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41.
NRSF regulates the fetal cardiac gene program and maintains normal cardiac structure and function 总被引:1,自引:0,他引:1
42.
A simple synthesis of beta-acaridial [(E)-1], the active principle of the sex, alarm and aggregation pheromone among astigmatid mites, was achieved in 5 steps from 1,2,4-butanetriol 2 in a 19% overall yield. Its analog, beta-acariolal 8, was also prepared in a 63% yield by oxidation of the intermediate, beta-acaridiol [(E)-7], with pyridinium dichromate (PDC). This synthetic route also gave beta-(Z)-acaridiol [(Z)-7] by using a Z-selective base in the Wittig reaction. (Z)-7 was oxidized to give a new monoterpene, beta-(Z)-acaridial [(Z)-1], which was detected as a trace component in the secretion of Caloglyphus polyphyllae, together with 8. 相似文献
43.
Isolation of Paenibacillus illinoisensis that produces cyclodextrin glucanotransferase resistant to organic solvents 总被引:1,自引:0,他引:1
A bacterium that secreted cyclodextrin glucanotransferase (CGTase) in a medium overlaid with n-hexane was isolated and identified as Paenibacillus illinoisensis strain ST-12 K. The CGTase of the strain was purified from the culture supernatant. The molecular mass was 70 kDa. The enzyme was stable at pH 6 to 10 and active at pH 5.0 to 8.0. The optimum temperature at pH 7.0 was 65 degrees C in the presence of 5 mM CaCl2. The enzyme produced mainly beta-cyclodextrin. The total yield of alpha-, beta-, and gamma- cyclodextrins was increased 1.4-fold by the addition of ethanol. In particular, the yield of beta-cyclodextrins in the presence of 10% (vol/vol) ethanol was 1.6-fold that without ethanol. The CGTase was stable and active in the presence of large amounts of various organic solvents. 相似文献
44.
Shimizu N Tarui H Mori N Nishida R Kuwahara Y 《Bioscience, biotechnology, and biochemistry》2003,67(2):308-313
The opisthonotal gland secretion of the acarid mite, Caloglyphus polyphyllae, contained two new monoterpenes, (E)-2-(2-hydroxyethylidene)-6-methyl-5-heptenal (1) and (E)-2-(2-hydroxyethyl)-6-methyl-2,5-heptadienal (2), to which we have given the trivial names alpha- and beta-acariolal in relation to alpha- and beta-acaridial (3 and 4), respectively. Elucidation of the structure of 1 was established mainly from 1H-NMR and GC/MS spectral data after partial purification, together with the fact that 1 was recovered in the more-polar fraction from a silica gel column than alpha- and beta-acaridial (3 and 4) present in the secretion. Compound 2 was obtained in the same fraction as a mixture with 1. Based on the facts that 2 had the same molecular weight by GC/MS and the same polarity as that of 1, compound 2 was assumed to be a structural analog of 1. The structures of compounds 1 and 2 were confirmed by their synthesis in nine and ten respective steps starting from alpha-bromo-gamma-butyrolactone. 相似文献
45.
Identification of volicitin-related compounds from the regurgitant of lepidopteran caterpillars 总被引:3,自引:0,他引:3
Mori N Yoshinaga N Sawada Y Fukui M Shimoda M Fujisaki K Nishida R Kuwahara Y 《Bioscience, biotechnology, and biochemistry》2003,67(5):1168-1171
Volicitin-related compounds were found in the oral secretion of the three noctuid species, Helicoverpa armigera, Mythimna separata and Spodoptera litura, and one sphingid species, Agrius convolvuli. Volicitin [N-(17-hydroxylinolenoyl)-L-glutamine], N-(17-hydroxylinoleoyl)-glutamine, N-linolenoylglutamine and N-linoleoylglutamine were identified in the secretion from the noctuid larvae. In secretions from the sphingid larvae, N-linolenoylglutamine and N-linoleoylglutamine were the main components. Furthermore, there were significant differences in the amounts of the N-acylamino acid conjugates in the secretions from the three noctuid species. These results suggest that the proportion of volicitin-related compounds in the regurgitant was species-specific. 相似文献
46.
Polymerization of guaiacol by lignin-degrading manganese peroxidase from Bjerkandera adusta in aqueous organic solvents 总被引:1,自引:0,他引:1
Lignin-degrading manganese (II) peroxidase (MnP) purified from the culture of a wood-rotting basidiomycete, Bjerkandera adusta, was used in the polymerization of guaiacol. MnP was found to catalyze polymerization of guaiacol in 50% aqueous acetone,
dimethyl formamide, methanol, ethanol, dioxane, acetonitrile, ethylene glycol and methylcellosolve. Maximum yield of polyguaiacol
was achieved in 50% aqueous acetone. The weight average molecular weight (M
w) of the polymer was estimated to be 30 300 by gel permeation chromatography. However, matrix-assisted laser desorption ionization
time of flight mass spectroscopy (MALDI-TOF-MS) analysis gave a more reliable M
w of 1690. IR, 13C-NMR, MALDI-TOF-MS and pyrolysis GC-MS analyses showed the presence of C–C and C–O linkages and quinone structure in polyguaiacol.
It was also indicated that polyguaiacol has a methoxy-phenyl group as the terminal moiety. This suggests that polyguaiacol
is a branched polymer in which guaiacol units are cross-linked at the phenolic group. Thermal gravimetric and differential
scanning calorimetric analyses were also carried out. MnP also catalyzed the polymerization of o-cresol, 2,6-dimethoxyphenol and other phenolic compounds and aromatic amines. M
w of these polymers ranged from around 1000 to 1500.
