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研究了在相转移催化或非相转移剂催化或硅胶支持下KMnO4-NaIO4对香紫苏醇的氧化。在3种不同条件下均得到成分单一的氧化产物香紫苏醚,收率分别为47%,21%和59%。 相似文献
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以紫苏醛结构为母体,设计合成了12个肟醚类化合物,其中6个为未见文献报道的化合物,并通过1H-NMR、13C-NMR和ESI-MS对其结构进行了表征。经体外抑菌活性数据表明,3C对白色假丝酵母和痤疮丙酸杆菌的MIC分别为800μg·mL-1、250μg·mL-1,抑菌活性优于紫苏醛(1.200mg·mL-1和0.740mg·mL-1)。化合物3C和6C对白色假丝酵母抑菌活性强于阳性对照药氟康唑。分子对接结果表明化合物与蛋白结合形成氢键、疏水作用和π-π共轭,从而增强抑菌活性。 相似文献
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以邻氨基苯甲酸或取代邻氨基苯甲酸为起始原料,应用电子等排原理设计并合成了一系列二喹唑啉二硒醚类化合物,化合物均经IR、~1H NMR、~(13)C NMR和元素分析进行结构确证。采用体外生长速率法测定了目标化合物的抑菌活性,结果表明,化合物1b、1c、1d、1h、1i和1j对小麦赤霉病原菌、辣椒枯萎病原菌、苹果腐烂病原菌、半夏立枯病原菌、水稻纹枯病原菌、油菜菌核病原菌、黄瓜灰霉病原菌、马铃薯晚疫病原菌、苹果炭疽病原菌等9种测试病原菌具有良好的抑菌活性。而且,化合物1b在药剂浓度为50μg/m L时抑菌活性强于商品化的阳性对照药剂恶霉灵。 相似文献
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根据拼合原理, 设计并合成了21个未见报道的新的二芳醚基哌嗪类衍生物, 其结构用1H NMR, ESI-MS, HRMS进行了确证, 初步生物活性测定实验证明部分目标化合物具有良好的细胞毒活性. 化合物4i分别对人食管癌(Eca109)细胞株和人鼻咽癌(CNE)细胞株的IC50为7.13和4.54 μmol8226;L-1, 与对照品顺铂(DDP)相近. 化合物5d对人鼻咽癌细胞株也表现较好的活性, 其IC50为8.49 μmol8226;L-1. 相似文献
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以2,4-二氯嘧啶为起始物设计并合成了一系列4-芳(硫)氧基-2-氯嘧啶和4-芳氧基-2-二甲氨基嘧啶化合物。利用2,4-二氯嘧啶2个氯原子的活性差异,酚取代嘧啶环上4位氯原子,然后二甲氨基取代2位的氯原子。所合成的化合物均经过了1H NMR和元素分析确证。为了确证酚首先在嘧啶环的4位发生亲核取代反应,用X衍射法测定了化合物3d的单晶结构。初步生物活性测定结果表明,大部分化合物都表现出一定的除草活性,其中化合物7c、7j、7k和7m在1.0×10-4g/mL质量浓度下对油菜的抑制率达到了80%以上。 相似文献
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新型荧光试剂1-(8-喹啉)-3-(2-吡啶)-三氮烯的合成及其分析应用 总被引:1,自引:1,他引:1
将具有荧光特性的8-氨基喹啉和吡啶类试剂结合, 并引入杂环三氮烯结构, 合成了新型荧光试剂1-(8-喹啉)-3-(2-吡啶)-三氮烯(QPyT). 其结构经元素分析、红外光谱和核磁共振谱证实. 研究结果表明, 在碱性介质中, 该试剂在λex/λem=216 nm/343 nm处产生强荧光, 并且能被Pb(Ⅱ)猝灭. 据此建立了QPyT测定Pb(Ⅱ)的新型荧光分析法. 该方法的线性范围为1.6×10-7~1.2×10-5 mol /L, 检测限为9.0×10-8 mol/L. 将其应用于水中Pb(Ⅱ)的测定, 结果令人满意. 相似文献
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Gard Gjessing Lars-Inge Gammelster Johnsen Simen Gjelseth Antonsen Jens M. J. Nolse Yngve Stenstrm Trond Vidar Hansen 《Molecules (Basel, Switzerland)》2022,27(7)
Monohydroxylated polyunsaturated fatty acids belonging to the oxylipin class of natural products are present in marine and terrestrial sources as well as in the human body. Due to their biological activities and role in diverse biosynthetic pathways, oxylipins biosynthesized from eicosapentaenoic acid and arachidonic acid have attracted great interest from the scientific community. One example is 3-hydroxyeicosapentaenoic acid where the absolute configuration at C-3 has only been tentatively assigned. In this paper, studies on acetate type aldol reactions that enabled the preparation of 3-(R)-hydroxyeicosapentaenoic acid (3R-HETE, 2) and its enantiomer are presented. 相似文献
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Highly efficient and selective syntheses of the title compounds are described. The cornerstone of the synthetic plan is the tandem inter [4 + 2]/inter [3 + 2] cycloaddition process. These syntheses differ from previous applications of this strategy in that they incorporate an alkylation in the hydrogenolysis step to close the second ring of the azabicyclic systems. Notable features of the sequence are (1) the highly regio- and stereoselective [3 + 2] cycloaddition of nitronate 15 