Diaqua(dipicolinato)oxovanadium (IV) ethanol solvate crystallizes in the triclinic space group P1. The complex was characterized by FTIR, elemental analysis, thermal gravimetric analysis, and solution visible spectral analysis. The complex alone cleaved DNA in the absence of hydrogen peroxide and its nucleolytic efficiency is greater than that of VOSO 4 . Its nucleolytic efficiency is affected by the choice of buffer used and pH. DNA cleavage can be inhibited by DMSO, NaN 3 and catalase, implying involvement of ROS. An MTT assay, involving the lung cancer cell line PC9, gave IC 50 values of 9.5 µM and 16 µM for the complex and VOSO 4 respectively. For breast cancer cell line MCF-7, this complex is less cytotoxic, with an IC 50 of 16 µM.

4-Chloro-1,2-phenylenediamine (4-Cl-o-PD) is a halogenated aromatic diamine that was used as a precursor for manufacturing permanent hair dyes. Despite its well-documented mutagenic and carcinogenic effects in a number of in vitro and in vivo models, its cytotoxicity and mode of action have not received similar attention. Here, we investigated the effect of 4-Cl-o-PD on Mardin-Darby canine kidney cells. It induced apoptosis and the evidence suggests its initiation by reactive oxygen species (ROS). The results of various assays used show a dose-dependent (i) decrease in cell viability, (ii) increase in cells at sub-G1 phase and the G0/G1 phase arrested in cell cycle, (iii) increase in intracellular ROS accompanied by depletion of glutathione, and (iv) that apoptotic cell death probably involves activation of both intrinsic and extrinsic pathways.