Received: 2 August 1999 / Received revision: 10 December 1999 / Accepted: 4 January 2000 相似文献
47.
Degradation of bisphenol A by the lignin-degrading enzyme, manganese peroxidase, produced by the white-rot basidiomycete, Pleurotus ostreatus 总被引:5,自引:0,他引:5
Hirano T Honda Y Watanabe T Kuwahara M 《Bioscience, biotechnology, and biochemistry》2000,64(9):1958-1962
Degradation of 2,2-Bis(4-hydroxyphenyl)propane (bisphenol A, BPA), an endocrine-disturbing chemical, by the growing mycelia of the white-rot basidiomycete, Pleurotus ostreatus, was examined. About 80% of BPA initially present decreased in 12 days of culture with this fungus. By in vitro experiments using the lignin-degrading enzyme manganese peroxidase (MnP), BPA was metabolized to phenol, 4-isopropenylphenol, 4-isopropylphenol, and hexestrol. The degradation products of BPA were assumed to be formed by the one-electron oxidation of the substrate. 相似文献
48.
Kuwahara C Kubosaki A Nishimura T Nasu Y Nakamura Y Saeki K Matsumoto Y Onodera T 《Biochemical and biophysical research communications》2000,268(3):763-766
In order to understand the fundamental and putative roles of PrP(c) in the central nervous system, neuronal cell lines were established. Cells were immortalized by recombinant retrovirus vector-mediated transduction of SV40 T-antigen gene. Among these, two cell lines were selected based on their RT-PCR expressions of neuron-specific neurofilament (NF-H, NF-M) and cell morphology. These cell lines showed the properties of neuronal progenitor cells in antigenicity, morphology and responses to differentiating agents. Expression of PrP(c) was detected by immunocytochemical analysis. These cell lines responded to differentiating agents such as dibutyl cyclic AMP (dcAMP) and phorbol 12-myristate 13-acetate (PMA) before developing into neuronal-like cells. Neurite extensions were observed 20 min after incubation with the differentiating agents. Treatment with nerve growth factor (NGF) and insulin induced cell differentiation and enhanced expression of PrP gene (Prnp) mRNA and protein. The latter phenomenon was not inhibited by wortmannin, which is a specific inhibitor of phosphatidylinositol 3-kinase. These results suggest that PrP(c) plays an important role in the differentiation-mediated classic signaling pathway of neuronal cell. 相似文献
49.
McKerrow JH Bhargava V Hansell E Huling S Kuwahara T Matley M Coussens L Warren R 《Molecular medicine (Cambridge, Mass.)》2000,6(5):450-460
BACKGROUND: Proteases facilitate several steps in cancer progression. To identify proteases most suitable for drug targeting, actual enzyme activity and not messenger RNA levels or immunoassay of protein is the ideal assay readout. MATERIALS AND METHODS: An automated microtiter plate assay format was modified to allow detection of all four major classes of proteases in tissue samples. Fifteen sets of colorectal carcinoma biopsies representing primary tumor, adjacent normal colon, and liver metastases were screened for protease activity. RESULTS: The major proteases detected were matrix metalloproteases (MMP9, MMP2, and MMP1), cathepsin B, cathepsin D, and the mast cell serine proteases, tryptase and chymase. Matrix metalloproteases were expressed at higher levels in the primary tumor than in adjacent normal tissue. The mast cell proteases, in contrast, were at very high levels in adjacent normal tissue, and not detectable in the metastases. Cathepsin B activity was significantly higher in the primary tumor, and highest in the metastases. The major proteases detected by activity assays were then localized in biopsy sections by immunohistochemistry. Mast cell proteases were abundant in adjacent normal tissue, because of infiltration of the lamina propria by mast cells. Matrix metalloproteases were localized to the tumor cells themselves; whereas, cathepsin B was predominantly expressed by macrophages at the leading edge of invading tumors. Although only low levels of urinary plasminogen activator were detected by direct enzyme assay, immunohistochemistry showed abundant protein within the tumor. CONCLUSIONS: This analysis, surveying all major classes of proteases by assays of activity rather than immunolocalization or in situ hybridization alone, serves to identify proteases whose activity is not completely balanced by endogenous inhibitors and which may be essential for tumor progression. These proteases are logical targets for initial efforts to produce low molecular weight protease inhibitors as potential chemotherapy. 相似文献
50.
Hatoko M Tanaka A Kuwahara M Tada H Imai K Muramatsu T 《Plastic and reconstructive surgery》2000,105(6):1940-1947
The authors present their experience with 25 hard palate mucosa grafts used as lining material in the reconstruction of full-thickness alar defects. Good "take" was obtained in 22 grafts; the other three grafts incurred necrosis of the overriding skin flaps and postoperative infection. Degree of shrinkage was 11 to 15 percent of grafted size in patients with the type of defect that did not include the alar margin; shrinkage was 26 to 35 percent in patients with the type that included more than 50 percent of the alar margin. In all patients who had a good graft take, the nasal cavities were maintained and there was no nasal obstruction or collapsing during strong breathing. The healing time of the palate donor site varied from 7 days to 5 weeks, depending on the size of the defect. No patients experienced any symptoms at the donor site after healing. The authors concluded that hard palate mucosa can be considered a useful material in alar reconstruction because of the ease in graft harvesting and its support features. When the defect is large enough to involve the total unilateral ala nasi, even though the degree of postoperative shrinkage is comparatively high, hard palate mucosa may be the most suitable material to ensure good take of the graft and less possibility of donor-site morbidity. 相似文献