Acyclic Triterpenoids from Alpinia katsumadai Inhibit IL-6-Induced STAT3 Activation.

The seeds of yielded two new acyclic triterpenoids, 2,3,6,22,23-pentahydroxy-2,6,11,15,19,23-hexamethyl-tetracosa-7,10,14,18-tetraene () and 2,3,6,22,23-pentahydroxy-2,10,15,19,23-hexamethyl-7-methylenetetracosa-10,14,18-triene (), as well as two known compounds, 2,3,22,23-tertrahydroxy-2,6,10,15,19,23-hexamethyl-tetracosa-6,10,14,18-tetraene () and 2,3,5,22,23-pentahydroxy-2,6,10,15,19,23-hexamethyl-tetracosa-6,10,14,18-tetraene (). The absolute configurations of and , which were determined by means of a modified Mosher's method, are suggested as (; ; ) and (; ), respectively. Compounds - inhibited IL-6-induced JAK2/STAT3 activity in a dose-dependent fashion, with IC values of 0.67, 0.71, 2.18, and 2.99 μM. Moreover, IL-6-stimulated phosphorylation of STAT3 was significantly suppressed in U266 cells by the administration of EtOH extract and Compounds and . These results suggest that major phytochemicals, Compounds and , obtained from may be useful candidates for designing new IL-6 inhibitors as anti-inflammatory agents.