naphthoquinone

noun

naph·​tho·​qui·​none

variants also naphthaquinone

ˌnaf-thə-kwin-ˈōn, ˌnap-, -ˈkwin-ˌōn 

: any of three isomeric yellow to red crystalline compounds C₁₀H₆O₂ derived from naphthalene

especially : one that occurs naturally in the form of derivatives (as vitamin K)