Synthesis and Structure–Activity Relationships of Ring-Opened 17-Hydroxywortmannins: Potent Phosphoinositide 3-Kinase Inhibitors with Improved Properties and Anticancer Efficacy

The phosphoinositide 3-kinase (PI3K) signaling pathway is frequently up-regulated in human cancer and is a promising target for the treatment of cancer. Wortmannin and its analogues are potent inhibitors of PI3K but suffer from inherent defects such as instability, insolubility, and toxicity. Opening of the reactive furan ring of 17-hydroxywortmannin with amines gives compounds with improved properties such as greater stability and aqueous solubility and a larger therapeutic index. Ring-opened analogues such as compound 13 containing basic amine groups have significantly increased PI3K inhibitory potency and greater efficacy in nude mouse xenograft assays.