Development of a Platform To Enable Efficient Permeability Evaluation of Novel Organo-Peptide Macrocycles

ACS Med Chem Lett. 2019 May 9;10(6):874-879. doi: 10.1021/acsmedchemlett.9b00036. eCollection 2019 Jun 13.

Abstract

As more macrocycle structures are utilized to drug intracellular targets, new platforms are needed to facilitate the discovery of cell permeable compounds in this unique chemical space. Herein, a method is disclosed that allows for the efficient synthesis and permeability evaluation of novel organo-peptide macrocycle libraries. Thoughtful library design allows for the collection of crude permeability data using supercritical fluid chromatography mass spectrometry (SFC-MS) (EPSA) by mass-encoding the stereochemistry, ring size, and organic linker of the desired macrocycles. Library synthesis was aided via the development of a new on-resin N-arylation reaction. Further insights on the permeation of these organo-peptide macrocycles will be discussed, such as the permeability enhancement when utilizing a 2-substituted phenethyl linker versus a 3-substituted phenethyl linker. Lastly, selected macrocycles were scaled up and tested in the MDCK-II permeability assay, and the results of this assay reiterated the permeability trends from the crude SFC-MS data.