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http://dx.doi.org/10.1021/jo981901h | DOI Listing |
Anal Chim Acta
January 2025
College of Pharmacy, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul, 06974, Republic of Korea. Electronic address:
Background: The simplicity of synthesis methods has facilitated the illegal manufacture of various fentanyl analogs, leading to numerous fatal overdoses worldwide, particularly in North America. Fentanyl analogs with similar structures are difficult to distinguish due to their fragmentation patterns, making separation using chromatography essential. Additionally, because fentanyl analogs are lethal even in trace amounts, they are easily smuggled, and commonly used fentanyl test strips often fail to detect them due to their low sensitivity.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Institute of Organic Chemistry, University Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany.
In ion-pair catalysis, the last intermediate structures prior to the stereoselective transition states are of special importance for predictive models due to the high isomerization barrier between - and -substrate double bonds connecting ground and transition state energies. However, in prior experimental investigations of chiral phosphoric acids (CPA) solely the early intermediates could be investigated while the key intermediate remained elusive. In this study, the first experimental structural and conformational insights into ternary complexes with CPAs are presented using a special combination of low temperature and relaxation optimized N HSQC-NOESY NMR spectroscopy to enhance sensitivity.
View Article and Find Full Text PDFNat Commun
January 2025
Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Chemical Biology Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing, China.
Helicene-shaped molecules are compelling chemical structures with unique twisted helical chirality and remarkable properties. Although progress occurs in the catalytic asymmetric synthesis of helicene (-like) molecules, the enantioselective synthesis of multiple helicenes, especially four or higher helicity, is still challenging and has yet to be achieved. Herein, we report an organocatalytic [4 + 2] cycloadditions to achieve double S-shaped quadruple helicene-like molecules with high enantioselectivity (up to 96% e.
View Article and Find Full Text PDFFood Res Int
January 2025
Faculty of Science & Technology, Meijo University, 1-501 Shiogamaguchi, Tempaku-ku, Nagoya, Aichi 468-8502, Japan; Graduate School of Environmental and Human Sciences, Meijo University, 1-501 Shiogamaguchi, Tempaku-ku, Nagoya, Aichi 468-8502, Japan. Electronic address:
Growing evidence indicates that the intake of trans-fatty acids (TFAs) has been associated with a higher risk of cardiovascular disease; therefore, various industrial measures have been taken to reduce the amount of TFAs consumed. However, research on TFAs formed during cooking is limited. Isothiocyanates and polysulfides, which are widely distributed in various vegetables, have recently been shown to promote the cis-trans isomerization of double bonds.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
Department of Molecular Sciences, Swedish University of Agricultural Sciences, Almas Allé 5, Uppsala 75651, Sweden. Electronic address:
Chitin is the second most abundant biopolymer in nature after cellulose and is composed of N-acetylglucosamine (GlcNAc) connected via β(1 → 4)-glycosidic bonds. Despite its prominence in nature and diverse roles in pharmaceutical and food technological applications, there is still a need to develop methods to study structure and function of chitin and its corresponding oligomers. Efforts have been made to analyse chitin oligomers by NMR spectroscopy, but spectral overlap has prevented any differentiation between the interior residues.
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