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Leaves of Hosta ventricosa yielded eight kaempferol glycosides, of which six: the 3-(2G-glucosylrutinoside)-7-glucoside, 3-sophoroside-7-glucoside, 3-rutinoside-7-glucoside, 3-(2G-glucosylrutinoside), 3-sophoroside, 3-rutinoside were fully characterized and two: the 3-xylosylrutinoside-7-glucoside and 3-xylosylrutinoside were tentatively identified. Investigations included 1H-1H COSY and 1H-1H 2D J NMR analysis.

Two unusual diglycosides, quercetin and kaempferol 3-rhamnosyl(1----2)galactosides and the new isorhamnetin 3-rhamnosyl(1----2)galactoside have been isolated from the aerial parts of Blackstonia perfoliata. Instead of C-glycosylflavones, the occurrence of flavonol glycosides in this species as well as in three other genera of the Gentianaceae: Centaurium, Coutoubea and Eustoma, is in agreement with the grouping of these four genera in the subtribe Chlorae of the Gentianeae.

Three new flavonol triglycosides quercetin, kaempferol and isorhamnetin 3-rhamnosyl(1----2)galactoside-7-glucosides have been isolated from leaves and stems of Blackstonia perfoliata. This species together with three other genera of the tribe Gentianeae, subtribe Chlorae: Centaurium, Coutoubea and Eustoma, is unusual in producing flavonol glycosides instead of C-glycosyl flavones, the more characteristic flavonoid constituents of the Gentianaceae.