Using a high throughput colorimetric bioassay three aporphine alkaloids, annonaine, nornuciferine and roemerine, were isolated and identified as the CD45 protein tyrosine phosphatase inhibitor metabolites of Rollinia ulei. The nor-aporphine alkaloids, anonaine (1) and nornuciferine (3), exhibited more potent inhibitory activity than that of the N-methylated alkaloid roemerin (2).