Abstract
Aspergillus favus (A. flavus) is a saprophytic fungus and a pathogen affecting several important foods and crops, including maize. A. flavus produces a toxic secondary metabolite called aflatoxin. Alpha-amylase (α-amylase), a hydrolytic enzyme produced by A. Flavus helps in the production of aflatoxin by hydrolysing the starch molecules in to simple sugars such as glucose and maltose. These simple sugars induce the production of aflatoxin. Inhibition of α-amylase has been proven as a potential way to reduce the production of aflatoxin. In the present study, we investigated the effect of selected carboxylic acid derivatives such as cinnamic acid (CA), 2, 4-dichlorophenoxyacetic acid (2,4-D), and 3-(4-hydroxyphenyl)-propionic acid (3,4-HPPA) on the fungal growth and for the α-amylase inhibitory activity. The binding potentials of these compounds with α-amylase have been confirmed by enzyme kinetics and isothermal titration calorimetry. Molecular docking and MD simulation studies were also performed to deduce the atomic level interaction between the protein and selected ligands. The results indicated that CA, 2,4-D and 3,4-HPPA can inhibit the fungal growth which could be partly due to the inhibition on fungal α-amylase activity.
Communicated by Ramaswamy H. Sarma
Acknowledgement
The authors acknowledge the Spices Board, Ministry of Commerce & Industry, Govt. of India (MKT-PD&R/0003/2021-MARKETING) for the research grant. The authors are also acknowledging the Laboratory for Structural Bioinformatics, RIKEN, Japan for extending computational resources. CR acknowledges the research associate fellowship from Department of Biotechnology, Govt. of India (DBT-RA/2022/January/N/1427).
Disclosure statement
No potential conflict of interest was reported by the authors.