ABSTRACT
The iridoids are a large group of naturally occurring monoterpenoids containing a dimethylcyclopenta[c]pyran (iridane, or 2-oxabicyclo[4.3.0]nonane) skeleton (Figure 28.1). The vast majority of iridoids are found in higher plants. Their ecological functions, physiological activity and pharmacology, and signicance as chemotaxonomic markers have attracted considerable interest. More than 1,500 distinct structures have been reported. Several review articles list most of the isolated iridoids along with their physical and spectral data and original sources [1-6].
