Withanolide
Withanolide
Group of steroid compounds
Withanolides are a group of at least 300 naturally occurring steroids built on an ergostane skeleton.[1][2] They occur as secondary metabolites primarily in genera of the Nightshade family, for example in the tomatillo.
Structurally, withanolides consist of a steroid backbone bound to a lactone or one of its derivatives; they are produced via oxidation of steroids. It remains unknown to what end withanolides are produced; they may act as a deterrent for feeding insect larvae and other herbivores.
Genera within the nightshade family that produce withanolides include: Datura,[3] Iochroma,[4] Lycium,[5] Nicandra,[6] Physalis,[7] Salpichroa,[8] Solanum,[9] Mandragora,[10] Withania,[11] and Jaborosa.[12] No withanolide has been discovered in Nicotiana to date.