Separation And Active Preliminary Research Of Secondary Metabolites In Aspergillus Fumigatus IMB-SX28 From Three Gorges Reservoir

Background:Much of natural product chemistry concerns a group of compounds known as secondary metabolites. These low-molecular-weight metabolites often have potent physiological activities. Penicillin, cephalosporin, ergotrate and the statins are well known fungal secondary metabolites.Three Gorges Reservoir is located to the middle-lower Yangtze plain Tibetan plateau, is China's transitional tilt of the key area of the ecological environment protection. Now to the region, soil fungus study also rarely, only to large fungi reports of research. So of three gorges of this unique geographical position of research can enrich the soil fungus strains resources for the future development and utilization provide some reference material.In this paper, one soil fungi with high anti-microbial activities was separated from the soil specimen derived from Three Gorges Reservoir.Aspergillus fumigatus is one important pathomycete, in which some ingredients and toxins can cause body damage. Meanwhile, the research on their metabolites can brings hope into the field of antimicrobial drugs investigation. In the past, many compounds separated from the metabolites are very difficult for the preparation of clinical drug due to its shortcoming such as high toxicity, weak pharmacological activities, and low yields. Recently, many attempts have been made towards development of some substances, which have new pharmacological activities and skeleton structure.Objective:Based on the diversity of chemical activity from different sources of Aspergillus fumigatus metabolites, great effort on the study of fermentation conditions and biological metabolic control is very necessary to get new secondary metabolites. Moreover, after the Aspergillus fumigatus genome sequencing work is completed, the research prospect of its secondary metabolites is bright because more functional gene will be discovered in the future. Given the above facts, the research of Aspergillus fumigatus secondary metabolites under different of fermentation medium condition is highly significant.Methods:Through studying ferment of the fungi IMB-SX28 in five different medium,that visit to smoke in different media activity under the condition of secondary metabolites produced situation. Choose medium for PD liquid medium, GC medium. Czapek's medium, Czapek's medium add 1% corn steep liquor. Czapek's medium add 1% soybean cake flour.In selected fermentation conditions,50L large-scale fermentation gets relevant some active substances. Following the bioactivity, compounds were isolated and purified by using solvent extraction, silica gel column, Sephadex LH-20, PHPLC and etc. Finally we obtained corresponding monomer compounds and using NMR and MS method to analyze compound structure. The compounds were tested for the antimicrobial and antitumor bioactivity. The antitumor activity against several cancer cell lines of the new compounds was assayed by MTT methods.Results:Using ITS conserved sequence of fungal genome for strain identification in the NCBI, it was assigned to Aspergillus fumigatus, named IMB-SX28. Found in Czapek's medium add 1% corn steep liquor as culture medium conditions, intracellular secondary metabolites is the best antimicrobial activity, and chromatographic peak determined by the largest. Through 50L large-scale fermentation tank processing. get 150g the mycelium acetone extraction ottelia alismoides parts.By means of spectral analysis (UV, MS, NMR, etc.), structures of 3 pure compounds were respectively determined. Respectively. SX-11 is dibutyl phthalate, SX-26 is stearic acid, SX-60 is nitrogen heterocvclic compounds. Compound SX-60 has stronger antimicrobial activity and antitumor bioactivity. SX-60 has strong resistance to s. aureaus active and antibacterial circle diameter of 13 mm. It has certain resistance to colon cancer SW480 tumor activity and IC50 was 71.6μg/mL.Conclusions:Through the research found that the secondary metabolites Aspergillus fumigatus is very complex. The research on its metabolites can be calculated with the potential of pharmacological activities of compound.