Alpha-guaiene isolated from patchouli oil exhibits antifungal activity against four pathogenic fungi

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.

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.

The results showed that the MIC and MFC value were 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.

Overall, this study reveals that α-guaiene is a promising agent effective against the studied pathogenic fungi.