The Extraction And Derivatization Of Lappaconitine And Anti-Tumor Activity Of Lappaconitine Derivatives

Lappaconitine,the main active ingredient of Aconitum sinomontanum Nakai in the Ranunculaceae family,has many pharmacological activities.Lappaconitine is the first none-addictive analgesic in China,and has great medicinal development value.In medicinal chemistry,natural products play a very important part for its inherent biological activity and clear target function.Extracting effective ingredients from natural products and modifying their structures to gain derivatives with strong pharmacological activity,have practical meaning for increasing the structural diversity of the drug molecule library.The structure of lappaconitine can be modified easily by introducting different substituents on multi-sites such as hydroxy,ester,amido,and lappaconitine derivatives with novel structure and strong activity are obtained in this way.In this thesis,we mainly focused on extraction and structure modification of lappaconitine and the anti-tumor activity of lappaconitine derivatives.1.The extraction and separation of lappaconitine.Ethanol refluxing extract method was used to extract the lappaconitine from the root of Aconitum sinomontanum Nakai.And the extraction method of lappaconitine was optimized by the single factor and orthogonal experiments,the lappaconitine content was taken as a key extract experimental index.The optimum conditions were confirmed to be: 80% ethanol as solvent and solid-to-liquid ratio of 10 mL/g for an extraction duration of 2 h for 3 times at 80℃.The lappaconitine was isolated and purified by liquid-liquid extraction,macroporous resin method and recrystallization procedures.Under these conditions,the lappaconitine purity was 96.85%.The structures of the lappaconitine was confirmed by 1H NMR and 13 C NMR spectra.2.The derivatization of lappaconitine.We designed and synthesized two kinds of novel lappaconitine derivative by modifying C8,9 adjacent dihydroxy at the same time,namely,lappaconitine isatin hybrid(A1-A9)and lappaconitine aromatic aldehyde hybrid(B1-B8).The optimal synthesis processes of lappaconitine was obtained by single-factor experiments,it was confirmed as follows: "one-pot procedure" of Lappaconitine,aldehyde or ketone compounds and trimethyl orthoformate(molar ratio 1:2:3)with toluene as solvent and methylbenzenesulfonic acid as catalyst.17 kinds of lappaconitine derivatives were obtained at these conditions.All the lappaconitine derivatives were purified by column chromatography and the structures were charactered by 1H NMR and 13 C NMR.3.The antitumor activity test of lappaconitine derivatives.Lappaconitine and its derivatives were assessed for their antitumor activity in vitro via the MTT assay using the Hep G2,A549 and He La cancer cell lines with 5-fluorouracil as positive control.The results showed that most lappaconitine derivatives had the inhibiting capacity to three cell lines in some degree,and compound A2,A3,B6 and B7 had stronger inhibitory activity among them and were significantly higher than those of lappaconitine,especially to He La cells,and the inhibitory effects were dose-dependent.The compound A2 showed the most prominent inhibition on the proliferation of Hep G2,A549 and He La with IC50 value 6.87 μmol/L,13.85 μmol/L and 3.16 μmol/L separately.