Diterpenoids from Callicarpa rubella and their in vitro anti-NLRP3 inflammasome activity.

Nine new diterpenoids, Rubellacrns A − I (1–9), including five isopimaranes (1–4, 9), four pimaranes (5–8), together with five known isopimarane analogues (10–14), were isolated from Callicarpa rubella. The structures of these compounds were unambiguously established by HR-ESIMS and NMR spectroscopic data, the absolute configurations of compounds 5 and 9 were determined by ECD. All the isolated compounds were tested for their anti-inflammatory effects and compounds 2 and 11–14 showed NLRP3-inflammasome inhibitory activity with IC 50 values ranging from 7.02 to 14.38 μM. Unlabelled Image • Nine new diterpenoids were isolated from Callicarpa rubella. • The absolute configuration of 5 and 9 was deduced by ECD. • The new compound 2 showed potent inhibition of inflammasome activation. [ABSTRACT FROM AUTHOR]