Synthesis Of Betulinal Thiosemicarbazone And Its Transition Metal Complexes

Betulin is a type of lupine alkyl compound belonging to pentacyclic triterpenoids. Previous researches shows that betulin have many effects, such as non-toxic, anti-tumor, anti-inflammatory, fast cure wounds, anti-allergies and other effects. Betulin have a wide range of applications in medicine, chemical industry and other fields. It is a very promising class of biologically active substance. Thiosemicarbazone is a kind of particular Schiff base which exhibited strong ability of coordination, various complexing pattern and potent bioactivity, such as antibacterial, anti-inflammatory, antiviral, anti-tumor, etc. Nevertheless, most metal complexes possesses better bioactivity than their corresponding thiosemicarbazone as certified by recent researches. Thus, this thesis in order to obtain better and more efficient compounds, we introduced thiosemicarbazone into betulin backbone and act in concert with the transition metals. Synthesized their complexes based on the principle of drug design principle of combination principles.Herein, the betulin raw extract from the birch powder. First, we protect 28-OH with triphenylchloromethane,and re-introduced at 3-OH with ester groups, then after deprotection, oxidation and hydrolysis to removing the protecting group on the C-3, we introduced thiosemicarbazone on the 28th position, and finally reacted with the various transition metal salt complexes to give the corresponding metal complexes (Betulinal thiosemicarbazone metal complexes). Ligands and their copper (II), silver (I), cadmium (II), palladium (II) metal complexes, were characterized by’H-NMR, IR, MALDI-TOF-MS, Elemental analysis and TGA. Its coordination modes of two ligands with metal ions to form a bidentate mode are finally demonstrated. Moreover ligands and their metal complexes were carried out in vitro experiments with cancer cell antiproliferative experiment. The data indicated that Ag(Li)2NO3-3H2O and Cd(Li)2Cl2·2H2O have relatively good antibacterial activity, Cu(Li)2Cl2 and Ag(Li)2NO3·3H2O can significantly inhibit the viability of Hela cell.