Xanthopterin (XPT)

Xanthopterin is a yellow, crystalline solid, that occurs mainly in the wings of butterflies and in the urine of mammals. Small microorganisms convert it into folic acid. It is the end product of a non-conjugated pteridine compound, and inhibits the growth of lymphocytes produced by concanovalin. High levels of the chemical were found in patients with liver disease and hemolysis, the latter increasing levels by 35%.

It has been suggested that the Oriental hornet uses xanthopterin as a light harvesting molecule to transform light into electrical energy, which may explain why the insects are more active when light intensity is greater. Although no explicit biochemical mechanism has been determined for this animal light to energy conversion system, it remains an active and important area of scientific research.