Studies On The Xanthones From Swertia Davidi Franch

Swertia davidi Franch,a precious Chinese Traditional Medica, belongs to Gentianaceae. It contains xanthones,iridoids,triterpenoids and flavonoids et al. Xanthone is one of the most important bio-active components.The extraction, purification, structure, standard, determination of demethylbellidifolin and methylswertianin, the supercritical fluid extraction and fingerprint of total xanthones; pharmacokinetics and the GLP-1 Receptor agonisteffect of demethylbellidifolin were systemically studied in the thesis.The resultswere as follows:(1)The extraction of total xanthones. The optimal extraction conditions were determined according to orthogonal experiments as extraction temperature 40℃, pressure 30MPa,entrainer 95%ethanol(volume fraction) and time 80min.The yield of total xanhtones was 1.61%Compared with the organic solvents method, the SFE method is more efficient,more rapid,morefriendly environmently and less cost. (2) The preparation of standard substance and identification of its structure. Demethylbellidifolin was isolated and prepared from super critical fluid CO2extract by using silica gel and micrite cellulose column chromatograph,Methylswertianin was isolated and prepared from super critical fluid CO2 extract by using silica gel column chromatograph and Pre-TLC. These methods are simple and stable. By employing physical andchemical properties, modern spectrometric analysis techniques such as UV,IR,EI-MS,1H-NMR,13C-NMR,and DEPT, their structures of demethylbellidifolin and methylswertianin have been elucidated.Demethylbellidifolin and methylswertianin have been chosen as the reference substance for qualitative and quantitative analysis of the crude drug forits speciality and content.(3)Quantitative determination of demethylbellidifolin by RP-HPLC. The RP-HPLC method was used todetermine the content of demethylbelli-difolin in different parts of S. davidi. Theanalysis was carried out on Hypersil C18 column (150mm×4.6mm,5μm).The mobile phase was CH3OH-0.5%H3PO4(56:44). Flow-rate was 1.0ml/min. Wave-lengthwas 254 nm. Temperature was room temperature. The method was simple, fast and had a good liner relationship.The liner range of demethylbellidifolin was 0.52～2.6μg and gave a correlation(r) of 0.9994.The recovery was 99.97%,RSD 0.94%.The content was 0.752-0.770%.(4) HPLC Fingerprint of Total xanthones o f S. david.The chromatographic fingerprint of total xanthones of S. davidi.has been setup by HPLC,The analysis was carried out on Hypersil C18 column(150 mm×4.6mm,5μm).The mobile phase was MeOH-H2O (54︰46).Flow-rate was 1.3mL/min.Wave-length was 254 nm and temperature was 20℃.The fingerprint of total xanthones of S. davidi was established.The method is repeatable and can be usedin quality assessment of S. davidi. (5) the pharmacokinetics of demethylbellidifolin in mice. In the present study HPLC method were developed to determine in mice.plasma. The standard curves were linear from 0.048 to 4.8μg/ml with correlationcoefficients of 0.9996.The methods were applied to a pharmacokinetic study of demethylbellidifolin in mice. The pharmacokinetic parameters were determined after intraperitoneal injections of demethylbellidifolin (0.8g/kg) to mice. The mainpharmacokinetic parameters of demethylbellidifolin in mice were t1/2αof (19.800±4.831)min and tl/2βof (411.475±52.838)min, AUC of(92.246±10.906)mg ml·min-1,The all fit to the two-compartment open model.(6)The effect of demethylbellidifolin activating GLP-1 Receptor.The human GLP-1R plasmid and reporter gene plasmid(MRE/CRE/LUC)werecotransfected HEK293 to establish a cell line. Result: demethylbellidifolin can activate GLP-1R. The above result has provided the experimental basis for the development of demethylbellidifolin as the treatment diabetes new drug.