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61.
Hosoe T Nozawa K Kawahara N Fukushima K Nishimura K Miyaji M Kawai K 《Mycopathologia》1999,146(1):9-12
An indole derivative, schizocommunin, was isolated along with indigotin (indigo), indirubin, isatin, and tryptanthrin, from
the liquid culture medium in which a culture of Schizophyllum commune, isolated from the bronchus of a human patient with allergic bronchopulmonary mycosis, had been grown. The structure of schizocommunin
was established by spectroscopic investigation. Schizocommunin showed the strong cytotoxicity against murine lymphoma cells.
The assignments of the 1H- and 13C-NMR signals of indigotin were also listed.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
62.
63.
The medaka, Oryzias latipes, has an XX/XY sex determination mechanism. A Y-linked DM domain gene, DMY, has been isolated by positional cloning as a prime candidate for the sex-determining gene. Furthermore, the crucial role of DMY during male development was established by studying two wild-derived XY female mutants. In this study, to find new DMY and sex-determination related gene mutations, we conducted a broad survey of the genotypic sex (DMY-negative or DMY-positive) of wild fish. We examined 2274 wild-caught fish from 40 localities throughout Japan, and 730 fish from 69 wild stocks from Japan, Korea, China, and Taiwan. The phenotypic sex type agreed with the genotypic sex of most fish, while 26 DMY-positive (XY) females and 15 DMY-negative (XX) males were found from 13 and 8 localities, respectively. Sixteen XY sex-reversals from 11 localities were mated with XY males of inbred strains, and the genotypic and phenotypic sexes of the F(1) progeny were analyzed. All these XY sex-reversals produced XY females in the F(1) generation, and all F(1) XY females had the maternal Y chromosome. These results show that DMY is a common sex-determining gene in wild populations of O. latipes and that all XY sex-reversals investigated had a DMY or DMY-linked gene mutation. 相似文献
64.
Ishibashi K Miura NN Adachi Y Tamura H Tanaka S Ohno N 《FEMS immunology and medical microbiology》2004,42(2):155-166
We have recently demonstrated that the cell wall beta-glucan of Candida albicans could be solubilized by sodium hypochlorite, followed by dimethylsulfoxide-extraction (NaClO-DMSO method). In this study, applying this method to Aspergillus spp., we prepared mycelial cell wall beta-glucan and examined its physical properties and immunotoxicological activity. The acetone-dried mycelia of Aspergillus spp. were oxidized by the NaClO-DMSO method. An analysis of (13)C NMR spectra revealed the preparations to be composed of alpha-(1 --> 3) and beta-(1 --> 3)-D-glucan. Also, the proportion of alpha-(1 --> 3) and beta-(1 --> 3)-D-glucan varied. Furthermore, a solubilized Aspergillus beta-glucan (ASBG) was prepared from OX-Asp by urea-autoclave treatment. ASBG showed limulus activity similar to Candida solubilized beta-glucan (CSBG), and there was little difference in the activity of ASBG between various Aspergillus spp. ASBG affected the production of IL-8 by human peripheral blood mononuclear cells (PBMC). ASBG should be useful for analyzing the clinical role of beta-glucan. 相似文献
65.
Soeda S Tsuji Y Ochiai T Mishima K Iwasaki K Fujiwara M Yokomatsu T Murano T Shibuya S Shimeno H 《Neurochemistry international》2004,45(5):619-626
Magnesium-dependent neutral sphingomyelinase (N-SMase) present in plasma membranes is an enzyme that can be activated by stress in the form of inflammatory cytokines, serum deprivation, and hypoxia. The design of small molecule N-SMase inhibitors may offer new therapies for the treatment of inflammation, ischemic injury, and cerebral infarction. Recently, we synthesized a series of difluoromethylene analogues (SMAs) of sphingomyelin. We report here the effects of SMAs on the serum/glucose deprivation-induced death of neuronally differentiated pheochromocytoma (PC-12) cells and on cerebral infarction in mice. SMAs inhibited the enhanced N-SMase activity in the serum/glucose-deprived PC-12 cells, and thereby suppressed the apoptotic sequence: ceramide formation, c-Jun N-terminal kinase phosphorylation, caspase-3 activation, and DNA fragmentation in the nuclei. Administration of SMA-7 (10 mg/kg i.v.) with IC50= 3.3 microM to mice whose middle cerebral arteries were occluded reduced significantly the size of the cerebral infarcts, compared to the control mice. These results suggest that N-SMase is a key component of the signaling pathways in cytokine- and other stress-induced cellular responses, and that inhibiting or stopping N-SMase activity is an important strategy to prevent neuron death from ischemia. 相似文献
66.
