Five undescribed ent-labdane diterpenoid glucosides from Andrographis paniculata and their anti-inflammatory activity.

A phytochemical investigation on the leaves of medicinal plant Andrographis paniculata resulted in the isolation of five previously undescribed ent-labdane diterpenoid glucosides (1-5), along with ten known ones (6-15). Their chemical structures with absolute configurations were thoroughly elucidated on the basis of comprehensive spectroscopic analysis, single-crystal X-ray crystallographic experiment and acid hydrolysis. All the isolated compounds were measured for the production of nitric oxide levels in LPS-induced RAW 264.7 macrophages to assess their anti-inflammatory activity. Compounds 4, 6, 10-12 and 14 showed potential anti-inflammatory activity.