Studies On The Cholesterol-lowering Bioactive Constituents From Mahonia Bealei And Chemical Constituents Of Metarhizium Anisopliae

The studies of cholesterol-lowering bioactive constituents of Mahonia bealei(fort.) carr. were carried out in this thesis. Mahonia bealei, belonged to the family of Berberidaceae,exhibits important medicinal value and generally are used as a substitute for berberine. Previous studies revealed that some fractions from the extract of Mahonia bealei showed HMG-Co A reductase inhibitory activity, suggesting that it may have cholesterol-lowering activity. Herein, alkaloid fractions were enriched and obtained from 60% aqueous ethanol extract of the stem of Mahonia bealei. Vious chromatographic methods including silica gel CC, Sephadex LH 20, RP ODS cc and preparative HPLC, were applied for the isolation and purification of chemical constituents from the alkaloid section. Six compounds(1-6) were obtained and their chemical structures were identified by using ESI-MS, 1H-NMR, 13C-NMR, DEPT135, 1H-1H COSY, HSQC, and HMBC spectroscopic methods. They were emassenspektrum(1), chilenine(2), berberine(3), 8-oxy-berberine(4), palmatine(5), and noroxyhydrastinine(6), which belonged to the isoquinoline alkaloids. Among them, compounds 1, 2, and 6 were obtained from the genus of Mahonia for the first time. Pharmacological results revealed that the extract of Mahonia bealei, the alkaloid fraction, and compounds berberine(3) and palmatine(5) exhibited medium HMG-Co A reductase inhibitory activities. Based on results mentioned above, the extraction process of alkaloids from the stem of Mahonia bealei was investigated by using orthogonal design method and the optimal combination of extraction process is as follows: 80% aqueous Et OH as the solvent(′ 6) and extracted for four times(2 hours/time).The thesis also described the chemical studies of Metarhizium anisopliae(DTH12-10) derived from wetland habitats. 27 compounds were obtained from the Et OAc extract of the fermentation broth of Metarhizium anisopliae(DTH12-10) by using various chromatographic methods. Among them, the chemical structures of six compounds(7-12) were determined by their physicochemical properties and modern spectroscopic methods, including two new compounds. Their biological activities were needed to be studied.