Synthesis, Activity, and Pharmacophore Development for Isatin-Beta-Thiosemicarbazones With Selective Activity Toward Multidrug-Resistant Cells

Matthew D Hall, Noeris K Salam, Jennifer L Hellawell, Henry M Fales, Caroline B Kensler, Joseph A Ludwig, Gergely Szakács, David E Hibbs, Michael M Gottesman

J Med Chem. 2009 May 28;52(10):3191-204.

PMID: 19397322

Abstract:

We have recently identified a new class of compounds that selectively kill cells that express P-glycoprotein (P-gp, MDR1), the ATPase efflux pump that confers multidrug resistance on cancer cells. Several isatin-beta-thiosemicarbazones from our initial study have been validated and a range of analogues synthesized and tested. A number demonstrated improved MDR1-selective activity over the lead, NSC73306 (1). Pharmacophores for cytotoxicity and MDR1 selectivity were generated to delineate the structural features required for activity. The MDR1-selective pharmacophore highlights the importance of aromatic/hydrophobic features at the N4 position of the thiosemicarbazone and the reliance on the isatin moiety as key bioisosteric contributors. Additionally, a quantitative structure-activity relationship (QSAR) model that yielded a cross-validated correlation coefficient of 0.85 effectively predicts the cytotoxicity of untested thiosemicarbazones. Together, the models serve as effective approaches for predicting structures with MDR1-selective activity and aid in directing the search for the mechanism of action of 1.

Chemicals Related in the Paper:

Catalog Number	Product Name	Structure	CAS Number	Price
AP79560740	NSC73306		79560-74-0	Price