Two Chroman Type Polyketides From Trichoderma sp. YUD24002 Associated With Aconitum

Area of Science:

• Natural Product Chemistry
• Mycology
• Plant Pathology

Background:

• Endophytic fungi, such as Trichoderma sp., are a rich source of novel bioactive compounds.
• The plant Aconitum forrestii Stapf. hosts various microorganisms, including endophytic fungi.
• Polyketides represent a diverse class of natural products with varied biological activities.

Purpose of the Study:

• To isolate and characterize new chroman-type polyketides from the endophytic fungus Trichoderma sp. YUD24002.
• To evaluate the antifungal potential of the isolated compounds against phytopathogenic fungi.

Main Methods:

• Isolation and purification of compounds using chromatographic techniques.
• Structure elucidation employing Nuclear Magnetic Resonance (NMR) and High-Resolution Electrospray Ionization Mass Spectrometry (HR-ESI-MS).
• Determination of absolute configurations via Time-Dependent Density Functional Theory Electronic Circular Dichroism (TDDFT ECD) calculations and Mosher's methods.

Main Results:

• Two new chroman-type polyketides, trichrontides A (1) and B (2), were identified.
• Four known homologous compounds were also isolated.
• Trichrontide A (1) displayed significant antifungal activity against Alternaria panax (MIC = 16 µg/mL).
• Trichrontide B (2) showed evident antifungal activity against Epicoccum nigrum (MIC = 32 µg/mL).

Conclusions:

• The endophytic fungus Trichoderma sp. YUD24002 produces novel chroman-type polyketides.
• Trichrontides A and B possess notable antifungal properties, suggesting potential applications in agriculture.
• Further investigation into the mechanism of action and broader spectrum activity is warranted.