Spectroscopic Analyses and Antimicrobial Activity of Novel Ciprofloxacin and 7-Hydroxy-4-methylcoumarin, the Plant-Based Natural Benzopyrone Derivative

Abstract

Coumarin is highly distributed in nature, notably in higher plants. The biological features of coumarin include antibacterial, anticancer and antioxidant effects. It is well known that metal ions present in complexes accelerate the drug action and the efficacy of organic therapeutic agents. The main aim of the current study is the synthesis of different complexes of the interaction between ciprofloxacin hydrochloride (CIP) and coumarin derivative 7-hydroxy-4-methylcoumarin (HMC) with Zr(IV). The chelates of CIP with Zr(IV) were prepared and characterized by elemental analysis, melting point, conductance measurements, spectroscopic techniques involving IR, UV-Vis, 1H NMR, and thermal behavior (TG-DTG) in the presence of HMC, dimethylformamide (DMF), pyridine (Py), and triethylamine (Et3N). Results of molar conductivity tests showed that the new synthesized complexes are electrolytes with a 1:1 or 1:2 electrolyte ratio, with the chloride ions functioning as counter ions. According to IR spectra, CIP acts as a neutral bidentate ligand with Zr(IV) through one carboxylato oxygen and the carbonyl group, HMC as a monodentate through the carbonyl group, and DMF through the oxygen atom of the carbonyl group and the N atom of Py and Et3N. The thermal behavior of the complexes was carefully investigated using TG and DTG techniques. TG findings signal that water molecules are found as hydrated and coordinated. The thermal decomposition mechanisms proposed for CIP, HMC, and Zr(IV) complexes are discussed and the activation energies (Ea), Gibbs free energies (∆G*), entropies (∆S*), and enthalpies (∆H*) of thermal decomposition reactions have been calculated using Coats–Redfern (CR) and Horowitz–Metzeger (HM) methods. The studied complexes were tested against some human pathogens and phytopathogens, including three Gram-positive bacteria (Bacillus subtilis, B. cereus, Brevibacterium otitidis) and three Gram-negative bacteria (Escherichiacoli, Pseudomonas aeruginosa and Klebsiella pneumoniae), and compared to the free CIP and HMC parent compounds.

A 7-Hydroxy 4-Methylcoumarin Enhances Melanogenesis in B16-F10 Melanoma Cells

“…Previous studies have shown that 7H-4M and its derivatives possess several biological properties. Known as a potent xanthine oxidase inhibitor, 7-hydroxy 4-methylcoumarin is effective in inhibiting both the settlement as well as the byssogenesis of mussels, modulating some of the effector functions of human neutrophils and exhibiting antioxidant activity [ 22 , 23 , 24 , 25 ]. We previously reported that 7H-4M alleviates the LPS-induced inflammatory response in RAW264.7 macrophage cells [ 26 ].…”

Umbelliferone and Its Synthetic Derivatives as Suitable Molecules for the Development of Agents with Biological Activities: A Review of Their Pharmacological and Therapeutic Potential

“…Sadeek et al demonstrated that compounds based on octahedral mixed-ligand complexes of Zr(IV) with ciprofloxacin hydrochloride as the primary ligand and 7-hydroxy-4-methylcoumarin as the secondary ligand with different coordination modes (CIP-HMC, Figure 23) possess promising biological activity against Gram-positive bacterial strains, including B. subtilis (MIC = 0.50-0.75 µg/mL) and B. cereus (MIC = 0.25-0.75 µg/mL), as well as Gram-negative bacterial strains, including P. aeruginosa (MIC = 0.50-1.0 µg/mL), K. pneumoniae (MIC = 0.50-1.0 µg/mL), and E. coli (MIC = 0.50-1.0 µg/mL), compared to the free ciprofloxacin (CP: G + ve bacterial strains MIC = 0.50 µg/mL, G − ve bacterial strains MIC = 0.5-0.75 µg/mL) and 7-hydroxy-4methylcoumarin (HMC: G + ve bacterial strains MIC = 0.25 µg/mL, G − ve bacterial strains MIC = 0.25-0.50 µg/mL). The chelation process accelerates the drug action, increasing the potency of both ciprofloxacin and coumarin molecules especially towards B. subtilis (diameter of inhibition zone: 48-66 mm vs. 18-26 mm) [103]. It should be mentioned that, in general, metal complexes are more active than their ligands and may serve as carriers to enhance the activity of ligands as the principal acting agents [101].…”

“…It should be mentioned that, in general, metal complexes are more active than their ligands and may serve as carriers to enhance the activity of ligands as the principal acting agents [101]. Thereby, these new Zr(IV) complexes build attractive molecules for further studies to determine the efficient concentrations of coumarin derivatives in the complexes and their mode of action [103].…”

Degradation of Aflatoxin B1 in Moldy Maize by Pseudomonas aeruginosa and Safety Evaluation of the Degradation Products

“…Pseudomonas aeruginosa is a gram-negative bacterium that is widely distributed in nature [ 19 ]. It requires simple nutrition for growth, has strong adaptability to the natural environment, and can produce substances that promote biodegradation [ 20 ].…”