Chemical Composition and Antifungal Evaluation of Essential Oil From Fresh Leaves of Myrcia spectabilis DC Against Candida spp. and Pichia kudriavzevii.

Fungal species of the genus Candida are commensal in immunocompetent individuals but may become pathogenic under immunosuppressive conditions. Likewise, Pichia kudriavzevii has emerged as an opportunistic yeast associated with nosocomial infections, especially in immunocompromised patients. The increasing resistance to conventional antifungal agents has stimulated the search for alternative therapies, including essential oils. This study investigated the chemical composition and antifungal activity of the essential oil from fresh leaves of Myrcia spectabilis (EOFLMS) against Candida spp. and P. kudriavzevii. The oil was obtained by hydrodistillation and analyzed by GC-MS, revealing a predominance of sesquiterpenes, mainly germacrene B, germacrene D, bicyclogermacrene, α-cadinol, cis-cadin-4-en-7-ol, and cubeban-11-ol. Antifungal activity was evaluated through fungal growth curves, IC50, Minimum fungicidal concentration (MFC), and pleomorphism assays. EOFLMS alone showed moderate activity, especially against Candida albicans, reducing fungal growth by 99.25% (IC50 = 1215 µg/mL). In combination with fluconazole, EOFLMS enhanced antifungal activity against C. albicans and Candida tropicalis, with IC50 values of 22.91 and 12.38 µg/mL, respectively. EOFLMS also inhibited hyphal and pseudohyphal formation, suggesting interference with fungal virulence factors.