Determination of some polyphenolic compounds in buds of Alnus and Corylus species by HPLC

The presence of 19 polyphenolic compounds was simultaneously assessed through a HPLC method in the buds of three species: Alnus glutinosa, Alnus incana, and Corylus avellana. The pattern of phenol carboxylic acids indicates that compounds like gentisic acid, sinapic acid, and the esters of tartaric acid (cichoric acid, caftaric acid) do not exist in buds, although they have been detected in mature organs. Buds only contain esters of quinic acid. Ferulic acid is a common compound in buds, being observed in all genus investigated. In the case of the flavonoid profile, young tissues of Alnus sp. and Corylus avellana only contain glycosides of quercetin. The preferred sugar for glycosylation is galactose, as the major flavonoid glycoside is in all cases hyperoside. The buds of A. glutinosa display the highest content in phenol carboxylic acids; this situation justifies their main prescription in the treatment of hepatic disorders.