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Abstract

The ocean has been large resource such as a marine flora, fauna and food resources. A marine bacterial strain that showed confluent growth on the marine broth and antibacterial activity, was isolated and identified based on the 16S rDNA sequence analysis as a strain of Pseudoalteromonas sp., thus named as Pseudoalteromonas sp. M2. This strain was produced various secondary metabolites as quinolone alkaloids, we identified nine 4-hydroxy-2-alkylquinoline secondary metabolites (pseudane-III, IV, V, VI, VII, VIII, IX, X, and XI) and closely related two unknown compounds by high-resolution and tandem mass spectrometry. The two unknown compounds were determined to be novel metabolites (2-isopentylquinolin-4-one and 2-(2,3-dimethylbutyl)quinolin-4-one) by NMR analysis. Among the isolated compounds, 2-(2, 3-dimethylbutyl) quinolin-4-one, pseudane-VI, and pseudane-VII showed the inhibition of melanin synthesis in the melan-a cells as 23.0, 28.2, and 42.7%, respectively. Especially, pseudane-VII showed the highest inhibitory effect at 8 �¼g/ml compared with other compounds. The production of 2-isopentylqunoline-4-one and 2-(2,3-dimetylbutyl) qunoline-4-(1H)-one from marine bacteria has not been reported before. The results of this study suggest that LC-MS/MS based metabolite screening was effective dereplication methods to improve the efficiency of the discovery process of novel metabolite and these compounds may be promising candidates for the development of effective bioactivity.

Biography

Email: wj5319@nate.com