Diterpenoids of Isodon Species in Yunnan Province

The genus Isodon (Labiatae) comprises approximately 150 species, most of which are endemic to China and have great medicinal value. During the past decades, great efforts have been made to explore the secondary metabolites of Isodon species, resulting in the isolation and identification of more than 1200 diterpenoids. These abundant diterpenoids have attracted considerable attention by virtue of their diverse and intriguing structures, as well as displaying a broad spectrum of bioactivities. There are abundant resources of Isodon plants in Yunnan Province. Among the estimated 49 Isodon species distributed in this region, several are employed as important folk medicines, including I. eriocalyx, I. scoparius, I. adenanthus, etc., mainly to combat infections, inflammation, cancers, and other diseases. In-depth research on these species has led to the discovery of a series of structurally and biologically interesting molecules. This chapter will give a brief introduction to the research progress on diterpenoids from Isodon species, including their structures, bioactivities, and chemical synthesis. Focus will be placed mainly on those Isodon species produced in Yunnan Province, and research on endophytes of Isodon species will also be briefly introduced.