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991.
992.
Xin Zhao Dong‐Hui Yang Qi‐Le Zhou Feng Xu Lei Zhang Jing Liang Guang‐Xue Liu Shao‐Qing Cai Xiu‐Wei Yang 《Biomedical chromatography : BMC》2013,27(6):720-735
Danshen (DS) is a widely used traditional Chinese medicine for treating cardiovascular and cerebrovascular diseases. A simple, rapid and sensitive method was developed for identification of the in vivo metabolites in urine of WZS‐miniature pigs after oral administration of DS decoction by HPLC coupled with diode array detection with electrospray ionization tandem ion trap and time‐of‐flight mass spectrometry. This method has been successfully applied to simultaneous identification of 50 compounds (including 11 new ones) in pig urine. In addition, one new compound, (3‐hydroxyphenyl) crylic acid glycine methyl ester (C1), along with eight known ones were first isolated by column chromatography and identified by spectroscopic means, including 1D/2DNMR and mass spectrometry, as reference substances. Ten phenolic compounds (protocatechuic aldehyde, protocatechuic acid, caffeic acid, danshensu, ferulic acid, isoferulic acid, rosmarinic acid and salvianolic acid A/B/D) were found to be the main absorbed original constituents of DS decoction, which underwent the metabolic reactions of glucuronidation, sulfation, methylation, hydrogenation and glycine conjugation in vivo. In conclusion, the developed method is applicable to the analysis and identification of constituents in biological matrices after administration of DS decoction. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
993.
994.
Dr. Jing Li Dr. Martin J. Lear Prof. Yujiro Hayashi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(19):5901-5905
Cyclopropanes are traditionally prepared by the formal [2+1] addition of carbene or radical based C1 units to alkenes. In contrast, the one-pot intermolecular cyclopropanation of alkanes by redox active C1 units has remained unrealised. Herein, we achieved this process simply by exposing β-aryl propionitriles and C1 radical precursors (N-oxy esters) to base and blue light. The overall process is redox-neutral and a photocatalyst, whether metal- or organic-based, is not required. Our findings support that single electron transfer (SET) from the α-cyano carbanion of the propionitrile to the N-oxy ester is facilitated by blue-light via their electron donor–acceptor (EDA) complex. The α-cyano carbon radical thus formed can then lose a β-proton to form a π-resonance stabilised radical anion that preferentially couples at the benzylic β-position with a decarboxylated C1 radical unit. This new transition metal-free chemistry tolerates both electron rich and electron deficient (hetero)aryl systems, even sulfide or alkene functionality, to afford a range of cis-aryl/cyano cyclopropanes bearing congested tetrasubstituted quaternary carbons. 相似文献
995.
SHANJU ZHANG YUBIN ZHENG ZHONGWEN WU MINGWEN TIAN DECAI YANG RYUTOKU YOSOMIYA 《Liquid crystals》2013,40(2):311-314
Novel main chain poly(aryl ether ketone)s containing a lateral phenyl group were synthesized by nucleophilic substitution reactions of 4,4-biphenol and phenylhydroquinone with either 4,4-difluorobenzophenone or 1,4-bis(4-fluorobenzoyl)benzene and their thermotropic liquid crystalline properties were characterized by a variety of experimental techniques. Thermotropic liquid crystalline behaviour was observed in the copolymers containing 50 and 70 mol% biphenol. Melting (Tm) and isotropization (Ti) transitions both appeared on the DSC thermograms. A banded texture was formed after shearing the sample in the liquid crystalline nematic state. As expected, each of the copolymers had a relatively lower melting transition than the biphenol-based homopoly(aryl ether ketone)s because of the copolymerization effect of the crystal-disrupting monomer phenylhydroquinone. 相似文献
996.
997.
Yang Yuchuan Wang Jing Liu Wei Deng Hao Zhao Peng Liao Wei Wang Guanquan Wei Hongyuan Zhuo Liangang Yang Xia 《Journal of Radioanalytical and Nuclear Chemistry》2021,330(3):997-1005
Journal of Radioanalytical and Nuclear Chemistry - Death receptor 5 (DR5) is overexpressed in many tumors. Combination of the anti-DR5 antibody with radionuclides such as lutetium-177 (177Lu) could... 相似文献
998.
A series of Mannich base derivatives of 2-hydroxy-chalcones were obtained expediently in good to excellent yields by microwave-assisted Mannich reaction. The regioselectivity of the reaction occurred preferentially at the C-3 position of the 2-hydroxy-chalcone backbone. In comparison with conventional results, results from microwave possesses give better yields in shorter times. Further vasorelaxation assay showed that 2-hydroxy-3-((4-methylpiperazin-1-yl)methyl)-4,6-dimethoxymethoxy-3′-bromo-chalcone 8 significantly decreased maximal PE-induced contraction (Emax = 100 ± 5.97%, EC50 = 10.2 ± 0.51 µM). 相似文献
999.
1,3‐Dichloro‐tetra‐n‐butyl‐distannoxane was firstly used to catalyze the direct substitution of 9H‐xanthen‐9‐ol with indoles at room temperature to afford a class of 3‐(9H‐xanthen‐9‐yl)‐1H‐indole derivatives in good to excellent isolating yield. Moreover, other nucleophiles (such as diketone and pyrrole) could also proceed smoothly in this methodology. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
1000.