Synthesis, structures, and urease inhibitory activities of oxovanadium(V) complexes with Schiff bases

摘要

A series of oxovanadium(V) complexes, [VO _2L ~1] _2 (1), [VO _2L ~2] _2 (2), [VO _2L ~3] _2 (3), [VO _2L ~4] _2 (4), [VO(OCH _3)L ~5] (5), and [VO(OCH _3)(HOCH _3)L ~6] (6) (HL ~1 = 2-ethoxy-6-{[2-(2-hydroxyethylamino)ethylimino]methyl}phenol, HL ~2 = 4-chloro-2-{[2-(2-hydroxyethylamino)ethylimino]methyl}phenol, HL ~3 = 2-methoxy-6-[(2-methylaminoethylimino)methyl]phenol, HL ~4 = 4-chloro-2-[(2-methylaminoethylimino)methyl]phenol, HL ~5 = N′-(2-hydroxy-3-ethoxybenzylidene)-3-hydroxy-2-naphthohydrazide, and HL ~6 = N′-(2-hydroxy-5-chlorobenzylidene)-3-hydroxy-2- naphthohydrazide), have been prepared and structurally characterized by physico-chemical methods and X-ray diffraction. The inhibition rates (%) with the concentration of 100 μM for the complexes on Helicobacter pylori urease are 18.96 ± 0.44 (1), 33.01 ± 1.80 (2), 35.83 ± 0.78 (3), 48.09 ± 1.23 (4), 45.91 ± 2.09 (5), and 90.72 ± 1.91 (6). The relationship between the structures and urease inhibitory activities indicates that the chloro-substituted complexes have stronger activity than the alkoxy-substituted complexes. It is notable that one of the chloro-substituted complexes has very strong urease inhibitory activity, with IC _(50) value of 17.35 ± 1.01 μM, which is much lower than that of the acetohydroxamic acid coassayed as a standard urease inhibitor. The kinetic studies reveal that the complex is a mixed-competitive inhibitor of urease. The molecular docking study of the complexes with the Helicobacter pylori urease was performed.