We do not intend to give information about the structure of human chromosome 21 in detail but to give a kind of perspective of the present status of our knowledge about human chromosome 21 in this article. Recent development of molecular biology has changed revolutionarily the status of our knowledge of the human chromosome in general. Therefore we will choose a few aspects of the development in this field and want to discuss how we are able to use such information to understand the genetic disease including Down's syndrome.

View full abstract

2, 4, 5-Trihydroxyphenylalanine (6-hydroxydopa, abbreviated as topa) is a perhydroxylated derivative of an amino acid, tyrosine. It rarely occurs in nature as the free amino acid, but is well known as a very strong neurotoxic agent. The neurotoxicity is ascribed mainly to its chemical reactivity and redox capacity. In addition, the oxidized form of topa, topa quinone, has been shown to be an active non-N-methyl-D-aspartate glutamatergic agonist and to produce neuronal cell death. Topa and topa quinone may be biosynthesized enzymatically and non-enzymatically from dopa or from tyrosine through dopa. On the other hand, topa quinone bound covalently in a protein has been identified in copper amine oxidase, in which topa quinone serves as an essential cofactor in catalyzing the oxidation of amines. The topa quinone cofactor is produced by post-translational modification of a specific tyrosine precursor with the participation of the enzyme-bound copper ion. These physiological and biochemical features of topa quinone as well as its chemical properties revealed by recent model studies are reviewed here.

View full abstract

Protein kinase activity in the embryos of rice (Oryza sativa L. cv. Nipponbare) during seed soaking in water was assessed under various conditions. The histone III-S phosphorylating activity in the membrane fraction prepared from control seedlings treated with water was increased by the addition of Ca²⁺ (0.2 mM), and it increased further up on the simultaneous addition of phosphatidylserine (PS). By contrast, the activity in extracts prepared from ABA-treated seeds increased by Ca²⁺ alone and PS did not augment this increased level of activity. In vitro phosphorylation of the membrane fraction from control seeds in the presence of Ca²⁺ and PS resulted in phosphorylation of two proteins with molecular masses and isoelectric points of 40 kDa/8.9 and 40 kDa/7.6, respectively. When seeds were treated with exogenous ABA, phosphorylation in vitro of these two proteins was dependent only on the addition of Ca²⁺. V(6-Aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W-7) did not block phosphorylation of these proteins, which is dependent on Ca²⁺. The varieties and quantities of phospholipids in the seeds after soaking in water containing ABA were the same as those after soaking only in water. Phosphorylation of the 40-kDa proteins in vitro in the membrane fraction from control seeds required higher Ca²⁺ concentrations (1-2 mM) compared to that observed in the membrane fraction from ABA-treated seeds.

View full abstract

Of the streptomycin-dependent strains, SD 510 isolated from Salmonella typhimurium TA 98 provided a sharp response to mutagens without any metabolic activation; This fact is in contrast to the original test of Ames in which S-9 mix is usually added for routine screening of mutagens. The desmutagenic activity of the Maillard reaction products of glycine with glucose and of lysine with glucose was studied. The Maillard reaction products were prepared by heating at various temperatures lower than 120°C for 30 min at pH 7.0, and at 120°C for 30 min under various pH conditions, and their desmutagenic activity against Trp-P1 toward the SD 510 Salmonella typhimurium TA 98 strepto-mycin-dependent strain was assayed in the absence of S-9 mix. This SD strain is effective with its strong response and would serve as a reliable indicator organism for assessing the desmutagenicity of Maillard reaction products in the presence or absence of S-9 mix.

View full abstract

The Clostridium thermocellum endoglucanase CelJ contains two different catalytic domains in a polypeptide, i.e., a subfamily E1 catalytic domain and a family J catalytic domain [J Bacteriol., 178, 5732-5740 (1996)], , The family J catalytic domain (CDJ-CelJ) was produced by a recombinant Escherichia coli and purified. The purified CDJ-CelJ gave a single band on SDS-polyacrylamide gel electrophoresis and the molecular weight of this enzyme (60, 000) was consistent with the value (60, 333) calculated from the DNA sequence. CDJ-CelJ hydrolyzed various cellulosic substrates, xylan, and lichenan but not p-nitropbenyl (PNP)-cellobioside, PNP-glucoside, or PNP-xyloside at all. CDJ-CelJ was active on Avicel, a microcrystalline cellulose, and the specific activity of CDJ-CelJ on Avicel (0.0078U/mg protein) was comparable to that of CelS, which is recognized as the most important catalytic subunit of the C. thermocellum, cellulosome, suggesting that CelJ is also an important catalytic subunit in the cellulosome of this bacterium, in addition to CelS.

