Azaphilones from the endophyte Chaetomium globosum

Area of Science:

• Natural Product Chemistry
• Mycology
• Microbiology

Background:

• Endophytic fungi, such as Chaetomium globosum, are prolific sources of structurally diverse secondary metabolites.
• Azaphilones represent a class of fungal metabolites with potential biological activities.

Purpose of the Study:

• To isolate and characterize new azaphilone derivatives from Chaetomium globosum.
• To evaluate the antibiotic potential of isolated compounds.

Main Methods:

• Isolation of compounds using chromatographic techniques.
• Structure elucidation via Nuclear Magnetic Resonance (NMR) and Mass Spectrometry (MS).
• Confirmation of structure using single-crystal X-ray diffraction and determination of absolute configurations using Mosher's method.
• Antibiotic activity assessment in an in vivo Caenorhabditis elegans infection model.

Main Results:

• Six new azaphilones (5'-epichaetoviridin A, 4'-epichaetoviridin F, 12β-hydroxychaetoviridin C, and chaetoviridins G-I) and six known azaphilones (chaetoviridins A-E and 4'-epichaetoviridin A) were isolated.
• The structures and relative configurations were determined through comprehensive spectroscopic analyses.
• Absolute configurations of key compounds were established.
• Antibiotic activity was evaluated in a relevant biological model.

Conclusions:

• The endophytic fungus Chaetomium globosum produces a variety of azaphilone compounds.
• The isolated compounds represent potential candidates for further investigation as antibiotics.