Cytotoxic indole alkaloids from Pseudovibrio denitrificans BBCC725

In this study, we investigated a culture supernatant of a Pseudovibrio denitrificans strain isolated from sea water. Five indole alkaloids were isolated from this culture. These include four known compounds, arundine (1), vibrindole A (2), 1,1,1-tris(indo1-3-yl)methane (3), 7,7-bis(indol-3-yl)-p-cresol (4) and the new tetra(indol-3-yl)ethanone (5). 'Compound 5 showed interesting cytotoxic effect against L929 cells (EC50 = 7 mu M) and A549 cells (EC50 = 8 mu M). (C) 2017 Elsevier Ltd. All rights reserved.