View full abstract

RNase LE from cultured tomato cells is a member of the RNase T₂ family. It is, however, distinguishable from RNase Rh from Rhizopus niveus, a typical RNase of the RNase T₂ family, by its CD spectrum in the 200-250 nm region. In order to reinvestigate the base specificity of RNase LE and to study the role of Asn44 in RNase LE, which is considered to correspond to the base recognition site Asp51 of RNase Rh, RNase LE, and its Asp mutant at the 44th position were expressed from yeast cells with the same expression system as RNase Rh [K. Ohgi, et al., L Biochem., 109, 776-785 (1991)]. RNase LE with four extra amino acid residues at the 2nd amino acid residue of mature RNase LE and its Asp44 mutant were secreted from yeast cells to give a yield of 10 mg/liter and 0.5 mg/liter culture broth, respectively. The expressed RNase LE (RNase RNAP LE) had the same characteristics as native RNase LE in the CD spectrum and specitic activity. This is the first example of the expression of plant RNase from microbes and in sufficient amount to perform further enzymological research. The base specificity of RNase LE was guanylic acid preferential and that of N44D was changed to a more adenylic acid preference as compared to that of RNase LE. These experiments showed that Asn44 of RNase LE is crucial for base recognition as the case of Asp51 in RNase Rh, and also suggested that the base recognition methanism of RNase LE is very similar to that of RNase Rh.

View full abstract

A strain of Acremonium sp. S4G13, which produced an enzyme producing nigerose, nigerosyl glucose, and nigerosyl maltose from maltooligosaccharides in high yield, was isolated from soil. From these observations, the enzyme was strongly supposed to be a novel enzyme that hydrolyzed maltooligosaccharides and released glucose, but also transferred the glucosyl moiety into the C-3 or C-4 position of the acceptor molecule by 2-form in significant amounts.

View full abstract

We investigated the effects of germinated barley foodstuff (GBF) on the fecal excretion and jejunum mucosal protein content in male Sprague-Dawley rats fed on various diets with the same protein and dietary fiber levels. Under these experimental conditions, GBF was confirmed to induce greater fecal output compared with commercial water-soluble or -insoluble dietary fibers. While the dietary fiber extracted from GBF increased the fecal output and mucosal protein content, the protein fraction of GBF degraded to the peptide form did not increase the fecal output or mucosal protein content. Increased mucosal protein and fecal output were thus found to require the presence of the dietary fiber fraction or possibly the protein fraction bound tightly to the dietary tiber of GBF. GBF feeding increaded the volatile fatty acids concentration in the cecum, indicating that GBF may be efficiently fermented in the intestinal tract.

View full abstract

We investigated the preventive effect of germinated barley foodstutf (GBF) added to the diet on diarrhea induced by the dietary water-soluble dietary fibers, polydextrose, hemicellulose, and poly-acrylic acid sodium salt, in Sprague-Dawley rats. The minimum content of GBF necessary for blocking diarrhea was 3% (by weight) of the diet. Since GBF is mainly derived from the aleurone and scutellum of malted barley, we assessed the physiological effects of the aleurone and scutellum fractions derived from barley grains before and after germination. The addition of fractions containing only germinated barley, and not barley collected before germination, increarsed the fecal output and jejunal mucosal protein content. The effects of malted barley were very similar to those of GBF. It was concluded that germination was necessary to bring about the physiological effects of GBF. Since non-lignified hemicellulose and Gln-rich protein were newly synthesized during germination, these might have contributed to the increased fecal output and jejunal mucosal protein content.

