This paper illustrates the use of the program CCBond to determine the carbon skeletons of bioorganic molecules in low concentration samples. Discussed is the structure elucidation of bistramide A, a compound extracted from a Fijian Lissoclinum sp. and cholesterol in 71- and 20-mumol samples, respectively. The detection limit of the automated bond extraction is shown to be dramatically improved compared to the manual interpretation of 2D INADEQUATE spectra.
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http://dx.doi.org/10.1021/ac00048a012 | DOI Listing |
Nat Commun
December 2024
Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland.
While H-H J-couplings are the cornerstone of all spectral assignment methods in solution-state NMR, they are yet to be observed in solids. Here we observe H-H J-couplings in plastic crystals of (1S)-(-)-camphor in solid-state NMR at magic angle spinning (MAS) rates of 100 kHz and above. This is enabled in this special case because the intrinsic coherence lifetimes at fast MAS rates become longer than the inverse of the H-H J couplings.
View Article and Find Full Text PDFJ Magn Reson
January 2025
Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181, UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France. Electronic address:
The two-dimensional (2D) refocused INADEQUATE NMR experiment, which correlates double-quantum (DQ) and single-quantum (SQ) coherences, is widely used to probe the chemical connectivities in solids. Nevertheless, the multiplets along the F dimension reduce the resolution and sensitivity of this experiment. The Composite-Refocusing (CR) technique with two excitation pulses has been proposed to suppress these multiplets in 2D INADEQUATE spectra of liquids.
View Article and Find Full Text PDFPhys Chem Chem Phys
November 2024
Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA.
Heavy-atom-free photosensitizers (HAF-PSs) have emerged as a new class of photosensitizers aiming to broaden their applicability and versatility across various fields of the photodynamic therapy of cancers. The strategy involves replacing the exocyclic oxygen atoms of the carbonyl groups of established biocompatible organic fluorophores with sulfur, thereby bathochromically shifting their absorption spectra and enhancing their intersystem crossing efficiencies. Despite these advancements, the photophysical attributes and electronic relaxation mechanisms of many of these HAF-PSs remain inadequately elucidated.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
State Key Laboratory of Bio-fibers and Eco-textiles, Collaborative Innovation Center of Shandong Marine Biobased Fibers and Ecological Textiles, Institute of Marine Biobased Materials, College of Materials Science and Engineering, Qingdao University, Qingdao, 266071, P. R. China.
Nat Prod Res
October 2024
Department of Biotechnology, Jaypee Institute of Information Technology, Noida, India.
, strain TD-062, a micro colonial black yeast, was obtained as part of a screening program from the Thar Desert of India, which has been inadequately explored for novel microorganisms/bioactive metabolites. The anticancer activity of aqueous and organic solvent extracts of culture supernatant of TD-062 was investigated against A-375 myeloma and MCF-7 breast cancer cell lines. Following column chromatography, bioactive fractions were subjected to GC-MS analysis in two cycles.
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