Phenolic substances in medicinal plants

Compositions of phenolic substances were studied in the leaves of 21 species of medicinal plants. Flavonoid levels varied from 1.94 to 5.42%, whereas total amounts of monomeric polyphenols and hydroxybenzoic acids were estimated as 0.27 to 0.57%; hydroxycinnamic acids and their esters with quinic acid, 0.09 to 0.18%. Condensed and polymerized polyphenols were detected in amounts of 0.41 to 1.20%. Qualitative compositions of flavonoids in leaves of the seven plants studied were presented. The developed analytical procedures may be useful for plant polyphenol studies and as a basis for hemotaxonomy.