Synthesis, structure, and biological evaluation of three Cu(II) and Ni(II) (E)-3-(3,4-dimethoxyphenyl)acrylate complexes with organic diamines as potential urease inhibitors

Abstract

Three new complexes (1–3) have been synthesized and characterized by X-ray single crystal determination and evaluated for inhibitory activity on jack bean urease. All the complexes contained a new cinnamic acid derivative as the ligand (C₁₁H₁₂O₄), (E)-3-(3,4-dimethoxyphenyl)acrylic acid, and crystallized in monoclinic C2/c space group. Complex 1 (C₁₁H₁₁O₄)₄(C₃N₂H₈)₂Cu₂ (C₃N₂H₈ = 1,2-diaminopropane) was obtained with a = 20.488(2), b = 19.596(2), c = 15.2500(13), β = 93.502(2)°, V = 6111.2(10) ų, Z = 4, R ₁  = 0.0616, and wR ₂  = 0.2059. Complex 2 (C₁₁H₁₁O₄)₄(C₃N₂H₈)₂Cu₂ (C₃N₂H₈=1,3-diaminopropane) was obtained with a = 20.2494(12), b = 19.5732(12), c = 14.8940(8), β = 96.884(2)°, V = 5860.6(6) ų, Z = 4, R ₁  = 0.0409, and wR ₂  = 0.1107. Complex 3 (C₁₁H₁₁O₄)₂(C₂N₂H₆)₂Ni₂·H₂O (C₂N₂H₆ = ethylenediamine) was obtained with a = 28.359(2), b = 6.5422(5), c = 16.8587(14), β = 101.359(2)°, V = 3066.5(4) ų, Z = 4, R ₁  = 0.0422, and wR ₂  = 0.1190. It was found that copper(II) complexes 1 [IC₅₀ = 4.71 μM] and 2 [IC₅₀ = 3.15 μM] showed strong inhibitory activity against jack bean urease compared with acetohydroxamic acid [IC₅₀ = 10.01 μM] as a positive reference. Unfortunately, 3 exhibited no inhibitory activity.

Keywords:

• Cinnamic acid ligand
• Transition metal complexes
• Crystal structures
• Urease inhibitors