Ligational, DFT modeling and biological properties of some new metal complexes with 3‐(bromoacetyl)coumarin and 1,10‐phenanthroline

Coumarin-transition metal complexes with biological activity: current trends and perspectives

Coumarin (2H-1-benzopyran-2-one) presents the fundamental structure of an enormous class of biologically active compounds of natural, semi-synthetic, and synthetic origin. Extensive efforts are continually being put into the research and development of coumarin derivatives with medicinal properties by the broad scientific community. Transition metal coordination compounds with potential biological activity are a "hot topic" in the modern search for novel drugs. Complexation with transition metals can enhance the physiological effect of a molecule, modify its safety profile, and even imbue it with novel attributes of interest in the fields of medicine and pharmacy. The present review aims to inform the reader of the latest developments in the search for coumarin transition metal complexes with biological activity, their potential applications, and structure-activity relationships, where such can be elucidated. Each section of the present review addresses a certain kind of biological activity (antiproliferative, antioxidant, antimicrobial, etc.), explores the most recent discoveries in the field, and, at the same time, tries to offer useful perspectives for potential future investigations.

Spectrophotometric determination of Zr(IV), Hg(II) and U(VI) in solution with their analytical applications: Structural characterization and molecular docking of the solid complexes

Spectrophotometry was used to determine trace amounts of Zirconium(IV), Mercury(II) and Uranium(VI) in environmental, biological, pharmaceutical and industrial samples. The determination depend on the complexation reactions between albendazole reagent and metal ions [Zr(IV), Hg(II) and U(VI)] at 555 nm, 485 nm and 510 nm, respectively. The experimental conditions were explored to reach the optimum conditions for albendazole-metal ions interaction, including detection of a suitable wavelength, medium (pH), reagent concentration, surfactants effect, reaction time and temperature. Under optimum conditions, the complexes displayed apparent molar absorptivities of 0.8350 × 10⁴, 0.6210 × 10⁴ and 0.7012 × 10⁴ L mol^-1 cm^-1; Sandell's sensitivity of 0.01092, 0.03230 and 0.03394 µg cm^-2 and with linearity ranges of 1.0-120.0, 3.0-200.0 and 1.0-150.0 µg mL^-1 for the developed methods, respectively. Furthermore, Elemental analysis, thermal analysis (TGA, DTG), IR, ¹HNMR, spectroscopies, electrical molar conductivity and magnetic moment measurements were used to determine the structures and characteristics of the complexes. A careful examination of the IR spectra revealed that the ligand interacted with all of the metal ions described as a bidentate via the oxygen of the carbonyl of the ester moiety and the nitrogen atom of the heterocyclic CN group. An octahedral geometry for Zr(IV), Hg(II) and U(VI) complexes has been postulated based on magnetic and electronic spectrum data. The band gap values indicated that these complexes were semi-conductors and belong to the same class of extremely effective solar materials. The albendazole ligand and its complexes have been biologically tested against a variety of bacterial and fungal strains, and molecular docking studies have been conducted to evaluate the optimal binding site and its inhibitory action.

3-(Bromoacetyl)coumarins: unraveling their synthesis, chemistry, and applications

This review emphasizes recent developments in synthetic routes of 3-(bromoacetyl)coumarin derivatives. Also, chemical reactions of 3-(bromoacetyl)coumarins as versatile building blocks in the preparation of critical polyfunctionalized heterocyclic systems and other industrially significant scaffolds are described. Recent advances of 3-(bromoacetyl)coumarins as attractive starting points towards a wide scale of five and six-membered heterocyclic systems such as thiophenes, imidazoles, pyrazoles, thiazoles, triazoles, pyrans, pyridines, thiadiazins as well as fused heterocyclic systems have been reported. Additionally, this review covers a wide range of analytical chemistry, fluorescent sensors, and biological applications of these moieties, covering the literature till May 2021.

Meloxicam and Study of Their Antimicrobial Effects against Phyto- and Human Pathogens

Recently, the design of new biological metal-ligand complexes has gained a special interest all over the world. In this research, new series of mixed ligand complexes from meloxicam (H₂mel) and glycine (Gly) were synthesized. Structures of the compounds were investigated employing elemental analyses, infrared, electronic absorption, ¹H NMR, thermal analyses, effective magnetic moment and conductivity. The estimated molar conductivity of the compounds in 1 × 10^-3 M DMF solution indicates the non-electrolyte existence of the examined complexes. Additionally, the effective magnetic moment values refer to the complexes found as octahedral molecular geometry. The data of the infrared spectra showed the chelation of H₂mel and Gly with metal ions from amide oxygen and nitrogen of the thyizol groups of H₂mel and through nitrogen of the amide group and oxygen of the carboxylic group for Gly. Thermal analyses indicated that the new complexes have good thermal stability and initially lose hydration water molecules followed by coordinated water molecules, Gly and H₂mel. The kinetic parameters were calculated graphically using Coats-Redfern and Horowitz-Metzeger methods at n = 1 and n ≠ 1. The density functional theory (DFT) calculations were performed at B3LYP levels. The optimized geometry of the ligand and its complexes were obtained based on the optimized structures. The data indicated that the complexes are soft with η value in the range 0.114 to 0.086, while η = 0.140 for free H₂mel. The new prepared complexes were investigated as antibacterial and antifungal agents against some phyto- and human pathogens and the minimum inhibitory concentration (MIC) data showed that complex (A) has the lowest MIC for Listeria and E. coli (10.8 µg/mL).