Ting Li,Yong Liao,Xiaoyan Jiang,Di Mu,Xiandeng Hou,Chunchun Zhang,Pengchi Deng
The chemical shifts of several important endogenous phosphorus compounds under different pH conditions were explored, including adenosine-5′-triphosphate, adenosine-5′-diphosphate, adenosine-5′-monophosphate, phosphorylcholine and phosphorylethanolamine. Their 31 P NMR and 1 H NMR chemical shifts were all pH-sensitive in the similar pH range. Two dimensional (2D) 1 H– 31 P NMR spectra were found helpful to identify these endogenous phosphorus markers in biological samples from rather complicated NMR spectra. Herein, for the first time, a pH sensor based on 2D 1 H– 31 P NMR was established and applied to biological samples analysis with pH values determined in good agreement with those by potentiometric method . Apart from being simple, green, rapid and less sample-consuming, information concerning both the endogenous phosphorus markers and pH status could be attained in a single NMR run, which demonstrated the great potential of this method in rare sample analysis and even disease diagnosis.
Wang Dai,Qiangqiang Liu,Xiaohui You,Zhongfei Zhou,Yanchun Guo,Yufen Zhao,Shuxia Cao
The Atherton–Todd-type reaction of hydrospirophosphoranes (HSPs) and sodium alcoholates was investigated. Direct alkoxylation of HSPs was accomplished with sodium alcoholates in acetonitrile under nitrogen atmosphere. The stereochemistry mechanism of the alkoxidation of HSPs was proposed by the 31 P NMR tracing experiment. The reaction proceeded via the chlorinated spirophosphorane intermediate with stereoretention of the configuration at phosphorus, followed by the rear and front attack of alkoxide anions to produce alkoxy spirophosphoranes. The reaction mechanism well explained the results of the reaction of HSPs with sodium alcoholates.
The oxidation of cold-pressed and commercial refined camellia oil stored at room temperature for one year was comparatively studied by 1 H and 31 P NMR spectroscopy. The oxidation of extra virgin olive oil (EVOO) under the same conditions was further compared. The 1 H NMR showed that no aldehydes were formed in the studied period. Coupled with the changes of unsaturated acyl groups, the oxidation degrees of the three oils could be obtained follow the order: commercial refined camellia oil > cold-pressed camellia oil > EVOO. The 31 P NMR showed that the evolution of diacylglycerols (DGs) and ratio D in commercial refined camellia oil was fairly different from other two oils. Besides, the kinetics curves of unsaturated acyl groups and ratio D both fit to an exponential equation with high coefficients which indicated that the oxidation of the studied oils progressed in an exponential way with storage time at room temperature.
危险品化学品经营许可证（带存储）