Four new alkaloids, nauclealines A (1) and B (2) and naucleosides A (3) and
B (4), together with six known compounds, strictosamide (5), vincosamide (
6), pumiloside (7), kelampayoside A, sitosterol, and sitosteryl beta -D-glu
coside, were isolated from the bark of Nauclea orientalis. The structures o
f 1-4 were elucidated using 1D and 2D NMR spectral methods, including COSY,
DEPT, HMQC, C-13-H-1 HMBC, and N-15-H-1 HMBC.