4-(3-Nitrophenyl)thiazol-2-ylhydrazone derivatives as antioxidants and selective hMAO-B inhibitors: synthesis, biological activity and computational analysis

A new series of 4-(3-nitrophenyl)thiazol-2-ylhydrazone derivatives were designed, synthesised, and evaluated to assess their inhibitory effect on the human monoamine oxidase (hMAO) A and B isoforms. Different (un)substituted (hetero)aromatic substituents were linked to N1 of the hydrazone in order to establish robust structure–activity relationships. The results of the biological testing demonstrated that the presence of the hydrazothiazole nucleus bearing at C4 a phenyl ring functionalised at the meta position with a nitro group represents an important pharmacophoric feature to obtain selective and reversible human MAO-B inhibition for the treatment of neurodegenerative disorders. In addition, the most potent and selective MAO-B inhibitors were evaluated in silico as potential cholinesterase (AChE/BuChE) inhibitors and in vitro for antioxidant activities. The results obtained from molecular modelling studies provided insight into the multiple interactions and structural requirements for the reported MAO inhibitory properties

Exploring 4-substituted-2-thiazolylhydrazones from 2-, 3-, and 4-acetylpyridine as selective and reversible hMAO-B inhibitors

A series of 4-substituted-2-thiazolylhydrazone derivatives have been synthesized and tested in vitro for their human monoamine oxidase (hMAO) A and B inhibitory activity. Our findings confirmed that the substitution at C4 of the thiazole ring was important to obtain highly potent and selective hMAO-B inhibitors with IC50 values in the nanomolar range. Moreover, these derivatives were endowed with a reversible mechanism of enzyme inhibition. Molecular modelling studies were performed to rationalize the recognition of all inhibitors with respect to hMAO-A and -B isoforms

An Activity-based Probe Targeting Non-catalytic, Highly Conserved Amino Acid Residues Within Bromodomains

Bromodomain-containing proteins are epigenetic modulators involved in a wide range of cellular processes, from physiological recruitment of transcription factors to pathological disruption of gene regulation and cancer development. Since the druggability of these acetyl-lysine reader domains was established, efforts were made to develop potent and selective inhibitors across the entire family. Here we report the development of a small molecule based approach to covalently modify recombinant and endogenous bromodomain-containing proteins by targeting a conserved lysine and a tyrosine residue in the variable ZA or BC loops. Moreover, the addition of a reporter tag, via copper-catalyzed alkyne azide coupling, to an alkyne handle on the probe allowed in-gel visualization and selective pull-down of the desired bromodomains using both recombinant and endogenous proteins.</b