共查询到20条相似文献,搜索用时 46 毫秒
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Kouji Kuramochi Ryo Takeuchi Masaharu Takemura Kengo Sakaguchi Susumu Kobayashi Fumio Sugawara 《Tetrahedron》2006,62(34):8006-8015
Synthesis of plakevulin A and structure-activity relationships of its related compounds against DNA polymerases is described. We have achieved a total synthesis and revised the structure of plakevulin A. Several analogues including untenone A, manzamenone A, and optically active plakevulin A, were prepared and tested with an enzyme inhibition assay for mammalian DNA polymerases. The effect of the methyl ester moiety, and the substituents at the 1- and 4-positions of plakevulin A on DNA polymerase activities are discussed. 相似文献
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High-speed counter-current chromatography (HSCCC) technique in semi-preparative scale has been applied to isolate and purify bioactive flavone compounds from the ethanol extract of Glycyrrhiza inflata Bat., a particular plant species of licorice. HSCCC separation was performed with a two-phase solvent system composed of n-hexane-chloroform-methanol-water (5:6:3:2, v/v) by eluting the lower mobile phase at a flow rate of 1.8 ml/min and a revolution speed of 800 rpm. Purification was performed with a two-phase solvent system composed of n-hexane-chloroform-methanol-water (1.5:6:3:2, v/v) by eluting the lower mobile phase at a flow-rate of 1.5 ml/min and a revolution speed of 800 rpm. Two major flavone peaks: inflacoumarin A and licochalcone A were collected and the respective yields of the peaks amount to 6 mg (8.6%, w/w) and 8 mg (11.4%, w/w) from 70 mg of the crude extract sample. The purities of inflacoumarin A and licochalcone A reached 99.6% and 99.1%, respectively, after a sequential purification run. The structures of inflacoumarin A and licochalcone A were positively confirmed by 1H NMR and 13C NMR, 1H-13C-COSY, UV, FT-IR and electron ionization MS analyses. 相似文献
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Wen-Zhang Chen Ling-Ling Fan Hai-Tao Xiao Ying Zhou Wan Xiao Jian-Ta Wang Lei Tang 《中国化学快报》2014,25(5):749-751
First total synthesis of cajanolactone A and cajanonic acid A has been achieved through steps of anion–anion condensations,cyclization,Williams etherification,selective demethylation,1 3-sigmatropic rearrangement and hydrolysis.This work provides an efficient method for future cajanonic acid A derivatives synthesis. 相似文献
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《合成通讯》2013,43(9):1723-1727
Abstract A number of benzodioxane compounds were synthesized using the palladium‐catalyzed etherification of aryl halides by employing triphenylphosphane ligands. This method was used as key step in the synthesis of two natural products isoamericanol A and isoamericanin A. 相似文献
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Arcyriarubin A was first isolated by Steglich in 1980; it is also the key intermediate in the synthesis of indolocarbazole compounds. A new synthetic approach to the natural products arcyriaflavin A and arcyriarubin A is described. The key step is a Suzuki cross-coupling reaction using indolylboronic acid as the starting material. The preparation of arcyriaflavin A was accomplished in eight steps from indole for a total yield of 21%. 相似文献
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The absolute configuration of blasticidin A, a strong inhibitor of aflatoxin production by Aspergillus parasiticus, was assigned by adding the data of relative configurations at its diol and pentaol moieties to previously known stereochemistry. Similarity of the NMR data of blasticidin A to those of aflastatin A allowed us to revise the stereochemistry of the diol and pentaol moieties of aflastatin A. 相似文献
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San‐Yong Wang Zhong‐Liang Xu Hui Wang Chun‐Rong Li Li‐Wu Fu Ji‐Yan Pang Jing Li Zhi‐Gang She Yong‐Cheng Lin 《Helvetica chimica acta》2012,95(6):973-982
The novel natural product xyloallenoide A, isolated from the marine mangrove endophytic fungus from the South China Sea, and its diastereoisomer xyloallenoide A1, which contain N‐methyl‐substituted amino acids, were synthesized. The absolute configurations of the amino acid units of xyloallenoide A were finally confirmed to be L ‐Lys, Me‐D ‐Val, and Me‐L ‐Ala. This report represents a practical and attractive alternative for the synthesis of N‐methyl‐substituted cyclotripeptides. In the preliminary bioassay, synthetic xyloallenoide A showed marginal activities against KB (IC50=9.6 μM ) and KBv200 cells (IC50=10.3 μM ), and xyloallenoide A1 was inactive against KB and KBv200 cells. 相似文献
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Calanolide A是从藤黄科红厚壳属植物(Calophyllum lanigerum)中分离的一种吡喃型香豆素类化合物, 对HIV-1- RT有很强的抑制作用, 是目前抗HIV的热点先导物. 综述了该化合物及其类似物的全合成研究进展, 分析了它的合成路线, 讨论了各合成方法的优缺点. 相似文献
