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21.
6[8'(Z)-pentadecenyl]salicylic acid, otherwise known as anacardic acid (C15:1), inhibited the linoleic acid peroxidation catalyzed by soybean lipoxygenase-1 (EC 1.13.11.12, type 1) with an IC50 of 6.8 microM. The inhibition of the enzyme by anacardic acid (C15:1) is a slow and reversible reaction without residual activity. The inhibition kinetics analyzed by Dixon plots indicates that anacardic acid (C15:1) is a competitive inhibitor and the inhibition constant, KI, was obtained as 2.8 microM. Although anacardic acid (C15:1) inhibited the linoleic acid peroxidation without being oxidized, 6[8'(Z),11'(Z)-pentadecadienyl]salicylic acid, otherwise known as anacardic acid (C15:2), was dioxygenated at low concentrations as a substrate. In addition, anacardic acid (C15:2) was also found to exhibit time-dependent inhibition of lipoxygenase-1. The alk(en)yl side chain of anacardic acids is essential to elicit the inhibitory activity. However, the hydrophobic interaction alone is not enough because cardanol (C15:1), which possesses the same side chain as anacardic acid (C15:1), acted neither as a substrate nor as an inhibitor.  相似文献   
22.
This is the first report for secondary metabolites in an African medicinal plant, Pachyelasma tessmannii (Leguminosae). Four novel saponins, pachyelasides A-D, were isolated from the methanol extract of the root bark by using recycling HPLC. These compounds showed molluscicidal activity (LD(50) < or =8.0 mug/mL) against the South American snail, Biomphalaria glabratus. The structures were determined on the basis of extensive nuclear magnetic resonance spectroscopic and matrix-assisted laser desorption/ionization time-of-flight mass spectrometric studies.  相似文献   
23.
Kubo AS  Rose DJ 《Science (New York, N.Y.)》1973,182(4118):1205-1211
For the present and the foreseeable future the following options appear to be either usable or worth further exploration: mausolea; disposal in mines of various sorts, and perhaps in ice; in situ melt; and further chemical separations. The options are interdependent. It is too early to assess disposal in space, and disposal in the oceans remains unsafe for lack of adequate knowledge. Table 3 is a summary of the main ideas for which we have worked out (sometimes uncertain) costs. For the short term, ultimate disposal in deep mines is the best-developed plan. However, the related concept of in situ melt has significant advantages and should be realistically appraised. Further chemical separation with subsequent recycling of the actinides in a LMFBR should be investigated and implemented, for it would be universally beneficial; on the other hand, additional removal of strontium and cesium does not seem attractive. Thus, for the near future we make the following recommendations: 1) Provide temporary storage facilities to ensure that the projected commercial high-level wastes do not become a public hazard. The AEC adopts this view, and has stated an intention to construct such facilities. But because of the capriciousness of man and nature, a workable ultimate disposal scheme must be developed soon. 2) Fund other ultimate disposal schemes at the same rate as the salt mine project-say $1 million a year or more-to sharpen the technological issues, so that a decision can be reached in the next few years. The schemes should include (i) in situ melt, and the variation with a central repository; (ii) burial in mines other than salt mines (including Antarctic rocks and permanent ice); (iii) further chemical separation of actinides and recycling actinides in a LMFBR. 3) Maintain liaison with the developing space shuttle technology to insure that no opportunity is lost. The AEC has a commitment to hold safety foremost in its waste management program, but budget considerations and management priorities have downgraded the program. Past funding levels and management emphasis have yet to produce, after a decade and a half, one operational long-term storage facility-a sign of both commendable caution and inadequate work. If nuclear power is to resolve our energy needs in the coming decades, its benefits should not be delayed for lack of a viable management program for high-level wastes.  相似文献   
24.
The penumbra of a sunspot is composed of numerous thin, radially extended, bright and dark filaments carrying outward gas flows (the Evershed flow). Using high-resolution images obtained by the Solar Optical Telescope aboard the solar physics satellite Hinode, we discovered a number of penumbral bright filaments revealing twisting motions about their axes. These twisting motions are observed only in penumbrae located in the direction perpendicular to the symmetry line connecting the sunspot center and the solar disk center, and the direction of the twist (that is, lateral motions of intensity fluctuation across filaments) is always from limb side to disk-center side. Thus, the twisting feature is not an actual twist or turn of filaments but a manifestation of dynamics of penumbral filaments with three-dimensional radiative transfer effects.  相似文献   
25.
Lipoxygenase inhibitory activity of octyl gallate   总被引:2,自引:0,他引:2  
Octyl gallate inhibited soybean lipoxygenase-1 (EC 1.13.11.12, type I) with an IC(50) of 1.3 microM. The inhibition of the enzyme by octyl gallate is a slow and reversible reaction without residual activity. The inhibition kinetics analyzed by Lineweaver-Burk plots indicates that octyl gallate is a competitive inhibitor, and the inhibition constant, K(I), was obtained as 0.54 microM. One molecule of octyl gallate scavenged six molecules of 1,1-diphenyl-2-picrylhydrazyl and inhibited autoxidative lipid peroxidation. In addition, octyl gallate was effective in preventing lipid peroxidation.  相似文献   
26.
In clinical, patients usually take many kinds of drugs at the same time. Thus, drug-drug interactions involving transporters can often directly affect the therapeutic safety and efficacy of many drugs. However, there have been few studies on food-drug interactions involving transporters. Dietary polyphenols have been widely assumed to be beneficial to human health. Polyphenols are commercially prepared and used as functional foods. We report here for the first time that ferulic acid, which is widely used as a functional food, affects the transport of clinical agents. It is important to be aware of the potential of food-drug interactions and to act in order to prevent undesirable and harmful clinical consequences.  相似文献   
27.
Four virus strains with identical antigenic properties were isolated from blood samples of 4 sentinel calves having a fever and leukopenea in cultures of HmLu-1 cells derived from baby hamster lung. The virus was identified as Fukuoka virus, classified as a member of the Kern Canyon serogroup viruses of the family Rhabdoviridae, on the basis of its antigenic properties.  相似文献   
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Tsuge S  Ochiai H  Inoue Y  Oku T  Tsuno K  Kaku H  Kubo Y 《Phytopathology》2004,94(5):478-483
ABSTRACT Xanthomonas oryzae pv. oryzae, the causal agent of bacterial leaf blight of rice, was subjected to transposon mutagenesis to generate mutants defective in pathogenicity. A novel mutant 74M913 was attenuated in virulence but retained its ability to cause the hypersensitive response in leaf blight-resistant rice and tomato. Cloning and sequence analysis revealed that the transposon in 74M913 was inserted in a gene homologous to the phosphoglucose isomerase (pgi) gene of X. axonopodis pv. citri. Growth of the mutant in a synthetic medium containing fructose or xylose as a sole carbohydrate source was much reduced, indicating the transposon disrupted pgi function. The interaction between expression of pgi and hypersensitive response and pathogenicity (hrp) genes was investigated because we had demonstrated previously that expression of hrp genes of X. oryzae pv. oryzae is induced in a synthetic medium containing xylose. However, pgi and the hrp gene (hrcU) were expressed independently. This study suggests that PGI is involved in pathogenicity of X. oryzae pv. oryzae.  相似文献   
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