Identification Of Active Fungi And The Secondary Metabolites Isolated From Marine Fungi

There were 218 marine fungi isolated from marine organisms at beach in Fujian, China,52 of which were saccharomycetes. Inhibitory activities of fermentation broth of marine fungi against TMV infection and replication was determined by half-leaf and leaf-disc methods, respectively. And anti-tumor activity of fermentation broth of marine fungi was determined by MTT methods. There were 39 marine fungi, the inhibition rate of the fermention broth of which against TMV replication were over 90%. There were also 6 marine fungi, the inhibitory activity of the fermention broth of which against TMV replication was higher. And there were 5 marine fungi, the inhibitory activity of the fermention broth of which against both cancer cells proliferation was higher.Then, active strains were identified by morphology characterization. The homology relationships between active fungi and other fungi from GenBank were deduced from sequences of ITS rDNA. The results showed that 1008F1 was identified as Neosartorya fischeri, 1002F2 was identified as Aspergillus sp., and 1009F1 was identified as Whalleya microplaca.Seven plant pathogenic fungi were selected for test. The inhibitory activity of 3 marine fungi and their water-soluble fraction of the secondary metabolites against plant pathogenic fungi were evaluated. The results showed that the inhibitory activities of water-soluble fraction of strain 1002F2 against Colletotrichum graminicola and Alternaria solani were higher, with EC50 values 1.34 g/L and 0.94 g/L. And the inhibitory activities of water-soluble fraction of strain 1009F1 against Pythium aphanidermatum and Alternaria solani were higher, with EC50 values 0.63 g/L and 0.65 g/L,Further screening test about anti-TMV replication was carried on crude extracts of 7 strains which showed more active after preliminary screening test. Strain 0312F1 and 1008F1 were determined as active strains for further test because of their high activity. Guided by anti-tumor activity, the results showed that the active fraction named 1008F1 was water-soluble.Nine compounds were isolated from strain 1008F1 by DCC, TLC and HPLC instrumentations. According to the chemical structures identification,2 compounds were anthraquinones,2 compounds were adenosines and 3 compounds were alkaloids. Inhibitory activities of compounds against TMV replication and cancer cells proliferation were determined by leaf-disc and MTT methods, respectively. Then, the EC50 values were examined on compounds showed higher activity. In the tested concentration, the anti-TMV replication activity of compounds 3,5 and 8 was much higher, with EC50 values 153.08μg/mL,83.80μg/mL and 96.99μg/mL, respectively. Anti-tumor activity of compound 5 against both cancer cells was higher, with EC50 values 91.15μg/mL and 100.02μg/mL. In addition, the structure-activity relationship (SAR) between structures of active compounds and anti-TMV replication and anti-tumor activity was analyzed. It was shown that anti-phytovirus activity was another new bio-activity about alkaloids. Take compounds 5-7 for example, maybe hydroxyl at C-7 inhanced the activity of compounds 5 and 7. And double bond between C-7 and C-8 perhaps decreased the activity of compound 6.