View full abstract

It was supposed that the solubility of (1→4)(1→6)-linked α-D-glucans, e.g., glycogen, phytoglycogen, and amylopectin, in water was related to the colloidal dispersion stability of such molecules and depended on the degree of branching. Since phytoglycogen has various degrees of branching according to the maturation of plant seeds, it was extracted from sweet corn kernels at several days after pollination (DAP), and we have investigated the effects of the degree of branching on the dispersion stability of phytoglycogen (DSP) by salting out, using ammonium sulfate ((NH₄)₂SO₄). As the sweet corn kernels matured, the concentration of (NH₄)₂SO₄ needed for salting out of phytoglycogen increased. According to the degree of branching mteasured by periodate oxidation analysis and β-amylolysis, the fraction of phytoglycogen precipitated at the high concentration with (NH₄)₂SO₄ has a highly branthed structure. The turbidity of phytoglycogen aqueous solution was also measured to discuss the relation between the dispersion stability of colloidal particles and the degree of branching. We found that the variation of the degree of branching is closely related to DSP in an aqueous solution.

View full abstract

An alcohol delhydrogenase (ADH) complex consisting of subunits I, II, and III and the free subunit II were purified from Acetobacter methanolicus, The kinetic parameters of the purified ADH were investigated with several artificial electron acceptors. Simultaneous reactions with different electron acceptors showed that these electron acceptors competed with each other. Although free subunit II did not show any enzyme activity, part of the activity was restored after reconstitution with subunit I/III complex purified from Gluconobacter suboxydans. 2-n-Heptyl-4-hydroxyquinoline-N-oxide (HQNO) non-competitively inhibited all the reductase activities of native ADH, while the ferricyanide reductase activity of hybrid ADH was not inhibited by HQNO but the ubiquinone reductase activity was inhibited competitively. The kinetic study of native and hybrid ADHs suggests that at least three heme c moieties are involved in the reduction of ferricyanide and that the reduction of ubiquinone occurs in subunit II at a site different from the ferricyanide reacting site.

View full abstract

The water activity and the activity coefficient of water (γw) were calculated from the freezing point depression by using the Hildebrand and Scott's equation for various. solutions of electrolytes, sugars, alcohols, amide, and urea. The water activity measured from the freezing point depression was very close to that at room temperature, showing that the effect of temperature on the water activity is neglegible. The activity coefficient of water was described well as a function of the solute mole fraction (X_s) by the following equation. γw =exp(αX²_S+βX³_S) The parameter α in this equation correlated well with the B-coefficient of viscosity for single-valent electrolytes, with the hydration parameter for nonelectrolytes, and with the number of equatorial-OH groups for sugars suggesting that the solution structure was reflected in this parameter

View full abstract

When grown on Fe²⁺-medium (pH 1.8) containing the following five L-amino acids: aspartic acid, glutamic acid, serine, arginine, and histidine, a moderately thermophilic iron-oxidizing bacterium, strain TI-1, produced hydrogen sulfide (H₂S) outside of the cells and synthesized a novel thiosulfate reductase, which catalyzed the reduction of thiosulfate with NAD(P)H as an electron donor to give H₂S. The activity of this enzyme in this bacterium increased 2-fold when elemental sulfur was added to this medium. Thiosulfate reductase was in the cytosol of the strain and was purified to an electrophoretically homogeneous state. The apparent molecular weight of thiosulfate reductase was 230, 000 by gel filtration and 58, 000 by SDS-PAGE, indicating that the enzyme is a homotetramer. The enzyme was most active at pH 6.0 and 60°C. Thiosulfate, but not elemental sulfur, sultite, or tetrathionate, was specifically used as an electron accepter of this enzyme. Both NADH and NADPH were used as electron donors. However, NADH was approximately 10 fold superior as an electron donor to NADPH. Reduced glutathione and mammalian cytochrome c were not used as electron donors. The Michaelis constants of this enzyme for thiosulfate, NADH, and NADPH were 0.29, 0.125, and 5.0mM.

