Two new secolignans with in vitro anti-inflammatory activities from Urtica fissa rhizomes.

Two new secolignans, urticin A (1) and urticin B (2), were isolated from the ethanol extract of Urtica fissa rhizomes. Their structures were elucidated on the basis of extensive spectroscopic evidence (UV, IR, HR-ESI-MS, and NMR). Urticin A and urticin B possessed in vitro anti-inflammatory activities, which significantly inhibited the TNF-α and NO release induced by LPS in RAW 264.7 cells.