Chemical Constituents from the Roots and Rhizomes of Asarum heterotropoides var. mandshuricum and the In Vitro Anti-Inflammatory Activity.

Anti-inflammatory compounds were investigated from the ethanol extract of the roots and rhizomes of var. , a traditional Chinese medicine called Xixin and used for pain and inflammatory. Nine new compounds were isolated, including six new lignans, neoasarinin A-C (-), neoasarininoside A and B ( and ), and asarinin B (), and one new monoterpene, asarincin A (), two new amides, asaramid II and III ( and ), and one new natural monoterpene, asaricin B (), along with 37 known compounds (, -). Their structures and absolute configurations were elucidated on the basis of spectroscopic methods and chemical analyses. This is the first report of the absolute configuration of asarinin A (). The 8--4' neolignans (-) were reported in the genus for the first time. The 15 compounds , , -, , , , , , , - were isolated from the genus , and compounds , , , and were isolated from var. for the first time. Thirty-seven of the isolates were evaluated for anti-inflammatory activity against the release of β-glucuronidase in polymorphonuclear leukocytes (PMNs) induced by the platelet-activating factor (PAF), and compounds , , , , , -, , , , , , , , -, , and showed potent anti-inflammatory activities in vitro, with 27.9%-72.6% inhibitions at 10 mol/L. The results of anti-inflammatory assay suggested that lignans obtained from the CHCl₃ extract might be the main active components of Xixin.