Two Novel Anti-Inflammatory 21-Nordammarane Saponins from Tetraploid Jiaogulan (Gynostemma pentaphyllum)

Two novel 20-oxo-21-nordammar-22, 24-diene saponins, 21-norgypenosides A (1) and B (2), were characterized from the aerial parts of tetraploid Jiaogulan (Gynostemma pentaphyllum), a popular tea ingredient. Their structures, including the absolute configurations, were comprehensively elucidated by HRESIMS, 1D and 2D NMR data, chemical degradation, and through comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. The two compounds suppressed the expression of interleukin (IL)-1β, cyclooxygenase (COX)-2, and tumor necrosis factor (TNF)-α mRNAs in the lipopolysaccharide-induced RAW 264.7 mouse macrophage cells at 10 and 100 μg/mL, suggesting their potential anti-inflammatory effects.