Novel metal complexes of naphthalimide-cyclam conjugates as potential multi-target receptor tyrosine kinase (RTK) inhibitors: Synthesis and biological evaluation

A novel series of metal complexes of naphthalimide-cyclam conjugates were synthesized and their in vitro antitumor activities were evaluated. The newly-synthesized compounds showed huge diversity of antiproliferative potency due to variety of metal ions and length of alkyl chains, among which the Zn(II) and Cr(III) complexes exhibited comparable antiproliferative activities with amonafide via multiple tyrosine kinase inhibition. Further research revealed that the representative compound 8a displayed broad-spectrum antiproliferative activity against 15 cancer cell lines with average IC₅₀ value 10.18 ± 3.25 μM, and effective antiangiogenic activity on human microvascular endothelial cells (HMEC-1). In brief, metal complexes of naphthalimide-cyclam conjugates were firstly designed and synthesized as multi-target tyrosine kinase inhibitors and proved of their antitumor capacities.