The availability of cryogenically cooled probes permits routine acquisition of data from low sensitivity pulse sequences such as inadequate and 1,1-adequate. We demonstrate that the use of cryo-probe generated 1,1-adequate data in conjunction with HMBC dramatically improves computer-assisted structure elucidation (CASE) both in terms of speed and accuracy of structure generation. In this study data were obtained on two dissimilar natural products and subjected to CASE analysis with and without the incorporation of two-bond specific data. Dramatic improvements in both structure calculation times and structure candidates were observed by the inclusion of the two-bond specific data.
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http://dx.doi.org/10.1002/mrc.2622 | DOI Listing |
J Am Chem Soc
August 2024
Frontiers Science Center for New Organic Matter, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), State Key Laboratory of Advanced Chemical Power Sources, College of Chemistry, Nankai University, Tianjin 300071, P. R. China.
J Am Chem Soc
February 2024
Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India.
Molecular recognition events mediated by glycans play pivotal roles in controlling the fate of diverse biological processes such as cellular communication and the immune response. The affinity of glycans for their target receptors is governed primarily by the hydrogen bonds formed by hydroxyl groups decorating the glycan surface. Hydroxyl exchange rate constants are therefore vital parameters that report on glycan structure and dynamics.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2023
Instituto de Ciencia de Materiales de Madrid (ICMM), CSIC, E-28049 Madrid, Spain.
Transition-metal chalcogenides with intercalated layered structures are interesting systems in material physics due to their attractive electronic and magnetic properties, with applications in the fields of magnetic refrigerators, catalysts, and thermoelectrics, among others. In this work, we studied in detail the structural, electronic, and magnetic properties of (Fe,Ti)-based sulfides with formula FeTiS ( = 0.24, 0.
View Article and Find Full Text PDFJ Nat Prod
December 2022
Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan.
A chemical investigation of strain RD003821, belonging to the underexplored actinomycetes genus , led to the discovery of three novel polyketides: two 20-membered glycomacrolides, krasilnikolides A () and B (), and an aglycone of , detalosylkrasilnikolide A (). A major challenge in the structure elucidation of was to determine the anomeric configuration of the α-l-6-deoxytalose (6dTal) unit, which was achieved by -based configuration analysis (JBCA) that incorporated anomeric carbon- and proton-specific two-bond C-H spin-spin coupling constants as diagnostic parameters. The updated criteria for the conformation/configuration assignment facilitated discrimination of three out of four stereochemical variants at the anomeric and the adjacent C2 positions, which expanded the scope of the JBCA method to determination of the anomeric configuration of aldohexopyranoses.
View Article and Find Full Text PDFAnal Chem
May 2021
Center for Environmental and Systems Biochemistry, Markey Cancer Center, and Dept. of Toxicology & Cancer Biology, University of Kentucky, 789 S. Limestone Street, Lexington, Kentucky 40536, United States.
A substantial fraction of common metabolites contains carboxyl functional groups. Their C isotopomer analysis by nuclear magnetic resonance (NMR) is hampered by the low sensitivity of the C nucleus, the slow longitudinal relaxation for the lack of an attached proton, and the relatively low chemical shift dispersion of carboxylates. Chemoselective (CS) derivatization is a means of tagging compounds in a complex mixture via a specific functional group.
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