Stable Benzotriazole Esters as Mechanism-Based Inactivators of the Severe Acute Respiratory Syndrome 3CL Protease

Abstract

Severe acute respiratory syndrome (SARS) is caused by a newly emerged coronavirus that infected more than 8000 individuals and resulted in more than 800 fatalities in 2003. Currently, there is no effective treatment for this epidemic. SARS-3CL(pro) has been shown to be essential for replication and is thus a target for drug discovery. Here, a class of stable benzotriazole esters was reported as mechanism-based inactivators of 3CL(pro), and the most potent inactivator exhibited a k(inact) of 0.0011 s(-1) and a K(i) of 7.5 nM. Mechanistic investigation with kinetic and mass spectrometry analyses indicates that the active site Cys145 is acylated, and that no irreversible inactivation was observed with the use of the C145A mutant. In addition, a noncovalent, competitive inhibition became apparent by using benzotriazole ester surrogates in which the bridged ester-oxygen group is replaced with carbon.

Diethylaminobenzaldehyde Is a Covalent, Irreversible Inactivator of ALDH7A1

“…23,24 In particular, reaction of the proteinase with 1-(4-dimethylaminobenzoyloxy)-benzotriazole results in acylation of the catalytic Cys with 1-(4-dimethylaminobenzoyloxy) (PDB code 2V6N), which is very similar to the covalent adduct that we observe. Donation of electrons from the amino substituent toward the dimethylaminobenzoyloxy thioester is thought to render the adduct resistant to hydrolysis.…”

“…Donation of electrons from the amino substituent toward the dimethylaminobenzoyloxy thioester is thought to render the adduct resistant to hydrolysis. 23,24 Analogous electronic effects may be at work in our case and may help explain why DEAB is an inactivator of ALDH7A1, whereas benzaldehyde is a substrate. 20 Alternatively, or at the same time, interactions of DEAB with active site residues may serve to disable the enzyme's hydrolytic machinery.…”

Synthesis, characterization, crystal structure and DFT studies on 3-(1H-benzo[d][1,2,3]triazol-1-yl)-1-oxo-1-m-tolylpropan-2-yl-nicotinate

“…3-(1H-Benzo[d] [1,2,3]triazol-1-yl)-1-oxo-1-m-tolylpropan-2-yl-nicotinate (BOTN) has been synthesized by four-step reactions and characterized by IR and UV-vis spectra. The crystal structure determinations show that the compound crystallizes in monoclinic, space group P2(1)/c.…”

“…However, to the best of our knowledge, among so many reported benzotriazoles, 1H-benzotriazole derivatives containing one nicotinato group are very rare. Herein, we report the four-steps synthesis and characterization on the title compound of 3-(1H-benzo[d] [1,2,3]triazol-1-yl)-1-oxo-1-m-tolylpropan-2-yl-nicotinate (BOTN). The crystal structure, fluorescent spectra along with the density functional theory (DFT) calculational results about BOTN are also reported.…”

“…As N-heterocyclic compounds, benzotriazole and its derivatives have attracted considerable attentions in industry and agriculture because of their significant biological activities including efficient antifungal, antitumor and antineoplastic activities [1][2][3][4]. Also, benzotriazoles are extensively used as synthetic auxiliaries in organic chemistry [5][6][7] and versatile ligands in coordination chemistry [8,9].…”