Keywords: Helenalin.svg Skeletal formula of helenalin Created using http //www acdlabs com/download/chemsk html ACD/ChemSketch 10 0 and Inkscape Own 2008-01-04 Fvasconcellos 22 56 4 January 2008 UTC Gamma-lactones Non-steroidal anti-inflammatory drugs Alkylating agents Diterpenes |