The anticancer traditional Chinese medicine (TCM), plumbagin (PLN), was isolated from Plumbago Zeylanica. Reaction of plumbagin with Cu(II) salt, afforded [Cu(PLN)(2)].2H(2)O (1). With 2,2'-bipyridine (bipy) as a co-ligand, PLN reacts with Cu(II) to give [Cu(PLN)(bipy)(H(2)O)](2)(NO(3))(2).4H(2)O (2). 1 and 2 were characterized by elemental analysis, IR, ESI-MS spectra. Their crystal structures were determined by single crystal X-ray diffraction methods. The in vitro cytotoxicity of PLN, 1 and 2 against seven human tumour cell lines was assayed. The metal-based compounds exhibit enhanced cytotoxicity vs. that of free PLN, suggesting that these compounds display synergy in the combination of metal ions with PLN. The binding properties of PLN, 1 and 2 to DNA were investigated through UV-vis, fluorescence, CD spectra, and gel mobility shift assay, which indicated that 1 and 2 were non-covalent binding and mainly intercalated the neighboring base pairs of DNA. PLN, 1 and 2 exhibit inhibition activity to topoisomerase I (TOPO I), but 1 and 2 were more effective than PLN.

Complexes of copper (II) with hesperetin, naringenin, and apigenin of general composition [CuL2(H2O)2] ⋅ nH2O (1–3) have been synthesized and characterized by elemental analysis, UV-Vis, FT-IR, ESI-MS, and TG-DTG thermal analysis. The free ligands and the metal complexes have been tested in vitro against human cancer cell lines hepatocellular carcinoma (HepG-2), gastric carcinomas (SGC-7901), and cervical carcinoma (HeLa). Complexes 1 and 3 were found to exhibit growth inhibition of SGC-7901 and HepG2 cell lines with respect to the free ligands; the inhibitory rate of complex 1 is 43.2% and 43.8%, while complex 3 is 46% and 36%, respectively. The interactions of complex 1 and its ligand Hsp with calf thymus DNA were investigated by UV-Vis, fluorescence, and CD spectra. Both complex 1 and Hsp were found to bind DNA in intercalation modes, and the binding affinity of complex 1 was stronger than that of free ligand.

Try-Cu exhibited its antitumor activity mainly via inhibiting telomerase by interaction with the c-myc promoter and disrupting mitochondrial functions.