http://hdl.handle.net/2436/22092 Sat, 25 May 2013 07:42:36 GMT 2013-05-25T07:42:36Z http://hdl.handle.net/2436/34152 Title: Determination of free and total available ferulic acid in different types of Chinese angelica by high performance liquid chromatography Authors: Lu, Guang-Hua; Leung, Kelvin Sze-Yin; Chan, Kelvin C.; Cheng, SiQi; Zhang, Hao; Zhao, Zhong-Zhen Abstract: Free and conjugated forms of ferulic acid (FA) are generally available in higher plant taxa such as Chinese Angelica (CA, the roots of Angelica sinensis (Oliv.) Diels). These various forms of FA were found readily inter-convertible and the extractable level of each depended on solvent properties and acidity. Extraction efficiency using various pH solutions namely, water, 70% methanol, methanol-formic acid (95:5) and methanol-2% NaHCO3 in water (95:5) was compared. Extractable FA were found varying in samples under neutral solvents extraction, whilst relatively consistent for slightly acidic and alkali solvents which were therefore chosen as the optimal media to extract and determine the reproducible levels of free and total available FA. An accurate and rapid high performance liquid chromatographic (HPLC) analysis was conducted using an Alltima C18 column (5 mum, 4.6 mm i.d. x 250 mm) with a guard column (C18, 5 mum, 4.6 mm i.d. x 7.5 mm) at 30degreesC, eluted with a mixture of 1.0% acetic acid and acetonitrile in a gradient program at a flow rate of 1.0 mL/min and detected at 320 nm. Altogether 20 different types of CA samples including whole root, root head, rootlets, whole root slice, Angelica processed by Chinese yellow wine, and charred Angelica were quantified for free and total available FA. Total available FA was found more abundant than free counterpart with an average ratio of 3.15 (n = 20) in the range of 1.29 to 8.23 for these CA samples. The extraction protocol was proven reliable to quantitatively convert all conjugated FA into its free forms and thereby accurately determined by HPLC method for quality assessment. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/2436/34152 2007-01-01T00:00:00Z http://hdl.handle.net/2436/29759 Title: The Chinese Quality Of Life Instrument: Development Of A New Health-Related Quality Of Life Instrument Using Factor Analysis And Structural Equation Modeling Authors: Zhao, Li; Chan, Kelvin C.; Leung, Kwok-fai; Liu, Feng-bin; Lang, Jian-ying; Fang, Ji-qian Abstract: A new Chinese Quality of Life Instrument (ChQOL) based on the principles of diagnosis and practice in Chinese medicine has been developed. This paper describes the development of the ChQOL instrument using factor analysis and structural equation modeling. An initial pilot version of the 78 items instrument was field tested in a sample 273 subjects recruited from different areas in China. The objective of this study was to determine the factor structure and latent constructs of the ChQOL based on factor analysis. A series of confirmatory factor analysis and structural equation models were used to determine the final model of the ChQOL. The results showed that the application of factor analysis and structural equation modeling is an effective method to develop the new health-related quality of life instrument, ChQOL, even though the practice of Chinese medicine is quite different from the practice of conventional western medicine. Sun, 01 Jan 2006 00:00:00 GMT http://hdl.handle.net/2436/29759 2006-01-01T00:00:00Z http://hdl.handle.net/2436/29758 Title: Building a bridge for integrating Chinese medicine into conventional healthcare: observations drawn from the development of the Chinese quality of life instrument. Authors: Zhao, Li; Chan, Kelvin C. Abstract: This paper describes the methods and theories of patient-reported outcomes, in particular to the health-related quality of life recently applied in Chinese medicine research. It begins with an investigation of the reasons for a patient-reported outcomes measure for Chinese medicine and the development of a new health-related quality of life instrument based on Chinese culture and Chinese medicine. Discussions on the importance and application of patient-reported outcomes as well as the relationship between quality of life and Chinese medicine are at the focus of this paper. Through a description of the Chinese Quality of Life Instrument and its development, the present work demonstrates an evidence-based approach using patient-reported outcomes or health-related quality of life measures to evaluate treatment efficacy of Chinese medicine, and thereby build a bridge for the integration of Chinese medicine into mainstream health care. Sat, 01 Jan 2005 00:00:00 GMT http://hdl.handle.net/2436/29758 2005-01-01T00:00:00Z http://hdl.handle.net/2436/29757 Title: Simultaneous qualitative and quantitative analyses of the major constituents in the rhizome of Ligusticum Chuanxiong using HPLC-DAD-MS. Authors: Yi, Tao; Leung, Kelvin Sze-Yin; Lu, Guang-Hua; Chan, Kelvin C.; Zhang, Hao Abstract: An HPLC-DAD-MS method was developed for the qualitative and quantitative analysis of the major constituents in Chuanxiong (the dried rhizome of Ligusticum chuanxiong Hort). Twenty compounds including phenolic constituents, alkylphthalides and phthalide dimers were identified using online ESI-MS and comparisons with literature data and standard compounds, and six of them were quantified by HPLC-DAD simultaneously. A comprehensive validation of the method including sensitivity, linearity, repeatability and recovery was conducted. The linear regressions were acquired with R(2) > 0.99 and limit of detection (LOD, S/N = 3) values were between 1.5 and 2.5 ng. The repeatability was evaluated by intra- and inter-day assays, and relative standard deviation (RSD) values were reported within 1.87%. The recovery studies for the quantified compounds were observed in the range of 96.36-102.37% with RSD values less than 2.63%. These phenolic constituents and alkylphthalides, the major constituents in Chuanxiong, are generally regarded as the index for the quality assessment of this herb. The overall procedure is accurate and reproducible, which is considered suitable for the qualitative and quantitative analyses of a large number of Chuanxiong samples. Sun, 01 Jan 2006 00:00:00 GMT http://hdl.handle.net/2436/29757 2006-01-01T00:00:00Z