Novel Sterically Crowded and Conformationally Constrained α-Aminophosphonates with a Near-Neutral pKa as Highly Accurate 31P NMR pH Probes. Application to Subtle pH Gradients Determination in Dictyostelium discoideum Cells
作者:Caroline Delehedde、Marcel Culcasi、Emilie Ricquebourg、Mathieu Cassien、Didier Siri、Bruno Blaive、Sylvia Pietri、Sophie Thétiot-Laurent
DOI:10.3390/molecules27144506
日期:——
overlapping those of phosphorus metabolites, and spectroscopic sensitivities (i.e., chemical shifts variation Δδab between the acidic and basic forms) ranging from 9.2–10.7 ppm, being fourfold larger than conventional endogenous markers such as inorganic phosphate. X-ray crystallographic studies combined with predictive empirical relationships and ab initio calculations addressed the inductive and
为了发现新的31 P NMR 标记物用于探测生物环境中的细微 pH 变化(<0.2 pH 单位),合成了 15 种新的构象受限或空间位阻的 α-氨基膦酸盐,它们源自二乙基(2-甲基吡咯烷-2-基)膦酸盐,并测试了它们的 pH 值报告和体外细胞毒性。所有化合物均显示出接近中性的 p K a s(范围为 6.28–6.97)、与磷代谢物不重叠的化学位移和光谱灵敏度(即化学位移变化 Δ δ ab介于酸性和碱性形式之间)范围为 9.2-10.7 ppm,比传统的内源性标记物(如无机磷酸盐)大四倍。X 射线晶体学研究与预测性经验关系和从头计算相结合,解决了与质子化胺功能相关的取代基的诱导和立体化学效应。在 p K a s 与二维结构和磷的金字塔化之间建立了令人满意的相关性,表明磷周围的空间拥挤对于调节 Δ δ ab至关重要。最后,命中31 P NMR pH 探针1b带有未取代的 1,3,2-二氧杂磷环烷环,它具有中等亲脂性,对