Discovery of Selective Small Molecule ROMK Inhibitors as Potential New Mechanism Diuretics

Area of Science:

• Pharmacology
• Nephrology
• Drug Discovery

Background:

• The renal outer medullary potassium (ROMK) channel, also known as Kir1.1, is a key target for developing novel diuretics.
• Hypertension and edematous states, like those in heart failure, represent significant unmet medical needs.
• Targeting ROMK offers a promising therapeutic strategy for managing these conditions.

Purpose of the Study:

• To identify potent inhibitors of the ROMK channel through high-throughput screening.
• To develop tool compounds for in vivo pharmacological assessment of ROMK inhibition.
• To optimize ROMK inhibitors for improved pharmacokinetic properties and selectivity.

Main Methods:

• High-throughput screening (HTS) of a chemical library to identify ROMK inhibitors.
• Structure-activity relationship (SAR) studies to optimize lead compounds.
• Pharmacokinetic (PK) profiling in rats.
• Selectivity assays against hERG and other inward rectifier potassium channels.

Main Results:

• A 1,4-bis(4-nitrophenethyl)piperazine derivative was identified as a potent ROMK inhibitor, initially found as an impurity.
• Analogues were synthesized with enhanced rat pharmacokinetic properties.
• The developed compounds demonstrated selectivity for ROMK over the hERG channel and other inward rectifier potassium channels.
• These tool compounds are suitable for in vivo pharmacological evaluation.

Conclusions:

• 1,4-bis(4-nitrophenethyl)piperazine derivatives are effective ROMK inhibitors.
• Optimized analogues possess favorable properties for further drug development.
• These compounds represent valuable tools for studying ROMK channel function in vivo.
• The findings support the development of a new class of diuretics targeting ROMK for hypertension and edema treatment.