Spectamines A and B, Possible Inhibitors of Superoxide Anion Production of Macrophages from Cassia spectabilis

Two novel piperidine alkaloids were isolated from an African legume, Cassia spectabilis, and identified as the O-benzoyl (1, named spectamine A) and ()-acetyl (2, named spectamine B) derivatives of (+)-iso-6-cassine (3). The absolute configurations of 1-3 were established to be (2R,3R,6R) using the modified Mosher's method. Compound (1) inhibited the superoxide anion production of macrophages, while it did not quench the superoxide anion which is produced by xanthine oxidase at a concentration of 25 μM.