Gentiopicroside Preparation And Pharmacokinetic Study

As a kind of natural compounds distributing widely in plants, iridoids can protect liver from damage by some toxicants and better function of gallbladder. Gentiopicroside, being one of them, is the main constituent in traditional Chinese medicine qinjiao and longdan. The pharmacodynamic researches on it have been reported in history, but not has its pharmacokinetic studies.To study it pharmacokineticly in rats, gentiopicroside was extracted and purified from qinjiao. The method was as following:The dried qinjiao was powdered and extracted with boiling water for three times. The extract solution was subjected to chromatography on DIOI macroporous resin column and the 30% alcohol elution was concentrated under low pressure. Then a column chromatography on silica gel. was carried out with EtOAc : MeOH I H2O(20 : 2 : 1) as mobile phase to give slightly yellow crystal. The crystal was examined by TLC, HPLC, NMR, MS and IR, and all the data were in accord with those recorded. Thus the crystal was identified as gentiopicroside and the purification determined by HPLC was 94.9%.In further research all rats were separated into three groups and were im given the drug. Nine blood samples were collected at different times after injection from eath group. The serum samples were obtained after centrifuge as the above layers in centrifuge tubes and were dealt with on solid phase extract(SPE) columns in advance for determination by HPLC with MeOH : H2O(3 I 7) as mobile phase and 270 nm as detection wavelength. All data were deposed of with software 3p97. The results indicated that when rats were injected gentiopicroside at 180mg/kg dose, the serum concentration-time curve made on two compartment model with tmax being 8 min, Cmax 119.9 u g/mg, and AUC 8143.9U g/mg ?min. When dosages were 120 and 60 mg/kg the curves made on one compartment model with tmax 9.8 and 8.2 min, Cmax 104.7 and 53.4 u g/mg, AUC 6120.8 and 1833.3 Ug/mg· min respectively.The results of distribution and excretion experiments illuminated that there was not the drug only in brain. The concentration in kidney was the highest and the relatively lower were liver, lung, womb, heart successively. There was also a little in other tissues. The main excretion way was in urine and 97% of the drug injected was eliminated within 8 hours after injection. There was no apparent accumulation in tissues of rats.