Antifungal potential and structure activity relationship of carrot seed constituents

The aim of this study was to evaluate in vitro antifungal potential of carrot seed extracts, its essential oil, different fractions, isolated compounds, and their derivatives against three phytopathogenic rice fungi (Fusarium moniliforme, Bipolaris oryzae, and Rhizoctonia solani) using poisoned food technique. Carrot seed essential oil was extracted using hydrodistillation method and extracts were prepared using different solvents viz. dichloromethane, hexane, and methanol. The pure compounds daucene, carotol, and daucol were isolated using column chromatography and derivatized using different reagents. The study demonstrated that antifungal potential of all tested compounds varied in a dose dependent manner. Structure activity relationship of isolated and derivatized compounds showed that polar moieties possessed more antifungal potential as compared to non-polar moieties. The results suggested that carrot seed methanol extract and carotol possessed strong antifungal potential as compared to other components tested. PRACTICAL APPLICATIONS: Phytopathogenic fungi are the major problems causing harmful damage to the rice crop. Only available control of these diseases is synthetic fungicides but their repeated use led to serious environmental issues, residual toxicity, and development of resistance. Therefore, it's better to find some natural alternatives. The current study was conducted to evaluate in vitro antifungal potential of carrot seed essential oil, its constituents and extracts against phytopathogenic fungi of rice. The methanol extract and carotol possessed highest antifungal potential which might be due to their polar nature. This information may add a new dimensions to biological activity of these natural molecules mainly in the field of agriculture as fungal diseases are found to be associated with major losses in agriculture. Hence these compounds can act as natural antifungal agents against rice fungi.