Dihydroflavones in Rhododendron concinnum

Objective: To study the chemical constituents of the whole plant of Rhododendron concinnum.

Methods: The compounds were isolated and purified by chromatography on silica gel and polyamide. Their structures were identified on the basis of spectroscopic data (MS,1H-NMR and 13C-NMR) and chemical evidence.

Results: Five dihydroflavones were isolated and identified as (2R)-farrerol-7-O-glucopyranoside (1), (2R,3R)-(-)-dihydroquercetin-3-O-beta-D-xylopyranoside(2), (2S,3S)-(-)-dihydroquercetin-3-O-beta-D-glucopyranoside(3), eriodictyol-7-O-beta-D-glucopyranoside (4) , (2R, 3R)-(+)-dihydroquercetin (5).

Conclusions: Except compound 5, others were firstly isolated from the genus Rhododendron.