Flavonoids from black chokeberries, Aronia melanocarpa

Black chokeberry, Aronia melanocarpa (Michx.) Elliott (Rosaceae), was investigated for its flavonoid content. The flavanone eriodictyol 7-O-β-glucuronide (1) together with the quercetin derivatives 3-O-(6″-O-β-arabinosyl-β-glucoside) (2), 3-O-(6″-α-rhamnosyl-β-galactoside) (3), 3-O-(6″-α-rhamnosyl-β-glucoside) (4), 3-O-β-galactoside (5) and 3-O-β-glucoside (6), were detected in the fruits and flower umbels. The rare compounds 1-3 were isolated and structurally elucidated by use of 1D- and 2D-nuclear magnetic resonance experiments together with electrospray mass spectrometry. Compounds 4-6 were characterized by co-chromatography and by liquid chromatography-mass spectrometry. The black chokeberries contained >71 mg flavonols per 100 g fresh weight.