Brevianamides with Antitubercular Potential from a Marine-Derived Isolate of Aspergillus versicolor

An Aspergillus versicolor isolated from sediment collected from the Bohai Sea, China, yielded the new dimeric diketopiperazine brevianamide S (1), together with three new monomeric cometabolites, brevianamides T (2), U (3), and V (4). Structures were determined by detailed spectroscopic analysis. Brevianamide S exhibited selective antibacterial activity against Bacille Calmette-Guérin (BCG), suggestive of a new mechanism of action that could inform the development of next-generation antitubercular drugs.