Monasnicotinic acid, a novel pyridine alkaloid of the fungus Aspergillus cavernicola: isolation and structure elucidation

A novel pyridine alkaloid, monasnicotinic acid, was isolated from the culture liquid of the type strain of the fungus Aspergillus amylovorus (currently this species has been synonymized with Aspergillus cavernicola). The structure of monasnicotinic acid was established using mass spectrometry, multinuclear NMR spectroscopy and X-ray diffraction; its chemical properties were ascertained by ESI source H/D exchange (HDX) in negative and positive ion modes.