A further minor alkaloid obtained from the stem, stem bark, root and root bark
of Cabucala fasciculata, isocarboxine B is an isomer of the preceding alkaloid. It
forms an amorphous powder which cannot be crystallized and has no definite
melting point. It is dextrorotatory with a specific rotation of [α]D + 53° (c 1.0,
CHC13). The structure given is based mainly upon spectroscopic evidence,
particularly the ultraviolet, NMR and mass spectra.
Titeux, Le Men-Olivier, LeMen, Phytochem., 14,565 (1975)