Abstract
Microorganisms are able to give rise to biofilm formation on food matrixes and along food industry infrastructures or medical equipment. This growth may be reduced by the application of molecules preventing bacterial adhesion on these surfaces. A new Schiff base ligand, derivative of hesperetin, HABH (2-amino-N′-(2,3-dihydro-5,7-dihydroxy-2-(3-hydroxy-4-methoxyphenyl)chromen-4-ylidene)benzohydrazide), and its copper complex, CuHABH [CuLH2(OAc)], were designed, synthesized and analyzed in terms of their structure and physicochemical properties, and tested as antibacterial agents. Their structures both in a solid state and in solution were established using several methods: FT-IR, 1H NMR, 13C NMR, UV-Vis, FAB MS, EPR, ESI-MS and potentiometry. Coordination binding of the copper(II) complex dominating at the physiological pH region in the solution was found to be the same as that detected in the solid state. Furthermore, the interaction between the HABH and CuHABH with calf-thymus DNA (CT-DNA) were investigated. These interactions were tracked by UV-Vis, CD (circular dichroism) and spectrofluorimetry. The results indicate a stronger interaction of the CuHABH with the CT-DNA than the HABH. It can be assumed that the nature of the interactions is of the intercalating type, but in the high concentration range, the complex can bind to the DNA externally to phosphate residues or to a minor/major groove. The prepared compounds possess antibacterial and antibiofilm activities against Gram-positive and Gram-negative bacteria. Their antagonistic activity depends on the factor-strain test system. The glass was selected as a model surface for the experiments on antibiofilm activity. The adhesion of bacterial cells to the glass surface in the presence of the compounds was traced by luminometry and the best antiadhesive action against both bacterial strains was detected for the CuHABH complex. This molecule may play a crucial role in disrupting exopolymers (DNA/proteins) in biofilm formation and can be used to prevent bacterial adhesion especially on glass equipment.
Highlights
Introduction distributed under the terms andDiverse microorganisms are able to grow on food matrixes and along food industry infrastructures and this growth may give rise to biofilms [1]
The strong bands of high intensity observed at 1630 cm−1, 1609 cm−1 and 1253 cm−1 were due to the carbonyl function ν(C=O), azomethine function ν(C=N) and phenolic function(C–O), respectively
As the decrease in the strength of the electronic interaction was expected as the cube of the distance between the chromophore and the DNA bases [62], the observed large hypochromism in our experiment strongly suggests a close adjacency of the HABH and especially the CuHABH to the
Summary
Introduction distributed under the terms andDiverse microorganisms are able to grow on food matrixes and along food industry infrastructures and this growth may give rise to biofilms [1]. Products, ready-to-eat foods or alimentary goods [1]. These human pathogens include, but are not limited to, Escherichia coli (which may include enterotoxic and even hemorrhagic strains), Listeria monocytogenes (a species ubiquitous in soil and water that can lead to abortion in pregnant women and other serious complications in children and the elderly), and Staphylococcus aureus (known to have numerous intestinal toxins) [1,2,3]. Biofilm formation represents a special mode of growth that renders microbial cells more resistant to antimicrobials enabling the pathogens to survive in hostile environments and to disperse and colonize new niches. Numerous studies have analyzed the possible relationship between biofilm formation and antimicrobial resistance [4,5,6]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
