Studies On The Secondary Metabolites Of Marine Actinomycetes

Objective To isolate the antimicrobial compounds from secondary metabolites of the sponge-associated Verrucosispora sp. FIM060022and marine Nonomurae sp. FIM040375. Methods16fermentation media were selected for fermentation to screen the secondary metabolites by HPLC-DAD-MS. Mordern chromatography methods were applied to isolate the antimicrobial compounds from Verrucosispora sp. FIM060022and Nonomurae sp. FIM040375. Their structures were identified by ESI-MS,1D-NMR and2D-NMR data. Their antimicrobial acitivities were detected with disk diffusion method. Results Seven compounds(1~7) were isolated from the fermentation broth of the two strains. They were identified as Abyssomicin B(5), Abyssomicin C(1), Abyssomicin H(6), Proximicin A(4), Lumichrome(2), Adenosine(3) and N-methyl-1H-indole-3-carboxamide(7), respectively. Another compound is o-Aminobenzoicacid (8) which was isolated from the crude extract of Verrucosispora sp. FIM060036. The above8compounds showed obvious antimicrobial activities against Micrococcus luteus except for compound2. Compound1also showed strong inhibitory activities against Staphylococcus aureus and weak activity against Bacillus subtilis and Bacillus pumilus. Furthermore, compound4and5showed weak antifungal activities against Aspergillus niger. Conclusion This research reported that the sponge-associated Verrucosispora sp. FIM060022simultaneously produced the antimicrobial compounds Abyssomicins and Proximicins. In the meanwhile, compound2and3were firstly discovered from marine-derived Verrucosispora. The compounds isolated have different structure style and antibacterial activities. The present study provided a basis for further exploriting marine rare actinomycetes.