17β-HYDROXY-16α-[125I]IODOWORTMANNIN, A SENSITIVE LABELING AGENT FOR PI 3-KINASES

To detect phosphatidylinositol (PI) 3-kinases with high sensitivity, we designed and prepared a radiolabeled derivative of wortmannin (1), a potent inhibitor of PI 3-kinases. The synthesized derivative, 17β-hydroxy-16α-[125I]iodowortmannin (7), showed an IC50 that was 100-fold higher than that of wortmannin itself and which bound to catalytic subunits of PI 3-kinases.