ABSTRACT
Aim To investigate the intracellular disposition process of doxorubicin (DOX) in human breast cancer MCF-7, providing reference for explaining the pharmacology and their side effects of anti-tumor drugs. Methods The drug-resistant cell line MCF-7/DOX of breast cancer with DOX indication was selected as the material, and ultra-high performance liquid chromatography quadrupole tandem time-of-flight high-resolution mass spectrometry (UPLC-Q-TOF-MS/MS) method was established to analyze the disposal of DOX by target cells. Results Two unreported trace a-mounts of new metabolites of doxorubicin were found, and their structures were deduced by high-resolution multistage mass spectrometry. Molecular docking showed that its affinity for DNA was lower than that of DOX. Conclusion Target cells have unique and diverse drug metabolism pathways for DOX, which may be related to drug resistance mechanisms.