Molecular docking-based identification of betel leaf bioactive compounds as potential cutinase inhibitors of Colletotrichum gloeosporioides.

Abstract

Anthracnose, caused by Colletotrichum gloeosporioides, is a major disease affecting horticultural crops because it can significantly reduce both the quality and quantity of harvested products. Cutinase plays a crucial role in the early stages of infection by enabling the pathogen to penetrate the plant cuticle, which serves as the first line of host defense. This study aimed to evaluate the potential of bioactive compounds from betel as inhibitors of C. gloeosporioides cutinase using molecular docking. A total of nine compounds were analyzed through PASS biological activity prediction, ADMET-based physicochemical and toxicity assessment, and molecular docking simulations. The PASS analysis revealed that all compounds had higher probability of activity (Pa) values than probability of inactivity (Pi) values, indicating potential antifungal activity. Among the tested compounds, β-sitosterol exhibited the highest Pa value (0.585) and the strongest binding affinity toward cutinase, with a binding energy of −7.1 kcal/mol and an inhibition constant (Ki) of 6.20 µM. These values were superior to those of the co-crystallized ligand (−4.8 kcal/mol; Ki = 301.60 µM) and the reference fungicide mancozeb (−3.2 kcal/mol; Ki = 4497.40 µM). Piperine and piperlonguminine also demonstrated strong binding affinities, with binding energies of −6.7 and −6.5 kcal/mol, respectively. The stability of the β-sitosterol–cutinase complex was primarily supported by hydrophobic and van der Waals interactions with key residues within the enzyme’s active site. Based on the in-silico analysis, β-sitosterol demonstrated the greatest potential as an inhibitor candidate among the compounds tested. However, these findings are predictive and require further validation through in vitro and in vivo studies to confirm its biological activity, efficacy, and safety.