Schindler Baptiste, Joshi Janhavi, Allouche Abdul-Rahman, Simon Daniel, Chambert Stéphane, Brites Vincent, Gaigeot Marie-Pierre, Compagnon Isabelle
Université de Lyon, F-69622, Lyon, France.
Phys Chem Chem Phys. 2014 Oct 28;16(40):22131-8. doi: 10.1039/c4cp02898h.
An original application of the coupling of mass spectrometry with vibrational spectroscopy, used for the first time to discriminate isobaric bioactive saccharides with sulfate and phosphate functional modifications, is presented. Whereas their nominal masses and fragmentation patterns are undifferentiated by sole mass spectrometry, their distinctive OH stretching modes at 3595 cm(-1) and 3666 cm(-1), respectively, provide a reliable spectroscopic diagnostic for distinguishing their sulfate or phosphate functionalization. A detailed analysis of the 6-sulfated and 6-phosphated d-glucosamine conformations is presented, together with theoretical scaled harmonic spectra and anharmonic spectra (VPT2 and DFT-based molecular dynamics simulations). Strong anharmonic effects are observed in the case of the phosphated species, resulting in a dramatic enhancement of its phosphate diagnostic mode.
本文介绍了质谱与振动光谱联用的一种原始应用，该应用首次用于区分具有硫酸酯和磷酸酯官能团修饰的等压生物活性糖类。尽管仅通过质谱无法区分它们的标称质量和碎片模式，但它们分别在3595 cm(-1)和3666 cm(-1)处独特的OH伸缩模式，为区分它们的硫酸酯或磷酸酯官能化提供了可靠的光谱诊断依据。本文还对6-硫酸化和6-磷酸化的D-葡萄糖胺构象进行了详细分析，并给出了理论缩放谐波光谱和非谐波光谱（基于VPT2和DFT的分子动力学模拟）。在磷酸化物种的情况下观察到强烈的非谐效应，导致其磷酸诊断模式显著增强。
