Highly functionalized \u03b2-lactams and 2-ketopiperazines as TRPM8 antagonists with antiallodynic activity

M.Ángeles Bonache,Ana María Roa,Alicia Medina,Cristina Martín-Escura,Antonio Ferrer-Montiel,Gregorio Fernández-Ballester,Roberto De La Torre Martínez,Andrés Francesch,Carmen Cuevas,Sara González-Rodríguez,Rosario González-Muñiz,Asia Fernández-Carvajal

doi:10.1038/s41598-020-70691-x

Abstract

The cool sensor transient receptor potential melastatin channel 8 (TRPM8) is highly expressed in trigeminal and dorsal root ganglia, playing a key role in cold hypersensitivity associated to different peripheral neuropathies. Moreover, these channels are aberrantly expressed in different cancers, and seem to participate in tumor progression, survival and invasion. Accordingly, the search for potent and selective TRPM8 modulators attracted great interest in recent years. We describe new heterocyclic TRPM8 antagonist chemotypes derived from N-cloroalkyl phenylalaninol-Phe conjugates. The cyclization of these conjugates afforded highly substituted β-lactams and/or 2-ketopiperazine (KP) derivatives, with regioselectivity depending on the N-chloroalkyl group and the configuration. These derivatives behave as TRPM8 antagonists in the Ca2+ microfluorometry assay, and confirmed electrophysiologically for the best enantiopure β-lactams 24a and 29a (IC50, 1.4 and 0.8 µM). Two putative binding sites by the pore zone, different from those found for typical agonists and antagonists, were identified by in silico studies for both β-lactams and KPs. β-Lactams 24a and 29a display antitumor activity in different human tumor cell lines (micromolar potencies, A549, HT29, PSN1), but correlation with TRPM8 expression could not be established. Additionally, compound 24a significantly reduced cold allodynia in a mice model of oxaliplatin-induced peripheral neuropathy.

Highlights

The cool sensor transient receptor potential melastatin channel 8 (TRPM8) is highly expressed in trigeminal and dorsal root ganglia, playing a key role in cold hypersensitivity associated to different peripheral neuropathies
As the structure of TRPM8 channel was unknown at the moment of conceiving this work, we hypothesized that compounds of general formula I (Fig. 1), which maintain the β-lactam ring, its substitution at position 4, but change the Asp- or Glu-derived N-substituent by phenylalaninol-derived moieties, could constitute a new chemoptype for TRPM8 modulation
To search for new TRPM8 antagonist chemotypes, we explore the base-assisted cyclization of linear phenylalaninol-Phe conjugates, which afforded chiral β-lactam and/or 2-ketopiperazine (KP) heterocyclic derivatives

Summary

Introduction

The cool sensor transient receptor potential melastatin channel 8 (TRPM8) is highly expressed in trigeminal and dorsal root ganglia, playing a key role in cold hypersensitivity associated to different peripheral neuropathies. Both series of compounds behave as TRPM8 antagonists and, among them, selected β-lactam derivatives display antitumor activity, and antiallodynic properties in a model of chemotherapy-induced cold allodynia. As for the β-lactam derivatives, the configuration of the stereocenter coming from the phenylalaninol moiety seems to dictate the antagonist activity, with 5R-KPs more potent than 5S-isomers (compare 15ab to 13ab) (Table 3).

Results

Conclusion