1 Introduction Iridoids constitute a structurally diverse and biologically significant class of bicyclic monoterpenes derived biosynthetically from iridodial. The first iridoid, iridomyrmecin, was identified in 1925 from the ant Iridomyrmex humilis. Iridoids are universally characterized by a cyclopenta[c]pyran skeleton [1]. Recently, iridoids have attracted increasing attention due to their antimicrobial [2], antiviral [3], anti-inflammatory [4], and antioxidant activities [5].
