Variations in lipophilic and polar flavonoids in the genus Tanacetum

Abstract

Seven species of Tanacetum of different geographical origins were analysed in leaf and flower for their lipophilic and polar flavonoids and the results were compared with the patterns previously recorded in T. parthenium and T. vulgare. The lipophilic constituents are based generally on 6-hydroxykaempferol 3,6,4′-trimethyl ether and quercetagetin 3,6,3′-trimethyl ether, but up to 11 other surface flavonoids are present. Methyl ethers of scutellarein and 6-hydroxyluteolin are present in species with corymbose capitula. A rare carbomethoxyflavone reported earlier in T. microphyllum could not be detected. The dominant pattern of vacuolar flavonoids is based on apigenin and luteolin 7-glucuronides. 6-Hydroxyluteolin 7-glucoside, present in T. vulgare, also occurs in T. pseudoachillea. Chrysoeriol 7-glucuronide is present in T. parthenium, T. macrophyllum and T. corymbosum. By contrast, quercetin 7-glucuronide characterises T. parthenium, T. corymbosum and T. cinerariifolium. On the basis of combined data of lipophilic and polar constituents, it is clear that several structures are useful chemotaxonomic characters at the species level in a taxonomically complex genus.