Further validation of strecker-type α-aminonitriles as a new class of potent human carbonic anhydrase II inhibitors: hit expansion within the public domain using differential scanning fluorimetry leads to chemotype refinement

Mikhail Krasavin,Stanislav Kalinin,Sergey Zozulya,Anastasia Griniukova,Petro Borysko,Andrea Angeli,Claudiu T Supuran

doi:10.1080/14756366.2019.1693556

Mikhail Krasavin, Stanislav Kalinin + Show 5 more

Open Access

https://doi.org/10.1080/14756366.2019.1693556

Copy DOI

Abstract

Testing of an expanded, 800-compound set of analogues of the earlier described Strecker-type α-aminonitriles (selected from publicly available Enamine Ltd. Screening Collection) in thermal shift assay against bovine carbonic anhydrase (bCA) led to further validation of this new class of inhibitors and identification a new, refined chemotype represented by inhibitors with 10-improved potency.

Highlights

Differential scanning fluorimetry (DSF), termed thermal shift assay (TSA), is an efficient technique for direct determination of a small molecule’s affinity to a protein target[1]
This led to the discovery of three compounds (1–3) that produced noticeable thermal shift of bovine carbonic anhydrase (bCA) Tm (DTm) which did not belong to any of -known classes of carbonic anhydrase inhibitors and which we dubbed as Strecker a-aminonitriles considering they could be obtained from various ketones via the Strecker reaction
As it was confirmed that compounds 1–3 acted as true inhibitors, we postulated that a-aminonitriles in general may act as suicide in situ donors of CN- anion and hCA inhibition in general can be expected from any representatives of this chemotype with sufficient complementarity to the enzyme’s active site

Summary

Introduction

Differential scanning fluorimetry (DSF), termed thermal shift assay (TSA), is an efficient technique for direct determination of a small molecule’s affinity to a protein target[1]. We conducted a high-throughput DSF screening of a chemically diverse set of 8000 compounds selected from the Enamine screening collection comprising over 2,000,000 compounds[2] against bovine carbonic anhydrase (bCA), a protein most closely resembling isoform II of the human carbonic anhydrase (hCA II). This led to the discovery of three compounds (1–3) that produced noticeable thermal shift of bCA Tm (DTm) which did not belong to any of -known classes of carbonic anhydrase inhibitors and which we dubbed as Strecker a-aminonitriles considering they could be obtained from various ketones via the Strecker reaction. In order to verify this hypothesis and to discover more potent inhibitors belonging to this class of compounds as well as to establish structure-activity relationships (SAR), we undertook more focussed screening of 800

Methods

Results

Conclusion