View full abstract

A kinetic study was done to identify the ionizable groups in the active site of Aspergillus niger α-glucosidase (ANGase). From dependence of V and K_m values on pH, we obtained the ionization constants of essential ionizable groups 1 and 2 of free enzyme; pKe₁ = 3.2 and pKe₂ = 6.4. When the dielectric constant of the reaction mixture was decreased, the pKe₁ and pKe₂ were shifted to higher values. The ionization heats (ΔH's) of ionizable groups 1 and 2 were measured to be - 0.4 kcal/mol and 0 kcal/mol, respectively. The water-soluble carbodiimide (WSC), a specific reagent for carboxyl groups, inactivated the enzyme activity completely, and maltose as substrate decreased the inactivation. The WSC did not modify the free Cys. These findings suggest that the essential ionizable groups of ANGase are two kinds of carboxyl groups: one is a charged type (-COO^-, ionizable group 1), and the other is a protonated type (-COOH, ionizable group 2).

View full abstract

The locations of double bonds and the linearity of each carbon chain in 5-alk(en)ylresorcinols present in rye and wheat whole flour were determined from collision-activated dissociation (CAD) spectra by tandem mass spectrometry. Among the determined alk(en)ylresorcinols, eleven alkenylresorcinols (C₁₇ to C₂₃) and four alkadienylresorcinols (C₁₉ to C₂₅) had not been previously identified. In this study, we found that identification of a radical-anion fragment peak due to a simple allylic cleavage on the methyl side was essential for determining the locations of double bonds in positionally isomeric alkenylresorcinols. In addition, an analysis of the CAD spectra of lithium-adduct cations as precursor ions was useful for determining the locations of the homoconjugated (Z, Z)-diene group in alkadienylresorcinols.

View full abstract

We prepared amylose samples each incorporating one of several free fatty acids and amylose with a 1% concentration of each added free fatty acid. We then examined the thermal properties of each sample to compare the results previously obtained for the thermal properties of starch incorporating free fatty acids. The incorporated free fatty acid value increased with increasing molecular weight of the amylose component. But the free fatty acid values were not linearly related to the molecular weight of the amylose component. The DSC reheating curve for each sample had characteristics resulting from a different form of recrystallization by each free fatty acid. It seems that a saturated free fatty acid, which is shorter than an unsaturated one, could efficiently re-form an amylose/free fatty acid complex. In contrast, linoleic acid doed not form a complex, but coexists within the amylose chain and/or chain segments.

View full abstract

The volatile compounds in the leaves of Japanese pepper (Zanthoxylum piperium DC, sanshoh in Japanese) were obtained by steam distillation, and the potent odorants were evaluated by an aroma extract dilution analysis. (Z)-3-Hexenol and other C-6 compounds, contributing to the grassy aroma character, and citronellal and citronellol were most characteristic of the sanshoh aroma. The glycoside-containing fraction of the methanol extract was obtained by Amberlite XAD-2 adsorption, and then hydrolyzed by β-glucosidase, Rohapect D5L, and acetone powder from fresh sanshoh leaves. (Z)-3-Hexenol, citronellol, benzyl alcohol and 2-phenylethanol were liberated by each enzyme, while geraniol was liberated by Rohapect D5L. These results suggest that the characteristic aroma precursors of sanshoh leaves existed as glycosides.

View full abstract

By GL-affinity column chromatography (HPLC), a GL-binding lipoxygenase (gbLOX) was selectively purified from a partially purified soybean LOX-1 fraction. gbLOX was identified as LOX-3 since the partial N-terminal amino acid sequences of at least four fragments generated from the purified gbLOX (p96 and p94) digested with trypsin were identical to the corresponding sequences of soybean LOX-3. Thb inhibitory effects of various flavonoids and their modified derivatives, epigallocatechin gallate (EGCG) and a derivativc (oGA) of glycyrrhetinic acid on the activities of two LOXs [gbLOX and ngLOX (non-GL-binding LOX)] were examined in vitro. It was found that (i) four compounds [quercetin, EGCG, a derivative (2', 4'-DDC) of 3, 4-dihydroxychalcone, and oGA] inhibit gbLOX activity in a dose-dependent manner, but do not affect ngLOX activity; and (ii) quercetin as well as EGCG effectively prevents phosphorylation of gbLOX by casein kinase II (CK-II) in vitro. The results provided here suggest that the potent gbLOX inhibitors function as suppressors for the LOX-3-catalyzed metabolic pathways in plant cells.

