Reactions of 3-methyl-1-phenyl-2-pyrazoline-5-one (MCI-186) with hypochlorous acid and superoxide were analysed by spectrophotometry and mass spectrometry. The results were applied to the neutrophil system to evaluate the scavenging activity of neutrophil-derived active oxygen species by MCI-186. MCI-186 reacted rapidly with hypochlorous acid (1 x 10(6) M(-1)s(-1)) to form a chlorinated intermediate, followed by a slow conversion to a new spectrum. MCI-186 consumed 3 moles of hypochlorous acid and did not react with superoxide. The newly synthesized fluorescence probes, 2-[6-(4'-amino)-phenoxy-3H-xanthen-3-on-9-yl]benzoic acid (APF) and 2-[6-(4'-hydroxy)phenoxy-3H-anthen-3-on-9-yl]benzoic acid (HPF) successfully detected neutrophil-derived active oxygens (Setsukinai K, Urano Y, Kakinuma K, Majima HJ, Nagano T. Development of novel fluorescence probes that can reliably detect reactive oxygen species and distinguish specific species. J Biol Chem 2003; 278: 3170-3175). The rate constants for the reaction of hypochlorous acid with MCI-186 and fluorescence probes was in the order of MCI-186 > APF > HPF. Fluorescence due to the oxidation of APF and HPF was observed with the stimulated neutrophils. The result that the intensity from APF oxidation was higher than that from HPF oxidation is compatible with reports that APF selectively reacts with hypochlorous acid. Fluorescence due to oxidation of both APF and HPF decreased when the reactions were carried out in the presence of a fluorescence probe and MCI-186 in a dose-dependent manner. These results indicate that MCI-186 effectively scavenges neutrophil-derived hypochlorous acid and other active oxygens.

中文翻译：

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MCI-186对中性粒细胞衍生活性氧的影响。

用分光光度法和质谱法分析了3-甲基-1-苯基-2-吡唑啉-5-酮（MCI-186）与次氯酸和超氧化物的反应。将结果应用于中性粒细胞系统，以评估MCI-186对中性粒细胞衍生的活性氧的清除活性。MCI-186与次氯酸（1 x 10（6）M（-1）s（-1））快速反应，形成氯化中间体，然后缓慢转化为新光谱。MCI-186消耗了3摩尔的次氯酸，并且未与超氧化物反应。新合成的荧光探针2- [6-（4'-氨基）-苯氧基-3H-黄嘌呤-3-on-9-基]苯甲酸（APF）和2- [6-（4'-羟基）苯氧基-3H-anthen-3-on-9-yl] benzoic acid（HPF）成功检测到中性粒细胞衍生的活性氧（Setsukinai K，Urano Y，Kakinuma K，Majima HJ，Nagano T. 可以可靠地检测活性氧种类并区分特定种类的新型荧光探针的开发。生物化学杂志2003; 278：3170-3175）。次氯酸与MCI-186和荧光探针反应的速率常数为MCI-186> APF> HPF。在刺激的嗜中性粒细胞中观察到由于APF和HPF氧化引起的荧光。APF氧化强度高于HPF氧化强度的结果与APF与次氯酸选择性反应的报道相吻合。当在荧光探针和MCI-186的存在下以剂量依赖性方式进行反应时，由于APF和HPF的氧化引起的荧光降低。这些结果表明，MCI-186有效清除中性粒细胞衍生的次氯酸和其他活性氧。