Screening of Heteroaromatic Scaffolds against Cystathionine Beta-Synthase Enables Identification of Substituted Pyrazolo[3,4-c]Pyridines as Potent and Selective Orthosteric Inhibitors

Abstract

Cystathionine β-synthase (CBS) is a key enzyme in the production of the signaling molecule hydrogen sulfide, deregulation of which is known to contribute to a range of serious pathological states. Involvement of hydrogen sulfide in pathways of paramount importance for cellular homeostasis renders CBS a promising drug target. An in-house focused library of heteroaromatic compounds was screened for CBS modulators by the methylene blue assay and a pyrazolopyridine derivative with a promising CBS inhibitory potential was discovered. The compound activity was readily comparable to the most potent CBS inhibitor currently known, aminoacetic acid, while a promising specificity over the related cystathionine γ-lyase was identified. To rule out any possibility that the inhibitor may bind the enzyme regulatory domain due to its high structural similarity with cofactor s-adenosylmethionine, differential scanning fluorimetry was employed. A sub-scaffold search guided follow-up screening of related compounds, providing preliminary structure-activity relationships with respect to requisites for efficient CBS inhibition by this group of heterocycles. Subsequently, a hypothesis regarding the exact binding mode of the inhibitor was devised on the basis of the available structure-activity relationships (SAR) and a deep neural networks analysis and further supported by induced-fit docking calculations.

Hydrolytic Activity of Mitochondrial F1FO-ATP Synthase as a Target for Myocardial Ischemia–Reperfusion Injury: Discovery and In Vitro and In Vivo Evaluation of Novel Inhibitors

“…Considering the established hydrolysis inhibitors BMS-199264 and BTB (Figure B), a similarity search was performed using the ROCS algorithm as implemented in OpenEye software. The similarity search was conducted on our in-house library of 2000 compounds (synthetic and natural products) named “Pharmalab”, and on National Cancer Institute (NCI) Open Database Compounds containing ∼260,000 molecules () (Supporting Information, Figure S1). Different steps of filtering through the in silico screening were followed as described previously in order to select different molecular scaffolds and resulted in 34 molecules from Pharmalab (Supporting Information, Table S1) and 15 molecules from the NCI database (Supporting Information, Table S2).…”

Synthesis and vectorial functionalisation of pyrazolo[3,4-c]pyridines

“…The pyrazolo[3,4-c]pyridine core has begun to attract attention as a therapeutic agent due to its structural similarity to purine. [20][21][22][23] Purine derivatives have a broad range of applications, as anti-inammatory, antiviral, and anti-cancer agents, arising from the prevalence of purine-based biological compounds and, subsequently, the variety of cellular proteins that contain purine-binding pockets. 20 Whilst routes have been reported for related products with different substituent patterns around the pyrazolo [3,4-c]pyridine core, most of these require discrete synthetic endeavour.…”