Novel Spin Traps for Biological Free Radical Detection

描述（由申请人提供）：在过去的二十年中，活性氧被认为是生理条件下氧化过程和疾病机制的关键介质。因此，拥有一种能够在自由基形成部位识别自由基的直接技术是至关重要的，这种技术可以从化学反应到酶促反应，从细胞到体内系统，以便了解生物系统中氧化损伤的机制和过程。本提案的总体目标是开发具有改进性能的新型自旋阱，可以应用于利用电子顺磁共振（EPR）光谱研究生物系统中的氧化应激。具体监测生物相关活性氧的形成，如？哦,O2 ?——,ROO ?或RS ?是通过加入自旋陷阱形成持久的自由基加合物后产生的独特的EPR光谱曲线来实现的。目前最常用的自旋捕集器有5,5-二甲基-1-吡咯啉n -氧化物（DMPO）、二氧氧磷基-5-甲基-1-吡咯啉n -氧化物（DEPMPO）和5-乙氧羰基-5-甲基-1-吡咯啉n -氧化物（EMPO），但它们捕获超氧自由基阴离子的效率较差、生物环境中形成的自由基加合物半衰期短、细胞毒性、敏感性和靶特异性较差。我们的目标是通过采用跨学科的方法来克服这些限制，包括理论预测，有机合成，动力学测定，毒性，以及最终的实验应用，以识别和检测自由基在体外和体内系统中形成的部位。这些技术的协同应用将为探索活性氧在生物机制中的作用提供一种有效的新材料。

DESCRIPTION (provided by applicant): Over the past two decades, reactive oxygen species have been implicated as critical mediators of oxidative processes and disease mechanisms under physiological conditions. Therefore, it is of critical importance to have a direct technique capable of identifying free radicals at their site of formation in systems ranging from chemical to enzymatic reactions, and cellular to in vivo systems so that the mechanisms and processes underlying the oxidative damage in biological systems can be understood. The overall objective of this proposal is to develop novel spin traps with improved properties that can be applied to study oxidative stress in biological systems using electron paramagnetic resonance (EPR) spectroscopy. The specific monitoring of the formation of biologically relevant reactive oxygen species such as ?OH, O2?-, ROO? or RS? is achieved by the distinctive EPR spectral profile they give after addition to spin traps to form a persistent radical adduct. The most commonly used spin traps, 5,5-dimethyl-1-pyrroline N-oxide (DMPO), diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide (DEPMPO) and 5-ethoxycarbonyl-5-methyl-1-pyrroline N-oxide (EMPO), are limited by their poor efficiency of trapping superoxide radical anion, short half-life of the radical adduct formed in biological milieu, cytotoxicity, sensitivity and target specificity. Our aim is to overcome such limitations by employing an interdisciplinary approach in spin trap development that encompasses theoretical prediction, organic synthesis, kinetic determination, toxicity, and ultimately, their experimental application to identify and detect free radical formation in in vitro and in vivo systems at their site of formation. The synergistic application of these technologies will provide an optimal strategy to provide new materials which can be effective in probing the role of reactive oxygen species in biological mechanisms.