Abstract

Introduction: Myrceugenia exsucca O. Berg (‘pitra’), a South American plant used in traditional medicine, holds potential antimicrobial properties. Against the backdrop of rising drug resistance in candidiasis, a significant global health issue, this study aimed to determine the chemical composition of M exsucca essential oil (EO), evaluate its in vitro antifungal efficacy against clinical Candida species, and predict interactions with key virulence proteins (Als9-2, CYP51) using molecular docking. Methods: The EO from fresh leaves was obtained by hydrodistillation and analysed by Gas Chromatography-Mass Spectrometry (GC-MS). Antifungal activity (minimum inhibitory concentration/minimum fungicidal concentration) of the EO and its major constituents was assessed against five clinical Candida spp. using broth microdilution. Cell morphology was analysed by transmission electron microscopy. Molecular docking was performed with AutoDock using Protein Data Bank structures. Results: GC-MS analysis identified terpinen-4-ol (13.20%), ?-pinene (12.15%), (E)-nerolidol (11.32%), and caryophyllene oxide (10.54%) as major constituents. The EO, (E)-nerolidol, and caryophyllene oxide exhibited significant antifungal activity. (E)-nerolidol demonstrated potent fungicidal action, particularly against C guilliermondii (MFC 1 µg/ml). Transmission electron microscopy analysis confirmed that the EO and (E)-nerolidol destabilise the C albicans cell membrane. In silico, (E)-nerolidol showed the highest predicted binding affinity for both Als9-2 and CYP51. Conclusions: This first report on the EO of fresh M exsucca reveals significant anti-Candida activity, primarily attributed to (E)-nerolidol and caryophyllene oxide. Supported by in silico data, the EO is a promising source for developing novel therapeutic strategies against candidiasis. © 2025 Elsevier GmbH