CUHK electronic theses & dissertations collection

A method is presented for the simultaneous identification of nine compounds in samples of A. membranaceus and A. membranaceus var. mongholicus. Compounds identified in the extracts of the two plants included glycosides, saponins and flavonoids. They are identified as Calycosin-7-O-beta-D-glucoside (C1), Ononin (C2), (6aR,11aR)-3-hydroxy- 9,10-dimethoxypterocarpan-3-O-beta-D-glucoside (C3), (3R)-7,2'-dihydr- oxy-3',4'-dimethoxyisoflavan-7-O-beta-D-glucoside (C4), Calycosin (C6), Astragaloside IV (C5 ), Formononetin (C7), (6aR,11a R)-3-hydroxy-9,10-di-methoxypterocarpan (C8), and Isomucronulatol (C9).An HPLC-DAD-MS method is proposed for the differentiation of Rhizoma Coptidis and Cortex Phellodendri samples. This method can also be used to identify two common species of Rhizome Coptidis, i.e., C. chinensis and C. deltoidea, and two species of Cortex Phellodendri, i.e., P. chinensis and P. amurense. From the experiment results, there are thirteen, twelve and seven common components found in samples Rhizoma Coptidis, P. amurense and P. chinensis, respectively. Nine compounds in Rhizoma Coptidis were identified to be alkaloids. The common components in Cortex Phellodendri included four alkaloids and two lactones, i.e., obaculacotone and obacunone, present in all samples of P. amurense.High Performance Liquid Chromatography-Atmospheric Pressure Chemical Ionization Mass-Spectrometry has been applied to the analysis and standardization of Chinese Herbal Medicines. The applications included quantitative study of Astragaloside in Radix Astragali, investigation on the chromatographic fingerprint of Radix Astragali, differentiation of Cortex Phellodendri and Rhizoma Coptidis, and identification of constituents in Sanhuang Xiexin Decoction.In the quantitative study of Astragaloside, an Multiple Reaction Monitoring scan mode was used. The linearity between 2 and 500 mg/L is 0.9996. The precision of injection and reproducibility of method is 1.72% and 3.27% respectively. A total of 20 samples from local market and mainland China were analyzed and the results are comparable to those obtained from HPLC-ELSD analysis.The present study also proposed a HPLC separation and online identification for the 15 constituents in a composite Chinese herbal formula, the Sanhuang Xiexin Decoction. It provided a possible starting point to evaluate related herbal preparations containing Rhizoma Coptidis, Radix Scutellariae and Rhizoma Rhei. Thirteen constituents in the decoction were identified, including five major alkaloids from Rhizoma Coptidis, five anthraquinones from Rhizoma Rhei and two favonoids and one glycoside from Radix Scutellariae."November 2007."Adviser: Chi Chun Tao.Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4726.Thesis (Ph.D.)--Chinese University of Hong Kong, 2007.Includes bibliographical references (p. 177-200).Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.Abstracts in English and Chinese.School code: 1307