Synthesis of thiourea benzoylthiourea derivatives as exogenous antioxidants and their plant growth- promoting effects

Five thiourea benzoylthiourea derivatives were synthesized by using benzoic acid， arylthiosemicarbazide or thiosemicarbazones as raw materials. Their structures were characterized by UV，IR， 1H-NMR and MS. Their scavenging effects on the superoxide radical（O2 -·），hydroxyl radical（·OH） and DPPH· radical and their total reduction capacity were compared with ascorbic acid（Vc） as the reference material. As exogenous antioxidants，their promoting effects on plant growth of rice and cucumber were tested by the methods of growth test，superoxide dismutase（SOD） and peroxidase（POD） activity determination. The results showed that at the determinated concentration，these compounds all had scavenging effects on these radicals，and also could promote the growth of rice and cucumber，at the same time increase their SOD and POD activity.