Isolation And Structural Modification Of Fostriecin And PD113270

Fostriecin is a structurally novel phosphate ester produced by Streptomyces pulveraceus that is active in vitro against leukemia, lung, breast, and ovarian cancer, and which exhibits efficatious in vivo antitumor activity. It has been investigated in a Phase I clinical trial at NCI that was halted even before dose-limiting toxicities because of drug purity and storage stabili-ty. The focus of this research is improving the yield of fostriecin analogues in experimental conditions and modifying the phosphate group with phosphate mimics, so that new derivativ-es can obtained and screened for antitumor activity and stability.In this dissertation, the methods of modification on C9 bit was studied. the phosphate group was removed by enzymatic reaction, selectively protected the hydroxyl groups with silyl ethers, modified the C9 bit with acetic acid and ally isocyanate, deprotected with fluoride, and finally obtained new derivatives. Their chemical structures were determined by MS and NMR. Antitumor activity and antiphosphatase activity was examined by MTT and Alkaline phosphatase respectively.The fermentation conditions of fostriecin (medium, incubation time, fermentation volu-me, etc.) under the experimental conditions was detemined:the frozen spore suspension was inoculated to YPD seed medium by appropriate ratio for 2 days, after which the seed culture was inculated to fermentation medium by appropriate ratio, and was cultured for 4 days under the same conditions. During the culture process, the production of fostriecin was monitored by HPLC analysis. After centrifugation, the fermentation broth was applied onto macroporous resin, C18-silica gel column and semi-prepared chromatography before being concentrated and dried to get the pure compounds. Through UV, MS, NMR analysis, the chemical structures of analogues were detemined.In this study, fostriecin and PD113270 were purified from the fermentation broth, and synthesized four fostriecin and PD113270 derivatives with the total yield of 36%,31%,21.4 %,24.3% respectively. Three derivatives have efficacious antitumor activity against MCF-8 (IC50=10μM,30μM,70μM), and fostriecin derivatives have good resistance to alkaline phosphatase. The results of this sudy set basis for developing new anticancer drugs.