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A five-step synthesis of the 6-6-6 tricyclic skeleton of the diterpene wickerol A is described. The synthesis features a diastereoselective d-proline-mediated Robinson annulation and N-heterocyclic carbene-catalyzed Stetter reaction as key transformations to give the tricyclic carbon skeleton of this promising anti-influenza A natural product. 相似文献
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JianXinPU JingFengZHAO XiaoDongYANG ShuangXiMEI HongBinZHANG LiangLI 《中国化学快报》2004,15(12):1454-1456
A new sesquiterpene lactone, Ainsliaolide A, was isolated from Ainsliaea bonatii. The structure was determined on the basis of spectral data. 相似文献
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建立了测定塑料饮料瓶中双酚A的Brij35增敏荧光分析法.实验考察了不同介质及pH、静置时间、介质用量、金属离子等因素对双酚A(BPA)荧光强度的影响.结果表明,在所探讨的7种介质中Brij 35荧光增敏效果最好,据此建立了一种用Brij35增敏荧光光度法测定双酚A的新方法.方法线性范围为2.0×10-8~1.0×10-5 mol/L,检出限为2.5×10-8 mol/L,相对标准偏差为1.92%.该方法快速、简便、灵敏度高,对实际样品塑料饮料瓶中双酚A的检测,结果满意. 相似文献
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Wei‐Guang Shan Tian‐Song Lin Hai‐Ning Yu Yan Chen Zha‐Jun Zhan 《Helvetica chimica acta》2012,95(8):1442-1448
A new polyprenylated xanthone (=9H‐xanthen‐9‐one) and a new polyprenylated benzophenone, namely oblongifolixanthone A ( 1 ) and garciniagifolone A ( 2 ), were isolated from the bark of Garcinia oblongifolia, together with five known compounds including the four xanthones 3 – 5 and 7 and a benzophenone 6 . The structures of 1 and 2 were established by detailed analysis of their spectroscopic data, especially 1D‐ and 2D‐NMR spectra and HR‐ESI‐MS data. All these compounds were assayed for their cytotoxic activities against three human tumor cell lines (HeLa, SGC7901, and HepG2). The 1,3,6,7‐tetrahydroxy‐9H‐xanthen‐9‐one ( 3 ) was inactive, and the other compounds showed weak to moderate activity. 相似文献
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Sayuri Kamikawa Emi Ohta Tatsuo Nehira Hisashi Ômura Shinji Ohta 《Helvetica chimica acta》2016,99(2):133-137
A known cassane‐type furanoditerpenoid, caesalpinista B ( 1 ), and a new diterpenoid, deoxycaesaljaponin A ( 2 ), were isolated from the cotyledons of Caesalpinia decapetala var. japonica. The previously reported configurational assignments of 1 and the related diterpenoid caesalpinista A ( 3 ) were revised on the basis of X‐ray crystallography and chemical conversion. The structure of 2 was elucidated by spectroscopic data and chemical conversion into 3 . 相似文献
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Xinan A. Huang Renzhou Yang Xiaoling Cai Sheng Ye Yingjie Hu 《Journal of Molecular Structure》2007,830(1-3):100-105
Four pigments including two new skeleton benzo-di-lactones fordianin A (1) and fordianin B (2), and another two new quinones fordianaquinone A (3) and fordianaquinone B (4) were firstly isolated from the acetone extract of the leaves of Lysimachia fordiana Oliv. Their structures were elucidated on the basis of spectroscopic methods, mainly 1D and 2D NMR. These four new pigments were evaluated for cytotoxicity against the A549 (human lung cancer) and HeLa (human cervical carcinoma) cell lines. 相似文献
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Ali I. M. Ibrahim Balqis Ikhmais Elisabet Batlle Waed K. AbuHarb Vibhu Jha Khaled T. Jaradat Rafael Jimnez Raquel Pequerul Xavier Pars Jaume Farrs Klaus Pors 《Molecules (Basel, Switzerland)》2021,26(19)
Aldehyde dehydrogenase 1A3 (ALDH1A3) has recently gained attention from researchers in the cancer field. Several studies have reported ALDH1A3 overexpression in different cancer types, which has been found to correlate with poor treatment recovery. Therefore, finding selective inhibitors against ALDH1A3 could result in new treatment options for cancer treatment. In this study, ALDH1A3-selective candidates were designed based on the physiological substrate resemblance, synthesized and investigated for ALDH1A1, ALDH1A3 and ALDH3A1 selectivity and cytotoxicity using ALDH-positive A549 and ALDH-negative H1299 cells. Two compounds (ABMM-15 and ABMM-16), with a benzyloxybenzaldehyde scaffold, were found to be the most potent and selective inhibitors for ALDH1A3, with IC50 values of 0.23 and 1.29 µM, respectively. The results also show no significant cytotoxicity for ABMM-15 and ABMM-16 on either cell line. However, a few other candidates (ABMM-6, ABMM-24, ABMM-32) showed considerable cytotoxicity on H1299 cells, when compared to A549 cells, with IC50 values of 14.0, 13.7 and 13.0 µM, respectively. The computational study supported the experimental results and suggested a good binding for ABMM-15 and ABMM-16 to the ALDH1A3 isoform. From the obtained results, it can be concluded that benzyloxybenzaldehyde might be considered a promising scaffold for further drug discovery aimed at exploiting ALDH1A3 for therapeutic intervention. 相似文献