Terrecyclic acid is a sesquiterpene originally isolated from A. terreus with antibiotic and anticancer activity. It is active against S. aureus, B. subtilis, and M. roseus (MICs = 25, 50, and 25 ug/ml, respectively). Terrecyclic acid induces a heat shock response, increases levels of reactive oxygen species (ROS), and inhibits NF-kappaB activity and cell growth in 3T3-Y9-B12 cells.