Studies On Purification And Derivatives Of Betulin

Birch, hardy deciduous trees, was bom in mountainous areas in China's Changbai Mountains region is rich in resources. "Compendium of Materia Medica" records, birch bark can be used for jaundice, Mastitis, treatment of diseases such as scabies. In addition, also for the treatment of chronic non-dysentery, and Qingrejiedu Mastitis, cough, asthma and so on. In recent years, the pharmacological effects of birch bark have been received widespread attention at home and abroad. Birch bark makes up of complex chemical substance and it has various pharmacological effects. Extract of birch bark is antibacterial, anti-viral, anti-tumor, lipid-lowering, and protective for gallbladder and liver. Scientists in foreign countries take a wide range of study in chemical composition of European and some other birch bark. The results show that the birch bark is rich in betulin and betulinic acid. It is meaningful and significant to take further research of these natural resourcesThe relatively mature method for purifying betulin is recrystallizing betulin in chloroform-methanol mixture solvent. In this thesis, orthogonal design had been taken to optimize the conditions of recrystallization, e.g. the volume ratio of chloroform: methanol mixture solvent. Moreover, the solubilities of betulin in fourteen commonly used organinc solvents were determined using HPLC methaod at T=(278.15, 288.15, 298.15, and 308.15) K. The experimental data can be used to guide the purification process in industry.Betulinic acid is more active than betulin in the anti-tumor. Betulinic acid and its derivatives are very much concerned as the new anti-tumor drugs. But content of betulinic acid is very limited in the birch bark. In the second chapter, betulinic acid was synthesed from betulin through a simple two-step reaction. Moreover, orthogonal experiments were taken to optimize the conditions and the feed ratio in the reaction. Problem of the high concentration of chromium-containing wastewater had been resolved by adding NaOH to make Cr³⁺ deposited as Cr(OH)₃, and the wastewater met the national effluent standards.Since betulin has the poor water-soluble, it need some derivatives in 3-or 28-hydroxy, for example, connection on glycoside or amino acids to increase its water-soluble and bio-availability. In the third chapter the reaction of betulin glycosylation was discussed.