Bifloratoxin, a Toxic Aminoglycoside of Carboxyatractyligenin, From Melanthera biflora

Abstract

The structure of the toxic kaurene aminoglycoside bifloratoxin (3) from Melanthera biflora (L.) Willd ( syn. Wedelia biflora DC.) has been determined, and complete ¹H and ¹³C n.m.r. spectral assignments achieved. The aglycon unit of bifloratoxin (3) is identical to carboxyatractyligenin (11), the aglycon of carboxyatractyloside (8).