Synthesis, isolation, characterization of C₃-C₁₁ bridge-bond isomer of paclitaxel and its antitumor effect via inducing A549 cells pyroptosis

During the chemical manufacturing control processing of new paclitaxel formulations, a photodegradation impurity called C3-C11 bridge-bond isomer appeared. Our work describes the synthesis, isolation, purification, and structural characterization methods using four spectroscopies: FT-IR, UV, NMR (1H and 13 C), and LC-MS. In addition, we discovered that the C3-C11 bridge-bond isomer can promote A549 cells pyroptosis, and increase pyroptosis-related proteins, including cleaved-caspase 3, cleaved-PARP, GSDME-N, and lactate dehydrogenase, thus making it anti-tumor effects. The study offered data suggesting that the C3-C11 bridge bond isomer may be used as an anti-tumour drug in the future.