From the CH2Cl2 extract of the root bark of Z. mucronata (Rhamnaceae),
a new cyclopeptide alkaloid, named mucronine J, was isolated together
with previously known alkaloids abyssenine A and mucronine D. The str
ucture of mucronine J was elucided by mass spectrometry and 1D and 2D
NMR. A solution conformation is proposed on the basis of NOE experimen
ts in combination with MM2 calculations.