Chemical constituents from Viburnum fordiae Hance and their anti-inflammatory and antioxidant activities

Three new neolignans, fordianoles A-C (1-3), characterized as (7S,8R)-4-hydroxy-3,3',5'-trimethoxy-8',9'-dinor-8,4'-oxyneolignan-7,7',9-triol, (7R,8R)-4-hydroxy-3,3',5'-trimethoxy-8',9'-dinor-8,4'-oxyneolignan-7,7',9-triol, and (7R,8R)-4-hydroxy-3,3',5'-trimethoxy-8,4'-oxyneolignan-7,9,9'-triol-7'-one, together with an unusual gamma-lactone, 3-(3,4-dihydroxyphenyl)-4-pentanolide (4), and twenty-five known compounds (5-29) were isolated from the aerial parts of Viburnum fordiae Hance. Their structures including absolute configurations were determined by spectroscopic and chemical methods. Among them, compounds 6, 7, 11-15, 17-28 were isolated from the Viburnum genus for the first time. The anti-inflammatory and antioxidant activities of all compounds were evaluated in vitro. Compounds 15, 19, 20 and 29 showed significant inhibitory activity on NO production in RAW264.7 cells stimulated by LPS with IC50 values ranging from 8.60 to 13.92 mu M. Meanwhile, compounds 1-4, 15, 19, 20, 22, 23, 25, 26 and 29 exhibited varying antioxidant activities through DPPH, ABTS free radical scavenging and FRAP assays.