Antioxidant lignans from the roots of Vladimiria muliensis.

Three new lignans (1, 2, and 8) and ten known ones (3-7, 9-13) were isolated from the roots of Vladimiria muliensis. Their structures and configurations were elucidated by means of spectroscopic techniques (IR, MS, NMR, and CD) and chemical methods. The isolated compounds were evaluated for their antioxidant and antibacterial activities. The antioxidant activity was the greatest for lignans 7 and 10 with IC50 values of 11.2 and 7.3 µM against DPPH radical, and of 1.6 and 1.7 µM against ABTS+ radical, respectively. Moreover, 7 also displayed broad-spectrum antibacterial activity with MIC values around 7.25 µg/mL.