What is "capsidiol"

Capsidiol is a terpenoid compound that accumulates in tobacco Nicotiana tabacum and chili pepper Capsicum annuum in response to fungal infection. Capsidiol is categorized under the broad term of phytoalexin, a class of low molecular weight plant secondary metabolites that are produced during infection. Phytoalexins are also characterized as a part of a two pronged response to infection which involves a short term response consisting of production of free radicals near the site of infection and a long term response involving the production of hormones and an increase in enzymes to biosynthesize phyoalexins such as capsidiol.