Rolf Baenteli

Special ergolines are highly selective, potent antagonists of the chemokine receptor CXCR3: discovery, characterization and preliminary SAR of a promising lead.

The special ergoline 1 is a highly potent, selective antagonist of the chemokine receptor CXCR3. The surprising selectivity of this LSD-related compound can be explained by different electronic and steric properties of the ergoline core structure caused by the urea portion of the molecule. Discovery, biopharmaceutical properties and first derivatives of this promising lead compound are discussed.

Special ergolines efficiently inhibit the chemokine receptor CXCR3 in blood

The structure-activity relationship of highly potent special ergolines which selectively block the chemokine receptor CXCR3 is reported. The most potent compounds showed IC(50) values below 10nM in both ligand binding and Ca(2+)-mobilization assays. However, these compounds were poorly active in an assay that measures receptor occupancy in blood. Introduction of polar substituents led to derivatives with IC(50) values below 10nM in this assay. Among them was compound 11a which showed both a favorable PK profile and cross reactivity with rodent CXCR3 making it a promising tool compound to further explore the role of CXCR3 in animal models.