Synthesis, characterization and anticancer activities of two lanthanide(III) complexes with a nicotinohydrazone ligand

Two isostructural acylhydrazone based complexes, namely [Ce(penh) 2 (H 2 O) 4 ](NO 3 ) 3 ·4H 2 O ( 1 ) and [Sm(penh) 2 (NO 3 ) 2 ](NO 3 )·C 2 H 5 OH ( 2 ) (penh = 2-acetylpyridine nicotinohydrazone), have been obtained and characterized by physico-chemical and spectroscopic methods. The ten-coordinated lanthanide metal ion in each complex is surrounded by two independent tridentate neutral acylhydrazones with two ON 2 donor sets. The other four coordination oxygen atoms are from four water molecules and two bidentate nitrate anions for complexes 1 and 2 , respectively, thus giving distorted bicapped square antiprism geometry. Both complexes have excellent antitumor activity towards human pancreatic cancer (PATU8988), human colorectal cancer (lovo) and human gastric cancer(SGC7901) cell line. Furthermore, the cell apoptosis of complex 1 is detected by AnnexinV/PI flow cytometry.