Molecular docking of potential antifungal compounds from Ulva fasciatamethanolic extract against Pseudopestalotiopsistheae

Abstract

Plant diseases caused by fungal pathogens significantly threaten global food security, accounting for nearly 40% of annual crop losses and incurring over US$220 billion in management costs worldwide. Among these, Pseudopestalotiopsistheae has emerged as notable phytopathogen in Sri Lanka, causing chlorosis in Solanum melongena. Its virulence is largely attributed to the secretion of pectinase enzymes, which degrade plant cell walls and facilitate host colonization. Excessive use of synthetic fungicides to manage such pathogens has led to environmental degradation, health risks, and the emergence of fungicide-resistant strains. Consequently, there is a growing interest in eco-friendly alternatives such as natural products derived from marine organisms. Marine macroalgae, particularly Ulva fasciata, commonly found in Thalpe reef, are known to produce a wide range of bioactive secondary metabolites with antifungal potential. In a previous study, methanolic extract of U. fasciata revealed numerous bioactive compounds with potential antifungal activity. The present studyaimed to evaluate the inhibitory potential of these compounds against the pectinase enzyme of P. theae using molecular docking, a powerful in silico approach for predicting interactions between small molecules and target proteins. The findings are expected to contribute to the development of sustainable, eco-friendly strategies for managing plant diseases, offering a cost-effective alternative to synthetic fungicides.This study highlights the potential of marine bioresources and computational tools in the discovery of novel antifungal agents targeting emerging phytopathogens.