Chemical Constituents of the Folk Medicinal Plant Argyreia acuta Lour. and Their Anti-Inflammatory Activity

Phytochemical investigation of the folk medicinal plant Argyreia acuta Lour. has led to the isolation of a pair of new 3-alkylated coumarin enantiomers, (±)-acutamarin [(±)-1] and 3 known structurally related coumarins (2-4), along with 4 known flavonoids (5-8). The structures of these compounds were elucidated on the basis of extensive spectroscopic (including one-dimensional and two-dimensional nuclear magnetic resonance) analyses and by comparison of their spectral data with those reported in the literature. The absolute configurations of ( − )-1 and ( + )-1 were proposed by comparison of experimental and calculated electronic circular dichroism data. Compounds 5 and 7 exhibited in vitro anti-inflammatory activity by inhibiting the production of nitric oxide with IC50 values of 24.54 ± 0.36 μM and 10.60 ± 0.15 μM, respectively.