Molecular modeling and anticholinesterasic activity of novel 2-arylaminocyclohexyl N,N-dimethylcarbamates

This work reports a detailed theoretical and experimental study of the novel isomer series cis- and trans-2-arylaminocyclohexyl N,N-dimethylcarbamates as potential inhibitors of cholinesterases. In vitro inhibition assay by Ellman's method with human blood samples showed that the new carbamates are selective to the inhibition of enzyme butyrylcholinesterase (BuChE) with maximum inhibition of 90% and IC50 of 6 and 8 mmol L-1 for the more actives compounds of the series. Molecular modeling studies point to significant differences for the conformations of the compounds in the active sites of enzymes BuChE and acetylcholinesterase (AChE). The results show that the compounds interact more effectively with the active site of enzyme BuChE since the carbamate group is close to the key residues of the catalytic triad.O presente trabalho reporta um estudo teórico e experimental detalhado das séries inéditas de isômeros cis- e trans-N,N-dimetilcarbamatos de cicloexila 2-arilaminossubstituídos como potenciais inibidores de colinesterases. Os testes de inibição in vitro, realizados através do método de Ellman em amostras de sangue humano, mostraram que os novos carbamatos apresentaram boa seletividade frente à inibição da enzima butirilcolinesterase (BuChE), com um máximo de inibição de 90% e IC50 de 6 e 8 mmol L-1 para os compostos mais ativos da série. Os estudos de modelagem molecular apontaram significantes diferenças entre as orientações destes compostos nos sítios ativos das enzimas BuChE e acetilcolinesterase (AChE). Os resultados mostraram que os compostos interagem de forma mais efetiva com o sítio ativo da enzima BuChE, pois o grupo carbamato está próximo aos resíduos chave da tríade catalítica.17981807Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Search for decays of the Higgs boson into a pair of pseudoscalar particles decaying into bb¯τ+τ− using pp collisions at √s = 13 TeV with the ATLAS detector

This paper presents a search for exotic decays of the Higgs boson into a pair of new pseudoscalar particles, H → aa, where one pseudoscalar decays into a b-quark pair and the other decays into a τ-lepton pair, in the mass range 12 ≤ ma ≤ 60 GeV. The analysis uses pp collision data at √s = 13 TeV collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 140 fb−1. No significant excess above the Standard Model (SM) prediction is observed. Assuming the SM Higgs boson production cross section, the search sets upper limits at 95% confidence level on the branching ratio of Higgs bosons decaying into bb¯ τ+τ−, B(H → aa → bb¯ τ+τ−), between 2.2% and 3.9% depending on the pseudoscalar mass