Herbacetin is a flavonol, a type of flavonoid. Herbacetin is a flavonol, a type of flavonoid. Herbacetin diglucoside can be isolated from flaxseed hulls. Rhodionin is a herbacetin rhamnoside found in Rhodiola species. Rhodiolin, a flavonolignan, is the product of the oxidative coupling of coniferyl alcohol with the 7,8-dihydroxy grouping of herbacetin. It can be found in the rhizome of Rhodiola rosea.