Discovery of Dihydro-1,4-Benzoxazine Carboxamides as Potent and Highly Selective Inhibitors of Sirtuin-1

Abstract

Sirtuins are signaling hubs orchestrating the cellular response to various stressors with roles in all major civilization diseases. Sirtuins remove acyl groups from lysine residues of proteins, thereby controlling their activity, turnover, and localization. The seven human sirtuins, SirT1–7, are closely related in structure, hindering the development of specific inhibitors. Screening 170,000 compounds, we identify and optimize SirT1-specific benzoxazine inhibitors, Sosbo, which rival the efficiency and surpass the selectivity of selisistat (EX527). The compounds inhibit the deacetylation of p53 in cultured cells, demonstrating their ability to permeate biological membranes. Kinetic analysis of inhibition and docking studies reveal that the inhibitors bind to a complex of SirT1 and nicotinamide adenine dinucleotide, similar to selisistat. These new SirT1 inhibitors are valuable alternatives to selisistat in biochemical and cell biological studies. Their greater selectivity may allow the development of better targeted drugs to combat SirT1 activity in diseases such as cancer, Huntington’s chorea, or anorexia.

Discovery of Novel N-Acylhydrazone Derivatives as Potent Inhibitors of Sirtuin-1

“…Due to the well-characterized structure, the catalytic domain of SIRT1 has been used as a target receptor for in silico screening of binding parameters of SIRT1 modulators. 44 45 46 47 48 49 50 , 58 , 61 62 63…”

“…The structural requirements for binding, modulating, and inhibiting of SIRT1 protein have been the subject of several recent studies, utilizing the available crystal structures of SIRT1 co-crystallized with known inhibitors. 45,[58][59][60] The catalytic deacetylase region (residues 241-516) of SIRT1 is a key domain for governing the inhibitory activity of the full-length protein. The catalytic domain consists of a large classical Rossmann fold and a small zinc-binding domain (Figure 1).…”

“…[44][45][46][47][48][49][50]58,[61][62][63] To test whether our molecular docking approach is able to reproduce properly the correct binding mode of the cocrystallized inhibitor Ex527, we first re-docked it against the corresponding crystal structure of SIRT1 (PDB 4I5I). 58 It has been suggested that the presence of the co-factor NAD + was essential for the activity of the SIRT1 enzyme 45 so it was maintained in the binding site for the docking study. Figure 2 shows that the applied docking protocol was able to correctly reproduce the binding mode of the Ex527 inhibitor, which is closely overlapping with its corresponding crystallographic structure.…”

Pan-cancer analysis of super-enhancer-induced LINC00862 and validation as a SIRT1-promoting factor in cervical cancer and gastric cancer

“…Owing to the infeasibility for targeting lncRNA in the clinical work now, we wanted to target SIRT1 to achieve the effect of inhibiting this signal axis in tumors. Recently, many new drugs targeting SIRT1 have been designed [ [58] , [59] , [60] , [61] ]. But the effect and toxicity of these drugs needs more in vitro and vivo assays to test.…”

Mechanism research and treatment progress of NAD pathway related molecules in tumor immune microenvironment

“…Sosbo is a SIRT-1-specific benzoxazine inhibitor screened from 170,000 compounds. It is more efficient and selective than Selisistat (EX527), permeates cell membranes and has no significant toxicity [ 129 ]. These studies suggest that advances in the development of specific pharmacologic sirtuins-related drugs are critical to understanding the potential of sirtuins activators or inhibitors in cellular function and clinical outcomes.…”