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Jih‐Jung Chen Tai‐Chi Wang Chieh‐Kai Yang Hsiang‐Ruei Liao Ping‐Jyun Sung Ih‐Sheng Chen Ming‐Jen Cheng Chien‐Fang Peng Jinn‐Fen Chen 《化学与生物多样性》2013,10(10):1903-1908
Two new pterosin sesquiterpenes, (2S)‐13‐hydroxypterosin A ( 1 ) and (2S,3S)‐12‐hydroxypterosin Q ( 2 ), were isolated from the whole plants of Pteris ensiformis, together with six known compounds. The structures of 1 and 2 were determined through extensive 1D/2D‐NMR and MS analyses. Compound 2 exhibited antitubercular activity (MIC 6.25 μg/ml) against Mycobacterium tuberculosis H37Rv in vitro. 相似文献
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Characterization and Physiological Function of Class I Low-Molecular-Mass,Heat-Shock Protein Complex in Soybean 总被引:1,自引:0,他引:1
Examination of an ammonium sulfate-enriched fraction (70-100% saturation) of heat-shock proteins (HSPs) by nondenaturing polyacrylamide gel electrophoresis revealed the presence of a high molecular mass complex (280 kD) in soybean (Glycine max) seedlings. This complex cross-reacted with antibodies raised against soybean class I low-molecular-mass (LMW) HSPs. Dissociation of the complex by denaturing polyacrylamide gel electrophoresis showed the complex to contain at least 15 polypeptides of the 15-to 18-kD class I LMW HSPs that could be detected by staining, radiolabeling, and western blotting. A similar LMW-HSP complex was observed in mung bean (Vigna radiata L.; 295 kD), in pea (Pisum sativum L.; 270 kD), and in rice (Oryza sativa L.; 310 kD). The complex was stable under high salt conditions (250 mM KCI), and the integrity was not affected by 1% Nonidet P-40 and 3 [mu]g/ML RNase treatment. The size of the isolated HSP complex in vitro was conserved to 55[deg]C; however, starting at 37.5[deg]C, it changed to higher molecular forms in the presence of soluble proteins. The isolated HSP complex was able to protect up to 75% of the soluble proteins from heat denaturation in vitro. 相似文献
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Two major polypeptides of the 15- to 18-kilodalton class of soybean (Glycine max) heat shock proteins (HSPs), obtained from an HSP-enriched (NH4)2SO4 fraction separated by two-dimensional polyacrylamide gel electrophoresis, were used individually as antigens to prepare antibodies. Each of these antibody preparations reacted with its antigen and cross-reacted with 12 other 15- to 18-kilodalton HSPs. With these antibodies, the accumulation of the 15- to 18-kilodalton HSPs under various heat shock (HS) conditions was quantified. The 15- to 18-kilodalton HSPs began to be detectable at 35° C, and after 4 hours at 40° C they had accumulated to a maximum level of 1.54 micrograms per 100 micrograms of total protein in soybean seedlings and remained almost unchanged up to 24 hours after HS. Accumulation of the HSPs was reduced at temperatures higher than 40° C. At 42.5° C the HSPs were reduced to 1.02 micrograms per 100 micrograms, and at 45° C they were hardly detectable. A brief HS at 45° C (10 minutes), followed by incubation at 28° C, which also induced HSP synthesis, resulted in synthesis of this class of HSPs at levels up to 1.06 micrograms per 100 micrograms of total protein. Taking into consideration the previous data concerning the acquisition of thermotolerance in soybean seedlings, our estimation indicates that the accumulation of the 15- to 18-kilodalton HSPs to 0.76 to 0.98% of total protein correlated well with the establishment of thermotolerance. Of course, other HSPs, in addition to this group of proteins, may be required for the development of thermotolerance. 相似文献