Monthly Archives: May 2013

CLIP-HSQMBC: Very easy, direct and accurate measurement of nJCH in organic molecules and natural products

Methods & Applications, Our Publications, Our Research,

CLIP-HSQMBC: Easy measurement of small proton-carbon coupling constants in organic molecules, by Josep Saurí, Teodor Parella and Juan F. Espinosa; Org. Biomol. Chem., 2013, 11, 4473-4478. DOI:10.1039/C3OB40675J

A user-friendly 2D NMR approach denoted as CLIP-HSQMBC is proposed for the very easy, direct and accurate measurement of long-range proton-carbon coupling constants in organic molecules and natural products. The J value can be extracted directly from the analysis of resolved in-phase 1H multiplets that show an additional splitting arising from the proton-carbon coupling. Continue reading CLIP-HSQMBC: Very easy, direct and accurate measurement of nJCH in organic molecules and natural products →

NMR confirms cysteine labelling with SFB in peptides

Our Publications, ,

issue 1 - RSC Advances_2012.indd“Efficient cysteine labelling of peptides with N-succinimidyl 4-[18F]fluorobenzoate: stability study and in vivo biodistribution in rats by positron emission tomography ( PET)” by Santiago Rojas, Pau Nolis, Juan D. Gispert, Jan Spengler, Fernando Albericio, José R. Herance, Sergio Abad.  RSC Advances. 2013. DOI: 10.1039/C3RA40754C

A rapid and high-yielding cysteine labelling of peptides has been observed with the specific labelling agent for amines, N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB). Interestingly, NMR demonstrates that conjugation of the 4-fluorobenzoyl (FB) moiety is selectively achieved through a cysteine (Cys) thiol of the peptides with high yield (>80%) in short time (<5 min), while for a Cys amino acid derivative, a slow process has been observed. Continue reading NMR confirms cysteine labelling with SFB in peptides →

J-selHSQMBC: Simultaneous measurement of JHH and two different nJCH using IPAP, J-resolved and E.COSY principles

Methods & Applications, Our Publications, Our Research, , , , ,

cover_MRC“Simultaneous measurement of J(HH) and two different nJ(CH) coupling constants from a single multiply-edited 2D cross-peak”, by Josep Saurí and Teodor Parella; Magn. Reson. Chem. 2013, 51, 397-402. DOI: 10.1002/mrc.3960

Three different J-editing methods (IPAP, E.COSY and J-resolved) are implemented in a single NMR experiment to provide spin-state-edited 2D cross-peaks from which simultaneous measurement of different homonuclear and heteronuclear coupling constants can be performed. Continue reading J-selHSQMBC: Simultaneous measurement of JHH and two different nJCH using IPAP, J-resolved and E.COSY principles →