Antimicrobial Activity of Cinnamomum cassia Essential Oil: Phytochemical Profiling, In Vitro Evaluation, and Molecular Docking
Asma Bouguerra, Asma Meziti, Hassina Guergour, Naouel Boussoualim, Imane Krache, Nadira Oukala, Amal Saidi, Daoud Harzallah, Shakilur Rahman, Hamdi Bendif, Gharieb S. El‐Sayyad, Stefania GarzoliABSTRACT
In this study, Cinnamomum cassia bark essential oil (CEO) was extracted with a yield of 2.51% and characterised by its organoleptic properties, physicochemical characteristics, and gas chromatography–mass spectrometry (GC–MS) profiling. Seven phytoconstituents were identified, with (E)‐cinnamaldehyde predominating (87.14%). CEO inhibited Staphylococcus aureus ATCC 25923 , Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 27853, with inhibition zones of 16.0 ± 1.0–47.0 ± 1.0 mm. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values ranged from 0.52–1.04 and 0.52–2.08 mg/mL, respectively, with greater susceptibility observed among the gram‐positive strains. Antifungal evaluation revealed potent activity against Alternaria alternata and moderate activity against Aspergillus niger , with direct‐contact exposure showing greater inhibition of As. niger than vapour‐phase treatment. Molecular docking identified coumarin, a minor constituent, as exhibiting the strongest predicted binding, with binding energies of −7.7 kcal/mol against the bacterial targets TEM‐1 β‐lactamase and D‐alanine:D‐alanine ligase, and −7.0 kcal/mol against tyrosyl‐tRNA synthetase. Coumarin also showed favorable predicted binding to the fungal targets cytochrome P450 51B (CYP51B) and epoxide hydrolase. These findings support the potential of CEO as a natural antimicrobial preservative, although further validation in real food systems is required.