Original Articles
Ramnath Prasanna, Mohamed Y. A
Abstract
Fungicidal chemicals in crude form have been in use for several decades worldwide. This study aims at evaluating the anti-fungal activity of several novel chiral Schiff bases 3 and their reduction products 4, which were derived from various salicylaldehydes 1 and naturally occurring amino acid L-valine 2, against plant and food pathogens. The anti-fungal activity was assessed in vitro using the Poisoned Food Technique. The studied Schiff base derivatives exerted potent anti-fungal activity even at 25 ppm concentration. Some Schiff base derivatives caused 100% inhibition of Rhizoctonia solani and Colletotrichum capsici, two plant fungal pathogens at 1000 ppm concentration. Even at 100 ppm concentration, many Schiff base derivatives caused potent % inhibition of four common plant fungal pathogens (Rhizoctonia solani, Colletotrichum capsici, Phyllosticta sp., and Curvularia lunata). Indeed, Schiff bases and their reduction products displayed differential anti-fungal activities. The minimum inhibitory concentration (MIC) values of the examined Schiff bases and their reduction products against the respective fungal pathogens were also determined. Our study also reveals that the studied Schiff bases and their reduction products display fungicidal efficacy against common food fungal pathogens including Rhizopus sp., Fusarium sp., Penicillium sp., and Botrytis cinerea at 50-100 ppm concentrations. Collectively, our study demonstrates that the studied Schiff bases and their reduction products possess fungicidal properties against several plant and food fungal pathogens at concentrations as low as 25-50 ppm, suggesting that such compounds can serve as broad-spectrum fungicidal agents for the control of common phytopathogenic fungi.