Abstract
Phytochemical investigation of the methanolic extract of the leaves of Andrographis paniculata Nees yielded a minor, new diterpene, 21-nor-3,19–isopropylidine-14-deoxy-ent-labda-8(17),13-dien-16,15-olide (1), together with five known labdane type diterpenes, andrographolide 3, 14-deoxyandrographolide 4, 14–deoxy–12–hydroxyandrographolide 5, 14–deoxy–11,12–dihydroandrographolide 6, neoandrographolide 7, and two acids, cinnamic acid 8, and ferulic acid 9. The chemical structures were established by spectroscopic analyses, including 1D- and 2D-NMR spectroscopic experiments, and on the basis of HR-ESI MS analyses. The methanolic extract of the leaves exhibited moderate antibacterial and antifungal activities at a dose of 200 μg/mL in comparison with the reference standards.