Succipenoids A-C: A dimeric abietane and nor-abietane diterpenoids from fossil Chinese medicinal succinum and their anti-inflammatory potential

Abstract

An unprecedented dimeric abietane, succipenoid A (1), and two previously undescribed nor-abietane diterpenoids featuring a rarely occurring naphthalene ring or with a large conjugated system, succipenoids B and C (2 and 3), along with seven known diterpenoids (4–10) were isolated from the CH2Cl2 extract of succinum. The structures of these compounds, including their absolute configurations, were elucidated using spectroscopic and computational techniques. Notably, compounds 1–4 and 6–10 were isolated from succinum for the first time. In order to evaluate their anti-inflammatory potential, in vitro tests were conducted. The results demonstrated that compounds 1, 2, 4, and 6–10 exhibite dose-dependent inhibition of iNOS expression in lipopolysaccharide-induced RAW 264.7 cells.