Two novel lignans from Gaultheria yunnanensis

Two new lignans, 9-salicyl-(+)-isolariciresinol (1) and gaultheroside G (2), together with seven known compounds, were isolated from the ethanolic extract of the whole plant of Gaultheria yunnanensis. Their structures were determined by extensive NMR and MS analyses. Gaultheroside G (2) was found to have an unusual ether linkage between the 2 and 9' positions of aryl-tetralin lignan skeleton. All nine compounds were assayed for inhibitory effects against nitric oxide and pro-inflammatory cytokines TNF-α and IL-6 release in LPS-induced RAW 246.7 macrophages, while no significant activities were observed for the evaluated compounds.