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211.
A New Ceramide from the Basidiomycetes Armillaria mellea 总被引:2,自引:0,他引:2
Jin Ming GAO Ze Jun DONG Ji Kai LIU* Kunming Institute of Botany Chinese Academy of Sciences Kunming Northwest Sci. 《中国化学快报》2001,(2)
As one part of our study on the bioactive metabolites of the higher fungi in Yunnan Province, the chemical constituents of Armillaria mellea (Tricholomataceae) collected at Zhong Dian in Yunnan Province have been investigated. The present report deals with the structural elucidation of a new ceramide 1, named armillaramide, isolated from the AcOEt extract of the fruiting bodies of this fungus.Figure 1 The structure of armillaramide 1Compound 1, white amorphous powder, mp 113(117(C, [(] + … 相似文献
212.
Surface Modification of Nanometer Silica by N, N''''-dicyclohexyl- carbodiimide Mediated Amidation 总被引:1,自引:0,他引:1
Zhao Xia GUO Jie YU Jian YU* Institute of Polymer Science Engineering Department of Chemical Engineering Tsinghua University Beijing 《中国化学快报》2001,(10)
Nanometer silica has gained ever more attention for its superior properties over conventional micrometer particles and has been widely used as a filler in the manufacture of paints, rubber, plastics and so on1. However it is difficult to get silica mono- dispersed in the matrix due to heavy agglomeration. Surface modification through organic reactions is an efficient way to improve the dispersibility and compatibility with the matrix, thus improving the mechanical properties of the composite… 相似文献
213.
Hong Chao GUO Shang Zhong LIU Xue Tai HOU Min WANG* Department of Applied Chemistry China Agricultural University Beijing 《中国化学快报》2001,(9)
4-Amino-6-tert-butyl-3-methylthio-1, 2, 4-triazin-5 (4H)-one I, named as Metribuzin1, is an excellent selective herbicide. In the course of studying the reaction of I, we have found an unexpected reaction. We have attempted to prepare 6-tert-butyl- 4-methylamino-3-methylthio-1, 2, 4-triazin-5 (4H)-one II from I with methyl iodide in the presence of sodium hydroxide in aqueous methanol, surprisingly, instead of II the product III 4-amino-6-tert-butyl-3, 4-dihydro-2-methyl-3-thioxo-1, 2, 4-… 相似文献
214.
Yu Xin LIU Xiao Tian LIANG* Institute of Materia Medica Chinese Academy of Medical Sciences &Peking Union Medical College Xian NongTan Street Beijing 《中国化学快报》2001,(1)
In our research on the ring enlargement of certain N-heterocycles, a general procedure for the ring enlargement with the insertion of an extra -CH2- was improved and shown in Scheme I1.Scheme IThe procedure had been carried out with such N-heterocycles as 2-methyl-1,2,3,4-tetrahydroisoquinoline2, tetrahydroberberine and strychnine3 with expected results. Thus, the procedure shown in Scheme I provides a new approach to the synthesis of larger N-heterocycles.Isoindolo[1,2-b][3]benzazepines a… 相似文献
215.
216.
Zhan Zhu LIU Shi Zhi CHEN* Institute of Materia Medica Chinese Academy of Medical Sciences & Peking Union Medical College Beijing 《中国化学快报》2001,(3)
1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid is a type of naturally occurring bio-active alkaloid1. Moreover, it can be used as building block for the synthesis of other natural products containing the 1,2,3,4-tetrahydroisoquinoline moiety2. Compound 2 was an intermediate in our attempt to the total synthesis of Ecteinascidin analogs. We employed the Bishler-Napieralski reaction to prepare this product and refluxed the N-acetyl phenylalanine compound 1 in POCl3/benzene. However, we fail… 相似文献
217.
Xiao Xia YE Ji Shuang CHEN Ming Kui WANG Ke Xin HUANG Li Sheng DING* Chengdu Institute of Biology Chinese Academy of Sciences Chengdu Department of Chemistry Wenzhou Medical College Wenzhou College of Life Science Zhejia 《中国化学快报》2000,11(11)
As a part of an investigation on plant of the genus Notoseris (Asteraceae), an endemic genus of seed plants of China1, we studied the chemical constituents of N. psololepis Shih. A new sesquiterpene lactone glucoside, named notoserolide C (1) was isolated from the methanolic extract of the whole plant of N. psilolepis by repeated column chromatography (MCI GEL, normal and reversed phase silica gel). This compound showed antibacterial activity against Bacillu cereus.Figure 1. The key HMB… 相似文献
218.
219.
糖基化反应能诱导食品中蛋白质的结构发生改变;Ara h2是花生中的主要蛋白组分之一,可以作为一种模式蛋白研究花生蛋白糖基化产物的结构变化。不同还原糖对Ara h2糖基化反应的影响目前未见相关报道。以花生蛋白Ara h2为研究对象,通过SDS-PAGE、内源荧光、同步荧光、紫外、圆二色谱、红外等光谱技术研究Ara h2糖基化前后分子量、二级、三级结构以及官能团的变化,分析六种还原糖(核糖、木糖、半乳糖、葡萄糖、果糖、乳糖)对花生蛋白Ara h2糖基化产物结构的影响,阐明经不同还原糖修饰后花生蛋白Ara h2的结构变化。SDS-PAGE电泳表明木糖和核糖修饰的花生蛋白Ara h2电泳条带明显上移,糖基化程度最大;紫外光谱分析表明糖基化反应会改变花生蛋白Ara h2的吸收峰强度。五碳糖修饰的花生蛋白Ara h2具有最强的吸收强度,其中五碳糖中木糖的吸收峰强度最大;内源荧光、同步荧光和三维光谱实验结果表明,糖基化修饰会使花生蛋白Ara h2的荧光强度降低,且五碳糖修饰的Ara h2荧光强度最低。分析认为由于糖基化修饰使花生蛋白Ara h2的结构展开,导致芳香族氨基酸暴露在水环境中,从而引起荧光... 相似文献
220.