Abstract
Two new flavonol glycosides were isolated from the leaves of Triantha japonica, together with eight known flavonols, kaempferol 3-O-sophoroside, kaempferol 3-O-sambubioside, kaempferol 3-O-glucosyl-(1→2)-[glucosyl-(1→6)-glucoside], quercetin 3-O-sophoroside, quercetin 3-O-sambubioside, isorhamnetin 3-O-glucoside, isorhamnetin 3-O-sophoroside and isorhamnetin 3-O-sambubioside. The new compounds were identified as kaempferol 3-O-β-xylopyranosyl-(1→2)-[β-glucopyranosyl-(1→6)-β-glucopyranoside] (1) and isorhamnetin 3-O-β-xylopyranosyl-(1→2)-[β-glucopyranosyl-(1→6)-β-glucopyranoside] (3) by UV, LC-MS, acid hydrolysis, and 1H and 13C NMR spectroscopy. Another two new flavonol glycosides were isolated from the leaves of Tofieldia nuda, and identified as kaempferol 3-O-β-glucopyranosyl-(1→2)-[β-glucopyranosyl-(1→6)-β-galactopyranoside] (4) and quercetin 3-O-β-glucopyranosyl-(1→2)-[β-glucopyranosyl-(1→6)-β-galactopyranoside] (5). Though the genera Triantha and Tofieldia were treated as Tofieldia sensu lato, they were recently divided into two genera. It was shown by this survey that their flavonoid composition were also different to each other.