Artemeriopolides A–D, two types of sesquiterpenoid dimers with rare carbon skeletons from Artemisia eriopoda and their antihepatoma cytotoxicity

Artemeriopolides A–D (1–4), four novel cadinane sesquiterpenoid dimers featuring the rare 2-oxaspiro[4.6]undecan-1,7-dione, 2-oxaspiro[4.5]decan-1-one, and 2-oxaspiro[5.5]undecan-1-one ring systems, were isolated from Artemisia eriopoda .