Methoxy Chalcone Derivatives: Promising Antimicrobial Agents Against Phytopathogens

Area of Science:

• Organic Chemistry
• Agricultural Science
• Mycology
• Parasitology

Background:

• Chalcones are a class of natural products with diverse biological activities.
• Developing novel agrochemicals is crucial for sustainable agriculture and crop protection.
• Fungal and protozoal plant pathogens pose significant threats to crop yields worldwide.

Purpose of the Study:

• To synthesize and characterize methoxylated chalcone derivatives.
• To evaluate the antifungal, antibacterial, and antiprotozoal activities of these compounds.
• To identify promising candidates for agricultural fungicide development.

Main Methods:

• Synthesis of chalcone and 14 methoxylated derivatives via Claisen-Schmidt aldol condensation.
• Characterization using FTIR, CG/MS/DIC, NMR (1D and 2D), and EMAR techniques.
• Biological activity screening against Sclerotium sp., Macrophomina phaesolina, Colletotrichum gloeosporioides, Acidovorax citrulli, and Phytomonas serpens.

Main Results:

• Unmodified chalcone (CH0) and derivatives CH1, CH2, and CH8 exhibited significant antifungal activity.
• CH0 showed potent activity against C. gloeosporioides (IC50 = 47.3 μM), disrupting hyphal cell membrane integrity.
• CH2, CH3, CH5, and CH14 demonstrated high antiprotozoal activity against P. serpens (IC50 values ranging from 0.98 to 10.25 μM).

Conclusions:

• Methoxylated chalcone derivatives, particularly CH2, show promise as agricultural fungicides.
• Unmodified chalcone and derivatives with specific methoxylation patterns are effective against key agricultural fungi.
• The study highlights the potential of chalcone derivatives in controlling plant pathogenic fungi and phytoparasites.