anthraquinone

/ˌænθrəˈkwinoʊn/
/ˌænθrəˈkwɪˌnoʊn/

noun

A yellow crystalline compound obtained by oxidation of anthracene. It is the basis of many natural and synthetic dyes.

The new algicide, the subject of a patent application, uses a product derivative based on the natural compound anthraquinone, found in rye grass.