Antifungal Potential of Essential Oil Chemotypes of Eugenia uniflora Against Phytopathogens.

This study investigated the chemical composition and antifungal activity of essential oils (EOs) from five chemotypes of Eugenia uniflora (E. uniflora) collected in the state of Rio de Janeiro, Brazil. GC-FID and GC-MS analyses revealed major compounds such as curzerene, selina-1,3,7(11)-trien-8-one, its epoxide, and spathulenol, indicating significant chemical variability. In vitro assays demonstrated that EOs from selected chemotypes exhibited strong inhibitory effects against the phytopathogens Colletotrichum gloeosporioides and Pestalotia sp., with inhibition rates comparable to the fungicide tebuconazole. IC₅₀ values ranged from 0.01 to 0.09 mg mL⁻¹. These findings reinforce the potential of E. uniflora as a natural source of bioactive compounds and support further exploration of its EOs for sustainable plant disease management. The observed intraspecific chemical diversity may influence biological effects and highlights the importance of chemotype selection in the development of botanical fungicides.