Bioguided Fractionation of Citrullus colocynthis Extracts and Antifungal Activity Against Fusarium oxysporum f.sp. albedinis

Abstract

Background: In the present study, a bioguided fractionation was realized to isolate bioactive compounds on Fusarium oxysporum f.sp. albedinis (Foa) from Citrullus colocynthis L. Foa is the causal agent of “ Bayoud”, a lethal disease of date palm. Methods: Extracts of Citrullus colocynthis fruits peels using four solvents (n-hexane, dichloromethane, ethanol, chloroform) were tested for antifungal effect on Foa with radial growth technique. The ethanolic extract was selected for fractionation to isolate bioactive compounds (Percentage of Growth Reduction “PGR”: 63.6%). The fractionation was realized using six solvents (hexane, dichloromethane, ethyl acetate, methanol, butanol, water). Through fractionation, methanolic and butanolic fractions (PGR= 57.6% and 69.7%, respectively) had been chosen for bioactive compounds isolation. Results: Chromatographic and spectroscopic analyses had led to isolation of six compounds deduced as: (C1): 2-O-β-D-glucopyranosylcucurbitacin E; (C2): 2-(Nonan-8-one)-(1H)-4-quinolone; (C3): 2- (Nonan-8-one) 4-methoxy-quinoline, (C4): Isosaponarin; (C5): Isovitexin; (C6): Isoorientin 3’-Omethyl ether. The isolated compounds had been tested for antifungal effect. The compound (C1) represents the best effect among isolated compounds (PGR, up to 54.5%). Conclusion: The efficiency of (C1) reflects its opportunity to be used for the development of efficient treatment against Bayoud disease.