Eucapsitrione, an Anti-Mycobacterium tuberculosis Anthraquinone Derivative from the Cultured Freshwater Cyanobacterium Eucapsis sp.

Eucapsitrione (1), an anthraquinone derivative with an indeno-anthracene-trione skeleton, was isolated from the cyanobacterium Eucapsis sp. (UTEX 1519) by bioassay-guided fractionation. The chemical structure was determined by analyzing MS and ID and 2D NMR spectroscopic data. Eucapsitrione (1) showed anti-Mycobacterium tuberculosis activity in the microplate Alamar blue assay and low-oxygen-recovery assay with MIC values of 3.1 and 6.4 mu M, respectively.