Three hesperetin Schiff bases N-[2,3-dihydro-5,7-dihydroxy-2-(3-hydroxy-4-methoxyphenyl)chromen-4-ylidene]thiosemicarbazide (HTSC), N-[2,3-dihydro-5,7-dihydroxy-2-(3-hydroxy-4-methoxyphenyl)chromen-4-ylidene]isonicotinohydrazide (HIN) and N-[2,3-dihydro-5,7-dihydroxy-2-(3-hydroxy-4-methoxy-phenyl)chromen-4-ylidene] benzhydrazide (HHSB) were synthesized and evaluated for their electronic and physicochemical properties using experimental and theoretical methods. In order to determine antioxidant activity of the above mentioned compounds a detailed kinetic study of hesperetin analogues has been performed and comprehensive results have been reported with DPPH^• assay using UV-Vis and ¹H NMR spectroscopy. Using DPPH assay, the order of the antioxidant activity increase was established as HTSC > HIN > HHSB > hesperetin. Based on the theoretical DFT(B3LYP) calculations it was concluded that in polar solvents (methanol and DMSO) the first step of free radical scavenging mechanism of hesperetin derivatives is deprotonation of the 7-OH groups leading to the formation of anionic forms. These anionic species are considered to be the entering species to the two coexisting or competing mechanisms: SPLET and SPL-HAT.

三种橙皮素希夫碱N- [2,3-二氢-5,7-二羟基-2-（3-羟基-4-甲氧基苯基）铬-4-亚烷基]硫代氨基脲（HTSC），N- [2,3-二氢- 5,7-二羟基-2-（3-羟基-4-甲氧基苯基）铬-4-亚丙基]异烟酰肼（HIN）和N- [2,3-二氢-5,7-二羟基-2-（3-羟基-合成了4-甲氧基-苯基）铬-4-亚甲基]苯并肼（HHSB），并使用实验和理论方法对其电子和物理化学性质进行了评估。为了测定上述化合物的抗氧化活性，已对橙皮素类似物进行了详细的动力学研究，并通过使用DP- ^•检测的UV-Vis和¹报道了全面的结果。1 H NMR光谱。使用DPPH测定，确定抗氧化剂活性增加的顺序为HTSC> HIN> HHSB>橙皮素。根据理论DFT（B3LYP）计算得出的结论是，在极性溶剂（甲醇和DMSO）中，橙皮素衍生物清除自由基的第一步是使7-OH基团去质子化，从而形成阴离子形式。这些阴离子物质被认为是两种共存或竞争机制的进入物质：SPLET和SPL-HAT。