Lactone ring-opening seco-guaianolide involved heterodimers linked via an ester bond from Artemisia argyi with NO inhibitory activity.

Investigation into the chemical diversity of Artemisia argyi led to the discovery of four new (1-4) and one known (5) guaianolide sesquitenpenoid dimers linked via ester bond, and five other known mono-sesquiterpenoids (6-10). Their structures were determined via extensive spectroscopic data, and the absolute configurations of these compounds were elucidated by calculated ECD analysis and chemical method. The dimeric sesquiterpenoids exhibited NO production inhibitory activity with IC₅₀ values ranging from 7.02 to 32.1 μM. The studies further suggested that compound 2 inhibited inflammatory responses via suppression of the expression of iNOS, resulting from activation of nuclear factor-kappaB (NF-κB) and phosphorylation of MAPKs (ERK and p38).