Nakayama K Kawato H Watanabe J Ohtsuka M Yoshida K Yokomizo Y Sakamoto A Kuru N Ohta T Hoshino K Yoshida K Ishida H Cho A Palme MH Zhang JZ Lee VJ Watkins WJ 《Bioorganic & medicinal chemistry letters》2004,14(2):475-479
The addition of substituents to the pyridopyrimidine scaffold of MexAB-OprM specific efflux pump inhibitors was explored. As predicted by a pharmacophore model, the incorporation substituents at the 2-position improved potency. Piperidines were found to be optimal, and further introduction of polar groups without compromising the activity was shown to be feasible. Careful positioning of the essential acidic moiety of the pharmacophore relative to the scaffold led to the discovery of vinyl tetrazoles with still greater potency. 相似文献
67.
DNA microarrays with unmodified oligonucleotides are a cost-effective alternative to cDNA microarrays. This study examined how purity, length, homology and GC content of the oligonucleotide probes influence the sensitivity and specificity of the method using cyanobacterial genes. Oligonucleotide purification by high pressure liquid chromatography was omitted without significant reduction in hybridization sensitivity. For two of three genes tested, a reduction in oligonucleotide length did not reduce hybridization sensitivity, and maximum sensitivity was achieved with probes that were 45 nt long. Oligonucleotide probes with 相似文献
68.
This paper reports chemical modification of silk sericin in LiCl/dimethyl sulfoxide (DMSO) solvent with 4-cyanophenyl isocyanate. Sericin is a highly hydrophilic protein secreted by Bombyx mori, serving as a protein glue in a cocoon. LiCl/DMSO was found to be a good solvent of sericin and useful for homogeneous modification of its abundant hydroxyl groups under nonaqueous condition. Fourier transform infrared (FTIR) analysis of the modified sericins revealed that 4-cyanophenyl groups were incorporated into sericin molecules mainly through urethane linkages. Several characteristics of the modified sericins such as solubility characteristic, hygroscopic property, and thermal stability were investigated. Secondary structure analysis using FTIR spectra suggested that formation of strong intermolecular hydrogen bonds was inhibited by the modification that is probably attributable to the incorporation of bulky 4-cyanophenyl groups. These results demonstrate that chemical modification of sericin using LiCl/DMSO solvent markedly alters its characteristics. 相似文献
69.
The synergistic effects of 6-alk(en)ylsalcylic acids, also known as anacardic acids, in combination with methicillin against Staphylococcus aureus ATCC 33591 (MRSA) was investigated. The double bond in C15-anacardic acids is not essential in eliciting the antibacterial activity but is associated with increasing the activity. The synergistic effects decreased with increasing the number of double bonds in the alkyl chain. On the other hand, the antibacterial activity of anacardic acids possessing different alkyl chain lengths against the same MRSA strain was found to be a parabolic function of their lipophilicity and maximized with the alkyl chain length of C10 and C12. Notably, the synergistic effects were noted to increase with increasing the alkyl chain length. 相似文献
70.
Izumi T Sakaguchi J Takeshita M Tawara H Kato K Dose H Tsujino T Watanabe Y Kato H 《Bioorganic & medicinal chemistry》2003,11(12):2541-2550
Structural modification of imiquimod (1), which is known as an interferon-alpha (IFN-alpha) inducer, for the aim of finding a novel and small-molecule tumor necrosis factor-alpha (TNF-alpha) suppressor and structure-activity relationship (SAR) are described. Structural modification of a imiquimod analogue, 4-amino-1-[2-(1-benzyl-4-piperidyl)ethyl-1H-imidazo[4,5-c]quinoline (2), which had moderate TNF-alpha suppressing activity without IFN-alpha inducing activity, led to a finding of 4-chloro-2-phenyl-1-[2-(4-piperidyl)ethyl]-1H-imidazo[4,5-c]quinoline (10) with potent TNF-alpha suppressing activity. The relation between conformational direction of 2-(4-piperidyl)ethyl group at position 1 and TNF-alpha suppressing activity is also demonstrated by NMR. 相似文献