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UM E-Theses Collection (澳門大學電子學位論文庫)

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Title

Chemical, metabolic and pharmacokinetic investigations of Peucedani Radix

English Abstract

As a widely employed traditional herbal drug, Peucedani Radix (Qian-hu) exhibited anti-hypertensive, coronary dilatory, myocardial protective and suppressing airway inflammatory activities. Angular-type pyranocoumarins (APs) were presumed to be the main active components to be responsible for the medicinal efficacy. In contrast to the well defined chemical constituents and pharmacological properties, the metabolic and pharmacokinetic properties of the main components and the crude extract were rarely taken into concern. Especially, enantioselective activity was observed for the enantiomers of praeruptorin A (PA), suggesting it is crucial to monitor enantiomers separately during characterization of metabolic and pharmacokinetic features, qualitative and quantitative analysis for APs in the herbal medicine. Therefore, a systematic study was carried out to offer available information for the further exploitation of APs and Qian-hu. Firstly, phytochemical investigations on Peucedani Radix, including isolation and the identification of 18 compounds, enantiomeric separation of 11 APs, and the absolute configuration determination by enzymatic hydrolysis coupled with chiral LC-MS/MS, were carefully conducted to provide definite reference compounds for subsequent evaluations. Chemical profiling was achieved using LC-MS/MS. The ESI-MSn fragmentation pathways of APs were proposed using reference components, and 44 coumarins were tentatively identified. Subsequently, a novel heart-cut achiral-chiral LC-MS/MS method was developed and applied to enantiospecific quantitation of the main components in Peucedani Radix. iv The metabolisms of more than twenty APs were screened using liver microsomes of rat and human, to aid characterizing the in vivo fates of the main constituents. Oxidation, hydrolysis and intra-molecular acyl migration were observed as the main metabolic pathways. Further, the structure-metabolism relationship was discussed based on the findings collected. Lastly, enantioselective pharmacokinetic and metabolic profiles of PA and its enantiomers were characterized using two administration routes and the enantiospecific hydrolysis of (-)-praeruptorin A (lPA) in the plasma should account for the chiral discrimination. Pharmacokinetic evalution of Qian-hu extract was achieved using online solid phase extraction-chiral LC-MS/MS. In summary, angular-type pyranocoumarins were revealed as the major constituents in the original plant, while cis-khellactone was the main active component in rat after Qian-hu dosing. The findings obtained will contribute to the further evaluations of this herbal medicine.

Issue date

2013.

Author

Song, Yue Lin,

Faculty

Institute of Chinese Medical Sciences

Degree

Ph.D.

Subject

Pharmaceutical chemistry

Materia medica, Vegetable -- China -- Analysis

Medicinal plants -- China -- Analysis

Supervisor

王一濤

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Full-text (Internet)

Location
1/F Zone C
Library URL
991005706889706306