排序方式: 共有41条查询结果,搜索用时 31 毫秒
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采用GC—MS技术,利用2种不同极性的毛细管柱分析了羽裂蟹甲草挥发油的化学组成,确定了31种成分的化学结构与相对含量,结果表明其挥发油主要由单萜、氧化单萜和倍半萜组成,其中倍半萜的含量32.1%尤其显著α-姜烯(13.49%)、大牦牛儿烯D(10.76%)、α-蒎烯(8.54%)、顺式丁香烯(6.36%)、芳樟醇(6.16%)、β-月桂烯(4.89%)、顺式β-罗勒烯(4.40%)和顺式罗勒烯酮(3.58%)是其主要成分.同时采用滤纸片琼脂平板扩散法和肉汤稀释法测试了其挥发油对2种真菌和12种细菌(包括6种临床致病菌)的抗菌活性.结果表明挥发油对大部分微生物均具有很好的抗菌作用,尤其对酵母菌、革兰氏阳性菌作用更强,其最低抑菌浓度(MIC)为0.16~5.00g/L,最低杀菌浓度(MBC)为0.16~5.00g/L. 相似文献
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Zhongshi Liang Yun Liu Sameul S. Ng Xiangyang Li Lihui Lai Shufang Luo Shunying Liu 《Journal of nanoparticle research》2011,13(8):3301-3311
The effect of the pH value of gold ion plating (PCG) solution on the growth of gold nanoshells with about 100-nm silica cores
and 15-nm gold shells was systematically investigated by dynamic light scattering, UV–Vis spectroscopy, scanning electron
microscopy, and transmission electron microscopy. The results showed that in PCG solutions, the rapid formation of monomers
which intensively influenced by the reducibility of formaldehyde contributed to the growth of gold nanoshells. The reducibility
of formaldehyde increased following the increasing pH value from 4.70 to 11.71. Thus at high pH value, it was easy to fabricate
the complete gold nanoshells (except of the Cannizzaro reaction of formaldehyde at high pH value). Furthermore, we found that
chloride ions also influenced the surface morphology of gold nanoshells by Ostwald ripening process through the Au–Cl complex. 相似文献
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LIU Shunying WANG Fajun WEI Lanhua XIAO Wang MENG Lingzhi & HE Yongbing Department of Chemistry Wuhan University Wuhan China 《中国科学B辑(英文版)》2004,(2)
~~Synthesis and anion recognition of neutral receptors based on multiamide calyx[4]arene~~ 相似文献
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Ruthenium(II)/Chiral Brønsted Acid Co‐Catalyzed Enantioselective Four‐Component Reaction/Cascade Aza‐Michael Addition for Efficient Construction of 1,3,4‐Tetrasubstituted Tetrahydroisoquinolines
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Dr. Jun Jiang Xiaochu Ma Dr. Changge Ji Dr. Zhenqiu Guo Taoda Shi Dr. Shunying Liu Prof. Wenhao Hu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(6):1505-1509
An elegant synergistic catalytic system comprising a ruthenium complex with a chiral Brønsted acid was developed for a four‐component Mannich/cascade aza‐Michael reaction. The ruthenium‐associated ammonium ylides successfully trapped with in situ generated imines indicates a stepwise process of proton transfer in the ruthenium‐catalyzed carbenoid N?H insertion reaction. The different decomposition abilities of various ruthenium complexes towards diazo compounds were well explained by the calculated thermodynamic data. The transformation features a mild, rapid, and efficient method for the synthesis of enantiomerically pure 1,3,4‐tetrasubstituted tetrahydroquinolines bearing a quaternary stereogenic carbon center from simple starting precursors in moderate yields with high diastereo‐ and enantioselectivity. 相似文献
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Naiqian Fan Kongrong Duan Chengyun Wang Shunying Liu Shufang Luo Jiahui Yu Jin Huang Yaping Li Daxin Wang 《Colloids and surfaces. B, Biointerfaces》2010,75(2):543-549
This research is aimed to develop a nanomicelle delivery system in order to enhance the solubility and stability of camptothecin (CPT) in aqueous media. In this case, α,β-poly[(N-carboxybutyl)-l-aspartamide] (PBAsp)–CPT was conjugated by the esterification between PBAsp and 20-OH of CPT, and hence used to fabricate nanomicelles with a particle size between the pore size of blood capillary in normal tissue and that in tumor tissue. It was worthy of note that the drug-loaded system of PBAsp–CPT nanomicelle improved the solubility and stability of CPT in aqueous media. However, with an increase of the CPT loading in PBAsp–CPT, the solubility sharply decreased. Meanwhile, the sizes of PBAsp–CPT nanomicelles showed a tendency of increase. Moreover, the drug release of PBAsp–CPT nanomicelles displayed a linear sustaining profile, and hence resulted in the essential decrease of cytotoxicity to L929 cell line. The assembled nanomicelles based on the PBAsp–CPT conjugates showed a great potential as polymer prodrug of tumor therapy, and the controlled nano-scale might achieve the passive tumor targeting. 相似文献
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Chengjin Wang Shunying Liu Dong Xing Xin Wang Xiang Wu Wenhao Hu 《Tetrahedron》2013,69(52):11203-11208
A three-component reaction based on trapping of ammonium ylides with formaldehyde was first reported. This reaction offers a new strategy for the synthesis of α-aryl serine derivatives and can be extended to the preparation of α-aryl threonine derivatives. Synthetic application of the three component reaction for the preparation of hydroquinoxaline derivative was also demonstrated. 相似文献