Scutellarein 4'-methyl ether glycosides as taxonomic markers in Teucridium and Tripora (Lamiaceae,Ajugoideae)

The flavonoid profiles of two monotypic genera, Teucridium and Tripora, have been studied by analytical methods. These genera were formerly placed in the Verbenaceae, but are now classified in the Lamiaceae, subfamily Ajugoideae. The major flavonoids of both genera were identified as glycosides of scutellarein 4'-methyl ether (5,6,7-trihydroxy-4'methoxyflavone) and acacetin (5,7-dihydroxy-4'-methoxyflavone). The new flavone glycoside, scutellarein 4'-methyl ether 7-O-rutinoside, was isolated from Teucridium parvifolium and the rare scutellarein 4'-methyl ether 7-O-glucuronide from Tripora divaricata. The latter compound has only been reported previously in the related genus Clerodendron. The potential of these flavonoids as taxonomic markers for the tribe Ajugoideae is discussed.