An efficient electrochemical transformation of structurally diverse sulfonyl hydrazides and thiols into thiosulfonates in the presence of ammonium iodide as redox catalyst and electrolyte in acetonitrile at ambient temperature is reported. Transition metal- and oxidant-free conditions are the striking features of this protocol. The in vitro cytotoxicity of all compounds is evaluated by MTT assay against four human cancer cell lines. The results reveal that 3ac and 3ag exhibit potential inhibitory activity against tumor cells. Furthermore, 3ag inhibits cell migration ability and tubulin polymerization in T-24 cells, leading to cell cycle arrest and apoptosis.

Three new oxoaporphine Co(II), Ni(II) and Zn(II) complexes 1–3 have been synthesized and fully characterized. 1–3 have similar mononuclear structures with the metal and ligand ratio of 1:2. 1–3 exhibited higher cytotoxicity than the OD ligand and cisplatin against HepG2, T-24, BEL-7404, MGC80–3 and SK-OV-3/DDP cells, with IC₅₀ value of 0.23−4.31 μM. Interestingly, 0.5 μM 1–3 significantly caused HepG2 arrest at S-phase, which was associated with the up-regulation of p53, p21, p27, Chk1 and Chk2 proteins, and decrease in cyclin A, CDK2, Cdc25A, PCNA proteins. In addition, 1–3 induced HepG2 apoptosis via a caspase-dependent mitochondrion pathway as evidenced by p53 activation, ROS production, Bax up-regulation and Bcl-2 down-regulation, mitochondrial dysfunction, cytochrome c release, caspase activation and PARP cleavage. Furthermore, 3 inhibited tumor growth in HepG2 xenograft model, and displayed more safety profile in vivo than cisplatin.