Chemical composition, phytotoxic and antibiofilm activity of Pinus canariensis, P. jeffreyi and P. taeda essential oils

This study aimed to investigate the chemical composition and some biological activities of the essential oils (EOs) from needles of Pinus canariensis, P. jeffreyi, and P. taeda cultivated in Tunisia. The chemical composition of the EOs revealed the presence of 119 components, with monoterpene hydrocarbons (in EOs of P. canariensis and P. taeda) and sesquiterpene hydrocarbons (in P. jeffreyi EO) being the main chemical classes. The EOs showed significant inhibitory effects on the germination and seedling and radical growth of the weeds, Sinapis arvensis, Lolium rigidum, and Trifolium campestre. The EO of P. jeffreyi exhibited the highest phytotoxicity, while T. campestre was the most tolerant seed. The EOs showed antibiofilm activity against Gram-positive (Staphylococcus aureus and Listeria monocytogenes) and Gram-negative (Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli) pathogenic bacterial strains, depending on the EO, and the concentration tested. Overall, the EOs displayed efficacy against mature biofilms and were effective also against the metabolism of the sessile cells in the biofilm. These findings provide valuable insights into the potential applications of these EOs in phytotoxic and antibiofilm strategies, for agriculture, food and pharmaceutical fields.