A phytochemical investigation on Isodon flavidus led to the isolation of flavidanolide A (1), a rearranged diterpenoid featuring a six/seven/five-membered tricyclic skeleton, together with flavidanolide B (2), an uncommon heterodimeric diterpenoid consisting of a norabietane and a seco-isopimarane monomeric units. Their structures were elucidated by extensive spectroscopic data and single-crystal X-ray diffraction analyses. Their plausible biosynthetic routes were also proposed. In the bioassay, flavidanolide B was found to exhibit good inhibitory effect against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 cells comparable to positive control pyrrolidinedithiocarbamate ammonium (PDTC), which provided evidence for the medicinal value of I. flavidus as a folk medicine for treating inflammatory diseases.
Scopus Subject Areas
- Antiinflammatory effects
- Heterodimeric diterpenoid
- Isodon flavidus
- Plausible biosynthetic pathway
- Rearranged six/seven/five-membered skeleton