Abstract
Maca (Lepidium meyenii Walp.), a famous food supplement, has drawn an unprecedented international interest over the last two decades. It was assumed that glucosinolates, macamides, macaenes, and alkaloids are the main bioactive components of Maca before. Recently, a series of novel thiohydantoins which generally exhibit a variety of activities have been isolated from Maca. This review focuses on the progress on the main bioactive components of Maca and their biosynthetic pathway, which indicates that macamides, thiohydantoins, and some alkaloids may originate from glucosinolates. Interestingly, thiohydantoins from Maca are the first type of thiohydantoin derivatives to be found from a natural source and may contribute to some significant effects of Maca.