Department of Chemistry, Faculty of Science, Yazd University, Yazd, Iran.
Faculty of Chemistry, Bu-Ali Sina University, 65178-38683, Hamedan, Iran.
Sci Rep. 2022 Mar 22;12(1):4921. doi: 10.1038/s41598-022-08770-4.
Electrochemical oxidation of imipramine (IMP) has been studied in aqueous solutions by cyclic voltammetry and controlled-potential coulometry techniques. Our voltammetric results show a complex behavior for oxidation of IMP at different pH values. In this study, we focused our attention on the electrochemical oxidation of IMP at a pH of about 5. Under these conditions, our results show that the oxidation of IMP leads to the formation of a unique dimer of IMP (DIMP). The structure of synthesized dimer is fully characterized by UV-visible, FTIR, H NMR, C NMR and mass spectrometry techniques. It seems that the first step in the oxidation of IMP is the cleavage of the alkyl group (formation of IMPH). After this, a domino oxidation-hydroxylation-dimerization-oxidation reaction, converts IMPH to (E)-10,10',11,11'-tetrahydro-[2,2'-bidibenzo[b,f]azepinylidene]-1,1'(5H,5'H)-dione (DIMP). The synthesis of DIMP is performed in an aqueous solution under mild conditions, without the need for any catalyst or oxidant. Based on our electrochemical findings as well as the identification of the final product, a possible reaction mechanism for IMP oxidation has been proposed. Conjugated double bonds in the DIMP structure cause the compound to become colored with sufficient fluorescence activity (excitation wave-length 535 nm and emission wave-length 625 nm). Moreover, DIMP has been evaluated for in vitro antibacterial. The antibacterial tests indicated that DIMP showed good antibacterial performance against all examined gram-positive and gram-negative bacteria (Staphylococcus aureus, Bacillus cereus, Escherichia coli and Shigella sonnei).
电化学氧化丙咪嗪（IMP）在水溶液中通过循环伏安法和恒电位库仑法技术进行了研究。我们的伏安结果表明，IMP 在不同 pH 值下的氧化行为很复杂。在这项研究中，我们专注于 pH 值约为 5 时 IMP 的电化学氧化。在这些条件下，我们的结果表明，IMP 的氧化导致 IMP 的独特二聚体（DIMP）的形成。通过紫外可见光谱、傅里叶变换红外光谱、核磁共振氢谱、核磁共振碳谱和质谱技术对合成的二聚体的结构进行了充分表征。似乎 IMP 氧化的第一步是烷基的裂解（IMPH 的形成）。在此之后，多米诺氧化-羟化-二聚化-氧化反应将 IMPH 转化为（E）-10,10',11,11'-四氢-[2,2'-联苯[b,f]吖庚因基]-1,1'（5H,5'H）-二酮（DIMP）。DIMP 的合成在水溶液中在温和的条件下进行，无需任何催化剂或氧化剂。基于我们的电化学发现以及最终产物的鉴定，提出了 IMP 氧化的可能反应机制。DIMP 结构中的共轭双键使该化合物具有足够的荧光活性而显色（激发波长 535nm，发射波长 625nm）。此外，还评估了 DIMP 的体外抗菌活性。抗菌试验表明，DIMP 对所有检查的革兰氏阳性菌和革兰氏阴性菌（金黄色葡萄球菌、蜡状芽孢杆菌、大肠杆菌和痢疾志贺菌）均表现出良好的抗菌性能。
