STRUCTURE AND ABSOLUTE STEREOCHEMISTRY OF FUSAPROLIFERIN, A TOXIC METABOLITE FROM FUSARIUM-PROLIFERATUM

Fusaproliferin is a toxic sesterterpene isolated from Fusarium prolife ratum, a widespread pathogen of cereals. Its absolute configuration ha s been determined by single crystal X-ray diffraction analysis. Fusapr oliferin is considered to be a sesterterpene with a new ring skeleton having four C=C double bonds and four chiral atoms. The configurations of the four chiral atoms C10, C14, C15, and C19 are (R), (S), (R), an d (S), respectively. In the solid state the macrolide shows a concave hydrophobic surface and hydrophilic convex face. The absolute configur ation of C14 and C15 is the same as that observed for retigeranic acid , consistent with fusaproliferin being formed via a sesterterpenic-typ e biosynthetic pathway.