Goldenrod Root Compounds Active against Crop Pathogenic Fungi

Area of Science:

• Phytochemistry
• Natural Product Chemistry
• Plant Science

Background:

• Goldenrod species (Solidago spp.) are known for their diverse secondary metabolites.
• Antimicrobial properties of plant extracts are of interest for various applications, including agriculture and medicine.
• Identifying novel bioactive compounds from plants is crucial for developing new therapeutic and crop protection agents.

Purpose of the Study:

• To screen root extracts of three goldenrod species for antimicrobial compounds.
• To identify and characterize specific antimicrobial compounds present in these goldenrod roots.
• To evaluate the antibacterial and antifungal activities of the isolated compounds.

Main Methods:

• High-performance thin-layer chromatography (HPTLC) combined with effect-directed analysis.
• Liquid chromatographic fractionation and isolation of compounds.
• High-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) spectroscopy for structural elucidation.
• Determination of half maximal inhibitory concentrations (IC50) against selected bacteria and fungi.

Main Results:

• Several matricaria esters were identified in European, grass-leaved, and showy goldenrod roots.
• These compounds exhibited antibacterial activity against Bacillus subtilis, Aliivibrio fischeri, and Pseudomonas syringae pv. maculicola.
• The identified esters also inhibited the crop pathogenic fungi Fusarium avenaceum and Bipolaris sorokiniana, with IC50 values ranging from 31 to 107 μg/mL.
• Benzyl 2-hydroxy-6-methoxybenzoate, a novel compound in showy goldenrod roots, demonstrated the strongest antifungal activity (IC50 of 25-26 μg/mL).

Conclusions:

• Root extracts of Solidago species contain bioactive compounds with significant antibacterial and antifungal properties.
• Matricaria esters and Benzyl 2-hydroxy-6-methoxybenzoate are key antimicrobial agents found in these goldenrod species.
• The findings suggest potential applications of these goldenrod-derived compounds in controlling plant pathogens and possibly in other antimicrobial uses.