Intracellular effects of prodrug-like wortmannin probes

Wortmannin, a known inhibitor of phosphoinositide 3-kinases (PI3Ks), their low selectivity and high toxicity is still problematic and less is known about their effects on PI3Ks in cellular systems. Hence, we have synthesized a series of multifunctional wortmannin probes with the ability to self-activate, by installing a clickable handle at C11 site, and secondary amine and cancer-targeting moiety at C20 site, respectively. MTT assay first confirmed that self-activating probes have better inhibition potency and biotin enhanced their cancer cell uptake. Further experiments showed most of probes can target PI3K/Akt/mTOR pathway with prolonged turn-over time. Protein profiling and pull-down results were observed that the derivatives not only labelled four PI3Ks with selectivity, but also engaged in covalent interactions with numerous cellular proteins which could be the major reason of their high toxicity.