Alpha-guaiene isolated from patchouli oil exhibits antifungal activity against four pathogenic fungi [version 1; peer review: awaiting peer review]

Background The major component of patchouli oil, patchouli alcohol, is used as fixative and has antimicrobial activity. The function of other components, such as α-guaiene, remains unknown. Therefore, this study reports the antifungal activity of α-guaiene isolated from patchouli oil against for pathogenic fungi: Aspergillus niger, Candida albicans ATCC 7102, Microsporum gypseum ATCC 14683, and Trichophyton mentagrophytes ATCC 16404. Methods The material from fraction (249°C-254°C) had the highest α-guaiene. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined using the microdilution technique to evaluate antifungal activity, with n-hexane and medium serving as negative controls, and ketoconazole and fluconazole serving as positive controls. Results The results showed that the MIC value was determined at 45%, 50% for C. albicans, 55%, 60% for A. niger, 50%, 60% for M. gypseum, and 95%, 100% for T. mentagrophytes, respectively. Positive and medium controls demonstrated no microbial growth, whereas negative and growth controls revealed the presence of microorganisms. Fungus resistance to α-guaiene T. mentagrophytes exhibited the highest MIC value. Conclusions Overall, this study reveals that α-guaiene is a promising agent effective against the studied pathogenic fungi.