Integrated strategy for the screening of cyclooxygenase‐2 inhibitors from triterpenoid saponins in Clematis tangutica

Abstract Introduction Screening of novel cyclooxygenase‐2 (COX‐2) inhibitors from complex natural products is not an easy task. Objectives To establish an efficient and feasible strategy for screening COX‐2 inhibitors from triterpenoid saponins (TPSs) in Clematis tangutica . Methods Taking TPSs in C. tangutica as example, an optimized macroporous resin (MR) method was established for the enrichment of TPSs. High‐performance liquid chromatography–quadrupole time‐of‐flight mass spectrometry (HPLC‐QTOFMS) was performed to establish the phytochemical profiling of TPSs. Molecular docking was performed to predict the ligand–target interactions and discover the active substances. Chemometric techniques were performed to visualize the structure–effect relationships. High‐speed countercurrent chromatography and preparative HPLC were performed to prepare the targets. In vitro activity experiment of COX‐2 was performed to verify the virtual screening results. Results TPSs in C. tangutica were well enriched with the recovery rate of (80.22 ± 2.37)%. Thirty‐four kinds of TPSs of oleanane type were deduced by HPLC‐QTOFMS. Five TPSs of clematangoside C, clematangoside D, clematangoticoside J, hederoside H 1 , and hederasaponin B showed stronger binding abilities with COX‐2. The structure with more sugar groups at C‐28 may be more conducive to the combination with COX‐2. Targets were prepared with purities all above 98%. The IC 50 values of target TPSs were 6.03 ± 0.24, 12.44 ± 0.15, 9.36 ± 0.19, 4.78 ± 0.13, and 2.59 ± 0.11 μmol/L, respectively. Conclusion The integrated strategy using MR, HPLC‐QTOFMS, molecular docking, chemometrics, target preparation, and in vitro verification was feasible for rapidly screening COX‐2 inhibitors from TPSs in C. tangutica .