Isopimarane diterpenoids from the aerial parts of Hymenocrater elegans with anti-inflammatory potential.

Eight previously undescribed and one fully characterized isopimarane diterpenoids, hymenocraterol (A-I), were isolated from n-hexane extract of the aerial parts of Hymenocrater elegans. Their structures were elucidated using HRMS, 1D and 2D-NMR, and electronic circular dichroism calculation techniques. Hymenocrater species are used traditionally for the treatment of different conditions such as inflammation. On this basis, the anti-inflammatory potential of the isolated compounds was evaluated in vitro using J774A.1 murine macrophages. Our results indicated that the majority of these compounds possess anti-inflammatory properties, among which compound 6 was identified as the most promising. Compound 6 significantly inhibited proinflammatory parameters in J774A.1 macrophages in inflammatory conditions, such as nitric oxide release and oxidative stress parameters. These results were additionally confirmed in mouse peritoneal primary macrophages. Our results support the reported anti-inflammatory properties and traditional use of H. elegans, presenting it as an interesting source of anti-inflammatory and antioxidant compounds.