N4Py

N4Py is a bleomycin-mimetic pentadentate ligand that targets intracellular FeII and reversibly chelates a variety of transition metals. N4Py chelates induce apoptosis through two pathways: DNA cleavage via ROS generation and XIAP downregulation via ZnII chelation, with only FeII/FeIII-N4Py exhibiting potent DNA cleavage activity. The folate conjugate of N4Py targets folate receptors, can be intracellularly cleaved, and selectively kills FR-positive cancer cells. N4Py can be used in research on various cancers including nasopharyngeal epidermoid carcinoma, ovarian cancer, and mammary adenocarcinoma^[1][2]. In Vitro:N4Py forms complexes with Fe²⁺, Fe³⁺, Cu²⁺, Mn²⁺, and Zn²⁺ that differ in spectral and electrochemical properties, and Fe²⁺-N4Py exhibits characteristic metal-to-ligand charge transfer absorption^[1].
N4Py can form Fe (II)-N4Py and Fe (III)-N4Py, both of which efficiently cleave supercoiled pUC18 plasmid DNA under cell-free conditions^[1].
Mn (II)-N4Py, Fe (II)-N4Py and Fe (III)-N4Py formed by N4Py significantly reduce the metabolic activity of A2780, SKOV3 and OSE-C2 cells, with IC₅₀ values of 5-10 μM^[1].
Mn (II)-N4Py, Fe (II)-N4Py and Fe (III)-N4Py induce significant late apoptosis/necrotic cell death in A2780, SKOV3 and OSE-C2 cells, among which free N4Py exhibits the strongest cytotoxicity, while Cu (II)-N4Py and Zn (II)-N4Py show minimal cytotoxicity^[1].
Mn (II)-N4Py, Fe (II)-N4Py, Fe (III)-N4Py, and Cu (II)-N4Py induce hROS production in A2780 cells, while Zn (II)-N4Py has no such effect; NAC abrogates hROS production induced by all these substances except Cu (II)-N4Py, and instead enhances hROS production induced by Cu (II)-N4Py^[1].