Yew Tissue Culture Component Analysis And Taxus Yunnanensis A Microbial Conversion

Paclitaxel, a diterpenoid of taxane with excellent activity against cancers, was isolated from the bark of Taxus plants. Taxus plants grow slowly, and yield relatively low amounts of paclitaxel, all of this cause supply crisis of paclitaxel. Tissue and cell cultures of Taxus spp., have rich supply of paclitaxel and related taxanes, this technology is viewed as a potential alternative to producing paclitaxel.Most compounds separated from tissue and cell cultures of Taxus spp., are similar to those in nature Taxus plants. This proves that cell cultures possess the ability of producing the same compounds as nature plant. Cell cultures of Taxus produce not only paclitaxel and related taxanes, but also some new taxanes. Some of the compounds can provide useful information for the biosynthesis pathway study.Microbial transformation is a kind of chemical reaction of structure modification catalyzed by enzymes produced by microrganisms, it has such advantages over chemical synthesis as highstereo-and regio-selectivity, as well as mild reaction conditions, lower cost, less byproducts and pollution. Microbial transformation is often used for modifing nature products to obtain more novel drug candidates and valuable intermediate for synthsis.In this thesis, ten compounds from cell culture Ts-19 cell line of Taxus were separated. On the basis of chemical and spectral data, the structures were identified as: 2α,5α,10β-triacetoxy-14β-(2-methyl- butyryloxy)-4(20),11-taxadiene(3);2α,5α,10β-triace- toxy-14β-propionyloxy-4(20),11-taxadiene(2);2α,5α,10β,14β-tetra-acetoxy-4(20),11-taxa- diene(1);5α-hydroxy-2α, 10β,14β-triaceoxy -4(20),11-taxadiene(4);2α,5α,10β-triacet- oxy-14β-(3-hydroxyl-2-methyl- butyryloxy) -4 (20), 11-taxadiene(7);14β-hydroxy-2α,5α, 10β-triacetoxy -4(20),11-taxadiene(8);the other four is new compounds:5α-hydroxy-2α, 10β-diacetoxy-14β-(3-hydroxyl- 2-methyl- butyryloxy)-4(20), 11-taxadiene (9) ;2α, 5α, 10β-triacetoxy-14β-(2-hydroxy)-propionyloxy-4(20),11-taxadiene(10);and a pair of isomers (5)and(6): 2α,5α, 10β- triacetoxy-14β-(2-hydroxyl- 3-methyl- butyryloxy )-4 (20), 11- taxadiene.Also 35 strains were employed to biotransform yunnanxane separated from cell culture...