Investigating the Antibacterial and Antitumoral Activities of New Copper(II) Complexes with Trifluoromethyluracil Isomers

Abstract New copper(II) complexes, derived from the isomers 5‐(trifluoromethyl)uracil ( L 1 ) and 6‐(trifluoromethyl)uracil ( L 2 ) with 2,2′‐bipyridine ( Bpy ), [Cu(H 2 O)(L 1 ) 2 Bpy] and [Cu(H 2 O)(L 2 ) 2 Bpy], were synthesized, characterized, and evaluated for their antibacterial and antitumoral properties. Chemical analyses suggest the molecular formula CuC 20 H 12 F 6 N 6 O 4 ·H 2 O for both complexes. Infrared spectroscopic analyses indicate that trifluoromethyluracil isomers coordinate to copper(II) by the oxygen atoms. Structural confirmation of the [Cu(H 2 O)(L 2 ) 2 Bpy] complex was obtained by single crystal X‐ray diffraction, where two L 2 molecules coordinate to the copper(II) ion by both oxygen atoms from carbonyl groups. The complexes demonstrated antibacterial activity against Gram‐positive Staphylococcus aureus and Bacillus cereus , and Gram‐negative Pseudomonas aeruginosa and Escherichia coli strains. The [Cu(H 2 O)(L 1 ) 2 Bpy] complex exhibited the most promising results against P. aeruginosa , with a minimum inhibitory concentration (MIC) value of 0.478 mmol L −1 . The [Cu(H 2 O)(L 1 ) 2 Bpy] complex demonstrated antiproliferative effects on U251 and MCF‐7 cells, with GI 50 values (concentration that inhibits 50% of cell growth) of 2.18 ± 1.17 and 16.00 ± 10.07 µmol·L −1 , whereas the [Cu(H 2 O)(L 2 ) 2 Bpy] complex inhibited the growth of FaDu and U251 cells (GI 50 values 4.70 ± 2.69 µmol·L −1 and 9.06 ± 3.86 µmol·L −1 , respectively). Neither the precursors nor the copper(II) complexes affected the structure of CT‐DNA at the evaluated concentrations, suggesting that DNA is not the main cellular target of the complexes.