with siloxymethyl (Z)-beta-silylvinyl ketone (Z)-22b and (2) the highly selective reduction of the resulting ketone 24a with L-Selectride. A single-crystal X-ray structure analysis of synthetic (-)-7-epiaustraline confirmed that the targeted structure was successfully synthesized. This stimulated a reexamination of the structural assignment of the natural product. (-)-1-Epicastanospermine was synthesized in four steps from the common intermediate 27a. The absolute configuration of (-)-1-epicastanospermine was assured by single-crystal X-ray structure analysis of intermediate (-)-27a. Thus, the sign of the optical rotation had to be revised. The overall efficiency of these syntheses were 9 steps and 23% yield for (-)-7-epiaustraline and 10 steps and 20% yield for (-)-1-epicastanospermine 相似文献
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以高藜芦胺为起始原料,经N-磺酰化反应制得高藜芦磺酰胺(2);2分别与芳乙烯甲醚经对甲苯磺酸催化的Pictet-Spengler反应后用金属钠脱除Ts基团合成了(±)-norlaudanosine(5a)和(±)-O,O-dimethylcoclaurine(5b);使用半量拆分法,以N-乙酰-L-苯丙氨酸为拆分剂,制得(S)-(-)-5a和(S)-(-)-5b,其结构经1H NMR,13C NMR,IR,MS和HR-ESI-MS确证。 相似文献
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Development of a Chromatographic Fingerprint of Tobacco Flavor by Use of GC and GC-MS 总被引:7,自引:0,他引:7
A new chromatographic fingerprinting method has been established for quality control of tobacco flavor. Three different extraction techniques, simultaneous distillation extraction (SDE), liquid–liquid extraction, and solid-phase microextraction were evaluated for isolation of the components of interest. After comparison of their performance, a combination of SDE and GC-MS was used for simple, reliable, and reproducible development of a chromatographic fingerprint of tobacco flavor. Twelve samples of the flavor from different batches were used to establish the fingerprint. Thirty-nine volatile components of the tobacco flavor samples, accounting for 86.54% of the total content, were identified and quantified. The 12 samples had 28 peaks in common. The method of fingerprint analysis was then validated on the basis of the relative retention times and relative peak areas of the common peaks, sample stability, and similarity analysis. The similarities of the 12 samples of tobacco flavor were >0.80, showing that samples from different batches were, to some extent, consistent. The chromatographic fingerprint developed was successfully used to differentiate tobacco flavor samples from tobacco extract prepared from tobacco leaf, both by similarity comparison and by principal-components projection analysis. The method can be used for quality control of tobacco flavor. 相似文献
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(-)-Slaframinel,anindolizidincalkal()idisolatedtYomthcfungusR/7i~()c't())IicllegIInlinicolainl965',usuallyinItctsleguminouscattle1tcdsandisrcsponsiblcli>rexcessivesalivationintheanimals.Also,lshowsthep()tcntialityinthetreatmentofdiseasesinvolvingcholinergenicdysfunction,andevenhassomebcneficialeffcctsonruminantdigestivefunction.Muchattentionhasbecndevotedtoitssynthesis'sinccitsabs()lutcstere()chcmistrywasestablishedas(lS,6S,8aS)-l-acetoxy-6-an1in()-ind()lizidine'.Thefirstenantioselectiveto… 相似文献