Obionin B: An o-pyranonaphthoquinone decaketide from an unidentified fungus (MSX 63619) from the Order Pleosporales

Tetrahedron Lett. 2011 Oct 5;52(40):5128-5230. doi: 10.1016/j.tetlet.2011.07.102.


A fungal extract (MSX 63619), from the Mycosynthetix library of over 50,000 fungi, displayed promising cytotoxicity against a human tumor cell panel. Bioactivity-directed fractionation led to the isolation of an o-pyranonaphthoquinone decaketide, which we termed obionin B (1). The structure of 1 was deduced via spectroscopic and spectrometric techniques. The IC(50) value of 1 was moderate, ranging from 3 to 13 μM, depending on the cell line tested.