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991.
992.
Wang Kang Xingqiong Du Lanzhi Wang Lijuan HU Yuhuan Dong Yanqing Bian Yuan Li 《中国化学》2013,31(10):1305-1314
Our studies examined the structural features responsible for the antifungal activity of 2-ethoxycarbonyl-1,5- benzothiazepine (7a). Three series of 1,5-benzothiazepine derivatives were synthesized and screened for their antifungal activity. The results suggested that the ethoxycarbonyl group at the 2 position and the imine moiety on the seven-membered ring are essential for activity. The most potent of the synthesized analogues (7a, 7b) were further studied by evaluating their cytotoxicity and mode of action (for 7a). The results showed that compounds 7a and 7b were relatively safe for BV2 cells, but compound 7a interfered with Cryptococcus neoformans cell wall integrity by increasing the chitinase activity. Therefore, compound 7a was considered safe as an antifungal agent for animal cells. 相似文献
993.
Two new guaianolide-type sesquiterpenoids,4β,9β-dihydroxy-1α,5α-H-guaia-6,10(14)-dien(1) and 4β,9β,10α-trihydroxy-1α,5α-H-guaia-6-en(2),along with four known sesquiterpenoids(3a,3b,4 and 5),were isolated from Kadsura interior.Their structures and configurations were elucidated by spectroscopic methods including 2D-NMR and HR-MS techniques.Compounds 3a and 3b were obtained as a pair of enantiomers,and their structure and absolute configuration were established from their extensive NMR spectra and by single-crystal X-ray analysis. 相似文献
994.
995.
Hui Qiang Tao Chen Zhuo Wang Wenqian Li Yunzhe Guo Jie Yang Xueshun Jia Hui Yang Weibo Hu Ke Wen 《中国化学快报》2021,31(12):3225-3229
The development of heterogeneous catalysts with substrate shape, size or electronic constitution selectivity is a huge challenge in photocatalysis. Reported herein is a host-guest interaction strategy to endow photocatalysts with special selectivity. By adjusting the precursors, conjugated macrocycle polymers (CMPs) with pillar[5]arene struts (CMP-1 and CMP-2) and a corresponding non-pillar[5]arene-contained conjugated organic polymer (COP-1) were prepared and the photocatalytic activities toward sulfide derivatives were investigated. The sulfides showed similar conversions when COP-1 was used as a photocatalyst, but exhibited significant differences when it turned to the CMPs. Remarkably, the conversion yield of S-1 achieved near 18 folds over the one of S-2 when CMP-2 was used as a catalyst. Mechanism studies confirmed that the “host-guest” effect of pillar[5]arene struts in CMPs was the main cause of the difference. The present work establishes CMPs as novel heterogeneous photocatalysts with substrate selectivity, and such a method will inspire the researchers concerning preparation of heterogeneous catalysts with excellent selectivity. 相似文献
996.
Dr. Benoit Colasson Dr. Thomas Devic Dr. Joël Gaubicher Dr. Charlotte Martineau-Corcos Prof. Philippe Poizot Dr. Vincent Sarou-Kanian 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(37):9589-9596
The synthesis and characterization of a polyrotaxanated covalent organic network (CON) based on the association between the viologen and pillar[5]arene (P[5]OH) units are reported. The mechanical bond allows for the irreversible insertion of n-type redox centers (P[5]OH macrocycles) within a pristine structure based on p-type viologen redox centers. Both redox units are active on a narrow potential range and, in water, the presence of P[5]OH greatly increases the electroactivity of the material. 相似文献
997.
《Analytical letters》2012,45(16):1311-1325
Abstract Electrochemical caracteristics of 2-mercaptopyridine-5-carboxylic acid and its methylic ester have been determined using recent polarographic techniques. Measurements have been carried out as a function of parameters such as frequency, others surimposed signals and as a function of concentration and pH. Results are compared to those obtained for selectively methylated on sulfur or nitrogen atoms derivatives. Interpretations of the data are given. The optimal conditions for a quantitative determination by D.C. and differential pulse polarography are fixed. 相似文献
998.
999.
Denis N. Tomilin Lyubov N. Sobenina Marina V. Markova Maxim D. Gotsko Igor A. Ushakov Vladimir I. Smirnov 《合成通讯》2013,43(14):1652-1661
5-Acylethynylpyrrole-2-carbaldehydes have been synthesized from the protected pyrrole-2-carbaldehydes by their transition-metal-free topochemical mechanoactivated ethynylation with acylbromoacetylenes in a solid Al2O3 medium (room temperature, 6 h, 41–54% yields). 相似文献
1000.