Secondary Metabolites From Marine Sponge Agelas Sp. MNP-2015 And Its Symbiotic Fungi

The special environment of marine makes it an important treasure trove of natural products.As one of the world's oldest invertebrates and an vital part of the ocean,marine sponges are widely distributed.What's more,marine sponges are hosts of microorganisms which can produce a lot of secondary metabolites.At present,researches about marine sponges and sponge-derived fungi have gained more and more attention.Study on marine sponge Agelas sp.and its associated fungi were evaluated.The sponge was extracted with methanol and then with ethyl acetate to obtain the crude extract ?.Combining the antimicrobial test and chemical composition prediction,the fungus named L14 was screened from 5 sponge-associated fungi.According to molecular phylogeny based on 18S rDNA sequence and morphological characterization by microscope,genus of L14 was classified as Aspergillus sp.(NCBI GeneBank:MF093522).Strain L14 was cultured in PDB and then the crude extract ? was obtained by extracting the fermentation broth with ethyl acetate.A bioassay-guided isolation led to nine secondary metabolites by pre-HPLC and semiprep-HPLC from crude extracts ? and ? in total.Compounds 1-5 were from crude extract ?,while compounds 6-9 were from crude extract ?.A total of seven compounds,named 4-bromo-1H-pyrrole-2-carboxamide(1),4-bromo-1H-pyrrole-3-carbox-amide(2),5-bromo-N-(methoxymethyl)-1H-pyrrole-2-carboxamide(3),methyl 2-(4-hydroxyphenyl)acetate(6),methyl 2-(2,5-dihydroxyphenyl)-acetate(7),dibutyl phthalate(8)and bis(6-methylheptyl)phthalate(9)were identified by spectroscopic techniques(NMR,MS et al.)and literature comparison.These nine compounds were evaluated for their antimicrobial activities against three human pathogenic strains(Candida albicans AY 204006,Escherichia coli AB 94012 and Staphyloccocus aureus AB 2010021).Unfortunately,the results indicated that tall compounds showed weak antimicrobial activity in vitro with MIC values of no less than 100 ?g/mL.