Synthesis, Identification and Antibacterial Activities of Amino Acid Schiff Base Cu(II) Complexes with Chlorinated Aromatic Moieties

Abstract

Amino acid Schiff base Cu(II) complexes were synthesized under microwave irradiation using methanol as a solvent, to maximize the best conditions to obtain the attained compounds, containing aromatics possessing no, one or two chlorine atoms. The compounds’ antibacterial activities were tested against Gram-positive and Gram-negative bacteria, and the most active were tested for their antioxidant activities, and as E. coli, in particular, was found to be sensitive to these compounds, their interaction with this bacterium was investigated. It was found that, depending on the amino acid used for the formation of the Schiff base ligand, its LogPo/w mono-chlorinated or bis-chlorinated compounds are the most efficient against the tested bacteria.

Crystal structure and Hirshfeld surface analysis of (1H-imidazole-κN 3)[N-(2-oxidobenzylidene)tyrosinato-κ3 O,N,O′]copper(II)

“…On the other hand, copper has various oxidation states, of which the divalent oxidation state is the most stable. Copper(II) ions readily form complexes and produce abundant coordination chemistry, while amino acid Schiff base-copper(II) complexes have been studied in terms of photoreaction with titanium dioxide (Takeshita et al, 2015), photocatalytic reduction of hexavalent chromium (Nakagame et al, 2019), and antibacterial activity (Otani et al, 2022). The ligand forms a tridentate chelate, but the introduction of a hydroxyl group is effective in increasing solubility in aqueous solvents (Miyagawa et al, 2020).…”

Crystal structure and Hirshfeld surface analysis of (1H-imidazole-κN 3)[4-methyl-2-({[2-oxido-5-(2-phenyldiazen-1-yl)phenyl]methylidene}amino)pentanoate-κ3 O,N,O′]copper(II)

“…On the other hand, copper has various oxidation states, of which the divalent oxidation state is the most stable. Copper(II) ions readily form complexes and produce abundant coordination chemistry, while amino acid Schiff basecopper(II) complexes have been studied in terms of photoreaction with titanium dioxide (Takeshita et al, 2015), photocatalytic reduction of hexavalent chromium (Nakagame et al, 2019), and antibacterial activity (Otani et al, 2022). The introduction of a hydroxyl group is effective in increasing solubility in aqueous solvents (Miyagawa et al, 2020).…”

Crystal structure and Hirshfeld surface analysis of mono/bis(aqua-κO)[N-(2-oxidobenzylidene)valinato-κ3 O,N,O′]copper(II): dimeric Schiff base copper(II) complexes having different numbers of coordinated water molecules

“…Furthermore, Schiff base complexes are considered to be an important class of organic compounds with a wide range of biological properties, including free radical scavenging, antibacterial, antitumor activities (Mo et al, 2022). In our laboratory, novel mono-chlorinated Schiff base Cu II complexes have been synthesized and their antibacterial activities tested against Gram-positive and Gram-negative bacteria; the most active were then tested for their antioxidant activities, and as E. coli, in particular, was found to be sensitive to these compounds, their interaction with this bacterium was investigated (Otani et al, 2022). Microwave irradiation is suitable for the synthesis of amino acid Schiff bases Cu II complexes in order to shorten the synthesis time and to obtain high purity.…”

“…Microwave irradiation is suitable for the synthesis of amino acid Schiff bases Cu II complexes in order to shorten the synthesis time and to obtain high purity. In the present study, the title compound was therefore synthesized by using microwave irradiation (Otani et al, 2022). Differences in chemical properties as a result of differences in structure are remarkable and it is important to report different crystal structures to discuss these features.…”