Determination of antimicrobial and antimutagenic properties of some Schiff bases.

In this study, we aimed to investigate for the first time antimicrobial and antimutagenic activities new two Schiff bases, obtained from a primary amine (p-toluidine, o-toluidine) and an aldehyde (Helicin). Synthesized compounds characterized with elemental analysis, fourier transform infrared spectroscopy, ultraviolet-visible spectrophotometry. 1H-13C nuclear magnetic resonance spectroscopy. Antimutagenic activity was evaluated by micronuclei assay. Antimicrobial activity of Schiff bases have been demonstrated against pathogenic four Gram-positive bacteria (Staphylococcus aureus, Staphylococcus epidermis, Micrococcus luteus, Bacillus cereus) and four Gram-negative bacteria (Pseudumonas aeroginosa, Salmonella typhi H, Brucella abortus, Escherichia coli) and two yeasts (Candida albicans and Saccharomyces cerevisiae). The results showed that both Schiff bases have antimutagenic activity. Especially, high concentration (20 µM) of (E)-2-(hydroxymethyl)-6-(2-((p-tolylimino)methyl)phenoxy)tetrahydro-2H-pyran-3,4,5-triol (Compound I) and (E)-2-(hydroxymethyl)-6-(2-((o-tolylimino)methyl)phenoxy)tetrahydro-2H-pyran-3,4,5-triol (Compound II) have strong antimutagenic activity against aflatoxin B1. On the other hand, both of studied compounds were found effective against pathogenic bacteria and yeasts. Compound I exhibited more activity against P. aeroginosa, S aureus, S.typhi H and C. albicans comparable to Compound II and standard antibiotics. Additionally, Compound II showed better inhibitory activity than Compound I against Candida albicans and Br. Abortus. Therefore, these compounds can be used in phytotherapeutic due to theirs antimutagenic and antimicrobial activities.

Crystal structure and Hirshfeld surface analysis of 2,2'-{(1E,1'E)-[ethane-1,2-diylbis(aza-nylyl-idene)]bis-(methanylyl-idene)}bis-[4-(tri-fluoro-meth-oxy)phenol]copper(II) hydro-quinone hemisolvate.

In the title com-plex, [Cu(C18H12F6N2O4)]·0.5C6H6O2, the CuII ion has a square-planar coordination geometry, being ligated by two N and two O atoms of the tetra-dentate open-chain Schiff base ligand 6,6'-{(1E,1'E)-[ethane-1,2-diylbis(aza-nylyl-idene)]bis-(methanylyl-idene)}bis-[2-(tri-fluoro-meth-oxy)phenol]. The crystal packing is stabilized by intra-molecular O-H⋯O and inter-molecular C-H⋯F, C-H⋯O and C-H⋯π hydrogen bonds. In addition, weak π-π inter-actions form a three-dimensional structure. Hirshfeld surface analysis and two-dimensional fingerprint plots were performed and created to analyze the inter-molecular inter-actions present in the crystal, indicating that the most important contributions for the crystal packing are from F⋯H/H⋯F (25.7%), H⋯H (23.5%) and C⋯H/H⋯C (12.6%) inter-actions.

Crystal structure and Hirshfeld surfaces analysis of the nickel(II) complex of the Shiff base ligand 6,6'-{(1E,1'E)-[ethane-1,2-diylbis(aza-nylyl-idene)]bis-(methanylyl-idene)}bis-[2-(tri-fluoro-meth-oxy)phenol].

In the title complex, (6,6'-{(1E,1'E)-[ethane-1,2-diylbis(aza-nylyl-idene)]bis(methanylyl-idene)}bis-[2-(tri-fluoro-meth-oxy)phenol]-κ4 O,N,N',O')nickel(II), [Ni(C18H12F6N2O4)], the nickel(II) ion has a square-planar coordination sphere, being ligated by two N and two O atoms of the Schiff base ligand 6,6'-{(1E,1'E)-[ethane-1,2-diylbis(aza-nylyl-idene)]bis-(methanylyl-idene)}bis-[2-(tri-fluoro-meth-oxy)phenol] (L). Inversion-related mol-ecules are linked by a short Ni⋯Ni inter-action of 3.2945 (6) Šforming a dimer. In the crystal, the dimers stack up the a axis, with a closest Ni⋯Ni separation of ca 3.791 Å. There are no other significant inter-molecular inter-actions present. However, the Hirshfeld surface analysis and the two-dimensional fingerprint plots indicate that the packing is dominated by H⋯F/F⋯H, H⋯H, O⋯H/H⋯O and C⋯H/H⋯C contacts.

Crystal structure and Hirshfeld surface analysis of N,N'-[ethane-1,2-diylbis(-oxy)]bis-(4-methyl-benzene-sulfonamide).

In the mol-ecule of the title compound, C16H20N2O6S2, the mid-point of the C-C bond of the central ethane moiety is located on a twofold rotation axis. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds into supra-molecular chains propagating along the [101] direction. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H⋯H (43.1%), O⋯H/H⋯O (40.9%), C⋯H/H⋯C (8.8%) and C⋯C (5.5%) inter-actions.

Synthesis, anti-microbial and anti-mutagenic activities of some Schiff bases derivatives containing thiophene group.

The aim of this study is to investigate for the first time in vitro antimicrobial and antimutagenic activities of Schiff bases included the azomethine group. Antimutagenic activity was evaluated by micronucleus (MN) assay. These group have been examined for antibacterial activity against pathogenic strains, Staphylococcus aureus, Escherichia coli, Salmonella typhi H, Brucella abortus, Micrococcus luteus, Bacillus cereus, Pseudomonas aeroginosa and antifungal activity against Candida albicans and Saccharomyces cerevisiae. The results of MN showed that Schiff bases ((E)-N-(4-chlorophenyl)-1-(5-nitrothiophen-2-yl)methanimine ; (E)-N-(2,4-dichlorophenyl)-1-(5-nitrothiophen-2-yl) methanimine) different concentrations decreased the toxic effects of Aflatoxin B1. Especially, high concentration (20µM) of (E)-N-(4-chlorophenyl)-1-(5-nitrothiophen-2-yl)methanimine (compound 1) has strong antimutagenic activity. In our in vitro test systems, it was observed that Schiff bases had antimutagenic effects on human lymphocytes. On the other hand these compounds were also found to possess antimicrobial activity against some test bacteria and yeast. The antimicrobial test results of these Schiff bases included the azomethine group exhibited better activity than some known antibiotics. In particular, Compound 1 were more potent bactericides than all of the substances synthesized. In conclusion, this Schiff bases included the azomethine group can be use pharmacy industries as recognized with their noncytotoxic, antimicrobial and antimutagenic features.