View full abstract

Phenylethylamine oxidase (EC class 1.4.3) of Arthrobacter globformis IFO 12137 (ATCC 8010) was purified to homogeneity. The enzyme had a M_r of 141, 000 and was composed of two apparently identical subunits, which had a M_r of 71, 000 and contained one copper ion. The absorption spectrum of the enzyme had maxima at 280 and 480nm, and the ratio A₂₈₀/A₄₈₀ was 61, 5. Hydrogen peroxide was formed in the oxidation of amines. The enzyme was most active and stable at pH 6.5. 2-Phenylethylamine and tyramine were the most actilve substrates. Several aromatic monoamines, aliphatic monoamines with 4-11 carbons, higher aliphatic diamines, and histamine were poor substrates. Benzylamine, putrescine, spermine, and spermidine were not oxidized. The K_ms for 2-phenylethylamine and tyramine were 18 and 85 μM, and the V_maxs for them were 27.1 and 26.4 μmol/min/mg of enzyme, respectively. Benzyl alcohol was a non-competitive and benzylamine was a mix-type inhibitor of the enzyme. Carbonyl-blocking reagents such as methylhydrazine, Cu²⁺ -chelators, HgCl₂, p-chloromercuribenzoate, and Cl^- also inhibited the enzyme.

View full abstract

1-Aminocyclopropane-1-carboxylate (ACC) deaminase catalyzes the cyclopropane ring fragmentation and deamination of ACC. Replacement of cysteine with alanine at a reactive thiol site, Cys-162, of ACC deaminase did not affect the enzyme activity, in spite of the previous result that modification of Cys-162 caused complete loss of the enzyme activity. Substitution of glycine or valine for the cysteine residue gave a higher K_m for ACC without a significant change of the k_o, indicating that changes of the amino acid side chain had structural effects on substrate binding. Replacement of lysine with alanine at the pyridoxal phosphate (PLP) binding site of the ACC deaminase caused a lower content of PLP and loss of detectable activity of ACC deamination. This mutant enzyme, K51A, showed absorption peaks at 330 nm and 405 nm. The peak at 405 nm was shifted to about 425 nm by the addition of ACC, D-, L-alanine, and D-, L-serine. The formation of aldimine complexes indicated by the spectral shift was reversible. It is suggested that lysine 51 affects the formation of holoenzyme and is important in catalysis.

View full abstract

Enzymatic reactions involving pyruvate : ferredoxin oxidoreductase and 2-oxoglutarate : ferredoxin oxidoreductase from a thermophilic, aerobic, chemolithoautotrophic, and hydrogen-oxidizing bacterium, Hydrogenobacter thermophilus TK-6, were investigated as the CO₂ exchange reaction and CO₂ fixation reaction using ferredoxin isolated from the same organism as a reductant. The reduced ferredoxin was required in the pyruvate synthetic reaction and the 2-oxoglutarate synthetic reaction by a cell extract that had been treated with a PD-10 column to remove the low molecular weight substances. [¹⁴C] Pyruvate and [¹⁴C] 2-oxoglutarate were detected as products of pyruvate synthetic and 2-oxoglutarate synthetic reactions, respectively. Further evidence for the operation of pyruvate : ferredoxin oxidoreductase and 2-oxoglutarate : ferredoxin oxidoreductase was obtained from experiments on CO₂ exchange reactions using the purified enzymes.

View full abstract

Atherosclerotic lesions of the thoracic aorta were induced in exogenously hypercholesterolemic (ExHC) rats by treating initially with hypervitamin D₂ and subsequently feeding on hyperoholesterolemic diets for 180 days. Dietary soybean protein, in comparison with casein, substantially decreased the degree of atherosclerotic lesions, which was evaluated by intimal thickening, although with a similar topographical distribution, The casein-fed rats tended to maintain a high concentration of serum cholesterol, particularly in triacylglycerol-rich lipoproteins. The concentrations of apo A-I and TBARS in the serum was comparable between the dietary protein groups. The data suggest that dietary soybean protein, compared to casein, produced lipoproteins which were less atherosclerotic by partitioning cholesterol in the triacylglycerol-poor lipoproteins.

