5,7,8-Trimethyl-benzopyran and 5,7,8-Trimethyl-1,4-benzoxazine Aminoamide Derivatives as Novel Antiarrhythmics against Ischemia−Reperfusion Injury
摘要:
6-Hydroxy-5,7,8-trimethyl-benzopyran derivatives and 5,7,8-trimethyl-1,4-benzoxazine analogues substituted by the lidocaine pharmacophore aminoamide functionality at C4 of N4, respectively, were synthesized and evaluated against arrhythmias associated with ischemia-reperfusion injury. The antiarrhythmic effect of substitutents at positions C2 and C6 was examined. Six out of the 11 new derivatives, exhibited arrhythmia scores 1.0-1.3 versus the control (4.5 +/- 1.2), which was also reflected to the % premature beats (0.5-3.9), control (13.7 +/- 3.6). Selected compounds were further studied by a conventional microelectrode method. 2-diethylamino-1-(5,7,8-trimethyl-2-phenyl-2,3-dihydro-benzo[1,4]oxazin-4-yl)-ethanotic (50) and the trolox-inspired 4-(2-diethylamino-acetyl)-2,5,7,8-tetramethyl-3.4-dihydro-2H-benzo[1,4]oxazine-2-carboxylic acid ethyl ester (62) Suppress reperfusion arrhythmias and reduce malondialdehyde (MDA) content, leading to a fast recovery of the heart after ischemia-reperfusion. They exhibit combined class IB and class III antiarrhythmic properties, which constitutes them as promising compounds for further studies because, due to their multichannel "amiodarone like" effect, less proarrhythmic complications can be expected.
Regulation of the Escherichia coli AtoSC two component system by synthetic biologically active 5;7;8-trimethyl-1;4-benzoxazine analogues
摘要:
The Escherichia coli AtoSC two component system; upon acetoacetate induction; regulates the expression of the atoDAEB operon; through His -> Asp phopshotransfer; thus modulating important cellular processes. In this report the effect of seven 5,7,8-trimethyl-1,4-benzoxazine derivatives on the regulation of the E. coli AtoSC system was studied. The new compounds were tested for their effectiveness on the expression of the atoC and the regulated atoDAEB operon. The non-substituted 5,7,8-trimethyl-1,4-benzoxazine (4a), was the most potent inducer on atoC transcription; resulting in accumulation of AtoC protein. The induction of atoC by 4a was specific; since no effect was observed on the other genes of the system (atoS and atoDAEB). Moreover; compound 4a was shown to significantly up-regulate the in vitro kinase activity of the histidine kinase AtoS without altering the protein levels in the cell. Interestingly; this compound appeared to modulate the acetoacetate-mediated induction of the atoDAEB promoter by the AtoSC system. These data provide the first evidence for a differential modulator role of 5,7,8-trimethyl-1,4-benzoxazine; on the AtoSC two component system mediated signaling. (C) 2011 Elsevier Ltd. All rights reserved.
An efficient and mild method for the chlorination and bromination of oxygenatedaromatics, with good regioselectivity and excellent yields, using a combination of HX/H 2 O 2 /AcOH in petroleum ether is presented. The effect of ultrasound was investigated.
提出了一种在石油醚中使用 HX/H 2 O 2 /AcOH 的组合对含氧芳烃进行氯化和溴化的有效和温和的方法,具有良好的区域选择性和优异的收率。研究了超声波的影响。
Divergent synthesis of 2,6-diaryl-substituted 5,7,8-trimethyl-1,4-benzoxazines via microwave-promoted palladium-catalyzed Suzuki–Miyaura cross coupling and biological evaluation
作者:Eftychia N. Koini、Nicolaos Avlonitis、Erica S. Martins-Duarte、Wanderley de Souza、Rossiane C. Vommaro、Theodora Calogeropoulou
DOI:10.1016/j.tet.2012.10.009
日期:2012.12
An efficient palladium-catalyzed Suzuki-Miyaura cross-coupling protocol effected in a mixture of DME/water (2:1) enables the reaction of sterically hindered and electron rich 6-chloro or 6-bromo-1,4-benzoxazines(ones) with a variety of aryl, vinyl or alkylboronic acids. Coupling is effected with catalyst loading of 5 mol % using sealed-vessel microwave processing. The resulting compounds exhibit potent activity against Toxoplasma gondii tachyzoite proliferation. (C) 2012 Elsevier Ltd. All rights reserved.