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[Display omitted] • Five new racemic alkyl-benzofuran dimers were discovered from Eupatorium chinense. • The 12,10′-epoxy, 12-nor, and 12,12′-dinor dimers (1 – 3) showed notably new feature. • Chiral resolution were performed on four racemic mixtures. • The absolute configurations were determined by quantum chemical calculations. • Compound 1 exhibited promising insulin-sensitizing and anti-inflammatory activities. Five new racemic alkyl-benzofuran dimers, (±)-dieupachinins I–M (1 – 5), were isolated from the root tubers of Eupatorium chinense , a well-known traditional Chinese medicine for the treatment of diphtheria in Guangdong province. The structures of these compounds, especially the first examples of 12,10′-epoxy dimer dieupachinin I (1), 12-nor-dimer dieupachinin J (2), and 12,12′-dinor-dimer dieupachinin K (3), were elucidated by spectroscopic data analysis. Chiral resolution were further carried out on a cellulose column by HPLC, and compounds 2 – 5 were successfully separated into two enantiomers, respectively. The absolute configurations of (+)-(2 – 5) and (−)-(2 – 5) were established by theoretical ECD calculation. All the compounds were evaluated for insulin-stimulated glucose uptake in C2C12 myotubes and (±)-dieupachinin I (1) exhibited the best activity. Compound 1 enhanced insulin-stimulated glucose uptake via activating the insulin receptor substrate 1/protein kinase B/glycogen synthase kinase-3 β signaling pathway. Moreover, all the isolates were tested for their nitric oxygen (NO) inhibitory effects in lipopolysaccharide-treated RAW264.7 macrophages, and compounds (±)- 1 , (±)- 2 , and (±)- 4 showed promising inhibitory effects with IC 50 values of 6.42 ± 1.85, 6.29 ± 1.94, and 16.03 ± 2.07 μM, respectively. (±)-Dieupachinin I (1) again dose-dependently suppressed LPS-induced expression of inducible NO synthase and nuclear translocation of p65. [ABSTRACT FROM AUTHOR]