From the EtOAc extract of the latex of Jatropha gossypifolia (Euphorbi
aceae), the new cyclic octapeptide, cyclogossine B (1), was isolated t
ogether with the known cyclic heptapeptide cyclogossine A. The structu
re of 1 was elucidated by chemical degradation, mass spectrometry, and
homonuclear and heteronuclear NMR experiments.