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Xiong Zhang Ming-You Peng En-Ming Feng Qing-Dan Li Lu Chen Hu-Cheng Yang Bing Guo Hong Liang Ying-Tong Di Lei Tang Ying Yan 《化学与生物多样性》2023,20(10):e202301061
Three previously undescribed diterpenoids, helioscopnoids A–C, and eight known compounds were isolated from the whole plants of Euphorbia helioscopia. Their structures were established by extensive analysis of spectra and data comparison with previous literatures. Among them, compound 4 was identified as 24,24-dimethoxy-25,26,27-trinoreuphan-3β-ol with revised configurations of C-13, C-14, and C-17 (13R*, 14R*, 17R*). Cytotoxicity assays revealed that all compounds exhibited varying levels of cytotoxicity against H1975 cells, with compound 9 displaying the most potent activity, as indicated by cell viability rates of 18.13 % and 20.76 % at concentrations of 20 μM and 5 μM, respectively. This study expands the understanding of E. helioscopia terpenoids’ structural diversity and biological activities, contributing to the exploration of potential therapeutic applications. 相似文献
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The gene (alyVI) encoding an alginate lyase of marine bacterium Vibrio sp. QY101, which was isolated from a decaying thallus of Laminaria, was cloned using a strategy of combined degenerate PCR and long range-inverse PCR (LR-IPCR), then sequenced and expressed in Escherichia coli. Gene alyVI was composed of a 1014 bp open reading frame (ORF) encoding 338 amino acid residues. The calculated molecular mass of alyVI product is 38.4 kDa, but a signal peptide is cleaved off, leaving a mature protein of 34 kDa. AlyVI was purified from culture supernatants to electrophoretic homogeneity using affinity chromatography. AlyVI was most active at pH 7.5 and 40 degrees C in the presence of 1 mM ZnCl2. A nine-amino-acid consensus region (YXRESLREM), which was only found in polyguluronate lyases, was also observed in the amino-terminal region of AlyVI. However, AlyVI could degrade both M block and G block. These results indicate that a novel alginate lyase-encoding gene has been cloned. 相似文献
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国家自然科学基金评审程序剖析──1993年和1994年植物学科面上基金项目分析陈峰,朱大保(中国科学院武汉植物研究所武汉430074)(国家自然科学基金委员会生命科学部北京100083)关键词基金,评审,科研立项,学科ANALYSLSFORJUDGE... 相似文献
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Isolation of two novel myb-like genes from Arabidopsis and studies on the DNA-binding properties of their products 总被引:2,自引:0,他引:2
Two novel myb-like genes (atmyb6 and atmyb7) were isolated from an Arabidopsis thaliana cDNA library. The entire proteins or the Myb domains encoded by the genes were expressed as fusion proteins in Escherichia coli. The DNA-binding domain of the murine c-Myb was also expressed in the same way for use in comparative studies. The fusion proteins were examined for their DNA-binding activity using the animal c-Myb DNA-binding site (MBS) and the binding site of the maize P gene product (PBS). The Myb domain of Atmyb6 bound to PBS more efficiently than to MBS. Complete Atmyb6 and Atmyb7 proteins preferentially bound to PBS but not MBS. This suggests that the in vitro binding consensus sequences for both Atmyb6 and Atmyb7 are similar to PBS. The binding of the Myb domain of Atmyb6 to both PBS and MBS raises the possibility that the protein recognizes multiple sequences in vivo. The third α-helix and three adjacent amino acids in the third repeat (R3) of c-Myb were replaced with the analogous sequence of Atmyb6 to create a chimeric Myb protein. This chimeric protein bound to PBS with a low affinity but failed to bind to MBS. Thus the binding pattern of the chimeric Myb protein is similar to that of the Atmyb6. This result suggests that the last 20 amino acids in the R3 repeat of Atmyb6 play a major role in DNA-binding. 相似文献
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山西朔县种子植物区系及其生态经济意义 总被引:10,自引:0,他引:10
上官铁梁;张峰;刘玉山 《武汉植物学研究》1991,9(4):355-362
朔县(现朔州市朔城区)植物种属相对丰富,具有维管束植物938种,隶属于420属,105科。其植物区系主要起源于古北大陆;种子植物属的地理成分复杂多样,以温带成分占绝对优势,具有典型的温带草原性质;与相邻地区植物区系的比较分析表明,联系最为密切的是蒙古草原植物区系,其次是黄土高原植物区系。该县植物资源利用应采取的对策是:既要合理开发利用,又要加强物种的保护。 相似文献