Flavonoids found in "Scorzonera" include apigenin, kaempferol, luteolin, and quercetin. It is the 7-O-neohesperidoside of luteolin. It is the 8-C glucoside of luteolin. It is a 7-O-glucoside of luteolin. The species' extract, which contains isorhamnetin, luteolin, and quercetin, is used to fight herpes. Other compounds identified in the fruit include the polyphenols, luteolin, and kaempferol. The plant is rich in luteolin, a flavonoid which produces a bright yellow dye. Chrysoeriol is a flavone, chemically the 3'-methoxy derivative of luteolin. Artichoke contains the bioactive agents apigenin and luteolin. Other flavonoids present in "P. incarnata" include chrysin, apigenin, luteolin, quercetin, kaempferol, and isovitexin. In 1896, the English chemist Arthur George Perkin proposed the correct structure for luteolin. Flavone 7-O-beta-glucosyltransferase adds a glucose to luteolin. I, tricin, cosmosin, apigenin-7-O-beta-D-(6-O-p-coumaryl)glucopyranoside, anisofolin A and luteolin. Luteolin is a flavone, a type of flavonoid, with a yellow crystalline appearance.