbl-antagonist. The results also indicate that mammalian cells do not contain a system for synthesizing complete vitamin B₁₂ from these analogues.

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The effects of oxygenated fatty acids were recorded as ED₅₀ values for inhibition of germination and germ tube elongation of the spores of rice blast fungus. The oxygenated fatty acids were potent inhibitors between 20-40ppm. When Sasanishiki rice plants were treated with the major components, epoxy-fatty acids, the rate of susceptible lesions formed on the leaves were lower than those of non-treated control, indicating induction of resistance to the pathogen by the epoxides in the plants. In addition, it was shown by an uptake experiment using [1-¹⁴C] derivatives that the epoxy-fatty acids were clearly incorporated into rice leaves.

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A very sensitive and efficient high performance liquid chromtographic (HPLC) method for measuring 0.5-50ng of free and acylated sterylglycosides (FSG and ASG) in oils in the form of their 1-anthroylnitrile derivatives has been developed. Before to derivatization, the whole sterylglycosides were simply isolated with silica gel cartridge then fractionated via thin layer chromatography (TLC) into pure FSG and ASG. Derivatization was done on the FSG molecular species, therefore ASG was converted into FSG with mild alkaline hydrolysis. The derivatives separated by reversed phase mode were detected at 254nm. Avenasterylglycoside can not be separated from isofucosterylglycoside and campesterylglycoside from stigmasterylglycoside. The method was successful with to different vegetable oils commercially extracted with hexane as well as those laboratory-extracted with a polar solvent mixture.

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Among 29 strains of zygomycetes screened for serine carboxypeptidases, Absidia zychae NRIC 1199 showed the highest enzyme production. Two serine carboxypeptidases, CPZ-1 and CPZ-2, were purified to a homogeneous state from an extract of koji culture of A. zychae NRIC 1199. Purified CPZ-1 and CPZ-2 showed similar properties except the isoelectric point (pI) ; The pI of CPZ-1 and CPZ-2 were 4.50 and 4.65, respectively. The molecular weights of the CPZ-1 and CPZ-2 were 48, 000 by SDS-PAGE and gel filtration. Among the proteinase inhibitors tested, phenylmethylsulfonyl fluoride and monoiodoacetic acid strongly inhibited the enzyme activity. The optimum pHs of CPZ-1 and CPZ-2 were 4.2 towards Z-Glu-Tyr. It is shown that the substrate specificities of CPZ-1 and CPZ-2 were dependent on the presence of bulky amino acid residues in the penultimate position (P₁) for the small Z-peptides. However, in spite of the presence of Gly, Asp, Arg, or Pro in the P₁ position, oligopeptides were hydrolyzed rapidly. CPZ-1 and CPZ-2 had not only carboxypeptidase but also carboxyamidase and amidase activities, and acted preferentially as a carboxyamidase for C-terminal amidated peptides. The hydrophobicity of P₂ and P₃ positions and the bulkiness of P₁ and P'₁ positions of the substrate may be important for carboxyamidase and amidase activities.

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The precise distributions of α-1, 4-unit-chains of several kinds of glycogens, average chain length 7-13, from different sources, e.g., mammals, shellfish, mushrooms, and microorganisms, were compared using high performance anion exchange chromatography (HPAEC). These glycogens were completely debranched, and a series of maltosaccharides derived from individual unit-chains were analyzed. Most glycogens had similar chromatographic profiles, with degrees of polymerization (DPs), from 4-5 to 35; oyster glycogen contained shorter chains of DP 2-3. On the other hand, molar-based distribution patterns of these glycogens appeared to be specific to their origins. Ratios of their A- to B-chains varied from 0.6 : 1 to 1.2 : 1, as estimated by quantitative HPAEC of maltosaccharides by debranching of the β-limit dextrins. Possible chain lengths of the exterior A-chains were also discussed.

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The conversion of prochaetoglobosins as plausible precursors into mycotoxin chaetoglobosin A (1) in a cell-free system of Chaetomium subaffine was unsuccessful. However, reductase activity of the 20-keto-analogues (1), and prochaetoglobosins II (5) and III (6) were found in a microsomal fraction of this fungi. Two new metabolites of chaetoglobosins, named chaetoglobosin F_ex (2) and 20-dihydro-chaetoglobosin A (3), were also isolated from the same micro-organisms. Their structures were elucidated by spectroscopic data and chemical transformation.

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Thienodolin, a new plant growth-regulating substance, was isolated from the fermentation broth of a streptomycete strain identified as Streptomyces albogriseolus. The active principle was extracted with ethyl acetate and purified by silica gel column chromatography and preparative HPLC. The substance showed growth promoting activity with 1.2×10^-6-1.2×10^-5M treatment to rice seedlings, and inhibitory activity with 4.0×10^-5M treatment.

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Thienodolin is a new plant growth-regulating substance produced by a Streptomycete strain. The structure of thienodolin was determined to be 6-chloro-8H-thieno[2, 3-b]indole-2-carboxamide by spectroscopic analyses and an X-ray crystallographic analysis.

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Many strains of a black yeast, identified as Aureobasidium sp., were isolated by a selective medium, which contained mannitol as a main carbon source, and found to produce an extracellular biopolyester from glucose. The biopolyester was recovered as its calcium salt (61g) from culture filtrate (1 liter). The acid hydrolysis and the transmethylation of the polyester proved L-malic acid to be its monomeric repeating unit. The saponification of the polyester, however, gave fumaric and maleic acids in about 20% yield, in addition to the malic acid. ¹H NMR analysis proved the main-chain ester linkage of the polyester to be β-type. The apparent molecular mass was estimated to be distributed between about 6 and 11 kDa in a buffer (pH 6.8) with a high ionic strength (0.2M).

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Three chitinases, designated RSC-a, -b, and -c, were purified from the seeds of rye (Secale cereal) using ammonium sulfate precipitation, CM-cellulose column chromatography, gel filtration on Sephadex G-75, and S-Sepharose column chromatography. RSC-a, -b, and -c are basic proteins having molecular masses of 33 kDa, 26 kDa, and 26 kDa, and isoelectric points of 9.7, 10, and > 10, respectively. RSC-b and -c were found to be homologous proteins having similar amino acid compositions and N-terminal sequences. RSC-a contains more Thr, Ser, Glu, Pro, Gly, and Cys than RSC-b and -c and has a different N-terminal sequence from them. They hydrolyze glycolchitin and colloidal chitin, but not cell walls of Micrococcus lysodeikticus. These enzymes are stable at pH 4-8 and their optimum pHs toward glycolchitin are 5.

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Four geometric isomers of the eri-silk moth pheromone, (11z)-4, 6, 11-hexadecatrienals, including the natural pheromone, (4E, 6E, 11Z)-4, 6, 11-hexadecatrienal (19), were prepared and their pheromone activities toward male eri-silk moths were evaluated. In the conventional fluttering test, each of the synthesized trienal fractions showed activity, the 50% active minimum concentration of natural pheromone 19 being observed to be 10^-3 mg/ml. The pheromone activities of these geometric isomers were compared by the EAG/GLC method and found in order of increasing activity to be (4Z, 6E, 11Z)-≥(4E, 6Z, 11, Z)->(4E, 6E, 11Z)-»(4Z, 6Z, 11Z)-hexadecatrienal.

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