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Single-compound analysis of stable or radioactive isotopes has found application in a number of fields ranging from archaeology to forensics. Often, the most difficult part of these analyses is the development of a method for isolating the compound(s) of interest, which can derive from a wide range of sample types including the hair, nails, and bone.Here we describe three complementary preparative HPLC techniques suitable for separating and isolating amino acids from bone collagen and hair keratin. Using preparative reversed-phase, ion-pair, or mixed-mode chromatography in aqueous carbon-free mobile phases, or those from which carbon can easily be removed, underivatized single amino acids can be isolated and further analyzed using mass spectrometric techniques.
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http://dx.doi.org/10.1007/978-1-4939-9639-1_7 | DOI Listing |
Org Lett
September 2025
Frontiers Science Center for Transformative Molecules, State Key Laboratory of Polyolefins and Catalysis, State Key Laboratory of Synergistic Chem-Bio Synthesis, Zhang Jiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China.
C-labeled α-amino acids are important molecules in biological studies and drug development. Cost-effective synthesis of α-amino acids with a high level of C incorporation under mild conditions remains limited. Herein, we report the development of a benzylic C(sp)-H carboxylation method to prepare highly C-labeled α-amino acids, i.
View Article and Find Full Text PDFPLoS One
September 2025
Guangdong Provincial Key Laboratory of Animal Molecular Design and Precise Breeding, School of Animal Science and Technology, Foshan University, Foshan, China.
Double-Layer Steamed Milk Custard (DLSMC) is a famous traditional Chinese dessert. This study aimed to analyze the flavor and the changes in metabolites during different stages of DLSMC preparation, including raw buffalo milk, thermo-processing, first and second-layer milk skin formation. Electronic nose and electronic tongue were employed to preliminarily assess the overall flavor characteristics between these stages.
View Article and Find Full Text PDFOrg Lett
September 2025
Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat 382355, India.
Herein, we report an easily tunable and regioselective Pd-catalyzed allene-alkyne coupling protocol for the stereodivergent synthesis of - and -1,3-enynes using purine allenamine by a simple switch of ligands P(-tolyl)Ph and Boc-Phe-OH. For the first time, we have explored mono--protected amino acids (MPAAs) as ligands in allene-alkyne coupling to furnish -1,3-enynes selectively. This protocol streamlined the access to chiral 1,3-enynes and addressed the long-standing stereoselectivity challenges associated with 1,3-enynes from allene-alkyne coupling.
View Article and Find Full Text PDFMar Biotechnol (NY)
September 2025
Department of Marine Life Science, Jeju National University, Jeju, 63243, South Korea.
This study assessed the optimum dietary vitamin B requirement of Pacific white shrimp, Penaeus vannamei, for growth, feed efficiency, hemocyte counts, innate immunity, and ammonia stress resistance. Semi-purified experimental diets were prepared by adding vitamin B at 0.0, 0.
View Article and Find Full Text PDFOrg Lett
September 2025
State Key Laboratory of Chemistry for NBC Hazards Protection, Beijing 102205, China.
Optically active α-aminophosphonic acids are unique analogues of α-amino acids, and numerous synthetic methods have been developed. Herein, we present a highly diastereoselective α-azidation approach to the CAMDOL-derived phosphonates, enabling ready access to 27 diverse α-azidophosphonates with defined chirality in up to 85% yield and more than 99:1 dr. Late-stage transformations through the Staudinger reaction or click reaction efficiently delivered the related pharmacological α-aminophosphonic acids or the unique α-triazolylphosphonate derivative, respectively.
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