The major toxic constituent of the plant, Wedeliaasperrima, is the diterpene aminoglycoside, wedeloside. MS and NMR analysis of the unusually substituted aminoglycosidic portion of wedeloside and comparison with synthetic analogues have permitted the assignment of its structure as a 2 - deoxy - 2 - (3 - methyl - 1 - oxobutyl)amino - 3 - 0 - (1 - oxo - 3 - phenylpropyl) - D - glucopyranoside, β-linked