Chemotypic and Seasonal Variations in Essential Oils from Mespilodaphne cymbarum (Kunth) Trofimov and Their Antibacterial and Antibiofilm Activities

This study investigated the essential oils (EOs) from leaf, bark, and fruit of Mespilodaphne cymbarum (Kunth) Trofimov (Lauraceae), focusing on their chemical composition and antimicrobial and antibiofilm activities. EOs were extracted from plants collected in the Amazon during dry and flood seasons and analyzed by gas chromatography–mass spectrometry. Although chemical differences were evident among plant organs and chemotypes, the influence of seasonality was not pronounced. Fruit EO was dominated by α- and β-santalene and limonene. Bark EO was rich in phenylpropanoids, including methyl eugenol, myristicin, and elemicin. Leaf EO showed the greatest metabolic diversity, with chemotype-specific variations. Leaf and bark EOs demonstrated superior antibacterial and antibiofilm activities compared to fruit EO, especially against Gram-positive bacteria such as Staphylococcus epidermidis, Staphylococcus aureus, and Micrococcus luteus. Chemotype-1 leaf and bark EOs inhibited S. epidermidis biofilm formation, while chemotype-2 reduced bacterial growth. The leaf EOs from both chemotypes reduced bacterial growth against S. aureus, and bark EO decreased biofilm formation. All leaf and bark EOs showed antibiofilm activity against M. luteus. These findings highlight the potential of M. cymbarum EOs as natural sources of bioactive compounds and emphasize the importance of chemotype and plant organ selection for optimized applications.