The Isolation And Structure Elucidation Of Metabolites Of Corallococcus Coralloides 085B04

The myxobacteria are Gram-negative, unicellular bacteria with rod-shaped vegetative cells, which have the unique morphological differentiation and amazing social behaviors. Besides the readily established microbial secondary metabolite producers actinomycetes and bacillus, myxobacteria have become the third largest one, which are known for their ability to produce a broad spectrum of secondary metabolites and form fruiting bodies upon starvation.In this thesis, the biological characteristics and secondary metabolites of Corallococcus coralloides 085B04 have been studied. By the methods of microscopic observation and fermentation, the growth characters and life cycle of myxococcus have been discovered, and the acetic ether extracts of the myxobacterial fermentation broth has been obtained.It is found that there are 12 more peaks in residue than that in acetic ether extracts of the VY-2 medium, by camparing with their HPLC procedure.Separation of the crude residue by column chromatography over Silica gel by consecutively employing petroleum ether and acetone as eluents gave some fractions. Then, fractions were isolated and purificated by Silica gel chromatography, Sephadex LH-20 gel chromatography and HPLC techniques. Finaly, 19 metabolites of the myxobacteria were obtained. The chemical structures were confirmed by 1H-NMR, 13C-NMR, 2D-NMR, MS, IR and UV. Compounds 2, 15 and 19 are novel, which are named 1-(1H-pyrrolo[3,2-c]quinolin-4-yl)ethanone, 5-(hydroxyimino)-1,3-dimethyl -1H–pyrrol-2(5H)-one and 8-(chroman-4'-yl)-cyclo(S) -Pro-(R)-Leu, respectively.The antitumor bioactivities of the prepared samples were evaluated with the MCF-7, Pc3 and YFP cell lines using a MTT assay. The results show that, compound 18 exhibited moderate activity with IC50 13.7μg/mL against MCF-7, and compound 16 exhibited high cytotoxicity against human tumor PC3 and YFP cell lines, with their IC50 7.8μg/mL and 10.3μg/mL, respectively. Moreover, some of these compounds may exhibite more significantly against other tumor cells, and this project needs more further study.