Three new flavone C-glycosides from the aerial parts of Paraquilegia microphylla

Three new flavone C-glycosides, paraquinins A-C, were isolated from the aerial parts of Paraquilegia microphylla (Royle) Dromm. et Hutch, a Tibetan medicine distributed in the Qinghai-Tibet plateau. On the basis of 1D and 2D NMR evidence, their structures were elucidated as acacetin-6-C--d-glucopyranosyl-(1 → 2)--d-glucopyranoside (1), acacetin-6-C-α-l-rhamnopyranosyl-(1 → 2)--d-glucopyranosyl-(1 → 2)--d-glucopyranoside (2), and acacetin-6-C-α-l-rhamnopyranosyl-(1 → 2)-(6'''-O-E-feruloyl)--d-glucopyranosyl-(1 → 2)--d-glucopyranoside (3).