Synthesis and anticancer activity of epipolythiodiketopiperazine alkaloids

The epipolythiodiketopiperazine (ETP) alkaloids are a highly complex class of natural products with potent anticancer activity. Herein, we report the application of a flexible and scalable synthesis, allowing the construction of dozens of ETP derivatives. The evaluation of these compounds against cancer cell lines in culture allows for the first expansive structure–activity relationship (SAR) to be defined for monomeric and dimeric ETP-containing natural products and their synthetic cognates. Many ETP derivatives demonstrate potent anticancer activity across a broad range of cancer cell lines and kill cancer cells via induction of apoptosis. Several traits that bode well for the translational potential of the ETP class of natural products include concise and efficient synthetic access, potent induction of apoptotic cell death, activity against a wide range of cancer types, and a broad tolerance for modifications at multiple sites that should facilitate small-molecule drug development, mechanistic studies, and evaluation in vivo.National Institute of General Medical Sciences (U.S.) (Grant GM089732)American Society for Engineering Education. National Defense Science and Engineering Graduate FellowshipCamille & Henry Dreyfus Foundation. Teacher-Scholar Awards Progra

Inhibition of renin secretion by platelet activating factor (acetylglyceryl ether phosphorylcholine) in cultured rat renal juxtaglomerular cells

Acetylglyceryl ether phosphorylcholine (AGEPC), commonly known as platelet activating factor, was found to strongly inhibit renin secretion in cultures rich in juxtaglomerular cells. This inhibitory action of AGEPC was accompanied by an enhanced calcium permeability of the cell membrane as evaluated from measurements of the uptake of 45Ca. Simultaneous addition of the calcium channel blocker verapamil abolished the effects of AGEPC on both renin secretion and calcium permeability. Furthermore, addition of AGEPC to the cell cultures led to a decrease of 32P-labeled phosphatidylinositol 4,5-bisphosphate and to an increase in 3H-labeled diacylglycerol, indicating an activation of phospholipase C by AGEPC