Chemical characterization and antifungal potential of Trigonella foenum-graecum L. followed by molecular docking studies

The present study involves the chemical characterization and antifungal potential of fenugreek Trigonella foenum-graecum L. (fenugreek) seeds/leaves essential oils and their major constituents along with computational molecular docking calculations. The fenugreek seeds and leaves essential oils were extracted by hydro-distillation and characterized by Gas chromatography-mass spectrometry and Gas chromatography-flame ionization detector. Benzyl acetate (51.70%) and gamma-tocopherol (42.09%), the major compounds in fenugreek seeds and leaves essential oils respectively were isolated by column chromatography. The essential oils and their major compounds were investigated for their antifungal activity against Rhizoctonia solani and Drechslera oryzae by the Poison food technique. Among all the treatments, fenugreek leaves essential oil was the most effective with ED50 values of 850 and 1120 ppm against R. solani and D. oryzae respectively. All the treatments were found more effective against R. solani than D. oryzae. Molecular docking studies of the major compounds present in the essential oils against R. solani agglutinin (PDB ID 4G9N and 4G9M) suggested that 9,19-cyclolanost-24-en-3-ol present in abundance in fenugreek leaves essential oil than the seeds essential oil bound effectively with the targeted protein with the docking score of -6.14 kcal mol(-1). Overall, our combined experimental and computational study provides scientific justification for the use of fenugreek leaves essential oil as a natural antifungal agent against R. solani. Moreover, fenugreek leaves essential oil being most effective against D. oryzae may also be used as a natural antifungal agent against it.