A synthetic scheme has been developed to prepare methylmethacrylate specifically 13C-labelled at all different positions and in any combination of positions, from simple, commercially available starting materials. According to this scheme methyl (1-13C)- and methyl (2-13C)methacrylate (1a and 1b) have been prepared with high label incorporation (99%).
5,5'-Diferulic acid (5,5'-DFA), which is one of the cross-linking residues in plant cell walls, was prepared by using a facile procedure. The phenol oxidation of vanillin with FeCl3 gave divanillin, which was further devoted to a Perkin reaction to give the desired product. It was found on (13)C-NMR that the chemical shift of C-5 of ferulic acid (FA) clearly shifted downfield, when this carbon is quaternarized
Amino Acid‐Derived Sensors for Specific Zn
<sup>2+</sup>
Detection Using Hyperpolarized
<sup>13</sup>
C Magnetic Resonance Spectroscopy
作者:Sinan Wang、David E. Korenchan、Paola M. Perez、Céline Taglang、Thomas R. Hayes、Renuka Sriram、Robert Bok、Andrew S. Hong、Yunkou Wu、Henry Li、Zhen Wang、John Kurhanewicz、David M. Wilson、Robert R. Flavell
DOI:10.1002/chem.201902771
日期:2019.9.12
Herein, enriched [1-13 C]cysteine and [1-13 C2 ]iminodiacetic acid were developed as Zn2+ -specific imaging probes usinghyperpolarized13Cmagneticresonancespectroscopy. [1-13 C]cysteine was used to accurately quantify Zn2+ in complex biological mixtures. These sensors can be employed to detect Zn2+ via imaging mechanisms including changes in 13C chemical shift, resonance linewidth, or T1 .
Synthesis of 13C-labeled γ-hydroxybutyrates for EPR studies with 4-hydroxybutyryl-CoA dehydratase
作者:Ulrike Näser、Antonio J. Pierik、Richard Scott、Irfan Çinkaya、Wolfgang Buckel、Bernard T. Golding
DOI:10.1016/j.bioorg.2004.09.001
日期:2005.2
4-Hydroxybutyryl-CoA dehydratase from Clostridium aminobutyricum catalyses the reversible dehydration of its substrate 4-hydroxybutyryl-CoA (4-HB-CoA) to crotonyl CoA. The enzyme contains one [4Fe-4S](2+) cluster and one flavin adenine dinucleotide (FAD) molecule per homotetramer. Incubation of the enzyme with its substrate under equilibrium conditions followed by freezing at 77 K induced the EPR-spectrum of a neutral flavin semiquinone (g = 2.005, linewidth 2.1 mT), while at 10 K additional signals were detected. In an attempt to characterize these signals, 4-HB-CoA molecules specifically labeled with C-13 have been synthesized. This was achieved via C-13-labeled gamma-butyrolactones, which were obtained from C-13-labeled bromoacetic acids by efficient synthetic routes. Incubation of the C-13-labeled 4-hydroxybutyrate-CoA molecules with 4-hydroxybutyryi-CoA dehydratase did not lead to marked broadening of the signals.(C) 2004 Elsevier Inc. All rights reserved.