Saccharobisindole, Neoasterric Methyl Ester, and 7-Chloro-4(1H)-quinolone: Three New Compounds Isolated from the Marine Bacterium sp.

Analysis of the chemical components from the culture broth of the marine bacterium sp. CNQ-490 has yielded three novel compounds: saccharobisindole (), neoasterric methyl ester (), and 7-chloro-4()-quinolone (), in addition to acremonidine E (), pinselin (), penicitrinon A (), and penicitrinon E (). The chemical structures of the three novel compounds were elucidated by the interpretation of 1D, 2D nuclear magnetic resonance (NMR), and high-resolution mass spectrometry (HRMS) data. Compound generated weak inhibition activity against KCTC2441 and KCTC1927 at concentrations of 32 μg/mL and 64 μg/mL, respectively, whereas compounds and did not have any observable effects. In addition, compound displayed weak anti-quorum sensing (QS) effects against KCTC1927 and SCO560.