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红景天甙(Salidroside)生源途径分子机制的解析是利用基因工程、代谢工程技术合成目标化合物的基础。糖基化是红景天甙生物合成的最后一步反应。在前期工作中,本课题组率先报道了与红景天甙生物合成相关的3个尿苷二磷酸葡萄糖基转移酶(UGTs)基因,在体外酶学性质研究的基础上,利用根癌农杆菌和发根农杆菌介导分别建立了相关转基因体系,鉴别了红景天甙生物合成最适UGT及植物和毛状根生物反应器系统合成红景天甙的效率差异;酪醇(Tyrosol)是红景天甙糖基化反应的甙元底物分子,其具体的代谢通路及其调控机制仍不明确。针对酪醇生物合成来源主要存在两种观点:一是酪醇可能来自于苯丙烷代谢途径产生的4-香豆酸,该途径起源于苯丙氨酸;二是生物碱代谢途径的中间产物酪胺可能是酪醇生物合成的前体,该途径则起源于酪氨酸。在后续工作中,否定了酪醇来源于苯丙烷代谢途径的可能性,进一步的工作证实酪氨酸脱羧酶(TyrDC)在酪醇生物合成的起始反应中担负着重要功能,酪醇作为一种苯乙烷类化合物衍生物,其生物合成来源于生物碱代谢途径。 相似文献
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红景天甙的生物合成及其关键代谢酶研究 总被引:4,自引:0,他引:4
红景天甙是红景天属植物的主要药效成分,是一种很有前途的环境适应药物,具有抗疲劳、抗衰老、抗微波辐射、抗病毒及抗肿瘤等特异功效,尤其在军事、航天、运动及保健医学上具重要应用价值,近年来备受关注。本文在介绍了红景天属植物的开发利用价值及资源现状的基础上,重点探索了红景天甙生物合成的可能途径。认为其甙元酪醇是经由莽草酸途径合成,再由UDP葡萄糖基转移酶(Glucosyltransferase)催化葡萄糖和酪醇合成红景天甙,而红景天甙又可能在β-D-葡萄糖苷酶作用下降解为甙元酪醇和葡萄糖。文章阐述了参与红景天甙代谢的上述两个关键酶的研究现状及前景。 相似文献
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高山红景天细胞悬浮培养中红景天甙生物合成代谢的调控 Ⅰ:前体的影响 总被引:1,自引:0,他引:1
探索了高山红景天(Rhodiola sachalinensis A.Bor)细胞培养中红景天甙生物合成的途径,认为甙元酪醇是经由莽草酸途径生成的。在此基础上研究了酪醇、L-酪氨酸与L-苯丙氨酸三种前体加入对红景天甙生物合成的调控作用。结果表明,酪醇、酪氨酸等前体易被多酚氧化酶氧化成褐色,用与前体浓度为1:1的V。来防止褐化效果显著;浓度为0.5mmol/L的酪醇,酪氨酸及苯丙氨酸在细胞培养15d时添加,使红景天甙含量由0.336%分别提高到1.43%、1.11%、0.85%。 相似文献
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高山红景天细胞悬浮培养中红景天甙生物合成代谢的调控:Ⅰ … 总被引:4,自引:0,他引:4
探索了高山红景天细胞培养中红景天甙生物合成的途径,认为甙元酪醇是红由莽草酸途径的。在此基础上研究了酪醇,L-酪氨酸与L-苯丙氨酸三种前体加入对就天甙生物合成的调控作用。结果表明,酪醇,酪氨酸等前体易被酚氧化成褐色,用与前体浓度为1:1的VC来防止褐化效果显著; 相似文献
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探讨红景天苷和西藏红景天粗提物对延长线虫寿命的影响及其体外抗氧化活性的比较。以红景天苷、红景天粗提物为研究对象、以Vc为阳性对照,分别检测以上三种物质对自由基的清除作用。结果表明红景天能够显著延长秀丽隐杆线虫的寿命;在相同浓度下,红景天苷清除DPPH自由基的EC50约为1291.53μg/mL,红景天提取物溶液约为489.76μg/mL;红景天苷清除羟自由基的EC50约为1120.94μg/mL,红景天提取物约为1068.37μg/mL;红景天苷清除超氧阴离子自由基的EC50约为55.57μg/mL,红景天提取物溶液约为40.49μg/mL。中药红景天中含有显著延长线虫寿命的抗氧化物质,而这种成分并非是红景天苷。 相似文献
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辛伐他汀的生物合成 总被引:1,自引:0,他引:1
辛伐他汀是洛伐他汀的半合成衍生物, 传统的生产工艺是以洛伐他汀为原料, 经化学合成得到辛伐他汀。洛伐他汀的直接甲基化方法已成为目前生产上使用最多的工艺路线。化学合成工艺的不足之处乃在于化学法合成过程中, 反应条件苛刻, 副反应多, 产品分离纯化难度大以及来自环保和劳动保护的压力。近年来, 随着洛伐他汀生物合成途径研究的深入, 人们已经将更多的注意力转向辛伐他汀的生物合成。就辛伐他汀侧链的化学水解路线和洛伐他汀的生物合成途径的国内外研究结果进行了分析比较, 进一步阐述了辛伐他汀生产中可实现生物催化的反应步骤以及用于辛伐他汀直接发酵生产的基因工程菌构建。 相似文献
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Relationship Between Protein Synthesis and Viral Deoxyribonucleic Acid Synthesis 总被引:12,自引:10,他引:2 下载免费PDF全文
Evidence is presented that poxvirus deoxyribonucleic acid (DNA) synthesis required concurrent protein synthesis. The protein requirement in question can be distinguished from viral-induced thymidine kinase and DNA polymerase by virture of the instability of its messenger ribonucleic acid and its stoichiometric rather than catalytic relation to DNA synthesis. The protein(s) required did accumulate in the presence of fluorodeoxyuridine, an inhibitor of DNA synthesis, and, thus, appeared to be an "early" poxvirus function. The protein(s) was stable since it did function several hours after its synthesis had been terminated by puromycin. Two possible roles for such a protein requirement are discussed. 相似文献
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Summary. Both 1,4-benzoquinones and 1,4-naphthoquinones were attached to the non-proteinogenic amino acid taurine to form N-quinonyl
taurine derivatives. The products were formed via the direct Michael-like addition or by substitution of a good leaving group.
