Enantiomeric analysis and empirical determination of the absolute configuration of amines and amino acids can be easily performed using acetyl-d(3) chloride as a nonchiral derivatizing agent (deuterium probe) and deuterium NMR in a chiral solvent (Courtieu's method). In the case of amino acids, derivatization to amido esters, performed with methanol-d(4) and acetyl-d(3) chloride, gives a double opportunity for enantiomeric analysis.
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http://dx.doi.org/10.1021/ol006066g | DOI Listing |
ACS Appl Bio Mater
January 2025
Department of Chemistry, Indian Institute of Technology Palakkad, Palakkad, Kerala 678 623, India.
The aggregation of proteins, peptides and amino acids has been a keen subject of interest owing to their implications in metabolic disorders. In this work, we investigated the self-aggregation of the unmodified aromatic amino acid l-tryptophan (Trp) into unusual spherical microstructures. Using fluorescence spectroscopy and field emission scanning electron microscopy (FE-SEM), we detail the time-dependent transformation of monomeric tryptophan into spherical aggregates with distinct fluorescence characteristics (λ = 345 nm, λ = 430 nm) compared to the monomer.
View Article and Find Full Text PDFMol Biol Rep
January 2025
College of Life Sciences, Liaoning Normal University, Dalian, Liaoning, 116029, China.
Background: High temperature is a critical environmental factor leading to mass mortality in oyster aquaculture in China. Recent advancements highlight the physiological regulation function of γ-aminobutyric acid (GABA) in the adaptation of environmental stress.
Methods And Results: This study examined the physiological responses of the Pacific oyster (Crassostrea gigas) upon high temperature exposure, focusing on the histopathological changes in gill, the GABA concentration, the mRNA expression and activities of apoptosis-related genes.
Cell Mol Neurobiol
January 2025
Department of Anesthesiology, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, China.
Immune and metabolic factors play an important role in the onset and development of insomnia. This study aimed to investigate the causal relationship between insomnia and immune cells and metabolites. Data for 731 immune cell phenotypes, 1400 metabolites, and insomnia in this study were obtained from the GWAS open-access database.
View Article and Find Full Text PDFJ Exp Bot
January 2025
Morden Research and Development Centre, Agriculture and Agri-Food Canada, Morden, MB, Canada.
Alternative oxidase (AOX) regulates the level of reactive oxygen species and nitric oxide (NO) in plants. While under normoxic conditions it alleviates NO formation, there are several indications that in the conditions of low oxygen such as during seed germination before radicle protrusion, in meristematic stem cells, and in flooded roots AOX can be involved in the production of NO from nitrite. Whereas the first reports considered this role as indirect, more evidence is accumulated that AOX can act as a nitrite: NO reductase.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Modelling of Cognitive Processes, Berlin Institute of Technology, Berlin 10587, Germany.
Neuronal processing of external sensory input is shaped by internally generated top-down information. In the neocortex, top-down projections primarily target layer 1, which contains NDNF (neuron-derived neurotrophic factor)-expressing interneurons and the dendrites of pyramidal cells. Here, we investigate the hypothesis that NDNF interneurons shape cortical computations in an unconventional, layer-specific way, by exerting presynaptic inhibition on synapses in layer 1 while leaving synapses in deeper layers unaffected.
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