Study On Preparation Of Epothilone B,

Epothilones are the biological active secondary metabolites produced by the myxobacterium Sorangium cellulosum. The way epothilones inhibite the microtubule depolymerization is similar to Taxol. Preclinical studies show epothilones have anticancer activity which can against several tumor cells including taxol-resistant cells. Several clinical trials of phase I and phase II are ongoing with Epothilone D, epothilone B and epothilone analogue BMS-247550. Epothilones have the potential of being anticancer drug. In this paper, fermentation and purification of epothilone B were studied.A strain of ATCC 15384 obtained by mutagenesis was used in our studies. The fermentation conditions including the component of culture medium,pH,inoculum size,antifoam and adsorber resin were optimized in shake flask, and 20L,40L,100L,250L fermentors. Desorption and purification process were also studied. HPLC method was developed for analyzing the production of epothilone B.The optimized culture conditions included culture medium, incubation temperature, inoculum size and adsorber resin.Culture medium was composed of potato starch 0.8%,glucose 0.2%,soybean meal 0.2%,yeast extract 0.2%,and was adjusted to pH7.4. Incubation temperature was at 32℃, inoculum size was 5% and adsorber resin was added 48h after the beginning of the fermentation. After 80 hours of incubation in shake flask, glucose was added to raise the production of epothilone B. Fed-batch fermentation process of 250L fermentation conditions were studied, included dissolved oxygen maintained 30 at least, air rat at 0.3-0.6 V/V min, pressure under 6.0 PSIG. The production of epothilone B was about 9.9mg/L.The adsorber resin was extracted exhaustively with ethyl acetate. Isolation of pure epothilone B was achieved by chromatography on a Sephadex LH-20 column and C18...