Phenolic glycosides and indole alkaloids isolated from the roots and rhizomes of Clematis chinensis and their anti-inflammatory activity.

Six undescribed compounds, including three phenolic glycosides (1 – 3) and three indole alkaloids (4 – 6), together with ten known alkaloids (7 – 16) and three known phenolic glycosides (17 – 19), were isolated from 70% EtOH aqueous extracts of the roots and rhizomes of Clematis chinensis Osbeck. The structures were elucidated by NMR, HRESIMS and X-ray diffraction spectroscopies. The anti-inflammatory activity of these compounds was evaluated, and twelve compounds showed significant inhibitory activity against TNF-α with an inhibition ratio from 47.87% to 94.70% at a dose of 10 μM. Compound 7 exhibited significant inhibitory activity against TNF-α and IL-6 with IC 50 values of 3.99 μM and 2.24 μM, respectively. Compound 8 displayed potent anti-inflammatory activity against mouse ear edema induced by croton oil. A mechanistic study suggested that compounds 7 and 8 decreased the activation of the NF-κB signaling pathway to reduce the secretion of inflammatory factors in LPS-induced RAW 264.7 cells. Six undescribed compounds together with thirteen known ones were isolated from Clematis chinensis. Mechanistic study suggested that compounds 7 and 8 could decrease the activation of NF-κB signaling pathway. [Display omitted] • Six undescribed compounds were isolated from the Clematis chinensis. • Twelve compounds showed inhibitory activity against TNF-α. • Three compounds exhibited potent inhibitory activity on NO. • Compounds 7 and 8 could decrease the activation of NF-κB signaling pathway. [ABSTRACT FROM AUTHOR]