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芫花花蕾中的新二萜原酸酯——芫花酯戊的分离与结构 总被引:1,自引:0,他引:1
我国科学工作者应百平等,曾从瑞香科瑞香属芫花(Daphne genkwa Sieb,et Zucc.)中,分离得多种抗生育成份如芫花酯甲(yuanhuacine),芫花酯乙(yuanhuadino),芫花酯丙(ynanhuafine,1)和12-苯甲酰氧基瑞香毒素(12-Benzoxydaphnetoxin)等.但对芫花花蕾中所含化学成份的研究,却未见报道.我们继分得芫花酯丁(yuanhuatine)后又从芫花花蕾中分出一种新的二萜原酸酯化合物,命名为芫花酯戊(yuanhuapine,2).2根据波谱分析与1对比、确定其结构为1的1,2-双氢化合物.它为白色无定形粉末,[α]_D~(20)+38.9°(c0.054,CHCl_3),有强烈的刺激性,易溶于乙醚、氯仿、丙酮、乙醇等溶剂中,不溶于水. 相似文献
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芫花 (DaphnegenkwaSieb.etZucc.)属于瑞香科植物[1] ,芫花的浸取液对棉蛉虫、稻螟虫、菜青虫、班蝥等害虫具有较好的杀虫效果 ,且对人畜无害 ,是一种理想的无公害农药[2 ] 。为了提高药效 ,更好地开发这种无公害农药 ,本文对芫花中杀虫有效成分的提取工艺与杀虫效果进行了初步研究。1 实验部分1 1 试剂和仪器苯 ,氯仿和 95 %的乙醇均为分析纯 ;岛津UV -2 40型紫外可见分光光度仪 ;FT -80ANMR仪。1 2 实验方法芫花枝条干粉 1 5 0 0g,加水 1 0 .0 0L煮沸 1 2小时 ,煮沸过程中陆续补加少量水分。将煮沸… 相似文献
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本文研究了三种可溶性聚酰亚胺(PI)在机溶剂和水溶液中的电化学行为,发现PI在有机溶剂中的电化学行为明显不同于水溶液,利用红外光谱技术才半经验发子轨道计算方法,结合电化学测试的结果,确证了PI的电化学反应的机理。 相似文献
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David Briers Lieven De Cremer Guy Koeckelberghs Stijn Foerier Thierry Verbiest Celest Samyn 《Macromolecular rapid communications》2007,28(8):942-947
A new chromophore, C1 , based on a similar DπA‐structure as in the FTC ‐chromophore but with a hydroxyalkyl spacer perpendicular to the direction of the dipole moment was synthesized. Both chromophores and the CLD ‐chromophore were used to prepare high Tg nonlinear optical vinyl polymers. The influence of the position of the spacer on the DπA‐system on the NLO response of the resulting polymers was investigated.
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The photooxidation of chloral was studied by infrared spectroscopy under steady-state conditions with irradiation of a blackblue fluorescent lamp (300 nm < λ < 400 nm, λmax = 360 nm) at 296 ± 2 K. The products were hydrogen chloride, carbon monoxide, carbon dioxide, and phosgen. The kinetic results reveal that the reaction proceeds via chain reaction of the Cl atom: The results lead to the conclusion that mechanism (B) is confirmed to be more likely than mechanism (A), which was favored at one time by Heicklen for the mechanism of the oxidation of trichloromethyl radicals by oxygen molecules: The ratio of the initial rates of CO and CO2 formation gave k7/k6 = 4.23M?1, and the lower limit of reaction (5) was found to be 3.7 × 108M?1 sec?1. 相似文献
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Neese F 《Journal of computational chemistry》2003,24(14):1740-1747
A straightforward modification of the resolution of the identity (RI) approximation to the Coulomb interaction is described. In the limit of basis sets that are dominated by high angular momentum functions the observed speedups in realistic test systems reach a factor of 2 compared to the standard RI algorithm, and a factor of up to 300 compared to the standard algorithm to form the Coulomb matrix. More moderate savings on the order of 0-20% are obtained for the more commonly used smaller basis sets. A series of test calculations is reported to illustrate the efficiency of the algorithm. 相似文献
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