View full abstract

Bacillus circulans, a soil bacterium, produced an exocellular polysaccharide of high viscosity. On the basis of the results of methylation analysis, mild acid hydrolysis, and 1D and 2D ¹H-NMR spectroscopy, it was concluded that the polysaccharide has a basic repeating unit composed of β-L-rhamnopyanose, α-D-mannopyranose, α-D-galactopyranose, and α-D-glucopyranuronic acid with the following structure:[numerical formula]

View full abstract

A carbazole-using bacterium was isolated from oil polluted soil and identified as Flavobacterium sp. OCM-1 from its taxonomical characteristics. Its optimal culture conditions were identified. The growth and carbazole-degradation were found in the ranges of 20-30°C and pH 6-8. We found microbial production of indole-3-acetic acid from carbazole by strain OCM-1. Indole-3-acetic acid was identified as a metabolite of carbazole using thin-layer chromatography, mass and ¹H-NMR-spectra. 1.5 mg of indole-3-acetic acid was formed from 250 mg of carbazole.

View full abstract

Three series of ferulic acid derivatives (feruloylaminoacid benzyl ester or methyl ester, feruloyla.minoacid, and 4-O-[N-(carbobenzyloxy)-aminoacyl] ferulic acid) were synthesized newly, and their superoxide dismutase (SOD)-like, platelet aggregation (PA)-in-hibitory, tyrosinase-inhibitory, and angiotensin converting enzyme (ACE)-inhibitory activities were evaluated. 4-O-[N(Carbobenzyloxy)isoleucyl]ferulic acid (20) and 4-O-[N(carbobenzyloxy)prolyl]ferulic acid (21) showed potent PA-inhibitory activities and tyrosinase-inhibitory activities, while they also had SOD-like activities at the same level as ferulic acid.

View full abstract

meta-Cleavage dioxygenase genes were isolated from the benzoate-assimilating bacteria Pseudomonas stutzeri A401 and Pseudomonas mendocina KC37. The gene products had the enzymatic activity of 2, 3-dihydroxy-biphenyl-1, 2-dioxygenase. Phylogenetic analysis based on the alignment of amino acid sequences suggests that these enzymes are distantly related to other metacleavage enzymes and may be members of a new family of extradiol dioxygenases.

View full abstract

Nondialyzable model melanoidin prepared from glucose and glycine was oxidized with potassium ferricyanide or reduced with sodium borohydride. Compared with intact melanoidin, the oxidation reduced the pI value and increased the chelating activity, while reduction had the completely opposite effect. Both reactions on melanoidin increased the molecular weight and reduced the E^1%_500nm value.

View full abstract

The inhibitory activity of aggregated SQDG toward the α-glucosidase reaction decreased with increasing turbidity of the SQDG suspension. Dideacylated derivatives of SQDG, sulfoquinovosylglycerol and sulfoquinovose, showed no inhibition toward the reaction. The expression of inhibition by the SQDG family would require a hydrophobic acyl group(s) to produce an aggregate and/or interact with a hydrophobic site in the enzyme.

View full abstract

The monosaccharides 2-O-methyl-L-rhamnose and 3-O-methyl-L-rhamnose were isolated and identified as components of the acidic polysaccharide of Chlorella vulgaris K-22. 2-O-Methyl-L-rhamnose was first found in algae.

View full abstract

Staphylococcus aureus P83 (ATCC 31890) produces five components, I to V for synergistic toxins, leukocidin and γ-hemolysin [Sudo et al., Biosci. Biotech. Biochem., 56, 1786-1789 (1995)]. We report here the identification of component II, which is designated LukF-PV(P83) and its gene (lukF-PV(P83)). The lukF-PV(P83) gene was found to be one base downstream of the stop codon of the lukM gene. The deduced amino acid sequence of LukF-PV(P83) showed 78.4% identity with that of LukF-PV. The lukM and lukF-PV(P83) genes were encoded as one operon like that of Panton-Valentine leukocidin.

