A versatile bioinspired metallocatalyst [Ni 2 L 2 (NCS)(Ac)(H 2 O) 0.5 (MeOH) 0.5 ]·1.25H 2 O (HL = 2-((E)-(2-(pyridin-2-yl)ethylimino)methyl)-4-chlorophenol) has been synthesized from a Schiff-base ligand and characterized as reported earlier (Sanyal et al., 2016). It portrays catecholase activity as an oxygen dependent enzymatic radical catalysis under completely aerobic conditions (λ max = 375 nm, ε = 1900 M −1 cm −1 ) against the model substrate 3,5-di-tert-butylcatechol (3,5-DTBC). Interestingly, Michaelis-Menten analysis of pseudo first-order reaction kinetics establishes that DMF medium provides a better catalytic pathway for catecholase activity (k cat = 2.8 × 10 −3 s −1 ) than acetonitrile (9.11 × 10 −4 s −1 ) under excess substrate conditions. Cell viability study, drug uptake assay, reactive oxygen species (ROS) formation, alteration of mitochondrial membrane potential (MMP), apoptosis study and DNA fragmentation demonstrates a significant dose dependent anti-leukemic activity on KG-1A (AML) and K562 (CML) cell lines. Notably, outstanding anti-bacterial property was also observed on multi-drug resistant E. coli and S. aureus bacteria. © 2016