Computational investigation of the antifungal potential of phytochemicals in Senna Alata against six 1 and six 6 targets in Fusarium Oxysporum F. Sp. Lycopersici

Abstract

Background: Fusarium oxysporum f.sp.lycopersici is a pathogen, causing  Fusarium wilt; a major fungi infection of tomatoes in Nigeria. This soilborne pathogen has proved difficult to control due to its ability to produce chlamydospores in the soil and strong resistance to the environmental factors and chemical fungicides.  Several studies have confirmed the antifungal properties of Senna. alata extracts and the phytochemicals in the plant’s extracts against clinical pathogens and skin infections, but research data on its activities against plant pathogens are rare. Objectives: The aim of this study was to examine the potential antifungal property of S. alata phytochemicals against F. oxysporum sp.lycopersici through their binding interactions with SIX1 and SIX6 effector proteins, implicated as virulent agents in F. oxysporum sp.lycopersici . Methods: The study was carried out using computer-aided drug discovery/design (CADD). Results: XP docking analysis predicted six flavonoid derivatives as potential fungicides with probable better inhibitory interaction with the protein targets than the five standard antifungal agents used as controls. These hit compounds are kaempferol 3-gentiobioside (CID:9960512), kaempferol 3-o-beta-d-glucofuranoside (CID:72551445), astragalin (CID:5282102), thermopsoside (11294177), rhamnetin (CID: 5281691) and quercetin (CID: 5280343) with docking scores -9.257 & -8.772, -8.373 & -6.565, -7.919 & -6.398, -7.162 & -6.693, -5.318 and -5.403 Kcal/mol respectively. Their respective binding free energy (ΔG) are; -37.77 & -42.68, -50.61 & -27.75, -37.34 & -35.59, -37.57 & -34.5, -33.58 and -39.61 Kcal/mol.  The binding scores and ΔG values for the reference antifungal compounds; prothioconazole, prochloraz, bromuconazole, thiophanate-methyl and azoxystrobin, ranged from -4.069 to -1.309 Kcal/mol and -42.84 to -9.57 Kcal/mol respectively. Conclusion: The higher binding affinity of the six compounds than the reference chemical fungicides in this study suggests their better fungicidal potential, they are therefore recommended for further studies.

Keywords: Fusarium oxysporum f.sp.lycopersici, Senna Alata, fungicides, virulent, proteins