NOVEL PATHWAY FOR THE SYNTHESIS OF DIAZIRINES, THAT MAY OR MAY NOT BE ENRICHED IN NITROGEN-15
申请人:UNIVERSITE DE ROUEN NORMANDIE
公开号:US20220098155A1
公开(公告)日:2022-03-31
The present invention concerns a novel method for synthesising diazirines, that may or may not be enriched in nitro-gen-15, from amino acids or imines, via a one-pot synthesis method, comprising the reaction of the starting amino acid or imine with ammonia, which may or may not be enriched in nitrogen-15, and a hypervalent iodine oxidant. The present invention also relates to a method for synthesising ammonia enriched in nitrogen-15. The invention also concerns certain diazirines of formula (I) likely to be obtained by the claimed synthesis method, and also refers to the
15
N
2
-diazirines of formula (I′). The claimed diazirines can be used in photoaffinity labelling. The
15
N
2
-diazirines can also be used in hyperpolarisation, in particular in the medical imaging field.
γ-Glutamyl transpeptidase acylation with peptidic substrates: free energy relationships measured by an HPLC kinetic assay
作者:Mylène Morin、Caroline Rivard、Jeffrey W. Keillor
DOI:10.1039/b606914b
日期:——
γ-Glutamyl transpeptidase (GGT, EC 2.3.2.2) is a highly glycosylated heterodimeric enzyme linked to the external cellular membrane that catalyzes the hydrolysis of glutathione as well as the transfer of its γ-glutamyl group to amino acids and dipeptides in a transpeptidation reaction. The measurement of both the hydrolytic and transpeptidation activity of this important enzyme is a challenge, since its native substrates are not highly chromogenic. We have developed an HPLC-based method for the quantitative photometric detection of numerous enzyme substrates and products, after their pre-column derivation with dabsyl chloride. The broad applicability of this method was demonstrated in the kinetic investigation of transpeptidation reactions of rat kidney GGT with glutathione, its native substrate, as well as a series of pertinent glutathione analogues. The pH-rate profile constructed for glutathione confirmed the dependence on the ionisation state of at least two residues. Analysis of the free-energy relationships in the series of synthetic peptidic substrate analogues revealed the importance of enzymeâsubstrate interactions unrelated to amine leaving group basicity during the acylation step. These results are further interpreted in the context of the recently published structure for a similar GGT.
Iodonitrene in Action: Direct Transformation of Amino Acids into Terminal Diazirines and <sup>15</sup>N<sub>2</sub>-Diazirines and Their Application as Hyperpolarized Markers
作者:Thomas Glachet、Hamid Marzag、Nathalie Saraiva Rosa、Johannes F. P. Colell、Guannan Zhang、Warren S. Warren、Xavier Franck、Thomas Theis、Vincent Reboul
DOI:10.1021/jacs.9b07035
日期:2019.8.28
terminal diazirines has been developed using phenyliodonium diacetate (PIDA) and ammonia. This PIDA mediated transformation occurs via three consecutive reactions and involves an iodonitrene intermediate. This method is tolerant to most functional groups found on the lateral chain of amino acids, it is operationally simple, and can be scaled up to provide multigram quantities of diazirine. Interestingly