Over the past decades, different software programs have been developed for the Computer-Assisted Structure Elucidation (CASE) with NMR data using with various approaches. WebCocon is one of them that has been continuously improved over the past 20 years. Here, we present the inclusion of 4J correlations (4J-HMBC) in the HMBC interpretation of Cocon and NOE data in WebCocon. The 4J-HMBC data is used during the structure generation process, while the NOE data is used in post-processing of the results. The marine natural product oxocyclostylidol was selected to demonstrate WebCocon's enhanced HMBC data processing capabilities. A systematic study of the 4J correlations of oxocyclostylidol was performed. The application of NOEs in CASE is demonstrated using the NOE correlations of the diterpene pyrone asperginol A known from the literature. As a result, we obtained a conformation that corresponds very well to the existing X-ray structure.
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http://dx.doi.org/10.3390/molecules26164846 | DOI Listing |
Chemistry
December 2024
Eotvos Lorand University, Organic Chemistry, Pazmany Peter Setany 1/A, 1117, Budapest, HUNGARY.
The present study reveals an unexpected anomaly observed in the acid-catalyzed hydrolysis of the 5,6-O-isopropylidene group in 3-O-protected D-gluco- and D-allofuranose derivatives. Although the removal of the 5,6-O-isopropylidene protecting group is typically rapid and quantitative under acidic conditions, an unexpected inhibition of this reaction is observed for the two C3-epimers, 3-O-imidazole sulfonyl moiety. X-ray data show a two-faced imidazole ring orientation in the crystal, while solution state NOE data reveal a critical interaction type between the isopropylidene and the imidazole rings.
View Article and Find Full Text PDFCirc J
December 2024
Department of Cardiology, Hirakata Kohsai Hospital.
Background: Previous randomized clinical trials did not support a benefit of screening for occult cancer after diagnosis of venous thromboembolism (VTE), although screening may be of potential benefit for selected high-risk patients.
Methods And Results: The COMMAND VTE Registry-2 enrolled consecutive patients with acute symptomatic VTE between 2015 and 2020 from 31 centers across Japan. The 3,706 patients in the registry without known active cancer at the time of VTE diagnosis were divided into 2 groups: those with (n=250) and without (n=3,456) newly diagnosed cancer during the follow-up period.
Cell Metab
December 2024
Institute of Food, Nutrition and Health, ETH Zurich, Schwerzenbach, Switzerland. Electronic address:
Precision medicine is still not considered as a standard of care in obesity treatment, despite a large heterogeneity in the metabolic phenotype of individuals with obesity. One of the strongest factors influencing the variability in metabolic disease risk is adipose tissue (AT) dysfunction; however, there is little understanding of the link between distinct cell populations, cell-type-specific transcriptional programs, and disease severity. Here, we generated a comprehensive cellular map of subcutaneous and visceral AT of individuals with metabolically healthy and unhealthy obesity.
View Article and Find Full Text PDFPhys Chem Chem Phys
December 2024
Universite de Lyon, CNRS, UCB Lyon1, Institut des Sciences Analytiques, UMR5280, Villeurbanne, France.
The emergence of very high NMR magnetic fields will certainly encourage the study of larger biological systems with their dynamics and interactions. NMR spin relaxation allows probing the dynamical properties of proteins where the N longitudinal () and transverse () relaxation rates in addition to the H-N heteronuclear NOE describe the ps-ns time scale. Their analytical representation involves the chemical shift anisotropy (CSA) effect that represents the major contribution at a very high magnetic field above 18.
View Article and Find Full Text PDFZh Vopr Neirokhir Im N N Burdenko
December 2024
Burdenko Neurosurgical Center, Moscow, Russia.
Unlabelled: The development of new drugs in nuclear medicine for diagnosis or treatment (chemotherapy) of brain tumors, in particular gliomas, is inextricably linked with the use of tumor models in animals (usually rats).
Objective: To compare the widely used glioma cell model C6 and the new experimental tissue model of glioblastoma 101.8.
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