植物外源抗氧化剂硫脲基肉桂酰基硫脲衍生物的合成

目的]合成植物外源抗氧化剂取代硫脲基肉桂酰基硫脲衍生物。方法]以肉桂酸为原料,通过酰氯化、置换和加成反应,得到5个相应的取代硫脲基肉桂酰基硫脲衍生物,经红外(IR)、质谱(MS)、核磁共振氢谱(~1H NMR)和元素分析(EA)确认了新化合物的结构。以维生素C(V_C)为对照,测定了这些新化合物体外清除超氧自由基(O_2~-·)、羟自由基(·OH)和2,2-二苯基-1-苦味酰基自由基(DPPH·)的活性及总还原能力。结果]在测定浓度下,这些化合物均具有抗氧化活性,其中N-对氯苯硫脲基-N'-肉桂酰基硫脲(1c)对DPPH·的清除活性强于V_C。结论]N-对氯苯硫脲基-N'-肉桂酰基硫脲(1c)具有较强的抗氧化性,作为外源抗氧化剂有望应用于植物氧化胁迫的保护中。

Synthesis of Thioureido Cinnamic Acyl Thiourea Derivatives as Plant Exogenous Antioxidants

Objective] To synthesize substituted thioureido cinnamic acyl thiourea derivatives as plant exogenous antioxidants.Method] Five cinnamic acyl thiourea derivatives had been gotten after the acylchlorination of cinnamic acid,thioureation with ammonium thiocyanate and then the reaction with arylthiosemicarbazide or thiosemicarbazones under solvent-free condition.Their structures were characterized by IR,1H-NMR,MS and EA.The scavenging effects of these compounds on the superoxide radical(O2-·),hydroxyl radical(·OH) and DPPH· and their total reduction capacity were also compared with ascorbic acid(VC) as the reference material.Result] They all had scavenging effects on these radicals,in which N-p-chlorophenylthioureido-N′-cinnamic acyl thiourea(1c) had stronger effect on DPPH· than the others and VC.Conclusion] As exogenous antioxidant N-p-chlorophenylthioureido-N′-cinnamic acyl thiourea(1c) could be used in the protection of plant oxidative stress.