A Novel Azaphilone Muyophilone A From the Endophytic Fungus 0307-2.

Two known azaphilone derivatives, 4,6-dimethylcurvulinic acid () and austdiol (), and their novel heterotrimer, muyophilone A (), were isolated and identified from an endophytic fungus, 0307-2. Their structures and stereochemistry were established by extensive spectroscopic analyses including HRMS, NMR spectroscopy, electronic circular dichroism (ECD) and vibrational circular dichroism (VCD) spectroscopic methods, as well as single crystal X-ray diffraction. In the structure of , two compound -derived azaphilone units were connected through an unprecedented five-membered carbon bridge which was proposed to be originated from compound . Compound represents the first example of azaphilone heterotrimers.