In an effort to identify methylene blue analogues having improved antioxidant activity, a series of new methylene violet analogues have been designed and synthesized. The analogues were prepared following a synthetic route that is more efficient than the previously reported methods, both in terms of yield and purity of the final products. The route involves the Smiles rearrangement as one of the crucial steps. Smiles rearrangement of suitably substituted diphenyl sulfide intermediates afforded the corresponding phenothiazine analogues in high yields, which were subsequently converted to the final products. The methylene violet analogues were evaluated for their ability to preserve mitochondrial function in Friedreich’s ataxia (FRDA) lymphocytes. The analogues were shown to be efficient ROS scavengers, and able to protect cultured FRDA lymphocytes from oxidative stress resulting from inhibition of complex I. The analogues also preserved mitochondrial membrane potential and augmented ATP production. The analogues were found to be better antioxidants than the parent compounds methylene blue and methylene violet.

为了鉴定具有改善的抗氧化活性的亚甲基蓝类似物，已经设计并合成了一系列新的亚甲基紫罗兰类似物。在最终产物的产率和纯度方面，按照比先前报道的方法更有效的合成路线制备类似物。这条路线涉及将微笑的重新安排作为关键步骤之一。适当取代的二苯硫醚中间体的微笑重排提供了高产率的相应吩噻嗪类似物，随后将其转化为最终产物。评价亚甲基紫罗兰类似物在Friedreich共济失调（FRDA）淋巴细胞中保持线粒体功能的能力。该类似物被证明是有效的ROS清除剂，并能保护培养的FRDA淋巴细胞免受复合物I抑制引起的氧化应激。类似物还保留了线粒体膜电位并增加了ATP的产生。发现类似物比母体化合物亚甲基蓝和亚甲基紫罗兰是更好的抗氧化剂。