Anti-inflammatory phenylpropanoid glycosides from the fruits of Forsythia suspensa.

Five new phenylpropanoid glycosides, susaroysides A-E (1-5) were isolated from the fruits of Forsythia suspensa. Their structures were elucidated by comprehensive spectroscopic data analysis. The absolute configurations of their sugars were determined by GC analysis. Notably, susaroysides A-D possessed a sugar with an unsubstituted anomeric carbon, which is relatively rare in natural sources. Compound 1 exhibited significant anti-inflammatory activity against the lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-α expression in macrophage cells with the IC₅₀ value of 1.053 μM.