Phytoecdysteroid

Phytoecdysteroids are plant-derived ecdysteroids. Phytoecdysteroids are a class of chemicals that plants synthesize for defense against phytophagous (plant eating) insects. These compounds are mimics of hormones used by arthropods in the molting process known as ecdysis. It is presumed that these chemicals act as endocrine disruptors for insects, so that when insects eat the plants with these chemicals they may prematurely molt, lose weight, or suffer other metabolic damage and die.

Chemically, phytoecdysteroids are classed as triterpenoids, the group of compounds that includes triterpene saponins, phytosterols, and phytoecdysteroids. Plants, but not animals, synthesize phytoecdysteroids from mevalonic acid in the mevalonate pathway of the plant cell using acetyl-CoA as a precursor.

Some ecdysteroids, including ecdysone and 20-hydroxyecdysone (20E), are produced by both plants and arthopods. Besides those, over 250 ecdysteroid analogs have been identified so far in plants, and it has been theorized that there are over 1,000 possible structures which might occur in nature. Many more plants have the ability to "turn on" the production of phytoecdysteroids when under stress, animal attack or other conditions.

The term phytoecdysteroid can also apply to ecdysteroids found in fungi, even though fungi are not plants. The more precise term mycoecdysteroid has been applied to these chemicals.

Some plants and fungi that produce phytoecdysteroids include Achyranthes bidentata, Tinospora cordifolia, Pfaffia paniculata, Leuzea carthamoides, Rhaponticum uniflorum, Serratula coronata, Cordyceps, and Asparagus.