Bioactive Ag() coordination complexes as dopants for castor oil plasticized ethylcellulose films

• Published in: Dalton transactions : an international journal of inorganic chemistry 2024-10, Vol.53 (38), p.15992-164
• Main Authors: Scarpelli, Francesca, Crispini, Alessandra, Aiello, Iolinda, Godbert, Nicolas, Marchetti, Fabio, Xhafa, Sonila, De Filpo, Giovanni, Baratta, Mariafrancesca, Berardi, Riccardo, Alfano, Pasquale, Giorno, Eugenia
• Format: Article
• Language: English
• Subjects: Acetic acid; Biological activity; Biopolymers; Castor oil; Coordination compounds; Distilled water; E coli; Ethanol; Ethyl cellulose; Food packaging; Imidazole; Low concentrations; Molecular chains; Molecular structure; Plasticizers; Polymer films; Polymers; Single crystals; Thin films
• ISSN: 1477-9226; 1477-9234; 1477-9234
• DOI: 10.1039/d4dt02201g

The effects exerted by new bioactive acylpyrazolonate Ag( i ) derivatives of the general formula [Ag(Q Py,CF3 )(R-Im)] containing different substituents on the imidazole (R-Im) ancillary ligands and the natural plasticizer castor oil when both are added to the ethylcellulose (EC) biopolymer in the preparation of thin films as potential active food packaging materials are presented. The Ag( i ) complexes [Ag(Q Py,CF3 )(Bn-Im)] and [Ag(Q Py,CF3 )(Bu-Im)] , having benzyl and butyl substituents, whose single crystal molecular structures are reported, have proved to be highly compatible for efficient incorporation between the EC polymer and the hydrophobic plasticizer chains, giving rise, even at low concentrations, to homogeneous, robust and elastic films. The concomitant presence of these Ag( i ) complexes and castor oil in the polymer EC matrix gives rise to thin films with improved antibacterial activity against Escherichia coli ( E. coli ) as a model of Gram-negative bacterial strains when compared to the non-plasticized ones, with very low Ag( i ) migration in the three food simulants used (distilled water, ethanol 10% v/v and acetic acid 3% v/v) under two assay conditions (70 °C for 2 h and 40 °C for 10 days). New ethylcellulose films doped with bioactive Ag( i ) complexes and a natural plasticizer are prepared and characterized. Their antibacterial activity makes them potential active food packaging materials.