Study On The Secondary Metabolites From Marine Fungi And Antimicrobial Activity

Marine-derived fungi are a rich source of promising natural products that have biological activities. The complex ocean’s environment has caused the marine microorganism’s multiplicity, because of the special survival environment, they have been produced much novel secondary metabolites with novel skeleton.A study on marine fungi(No.Z81) was carried out to investigate the potential antibacterial compounds.Studies mentioned above provided novel structures for searching leading antibacterial compounds,and gave a good example for the deep development of the active strains.The main research contents and results were as follows:(1)Following the bioactivity, compounds were isolated and purified by using column chromatography..reverse phase chromatography and preparative HPLC combined with TLC,HPLC from marine fungi(No.Z81),11 compounds were isolated. Their structures were established by physicochemical properties and spectral analysis(UV,MS,NMR).compound 11 was identified as new compound.(2)We use resazurin for antibacterial active substance and apply it to the screen of antibacterial marine active substance. It is a rapid screening and evaluating method. The concentration of the compounds is 50 ug/mL, the inhibition of compound 2,compound 5,compound 7 and compound 10 is above 90%.The compound 5 exhibited highest activity. Compound 5 showed good antibacterial activities to MRSA CGMCC 1.12409,The MIC was 3.125μg/mL, the MBC was 6.25～12.5ug/mL; To MRSA ATCC 43300,the MIC was 3.125～6.25μg/mL, the MBC was 6.25～12.5μg/mL(3)Target Identification of compound 5 in MRSA ATCC 43300 using Drug Affinity Responsive Target Stability (DARTS) Technique. According LC/MS analysis, we used to submit the data to MASCOT(Mass Spectrometry data analyses software) for database searching and the Percolator algorithm rescored peptide and protein matches. The target protein of compound 5 is probably Enolase.