3-Oxo-γ-costic acid fungal-transformation generates eudesmane sesquiterpenes with in vitro tumor-inhibitory activity.

While select eudesmane sesquiterpenes exhibit anti-neoplastic activity, tumor-inhibition for costic-acids has not been established. Here biological activity of 3-oxo-γ-costic acid ( 1 ), previously isolated from Chiliadenus montanus , as well as new sesquiterpenes ( 2 – 5 ) and the known derivative, 3-oxoeudesma-1,4,11(13)-trien-7-1061αH-l2-oic acid ( 6 ), all produced from 1 by the fungus Athelia rolfsii , are reported. Structures were elucidated using MS and NMR spectroscopy with activity-screening utilizing human colon- and lung-tumor lines, Caco-2 and A549 respectively. Compound 1 exhibited anti-proliferative activity against Caco-2 (IC 50 39 µM) and 2 was active against A549 (IC 50 74 µM) suggesting therapeutic potential for the original substrate and a bio-transformed product. [ABSTRACT FROM AUTHOR]