Extraction Of Betulin From Changbai Mountain Birch Bark, Synthesis Of Its Derivatives And Study On Their Bioactivities

Betulin and betulinic acid are remarkable natural products. They are obtained from avariety of botanical sources and betulinic acid can be easily prepared from the more plentifulprecursor betulin in a simple two-step process. Betulin,betulinic acid and many of theirderivatives exhibit great promise as bioactive agents for the treatment of HIV infection andcancer.It is significant to study the pharmaceutical activities of betulin ,betulinic acid andtheir derivatives and to confirm the relationship between their construction and activity forselecting the more efficient medicine. In our country, birch sources are enriched , but the littlehave been explored. In consequence, we decide to study the sources of Changbai Mountainbirch. The main content of this thesis as following: 1. The contain of betulin and betulinic acid are analyzed by GC. The contain of betulin is18.25% and betulinic acid is 0.975%. Therefore, it is remarkably promising to explore theChangbai Mountain birch sources. 2. We have extracted betulin(comp.1) from Changbai Mountain birch bark. In meantime,we design and sythesize 4 compounds and 1 intermediate. They are characterized by 1~H NMR, 13C NMR and IR. 3. In order to investigate their biological activities, 4 medical regents are tested in vitroagainst oesophagus cancer cells EC109 using MTT assay. It is indicated that these compoundsexhibit satisfactory activities. Especially, betulinic acid and extracted compound exhibit moreexcellent activities.