Purification Of The Effective Fraction Of The Alkaloids In Dicranostigma Leptopodum(Maxim.) Fedde And The Pharmacokinetics Study Of 8-acetamino-isocorydine

Dicranostigma leptopodum(Maxim.) Fedde(DLF) contains many alkaloids which have widely pharmacological activities. The preliminary study has shown that the total alkaloids of DLF have the analgesic and anti-inflammatory activity. Pharmacological studies of isocorydine, which has the highest content in DLF, shown that it has the good activity about against hepatic carcinoma, but its half-life was short and the central side effects was serious. With stable chemical structure and better anti-cancer effects, 8- acetylamino isocorydine was obtained by structural transformation of isocorydine. For the further exploitation of effective fraction of the alkaloids(EFA) and isocorydine, the following aspects were studied in the present paper based on the comprehensive summary of the literature of pharmacological activities and analysis methods of alkaloids:1) Preparation technique of EFA in DLF: the acid aqueous was used to extract the EFA of DLF with the reflux method. To remove most of tannins ingredients, the initial purif ication was performed by alcohol precipitation method. After the screening, D101 macroporous resin(MARs) was identif ied as the further purification substance of EFA and the technical parameters of the purification method was also screened. The results showed that the content of each alkaloid in EFA was greatly improved after the purification.2) Total alkaloid content determination of EFA in DLF : the HPLC and ultraviolet spectrophotometry(UV) method was used for the total alkaloid content determination of EFA. In the process of HPLC determination, the peak shape of tertiary alkaloids and quaternary amine alkaloids were improved by using of new-generation Megres C18 column and ionic liquids. After determination of eight known alkaloids, the result of total alkaloid content was finalized as 19.04 ± 1.23%. In the process of UV determination, the acidic condition was better for the alkaloids combined the chromogenic reagent into a colored ion pair, which could be quantitatively extracted with an organic solvent, by measuring the absorbance of colored ion pair, the content of total alkaloids was calculated as 65.92 ± 1.33%.3) Pharmacokinetics study of 8-acetamino-isocorydine: a new HPLC and liquid- liquid extraction method was established for determining the pharmacokinetics and tissue distribution of 8-acetamino-isocorydine. By measuring the concentration of 8-acetamino-isocorydine in rat plasma and tissue homogenates, the concentration-time curve was achieved. Then, the pharmacokinetic parameters and tissue distribution in rats was obtaine. The result demonstrated that 8-acetamino-isocorydine has the longer in vivo effects than isocorydine. The result also proved the structural transformation could improve pharmacological activity and pharmacokinetic behavior of the target compounds.