[A novel isoflavone glycoside from Caragana alaica].

3-O-Rhamnopyranosylisorhamnetin, 3-O-glucopyranosylisorhamnetin, 7-O-galactopyranosylluteolin, quercitrin isoquercitrin, wistin, and a novel isoflavonoid, 3'-hydroxy-6,4'-dimethoxy-7-O-beta-D-glucopyranosylisoflavone, were isolated from the aerial parts of Caragana alaica. Of these, the previously described compounds were identified on the basis of their physicochemical and spectral characteristics, whereas the spectral analysis and conversion to a known compound, cladrastin, allowed the structural elucidation of the novel isoflavone glycoside.

[Glabrizoflavone--a novel isoflavone from Glycyrrhiza glabra L].

7-O-Methylglabranin, 6-C-prenylpinocembrin, glabranin, pinocembrin, galangin, and a novel isoflavonoid, (E)-5,7,4'-trihydroxy-6-(3-hydroxymethyl-2-butenyl)isoflavone (glabrisoflavone) were isolated from the aerial parts of Glycyrrhiza glabra L. The structure of the novel isoflavonoid was elucidated on the basis of chemical transformations and spectral data.

Inhibition of Na+,K(+)-ATPase by flavonoids and their inotropic effect. Investigation of the structure-activity relationship.

The relationship between the structures of 39 natural flavonoids (including flavones, flavonols, flavonones, and isoflavones) and their inhibitory and positive inotropic effects have been found. It is shown that flavonoids considerably inhibit the activity of the purified preparation of pig kidney medulla Na+,K(+)-ATPase with Ki = 1.4-22.