Study Of Secondary Metabolites Of Two Marine Fungi

Adapting to the unique survival environment, such as high salt, high pressure, oligotrophic,marine fungi can produce a series of secondary metabolites with novel chemical structures andspecial biological activities.They are an important source of new drug.Therefore, studying thesecondary metabolites of marine fungi is an important way to get new prodrugs with novelchemical structures and strong biological activities. This paper identified two former obtainedmarine fungi zl01a-11and BY5, investigated their secondary metabolites and analyzed thebiological activities of the purified compounds. The main results are as follows:(1)The colony and microscopic morphology of the strain zl01a-11belonged to typicalmorphology characteristics of Penicillium sp., and the26S rDNA sequence of the strain zl01a-11was100%similar to the strain Penicillium rugulosum DAOM216317(JN938937.1).So thestrain zl01a-11was identified as Penicillium rugulosum. The colony and microscopicmorphology of the strain BY5belonged to typical morphology characteristics of Aspergillus sp.,and the26S rDNA sequence of the strain BY5was100%similar to the strain Aspergillustubingensis ATCC MYA-4879(JQ812704.1). So the strain BY5was identified as Aspergillustubingensis.(2)13compounds were isolated from the metabolites of the strain zl01a-11, and18purecompounds were isolated from the metabolites of the strain BY5. The structures of compoundsLL-5, LL-12and SS-2were determined by the NMR and MS spectral analysis methods. As aresult, compounds LL-5and LL-12were the same compounds belonging to coumarincompounds, and the chemical name of compound SS-2was2,2-bis[4-(3-amino-2-hydroxypropoxy) phenyl] propane.(3) When the concentration of tested compounds was1mg/mL, they showed no inhibitoryactivity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Micrococcus luteusand Saccharomyces cerevisiae, but they showed certain antioxidant activity（clearance rate＜50%）against·OH free radical, and compounds SS-13and AA-2showed strong antioxidantactivity to ABTS+free radical (EC50＜1). With the method of CKK-8, compounds LL-5andSS-2did not show the cytotoxic activity to HeLa tumor cells when the concentration was10μg/mL. In this study,31compounds were isolated from the secondary metabolites of marine fungizl01a-11and BY5, and the chemical structures of three compounds were identificated. In thetested compounds, SS-13exhibited strong antioxidant activity that worth of further study. Thisstudy enriched the types of secondary metabolites of marine fungi and provided theoretical basisfor developing and utilizing the metabolites of marine fungi.