An attempt to bridge the two moieties via an ureido spacer resulted in the formation of a bis-quinonylamino isocyanurate derivative.
Preliminary MO calculations provided internal ground-state geometries and orbital coefficients of the HOMO levels in two representing
taurine conjugates.
Received May 6, 2002 Accepted August 13, 2002 Published online December 18, 2002
Acknowledgments This research was supported by the Israel Science Foundation founded by the Academy of Science and Humanities. We wish to
thank Ms. Ethel Solomon for skilled technical help.
Authors' address: Prof. Shmuel Bittner, Department of Chemistry, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105, Israel,
Fax: (972)-8-6472943, E-mail: bittner@bgumail.bgu.ac.il 相似文献
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巴洛沙星的合成研究 总被引:4,自引:0,他引:4
合成新型抗菌药——巴洛沙星。以3-溴吡啶为原料,在催化剂作用下经氨解、加氢还原制备关键中间体3-甲胺基哌啶,并考察加氢过程中催化剂类型和反应温度的影响,再以甲氧环合酯(1-环丙基-6,7-二氟-8-甲氧基-1,4二氢-4-氧代喹啉-3-羧酸乙酯)为起始物,在乙酐中与硼酸螯合,并与3-甲胺基哌啶缩合,最后水解制备巴洛沙星。合成巴洛沙星的总质量收率58.7%,合成3-甲胺基哌啶的质量收率为74.1%。使用乙腈作为缩合的溶剂和后期水解反应的碱性物质,改进合成巴洛沙星的路线,提高了收率;制备3-甲胺基哌啶的加氢反应,在选择Rh/C为催化剂、反应温度为80℃时,质量收率为78%。 相似文献
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A strategy allowing both stereocontrol and control over structural isomer formation has been defined for the antimalarial flindersial alkaloids. The recently reported flinderoles were demonstrated to be derived from the natural product borrerine. The structural isomers of flinderoles, the borreverines, were also produced in vitro along with the flinderoles through the dimerization of borrerine in acidic conditions. This result is thought to replicate the biosynthesis of these compounds. Flinderoles A, B, and C, desmethylflinderole C, isoborreverine, and dimethylisoborreverine can each be synthesized in three steps from tryptamine. Furthermore, progress toward a concise enantioselective synthesis of flinderoles A, B, and C is described. This work includes enantioselective conjugate addition to an unprotected indole‐appended enone. Chirality 27:14–17, 2015. © 2013 Wiley Periodicals, Inc. 相似文献
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Paul W. R. Harris Geoffrey M. Williams Peter Shepherd Margaret A. Brimble 《International journal of peptide research and therapeutics》2008,14(4):387-392
A series of phosphorylated peptides were synthesised using microwave mediated solid phase peptide synthesis. Acidic cleavage
of peptides from the solid support using microwave irradiation often resulted in reattachment of the phosphate benzyl protecting
group to the peptide chain. However for most phosphopeptide sequences performing the cleavage reaction at room temperature
in order to minimize this undesired alkylation was successful. Notably for phosphopeptides containing a methionine residue
flanking the phosphorylated residue (for serine and threonine) the trifluoroacetic acid mediated cleavage afforded the benzylated
side product as a major component. This detrimental process was not observed for a corresponding tyrosine containing sequence. 相似文献
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Synthesis of Bacterial Flagella: Chromosomal Synchrony and Flagella Synthesis 总被引:1,自引:1,他引:0 下载免费PDF全文
Synchronous cultures of Bacillus subtilis 168 M were obtained from light-density spores germinated at 46 C and grown at 37 C. This procedure synchronizes both cell division and chromosome replication. The chromosome synchrony was demonstrated by using transformation to measure changes in marker frequency during the cell cycle. The synthesis of two enzymes and of bacterial flagellar protein was also followed. All of the proteins were found to be synthesized continuously with an abrupt doubling in the rate of synthesis at a specific time in the cell cycle. The time at which the doubling occurred for each enzyme corresponded to the time at which the structural gene for the enzyme was replicated. The doubling of the rate of flagella synthesis corresponded to the time of replication of the hisA1 gene. We conclude that the genetic locus for the factors involved in the rate-limiting steps in flagella synthesis are located on the genetic map near the hisA1 locus. 相似文献
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Kazuo Ina Takenosuke Takano Yasuo Imai Yajiro Sakato 《Bioscience, biotechnology, and biochemistry》2013,77(6):1033-1036
β-Ionone (I) was oxidized to 2,3-epoxy-/β-ionone (II), which was converted to 2,3-dihydroxy-β-ionone (III) by acid treatment. III was reduced to 4-(1,2-dihydroxy-2,6,6-trimethylcyclohexan-1-yl)-2-butanol (V), which was converted, by oxidation, to cis- and trans-theaspirone (1-oxa-8-oxo-2,6,10,10-tetramethyl spiro-(4,5)-6-decene) (VII-A), (VII-B) and dihydroactinidiolide (2-hydroxy-2,6,6-trimethylcyclohexyliden-1-acetic acid lactone) (IX). 相似文献