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One new sesquiterpene compound, namely, illihenlactone A(1), and one new prenylated C_6–C_3 compound, illihenryione H(2), along with three known sesquiterpenes(3–5) were isolated from the stems of Illicium henryi. The structures of 1 and 2 were elucidated by spectroscopic evidence including NMR, HRESIMS and circular dichroism(CD). Compound 2 exhibited a weak inhibitory ratio for bglucuronidase release induced by platelet-activating factor(PAF) in rat polymorphonuclear leukocytes(PMNs) in vitro. 相似文献
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Yan Zhang Yun-Bao Liu Yong Li Shuang-Gang Ma Li Li Jing Qu Dan Zhang Jian-Dong Jiang Shi-Shan Yu 《中国化学快报》2017,28(1):32-36
Three new phenolics(1–3) and twenty-eight known compounds(4–31) were isolated from an ethanolic extract of roots of Alangium chinense. Compound 11 exhibited antiviral activity against Coxsackie virus B3 with IC50 values of 16.89 mmol/L. Compounds 1, 10–17, 19–21, and 23 showed strong antioxidant activity against Fe~(2+)-cysteine-induced rat liver microsomal lipid peroxidation, with IC_(50) values of 0.14–8.18 mmol/L. 相似文献
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Chang-Shan Niu Yong Li Yun-Bao Liu Shuang-Gang Ma Fei Liu Li Cui Hai-Bo Yu Xiao-Jing Wang Jing Qu Shi-Shan Yu 《Tetrahedron》2018,74(3):375-382
During our continuing study on the roots of Pieris formosa, twelve new grayanane diterpenoids (1–12), together with eight known compounds (13–20), were obtained. Their structures with absolute configurations were characterized by a series of spectroscopic methods and X-ray diffraction. Compounds 1, 2, 4–5, 7–8, 14, and 19 exhibited significant analgesic activity in an acetic acid-induced writhing test. In particular, 7 and 14 were found to be 5 times more potent than morphine in the acetic acid-induced writhing test model. Compounds 1, 4, 9, 13, and 18 showed antifeedant activity against Plutella xylostella at 0.5 mg/mL. Compound 4 exhibited a 38.3% inhibitory effect against the KCNQ2 potassium channel at a concentration of 10 μM. 相似文献
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Yong Li Yu-Xun Zhu Zhao-Xin Zhang Yang-Lan Liu Yun-bao Liu Jing Qu Shuang-Gang Ma Xiao-Jing Wang Shi-Shan Yu 《Tetrahedron》2018,74(7):693-699
Rhododendron molle G. Don is one of the most potent traditional Chinese medicines for pain relief. Prior investigations have shown that Rhododendrons are rich sources of terpenoids. In our continuing efforts to identify structurally unique and biologically interesting diterpenoids, the fruits of R. molle were collected from Guangxi Province. A chemical study was carried out on the EtOH extract, which led to the isolation of 18 diterpenoids including 12 new compounds. The isolation and structural elucidation of new compounds 1–12, as well as the evaluation of the antinociceptive activities of these compounds were reported. 相似文献
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本文利用NO或/和CO吸附的TPD-MS方法, 结合IR和XPS对还原态的Co, Mo, Co-Mo/Al_2O_3催化剂进行了深入考索. 结果表明, 还原态的Co-Mo/Al_20_3表面上存在着两种吸附NO的Mo中心. 弱吸附NO(T_(max)为100 ℃)可被吸附的CO取代和强吸附NO(T_(max)为300 ℃)不能被CO取代. 同时存在三种吸附NO的CO中心, T_(max)分别为80 ℃、180 ℃和330 ℃. 前两者能吸附CO, 后者只吸附NO. IR结果对这些不同的Mo中心和Co中心的存在提供了进一步旁证. XPS结果表明提高还原温度, Mo/Al比保持恒定, 但Mo~(4+)浓度增加, 而Co/Al比却因部分Co进入Al_2O_3体相而降低。 相似文献
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LaCoO3模型催化剂SO2中毒机理的研究 总被引:3,自引:0,他引:3
运用AES,XPS,XRD和TEM等手段研究了LaCoO3模型催化剂SO2中毒过程表面化学状态、晶相结构及表面形貌的变化状况,初步推断了LaCoO3钙钛矿型复合金属氧化物催化剂的SO2中毒机理.在SO2强化中毒过程中,SO2与催化剂的活性组分LaCoO3反应生成硫酸镧和氧化亚钴,而在催化剂膜层内部则生成硫酸镧、亚硫酸镧及氧化亚钴.SO2对活性组分层的侵入及硫与LaCoO3活性组分的反应破坏了催化剂的钙钛矿结构,使得催化剂彻底中毒.当中毒温度较低及中毒时间较短时,硫在膜层中呈峰形分布,其浓度随中毒温度及时间的增加而增加.随中毒温度的升高及中毒时间的增长,由于亚硫酸盐的分解作用,S在活性层中的浓度反而降低,中毒深度则继续增加. 相似文献
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景洪哥纳香和大叶紫玉盘化学成分研究 总被引:2,自引:0,他引:2
从景洪哥纳香和大叶紫玉盘根醇提物中,采用色谱分离方法,分别得到43个和 33个化合物,通过波谱技术和化学方法鉴定了这些化合物的结构。其中,从景洪哥 纳香根中得到1个新化合物,命名为8-乙酰基-9-去氧哥纳香吡喃吡喃酮(1); 从大叶紫玉盘根中得到1个新化合物,命名为大叶素A(2)。另外,从景洪哥纳香 根中,还分离得到一个神经鞘胺醇苷成分混合物asteriacerebrosides (3),并通 过GC-MS技术,鉴定了该混合物的脂肪酸部分(FAM)和长链胺部分(LCB)的种类 数目及碳链长度。结果表明,3中脂肪酸部分,含7个脂肪酸,碳链长度分别是16, 18, 19, 20, 21, 22和23个碳;其长链胺部分包含5个脂肪胺,对应链长度为21, 22,23,24和25个碳。 相似文献
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尼龙66(PA66)是工程塑料的重要品种之一,具有高强度、耐磨、耐油、自润滑和使用温度范围广等优良特性,广泛应用于机械、汽车、电子电器等行业.但PA66在干态和低温下冲击强度偏低,吸水率大,尺寸稳定性差,使其应用范围受到一定的限制。 相似文献
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Liverton NJ Holloway MK McCauley JA Rudd MT Butcher JW Carroll SS DiMuzio J Fandozzi C Gilbert KF Mao SS McIntyre CJ Nguyen KT Romano JJ Stahlhut M Wan BL Olsen DB Vacca JP 《Journal of the American Chemical Society》2008,130(14):4607-4609
Molecular modeling of inhibitor bound full length HCV NS3/4A protease structures proved to be a valuable tool in the design of a new series of potent NS3 protease inhibitors. Optimization of initial compounds provided 25a. The in vitro activity and selectivity as well as the rat pharmacokinetic profile of 25a compare favorably with the data for other NS3/4A protease inhibitors currently in clinical development for the treatment of HCV. 相似文献