Copper(II) and Cobalt(II) Complexes Based on Abietate Ligands from Pinus Resin: Synthesis, Characterization and Their Antibacterial and Antiviral Activity against SARS-CoV-2

Jamille de S Correa; Julia de O Primo; Nayara Balaba; Christoph Pratsch; Stephan Werner; Henrique E Toma; Fauze J Anaissi; Ruddy Wattiez; Cristina M Zanette; Rob C A Onderwater; Carla Bittencourt

doi:10.3390/nano13071202

Copper(II) and Cobalt(II) Complexes Based on Abietate Ligands from Pinus Resin: Synthesis, Characterization and Their Antibacterial and Antiviral Activity against SARS-CoV-2

Nanomaterials (Basel). 2023 Mar 28;13(7):1202. doi: 10.3390/nano13071202.

Affiliations

¹ Departament of Chemistry, Universidade Estadual do Centro-Oeste, UNICENTRO, Alameda Elio Antonio Dalla Vecchia, 838, Guarapuava 85040-167, PR, Brazil.
² Department X-ray Microscopy, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin, Germany.
³ Institute of Chemistry, University of São Paulo, São Paulo 05508-000, SP, Brazil.
⁴ Department of Chemistry, University of Mons, Place du Parc 23, 7000 Mons, Belgium.
⁵ Department of Food Engineering, Universidade Estadual do Centro-Oeste, UNICENTRO, Alameda Elio Antonio Dalla Vecchia, 838, Guarapuava 85040-167, PR, Brazil.
⁶ Materia Nova ASBL, 7000 Mons, Belgium.

Abstract

Co-abietate and Cu-abietate complexes were obtained by a low-cost and eco-friendly route. The synthesis process used Pinus elliottii resin and an aqueous solution of CuSO₄/CoSO₄ at a mild temperature (80 °C) without organic solvents. The obtained complexes are functional pigments for commercial architectural paints with antipathogenic activity. The pigments were characterized by Fourier-transform infrared spectroscopy (FTIR), mass spectrometry (MS), thermogravimetry (TG), near-edge X-ray absorption fine structure (NEXAFS), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and colorimetric analysis. In addition, the antibacterial efficiency was evaluated using the minimum inhibitory concentration (MIC) test, and the antiviral tests followed an adaptation of the ISO 21702:2019 guideline. Finally, virus inactivation was measured using the RT-PCR protocol using 10% (w/w) of abietate complex in commercial white paint. The Co-abietate and Cu-abietate showed inactivation of >4 log against SARS-CoV-2 and a MIC value of 4.50 µg·mL^-1 against both bacteria Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The results suggest that the obtained Co-abietate and Cu-abietate complexes could be applied as pigments in architectural paints for healthcare centers, homes, and public places.

Keywords: SARS-CoV-2; abietic acid; antimicrobial pigments; antiviral surfaces; natural resin.

Grants and funding

J.d.S.C. appreciates the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES) (88882.429761/2019-01) for a graduate scholarship and the FNRS for mobility grant. F.J.A. is thankful for a CNPq Productivity grant (308625/2019-6) and the grants CNPq-427127/2018-1 and Fundação Araucária—CBPA-001/2016. CB is a Research Associate of the National Funds for Scientific Research (FRS-FNRS, Belgium).