Virtual Structural Similarity Elucidates Bioactivity of Fenchone: A Phytochemical Enriched in Fennel Essential Oil

Background: Fenchone is a natural monoterpene abundantly present in fennel essential oil. It is known for its wound healing properties but its other biological activities are less explored. Methods: We used an in silico structural similarity searching approache to identify various biological activities of fenchone. The identified biological activities of fenchone (purchased from Sigma Aldrich) were validated by conducting DPPH free radical scavenging assay, MTT assay, well diffusion assay for antimicrobial activity and enzymatic assays to analyze the activity of different antioxidant enzymes. Results: Camphor was found to possess maximum structural similarity with fenchone (similarityindex 100). Molecular docking demonstrated that the binding modes of fenchone were also similar to camphor against protein Cytochrome CYP101D1 (PDB ID: 4C9K). Fenchone also demonstrated to possess an antioxidant activity (IC50: 3.32±0.008mM), an antimicrobial activity (MIC: 0.49mM) and a very strong antifungal activity. Fenchone protects yeast cells from H2O2 induced cytotoxicity and is cytotoxic to cancerous Hela cells (IC50: 12.63±0.12 μM). Fenchone treatment also showed the reduced activity of antioxidant enzymes i.e glutathione-S-transferase, catalase and lipid peroxidase. Conclusion: To the best of our knowledge, this is the first report that used structural similarity searching to explore the biological activities of fenchone.