抽象的 胆碱酯酶 (ChE) 已被确定为阿尔茨海默病 (AD) 的诊断标志物。已合成基于底物的探针来检测 ChE,但尚未检测到与 AD 病理相关的 ChE 分布变化。通常使用分光光度法和纯酶来筛选探针的特异性和动力学。然而,与 AD 病理相关的 ChE 的生化特性发生了改变。目前的工作是确定卡诺夫斯基根 (KR) 组织化学方法是否可用于评估病理部位的探针。合成了 30 种硫酯和酯,并使用酶动力学和 KR 方法进行了评估。分光光度法证明所有硫酯都是 ChE 底物,但只有少数硫酯通过 KR 方法在大脑中提供染色。酯是与脑 ChE 相互作用的 ChE 底物。这些结果表明 KR 方法可能提供一种有效的方法来筛选化合物作为 AD 相关 ChE 成像的探针。
Thioesters for the in vitro evaluation of agents to image brain cholinesterases
摘要:
Cholinesterases are associated with pathology characteristic of conditions such as Alzheimer's disease and are therefore, considered targets for neuroimaging. Ester derivatives of N-methylpiperidinol are promising potential imaging agents; however, methodology is lacking for evaluating these compounds in vitro. Here, we report the synthesis and evaluation of a series of N-methylpiperidinyl thioesters, possessing comparable properties to their corresponding esters, which can be directly evaluated for cholinesterase kinetics and histochemical distribution in human brain tissue. N-methylpiperidinyl esters and thioesters were synthesized and they demonstrated comparable cholinesterase kinetics. Furthermore, thioesters were capable, using histochemical method, to visualize cholinesterase activity in human brain tissue. N-methylpiperidinyl thioesters can be rapidly evaluated for cholinesterase kinetics and visualization of enzyme distribution in brain tissue which may facilitate development of cholinesterase imaging agents for application to conditions such as Alzheimer's disease.