We investigate the tandem mass spectrometry of regiospecifically labeled, deprotonated sucrose analytes. We utilize density functional theory calculations to model the pertinent gas-phase fragmentation chemistry of the prevalent glycosidic bond cleavages (B₁-Y₁ and C₁-Z₁ reactions) and compare these predictions to infrared spectroscopy experiments on the resulting B₁ and C₁ product anions. For the C₁ anions, barriers to interconversion of the pyranose [α-glucose-H]⁻, C₁ anions to entropically favorable ring-open aldehyde-terminated forms were modest (41 kJ mol⁻¹) consistent with the observation of a band assigned to a carbonyl stretch at ~ 1680–1720 cm⁻¹. For the B₁ anions, our transition structure calculations predict the presence of both deprotonated 1,6-anhydroglucose and carbon 2-ketone ((4S,5S,6R)-4,5-dihydroxy-6-(hydroxymethyl)dihydro-2H-pyran-3(4H)-one) anion structures, with the latter predominating. This hypothesis is supported by our spectroscopic data which show diagnostic bands at 1600, 1674, and 1699 cm⁻¹ (deprotonated carbon 2-ketone structures), and at ~ 1541 cm⁻¹ (both types of structure) and RRKM rate calculations. The deprotonated carbon 2-ketone structures are also the lowest energy product B₁ anions.

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我们研究了区域特异性标记的去质子化蔗糖分析物的串联质谱。我们利用密度泛函理论计算来模拟流行的糖苷键裂解（B ₁ -Y ₁和C ₁ -Z ₁反应）的相关气相裂解化学，并将这些预测与红外光谱实验对所得的B ₁和C进行比较_1个产品负离子。对于C ₁阴离子，是吡喃糖[α-葡萄糖-H] ^-，C ₁相互转化的障碍阴离子为熵有利的开环醛末端形式是适度的（41 kJ mol ^-1），与在〜1680–1720 cm ^-1处分配给羰基的谱带的观察结果一致。对于B ₁阴离子，我们的过渡结构计算预测了去质子化的1,6-脱水葡萄糖和碳2-酮（（4S，5S，6R）-4,5-二羟基-6-（羟甲基）二氢-2H- pyran-3（4H）-one）阴离子结构，其中后者占主导地位。这一假设是由我们其中在1600，1674显示诊断条带的光谱数据，并且1699厘米支持^-1（去质子化的碳-2-酮结构），并在〜1541厘米^-1（两种类型的结构）和RRKM速率计算。去质子化的碳2-酮结构也是能量最低的产物B ₁阴离子。

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