Fourteen pyridine-based 1,3,4-oxadiazole derivatives were synthesized from pyridine-2-carboxaldehyde via iodine-mediated oxidative cyclisation with substituted hydrazide by using the impregnation method. Their structures were confirmed by melting point, 1H NMR, 13C NMR and HRMS. Preliminary bioassay of these derivatives' activities inhibiting acetylcholinesterase (AChE) was also evaluated in vitro at the concentration of 1 μmol/mL. The result showed that compounds 4c, 4j and 4k had moderate inhibitory activities with 52%, 59% and 59%, respectively. The preliminary structure-activity relationships revealed that the introduction of pyridine ring could enhance the activity. Molecular docking study demonstrated that compound 4k possessed an optimal docking pose with interactions at the middle of the catalytic active site (CAS) and peripheral anionic site (PAS) of AChE.

中文翻译：

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吡啶基1,3,4-恶二唑衍生物的制备及乙酰胆碱酯酶抑制活性

吡啶-2-羧甲醛经碘与取代的酰肼介导的氧化环化反应，采用浸渍法合成了十四种吡啶基的1,3,4-恶二唑衍生物。通过熔点，1 H NMR，13 C NMR和HRMS确认了它们的结构。这些衍生物抑制乙酰胆碱酯酶（AChE）活性的初步生物测定方法也已在体外以1μmol / mL的浓度进行了评估。结果表明化合物4c ，4j和4k具有中等抑制活性，分别为52％，59％和59％。初步的结构活性关系表明，吡啶环的引入可以增强活性。分子对接研究表明，化合物4k具有最佳的对接姿势，在AChE的催化活性位点（CAS）和外围阴离子位点（PAS）的中间具有相互作用。