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The beneficial effect of polyphenols and magnesium­(II) against oxidative stress motivated our research group to explore the antioxidant activity of phenMgIso, an aqueous soluble magnesium­(II) complex containing 1,10-phenanthroline (phen) and isovanillic acid (Iso) as ligands. Combined electrospray ionization–mass spectrometry and DOSY-NMR techniques identified two complexes in methanolic solution: hexacoordinated [Mg­(phen)2(Iso)]+ and tetracoordinated [Mg­(phen)­(Iso)]+. The cyclic voltammogram of phenMgIso in the anodic region showed a cyclic process that interrupts the isovanillic acid degradation, probably by stabilization of the corresponding phenoxyl radical via complexation with Mg­(II), which is interesting for antioxidant applications. phenMgIso competes with 2,2,6,6-tetramethylpiperidine by 1O2 with IC50(1O2) = 15 μg m–1 and with nitrotetrazolium blue chloride by superoxide ions (IC50(O2 •–) = 3.6 μg mL–1). Exposure of both zebrafish (2 mg L–1) and wistar male rats (3 mg kg–1 day–1 dose for 21 days) to phenMgIso does not cause mortality or visual changes compared with the respective control groups, thus phenMgIso could be considered safe under the conditions of this study. Moreover, no significant changes in comparison to both control groups were observed in the biochemical parameters on the brain-acetylcholinesterase activity, digestive tract enzyme catalase, and glutathione-S-transferase. Conversely, the performance of superoxide dismutase activity in wistar male rats increased in the presence of a complex, resulting in enhanced capacity of rats for superoxide radical enzymatic scavenging. The synergistic action of phenMgIso may be explained by the strong electrostatic interaction between Mg­(II) and the O,O­(phenolate) group, which makes the Iso ligand easier to oxidize and deprotonate, generating a cyclic stable species under oxidative conditions.

Storing fresh meat in a cold storage cabinet offers a simple, cost-effective solution to ensure safer and fresher food, satisfying the increasing demand for ready-to-use products. However, lipid oxidation is a limiting factor for longer shelf life. This study explores the potential of a nontoxic Mg­(II) containing isovanillate anion complex (Mg–Iso) to inhibit oxidative deterioration in minces of porcine muscles (longissimus lumborum and psoas major). The Mg–Iso complex decreased the consumption of oxygen by longissimus lumborum and psoas major by 44 and 57%, respectively, within a time interval of 170 min under ambient conditions. The complex also inhibited propagation of lipid peroxidation from preformed initiators in minces of porcine muscles for at least 14 days in the dark in an accelerated stability experiment at 70 °C. Computational calculations were used to provided further insight into the free-radical mechanism to explain the scavenging of radicals in porcine muscles. The mode of action, demonstrated by DFT, showed a preference for hydrogen atom transfer since the BDE value of 82 kcal mol–1 is lower than the IP value (220 kcal mol–1).

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This study describes the synthesis and characterization of the photoluminescent and water‐soluble complex cis‐[Ru(phen)2(2Apy)]2+ (Ru2Apy, phen=1,10‐phenanthroline and 2Apy=2‐aminopyridine), which exhibits spectroscopic and physicochemical properties favorable for biological applications. 1H‐NMR, photoluminescence, and UV‐vis spectroscopy experiments show bidentate coordination of the 2Apy ligand, which leads to a blue shift in the emission spectrum and places the 3MLCT in proximity to the 3MC excited states, thus enabling a photochemical pathway. Under continuous light irradiation at 450 nm, Ru2Apy opens the coordinating site of the NH2 group in 2Apy to form the monoacetonitrile complex cis‐[Ru(phen)2(2Apy)(CH3CN))2+, with a quantum yield of 0.457. Further irradiation leads to a second photoprocess to form the bis‐acetonitrile cis‐[Ru(phen)2(CH3CN)2]2+ complex, with a quantum yield of 0.002. Ru2Apy binds to human serum albumin via non‐covalent interactions with Kb=4.63×10−9 mol L−1, ΔH=−3.4×10−3 kcal mol−1, and ΔS=8.7 kcal mol−1K−1, and displays a moderate inhibition of AChE with an IC50 of 13.2±2.0 μmol L−1. The complex also exhibited high uptake into HeLa cells with no cytotoxicity. Furthermore, the emissive response of Ru2Apy was be used to assess, in real‐time, the aggregation of Aβ1–40 in a dose‐dependent manner.

This study reports the photochemical behavior of fac-[Mn-(phen)CO 3 (4MeImH)] + in neutral aqueous solution. The complex presents two 4MeImH linkage isomers, adjacent (A) and remote (R), which coexist in solution although with marked stability differences. In water, the steric effect converts A into an aqua-complex while R remains stable. Photolysis of the mixture followed by UV-vis, infrared (IR), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), and cyclic voltammetry showed changes in the coordination sphere and oxidation state of each Mn center. Upon light irradiation, the mixture behaves as an antenna system to absorb light, producing the {Mn(II)(phen *À )} + moieties and releasing CO, which provides open sites for water coordination. Upon successive irradiation, the EPR spectra showed an increasing signal at g = 2.0 corresponding to Mn(II) centers, a phenanthroline anion (2.0046) that vanishes at longer irradiation time, and an increasing component (g x ∼ 9.85 and g y ∼ 3.9) corresponding to Mn(IV). This makes the spectroscopic properties, excited state character, and dynamics of fac-[Mn-(phen)(CO) 3 (4MeImH)] + significantly different from those of all manganese complexes studied so far.

Pesticides offer a simple, cost-effective solution to ensure food supplies for a growing world population. However, their environmental performance needs improvement if pesticides are to continue contributing importantly. This study explores the insecticidal potential of a magnesium (II) metal complex containing 1,10-phenanthroline and isovanillic acid (MgPhenIso) against leaf-cutting ant (Atta sexdens rubropilosa) and its symbiotic fungus (Leucoagaricus gongylophorus). The MgPhenIso complex is easy-to-prepare, stable in solid state and in aqueous solution, and resistant to sunlight irradiation. The insecticidal activity of MgPhenIso-containing bait against A. sexdens rubropilosa and L. gongylophorus showed a delayed action mode at 2 mg g-1 (100% kill, 6th day, S50=2b) and suppressed fungus development and growth. These results, together with earlier investigations on MgPhenIso regarding its absence of toxicity to Zebrafish and Wistar male rats, emphasize the potential of this complex as an environmentally friendly insecticide candidate.