A comprehensive investigation of anti-inflammatory diarylheptanoids from the leaves of Alnus formosana.

This study was aimed to investigate thoroughly the diarylheptanoids in the n-BuOH soluble fraction of leaves of Alnus formosana in order to examine their anti-inflammatory activities. The application of HPLC-SPE-NMR as a preliminary chemical screening led to characterization of eleven compounds. Further separation resulted in isolation of 28 compounds, of which 10 diarylheptanoids and 2-coumaroylxyloside are new natural products. Compound 1 and alnuside A (27) were found to possess good activities against LPS-induced NO production with respective IC(50) values of 7.99 and 8.08 μM, and which were devoid of significant cytotoxicity.