NMR spectral assignments of three aspidofractinine alkaloids, kopsine, fruticosine and fruticosamine.

1D and 2D NMR techniques were used to assign fully the spectra of three aspidofractinine alkaloids, kopsine (1), fruticosamine (2) and fruticosine (3), isolated from a cultivated specimen of the plant Kopsia fruticosa (Apocynaceae). The assignment of the NMR data for 1, 2 and 3 will help in the future assignments of related alkaloids.
(Copyright 2005 John Wiley & Sons, Ltd.)