A steroid C-21 acid having a 29-nordammarane skeleton substituted with an acetoxy group at C-16 and oxo groups at C-3 and -7, with double bonds at C-1, -17(20) and -24. ChEBI: Helvolic acid is a steroid C-21 acid having a 29-nordammarane skeleton substituted with an acetoxy group at C-16 and oxo groups at C-3 and -7, with double bonds at C-1, -17(20) and -24. It has a role as a mycotoxin, an antibacterial agent and a fungal metabolite. It is a steroid acid, a monocarboxylic acid, a 3-oxo-Delta(1) steroid and an acetate ester. It is a conjugate acid of a helvolate. It derives from a hydride of a dammarane.