Dehydroandrographolide (DA) is a diterpene compound of biological interest that contains one α,β-unsaturated lactone group and two hydroxy groups. In the ESI (electrospray ionization) negative ion mode mass spectral analysis of 15-dideuterodehydroandrographolide (15-D₂-DA), the deuterium nucleus at the γ position of the α,β-unsaturated lactone was more easily dedeuterated than deprotonation of the protons from the hydroxy groups. Exploring the rationality of deuteration as a tool for deprotonation position tracking is significant for gas-phase acidity.

中文翻译：

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氘代电喷雾电离质谱法追踪脱氢穿心莲内酯的去质子化位点

脱氢穿心莲内酯 (DA) 是一种具有生物学意义的二萜化合物，包含一个 α,β-不饱和内酯基团和两个羟基。在 15-dideuterodehydroandrographolide (15-D ₂ -DA)的 ESI（电喷雾电离）负离子模式质谱分析中，α,β-不饱和内酯的 γ 位置的氘核比质子的去质子更容易去氘化来自羟基。探索氘化作为去质子化位置跟踪工具的合理性对于气相酸度具有重要意义。