cis-Clerodane Diterpenoids with Structural Diversity and Anti-inflammatory Activity from Tinospora crispa

Twelve new cis-clerodane diterpenoids, designated as crispinoids A—L (1—12), together with three known analogues (13—15), were isolated from Tinospora crispa. Their structures were fully assigned by comprehensive spectroscopic techniques, single-crystal X-ray diffraction experiments, and electronic circular dichroism (ECD) analyses. The isolated clerodanes displayed diverse heterocyclic frameworks including 6/6/6-, 6/5/6/6-, 6/6/5-, 6/6-, and 6/5/6-fused ring systems. Some of the isolates showed ATP-citrate lyase (ACLY) and nuclear factor kappa B (NF-κB) pathway inhibition. The NF-κB inhibitors further suppressed the lipopolysaccharide (LPS)-induced inflammatory responses in RAW 264.7 cells.