Synthesis Of Triphenylpyrazole Ketone Chlorophenols Monoamine Oxidase Inhibitors And Their Protective Effect On SH-SY5Y Cells

Objective:Monoamine oxidase inhibitors?MAOIs?have shown therapeutic value in depressive illness and neurodegenerative diseases.Efforts have been oriented toward the discovery of reversible and selective inhibitors of MAO leading to a new generation of compounds.We have obtained high activity halophenol 2,4',5'-trihydroxy-5,2'-dibromobenzophenone?LM49?with various pharmacological activities in cardiovascular and cerebrovascular diseases.The main mechanism is anti-oxidation and anti-inflammatory,which is highly compatiblewiththepathogenesisofneurologicaldiseases.Theimportant pharmacodynamic mother-nuclear 2-pyrazoline of MAOI was added to the structure of the lead compound LM49 and series of triphenylpyrazole ketone chlorophenols were synthesized and screened MAO inhibitoryactivity by UV spectrophotometry.In addition,The protective effect of the target compounds on 6-hydroxydopamine?6-OHDA?-induced SH-SY5Y cell injury and the effect on ROS levels were examined.It is expected to find highly active,selective and reversible monoamine oxidase inhibitors.Methods:We obtained the target compounds by taking methoxy and chloro-substituted acetophenone and benzaldehyde as the starting materials,through the Claisen Schmidt reaction,ring-closing reaction,and demethylation reaction.UV spectrophotometry was used to screen the inhibitory activity of the target compounds on MAO in vitro and the reversibility of enzyme inhibition.The MTT assay was used to detect the protective effect of the target compounds on 6-OHDA-induced SH-SY5Y cell injury and its effect on ROS levels was measured using flow cytometry.Results:A total of 32 target compounds and 32 corresponding intermediate compounds were synthesized,60 of which were not reported in the literature.All compounds were structurally confirmed by IR,ESI-MS,¹H NMR and ¹³C NMR.The results of the enzyme inhibitory activity showed that there was no inhibition of MAO-A at a compound concentration of 50?M.There are 16 target compounds that inhibit MAO-B,of which the best one is 6d(IC₅₀=12.2±2.3?M),which is lower than the positive drug Rasagiline,but the combination of 6d and MAO-B is reversible and its selectivity is higher than Rasagiline?irreversible MAO-B inhibitor?;Compounds 11d,12d,25d,29d,30d,31d,and32d have significant protective activity against 6-OHDA-induced SH-SY5Y cell injury,and their EC₅₀0 are 1.2±0.7?M,0.5±0.3?M,0.3±0.1?M,0.6±0.3?M,0.6±0.1?M,0.6±0.4?M,0.9±0.5?M,both higher than the lead LM49?2,4',5'-trihydroxy-5,2'-dibromobenzophenone?and Rasagiline?EC50=1.1±0.6?.Moreover,they can significantly reduce the increase in ROS levels caused by 6-OHDA.Conclusion:?1?A total of 32 target compounds and 32 key intermediates were synthesized,of which 60 compounds were not reported in the literature;?2?There are 16 target compounds that have selective inhibition of MAO-B,in which the selectivity of compound 6d to MAO-B is higher than that of the positive drug Rasagiline,and it is reversibly combined with MAO-B;?3?The seven target compounds 11d,12d,25d,29d,30d,31d,and 32d have a protective effect on SH-SY5Y cells with 6-OHDA damage,and their activity is higher than that of the positive control Rasagiline,and can significantly reduce ROS levels.?4?The target compounds selectively inhibit MAO-B and may protect against6-OHDA-damaged neurons by anti-oxidative stress.