Two New Dihydroflavanoids from Patrinia villosa Juss (Ⅱ)

Two new dihydroflavonoids named villosin A and villosin B were obtained from the traditional Chinese medicinal herb Patrinia villosa Juss. Their structures were elucidated as (2S)-5, 2', 6'-trihydroxy-2", 2"-dimethylpyrano [5", 6":6, 7]flavanone 1 and (2S, 3"S)-5, 2', 6'-trihydroxy-3"-γ, γ-dimethylallyl-2", 2"-dimethyl-3", 4"-dihydropyrano [5", 6":6, 7] flavanone 2 by spectroscopic methods including UV, IR, HR-TOF-MS, 1D NMR and 2D NMR techniques.