View full abstract

Maize C₄-type phosphoenolpyruvate carboxylase (PEPC) was expressed in E. coli with the pET32 system. The expressed fusion PEPC was active and its amount comprised more than 10% of total soluble protein. The specific activity inbreased by about 45-fold, compared with our previous system [S. Yanagisawa and K. Izui, Agric. Biol. Chem., 54, 241-243 (1990)]. The fusion PEPC was rapidly purified with His bind metal chelation resin, showing a single band on SDS-PAGE. Moreover, the tag domain fused at the N-terminus did not have any effect on catalytic and regulatory properties of PEPC.

View full abstract

Direct enantiomeric resolution of the germacrene-D derivative, (5E, 7S^*, 9S^*)-9-hydroxy-7-isopropyl-4, 10-bis(methylene)-5-cyclodecen-1-one, was carried out by HPLC with a chiral stationary phase. This method showed that germacrene-D contained in ylang ylang oil was 98% e.e., whereas germacrene-D extracted from Solidago altissima L. was almost racemic.

View full abstract

1, 5-Dihydroxyiridanyl-lycopene was isolated from tomato puree. The oxidation of lycopene by hydrogen peroxide also afforded 1, 5-dihydroxyiridanyl-lycopene, in addition to lycopene-1, 2-epoxide and 1, 5-epoxyiridanyl-lycopene. A reaction pathway for this dihydroxy compound is proposed.

View full abstract

Two arrestants of the sawtoothed grain beetle (Oryzaephilus surinamensis L.), 13-oxo-(Z)-9-octadecenoic acid and 15-oxo-(Z)-11-icosenoic acid, were synthesized for the first time by utilizing a Z-selective Wittig reaction.

View full abstract

The gpd1⁺ gene of Schizositccharomyces pombe, encoding an isozyme of NADH-dependent glycerol-3-phosphate dehydrogenase, is responsible for an osmoinducible glycerol production in response to external high osmotic stimuli, and its expression is osmoregulated at the level of transcription. In this study, the structure of the osmoinducible promoter of gpd1⁺ is described. Not only the core promoter element including the putative TATA-box and transcription start site, but also a short upstream activation sequence (UAS) was identified, which are involved in the osmotic induction of the gpd1⁺ gene through the Wisl MAP (mitogen activated protein) kinase pathway.

View full abstract

Evidence is presented for gibberellin A₁ (GA₁) being bioactive per se in regulating the shoot elongation of Phaseolus vulgaris. It is also suggested that the lower response of cv. Masterpiece (dwarf) to GA₁ than of cv. Kentucky Wonder (normal) was not due to any difference in GA₁ metabolism, but to a defect in the sequence of events from the reception of GA₁ to elongation.

View full abstract

To clarify the immunoglobulin production-regulating activity of vegetable extracts, mesenteric lymph node lymphocytes of Sprague-Dawley rats were cultured in the presence of 25 different vegetable extracts. The immunoglobulin content in the culture medium determined by ELISA indicated that the lily family (Liliaceae) vegetables most strongly enhanced the production of IgA and IgG, whereas they suppressed IgE production.

View full abstract

An inhibitor of Serratia metalloproteinase was found in the cultured broth of strain SI-23, which was identified to be Actinosynnema sp. The inhibitor had a potent inhibitory effect on Serratia metalloproteinase and a weak effect on thermolysin, but no effect on other groups of proteinases. The structure of the inhibitor was deduced to be propioxatin A, reported as an enkephalinase B inhibitor.

View full abstract

To control the extent of deacidification in wine making, we screened Kluyveromyces strains by their activity to kill the fission yeast Schizosaccharomyces pombe. Among Kluyveromyces IFO strains tested, K. waltii IFO 1666T was shown to have the desired activity. The killer spectrum of this strain was different from those of the other known killer yeasts. The activity was found in the culture medium and was lost by protease treatment. The activity was associated with the precipitate obtained by an increase of ammonium sulfate concentration. The toxin was larger than 10, 000 daltons as judged by ultrafiltration.

View full abstract