Three new ursane-type triterpenoids from Rosmarinus officinalis and their biological activities

Three new ursane-type triterpenoids, 3-oxours-12-en-20, 28-olide (1), 3β-hydroxyurs-12-en-20, 28-olide (2) and 3β-hydroxyurs-11, 13(18)-dien-20, 28-olide (3), were isolated from a potent anti-inflammatory and antibacterial fraction of the ethanolic extract of Rosmarinus officinalis. Their structures were elucidated by a combination of extensive 1D- and 2D-NMR experiments, MS data and comparisons with literature reports. Compounds 1—3 exhibited significantly inhibitory effects on nitric oxide production in lipopolysaccharide-activated mouse RAW264.7 macrophages, but no antibacterial activity was found at a concentration of 128 μg·mL—1.