1996 Volume 49 Issue 2 Pages 124-128
The novel calcineurin inhibitor, dibefurin, has been isolated from the fungal culture AB 16501-759. The isolation was bioactivity-directed fractionation using an assay which measures the phosphatase activity of calcineurin. The compound was purified by countercurrent, reverse phase and gel filtration chromatographics. Several studies, including crystallographic, NMR and MS, revealed that dibefurin is a novel dimeric compound of a unique structural type.