The flavonoids of Tanacetum parthenium and T-vulgare and their anti-inflammatory properties

The lipophilic flavonoids in leaf and flower of Tanacetum parthenium and T. vulgaris have been compared. While those of T. parthenium are methyl ether s of the flavonols 6-hydroxykaempferol and quercetagetin, the surface flavo noids of T, vulgare are methyl ethers of the flavones scutellarein and 6-hy droxyluteolin. Apigenin and two flavone glucuronides are surprisingly prese nt in glandular trichomes on the lower epidermis of the ray florets of T. p arthenium. The opportunity has been taken to revise the structures of the f our 6-hydroxyflavonol methyl ethers of T. parthenium based on NMR measureme nts. These are now shown to be uniformly 6- rather than 7-O-methylated, Tan etin, previously thought to be a new structure, is now formulated as the kn own 6-hydroxykaempferol 3,6,4'-trimethyl ether. The vacuolar flavonoids of both plants are dominated by the presence of apigenin and luteolin 7-glucur onides; nine other glycosides were present, including the uncommon 6-hydrox yluteolin 7-glucoside in T. vulgare. When the major flavonol and flavone me thyl ethers of the two plants were tested pharmacologically, they variously inhibited the major pathways of arachidonate metabolism in leukocytes. The re were significant differences in potency, with the tansy 6-hydroxyflavone s less active than the feverfew 6-hydroxyflavonols as inhibitors of cyclo-o xygenase and 5-lipoxygenase. (C) 1999 Elsevier Science Ltd. All rights rese rved.