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961.
Chia-Chi Huang 《应用光谱学评论》2016,51(1):1-11
Raman spectroscopic techniques are a group of chemical fingerprint detection methods based on molecular vibrational spectroscopy. They are compatible with aqueous solutions and are time saving, nondestructive, and highly informative. With complementary and alternative medicine (CAM) becoming increasingly popular, more people are consuming natural herbal medicines. Thus, chemical fingerprints of herbal medicines are investigated to determine the content of these products. In this study, I review the different types of Raman spectroscopic techniques used in fingerprinting herbal medicines, including dispersive Raman spectroscopy, resonance Raman spectroscopy, Fourier transform (FT)–Raman spectroscopy, surface-enhanced Raman scattering (SERS) spectroscopy, and confocal/microscopic Raman spectroscopy. Lab-grade Raman spectroscopy instruments help detect the chemical components of herbal medicines effectively and accurately without the need for complicated separation and extraction procedures. In addition, portable Raman spectroscopy instruments could be used to monitor the health and safety compliance of herbal products in the consumer market. 相似文献
962.
Frontispiece: Irreversible Denaturation of Proteins through Aluminum‐Induced Formation of Backbone Ring Structures 下载免费PDF全文
963.
LC–MS/MS determination and interaction of the main components from the traditional Chinese drug pair Danshen–Sanqi based on rat intestinal absorption 下载免费PDF全文
Juan Huang Jing Zhang Junqi Bai Wen Xu Dinghong Wu Xiaohui Qiu 《Biomedical chromatography : BMC》2016,30(12):1928-1934
The Chinese drug pair Danshen (Salvia miltiorrhiza)–Sanqi (Panax ginseng) has been widely used for centuries treating various cardiovascular disorders, among which salvianlic acid B (SAB), ginsenoside Rg1 (GRg1), ginsenoside Rb1 (GRb1) and notoginsenoside R1 (NGR1) were identified as the major components. The present study focused on the interaction between these components based on investigating their intestinal absorption using the Ussing chamber technique. The concentrations of SAB, GRg1, GRb1 and NGR1 in the intestinal perfusate were determined by LC–MS/MS method, followed by Q (accumulative quantity) and Papp (apparent permeability). The results showed that all these four main components displayed very low permeabilities, which implied their poor absorption in the rat intestine. The intestinal absorption level of SAB displayed regioselectivity: duodenum < jejunum < ileum. However, there was no significant difference in the absorption of GRg1 and GRb1 in the different segments. The Q and Papp values of the four main components were obviously increased in jejunum when co‐administrating Danshen extract with Sanqi extract. In conclusion, compatibility of Danshen and Sanqi could remarkably improve the intestinal absorption level of the main components in the pair. To some extent, this might explain the nature of the compatibility mechanisms of composite formulae in TCMs. 相似文献
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Lin-Feng You Tao Wei Qian-Wang Zheng Jun-Fang Lin Li-Qiong Guo Bing-Hua Jiang Jia-Jun Huang 《Applied biochemistry and biotechnology》2018,186(4):949-959
Taxoid 10β-O-acetyl transferase (DBAT) is a key enzyme in the biosynthesis of the famous anticancer drug paclitaxel, which catalyses the formation of baccatin III from 10-deacetylbaccatin III (10-DAB). However, the activity essential residues of the enzyme are still unknown, and the acylation mechanism from its natural substrate 10-deacetylbaccatin III and acetyl CoA to baccatin III remains unclear. In this study, the homology modelling, molecular docking, site-directed mutagenesis, and kinetic parameter determination of the enzyme were carried out. The results showed that the enzyme mutant DBATH162A resulted in complete loss of enzymatic activity, suggesting that the residue histidine at 162 was essential to DBAT activity. Residues D166 and R363 which were located in the pocket of the enzyme by homology modelling and molecular docking were also important for DBAT activity through the site-directed mutations. Furthermore, four amino acid residues including S31 and D34 from motif SXXD, D372 and G376 from motif DFGWG also played important roles on acylation. This was the first report of the elucidation of the activity essential residues of DBAT, making it possible for the further structural-based re-design of the enzyme for efficient biotransformation of baccatin III and paclitaxel. 相似文献
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α,β-Unsaturated nitriles were synthesized by the reaction of haloacetonitriles with carbonyl compounds mediated by tri-n-butylstibine in excellent yields. 相似文献