Synthesis and FT-IR Characterization of a Novel Zinc(II) 3-Methoxybenzoate N,N′-Diethylnicotinamide Complex and Its Toxicological Effects on the Greater Wax Moth, Galleria mellonella

The greater wax moth, Galleria mellonella, is a major pest of stored honeycombs. In this study, a novel Zn(II) 3-methoxybenzoate N,N′-diethylnicotinamide complex (Zn 3MBA DENA) was synthesized and characterized by FT-IR spectroscopy and elemental analysis. The elemental composition and FT-IR spectral features were consistent with the proposed formulation of the Zn(II) complex and supported the coordination of the 3-methoxybenzoate ligand to the metal center. The effects of the Zn 3MBA DENA complex on antioxidant enzyme activities such as catalase (CAT), superoxide dismutase (SOD), and glutathione S-transferase (GST) in G. mellonella larvae were investigated. CAT activity increased significantly at 400 and 800 mg/L, peaking at 400 mg/L, while SOD and GST activities were significantly elevated only at 800 mg/L, indicating an enzyme-specific pattern of antioxidant and detoxification enzyme activation, with threshold-dependent induction of SOD and GST at the highest concentration. Molecular docking analyses showed that the complex forms favorable, low-energy interactions with the binding sites of CAT, SOD, and GST through hydrogen bonding, π-type, and hydrophobic contacts, providing mechanistic support for the observed biochemical changes. These findings demonstrate that the Zn 3MBA DENA complex alters key antioxidant and detoxification-related enzyme activities in G. mellonella in an enzyme-specific, concentration-related manner, identifying it as a candidate compound warranting further toxicological evaluation for potential application in moth management.