Candidate drugs that can be metabolically transformed into reactive electrophilic products, such as epoxides, quinones, and nitroso compounds, are of special concern because subsequent covalent binding to bio-macromolecules can cause adverse drug reactions, such as allergic reactions, hepatotoxicity, and genotoxicity. Several strategies have been reported for screening reactive metabolites, such as a covalent binding assay with radioisotope-labeled drugs and a trapping method followed by LC–MS/MS analyses. Of these, a trapping method using glutathione is the most common, especially at the early stage of drug development. However, the cysteine of glutathione is not the only nucleophilic site in vivo; lysine, histidine, arginine, and DNA bases are also nucleophilic. Indeed, the glutathione trapping method tends to overlook several types of reactive metabolites, such as aldehydes, acylglucuronides, and nitroso compounds. Here, we introduce an alternate way for screening reactive metabolites as follows: A mixture of the light and heavy isotopes of simplified amino acid motifs and a DNA motif is used as a biomimetic trapping cocktail. This mixture consists of [²H₀]/[²H₃]-1-methylguanidine (arginine motif, Δ 3 Da), [²H₀]/[²H₄]-2-mercaptoethanol (cysteine motif, Δ 4 Da), [²H₀]/[²H₅]-4-methylimidazole (histidine motif, Δ 5 Da), [²H₀]/[²H₉]-n-butylamine (lysine motif, Δ 9 Da), and [¹³C₀,¹⁵N₀]/[¹³C₁,¹⁵N₂]-2′-deoxyguanosine (DNA motif, Δ 3 Da). Mass tag triggered data-dependent acquisition is used to find the characteristic doublet peaks, followed by specific identification of the light isotope peak using MS/MS. Forty-two model drugs were examined using an in vitro microsome experiment to validate the strategy.

中文翻译：

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仿生捕获混合物以筛选反应性代谢物：使用氨基酸和DNA基序混合物作为质量转移不同的轻/重同位素对

可能被代谢转化为反应性亲电产物的候选药物，例如环氧化物，醌和亚硝基化合物，受到特别关注，因为随后与生物大分子的共价结合会引起药物不良反应，例如变态反应，肝毒性和遗传毒性。已经报道了几种筛选反应性代谢物的策略，例如用放射性同位素标记的药物进行共价结合测定，采用捕获方法，然后进行LC-MS / MS分析。其中，使用谷胱甘肽的诱捕方法最为常见，尤其是在药物开发的早期阶段。然而，谷胱甘肽的半胱氨酸并不是体内唯一的亲核位点；赖氨酸，组氨酸，精氨酸和DNA碱基也是亲核的。确实，谷胱甘肽捕获法往往忽略了几种类型的反应性代谢产物，例如醛类，酰基葡糖醛酸苷和亚硝基化合物。在这里，我们介绍了一种筛选反应性代谢物的替代方法，如下所示：简化氨基酸基序和DNA基序的轻同位素和重同位素的混合物用作仿生捕获混合物。该混合物由[² H ₀ ] / [ ² H ₃ ] -1-甲基胍（精氨酸基序，Δ3 Da），[ ² H ₀ ] / [ ² H ₄ ] -2-巯基乙醇（半胱氨酸基序，Δ4 Da），[ ² H ₀ ] / [ ² H ₅ ] -4-甲基咪唑（组氨酸基序，Δ5 Da），[ ² H ₀ ] / [ ² H ₉ ]-正丁胺（赖氨酸基序，Δ9 Da）和[ ¹³ C ₀，¹⁵ ñ ₀ ] / [ ¹³ C ^ ₁，¹⁵N ₂ ] -2′-脱氧鸟苷（DNA基序，Δ3 Da）。质量标签触发的数据相关采集用于查找特征性双峰，然后使用MS / MS特异性鉴定轻同位素峰。使用体外微粒体实验检查了42种模型药物，以验证该策略。