Digalactosyldiacylglycerol (DGalDAG) is one of the major lipids in the cells of higher plants. DGalDAG forms a lamellar liquid crystalline phase together with water. Lipid aggregates can thus be prepared which are of potential interest for use within the cosmetic and pharmaceutical industries. Oats may be an important source for preparation of DGalDAG, but the structure has not been determined for the DGalDAG lipid occurring in this plant. In the present study the structure of a high-purity DGalDAG preparation, isolated from commercial oat flakes, was determined by high resolution 1H- and 13C-NMR spectroscopy. The lipid was found to have the structure 1,2-diacyl-3-O-[alpha-galactopyranosyl-(1-->6)-O-beta-galactopyranosyl]- glycerol. By using 1H- and 13C-NMR spectroscopy techniques it is thus possible to determine, among other things, the identity of the glycosyl moieties in the polar head group, to establish the linkage positions between these moieties, and to establish the anomeric configurations of the moieties, without making any chemical modifications of the lipid.
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http://dx.doi.org/10.1016/0009-3084(95)02483-y | DOI Listing |
RSC Adv
January 2025
Dipartimento di Scienze e Innovazione Tecnologica, Università Del Piemonte Orientale A. Avogadro Viale T. Michel 11 15121 Alessandria Italy
A novel synthesis of a nanometric MCM-41 from biogenic silica obtained from rice husk is here presented. CTABr and Pluronic F127 surfactants were employed as templating agents to promote the formation of a long-range ordered 2D-hexagonal structure with cylindrical pores and to limit the particle growth at the nanoscale level thus resulting in a material with uniform particle size of 20-30 nm. The physico-chemical properties of this sample (RH-nanoMCM) were investigated through a multi-technique approach, including PXRD, Si MAS NMR, TEM, -potential and N physisorption analysis at 77 K.
View Article and Find Full Text PDFACS Omega
January 2025
Applied Chemistry and Environment Laboratory, Applied Bioorganic Chemistry Team, Faculty of Science, Ibn Zohr University, Agadir 80000, Morocco.
The goal of this study was to synthesize and evaluate new antimicrobial compounds. We specifically focused on the development of 2,5-disubstituted tetrazole derivatives containing the O-methyl-2,3-O-isopropylidene-(D)-ribofuranoside groups through N-alkylation reactions. The synthesized compounds were characterized using H and C nuclear magnetic resonance (NMR) spectroscopy.
View Article and Find Full Text PDFACS Omega
January 2025
School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom.
Seventeen 3-alkylaminoquinoxaline-2(1)-thiones and 3-alkyloxyquinoxaline-2(1)-thiones were prepared by a novel thionation protocol from the readily available quinoxaline-2,3-dione in excellent overall yields. This protocol starts with the chlorination of dione using thionyl chloride to give 2,3-dichloroquinoxaline followed by the reaction with equimolar amounts of -nucleophiles (primary amines and secondary amines) or -nucleophiles (phenols and alcohols) to principally afford 2-alkanamino-3-chloroquinoxalines or 2-alkyloxy-3-chloroquinoxalines, respectively. The chloroquinoxalines reacted with the thionation reagent -cyclohexyl dithiocarbamate cyclohexyl ammonium salt in ethanol under reflux to principally give the corresponding quinoxalin-2-yl cyclohexylcarbamodithioate that finally rearranges to give the corresponding thiones in 76-93% overall yields.
View Article and Find Full Text PDFMagn Reson Chem
January 2025
Laboratório de Química Computacional e Modelagem Molecular (LQC-MM), Departamento de Química Inorgânica, Instituto de Química, Universidade Federal Fluminense (UFF), Niterói, Rio de Janeiro, Brazil.
We present a DFT-PCM NMR study of 3-indoleacetic acid (3-IAA), used as a working example, including explicit solvent molecules, named PCM-nCHCl, PCM-nDMSO (n = 0, 2, 4, 8, 14, 20, and 25), to investigate the dimer formation in solution. Apart from well-known cyclic (I) and open (II) acetic acid (AA) dimers, two new structures were located on DFT-PCM potential energy surface (PES) for 3-IAA named quasicyclic A (III) and quasicyclic B (IV), the last one having N-H…O hydrogen bond (instead of O-H…O). In addition, four other structures having π-π type interactions named V, VI, VII, and VIII were also obtained completing the sample on the PES.
View Article and Find Full Text PDFJ Biosci Bioeng
January 2025
Department of Biology, College of Science, Shantou University, Shantou 515063, Guangdong, China; Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Sciences, Shantou University, Shantou 515063, China; Shantou Key Laboratory of Marine Microbial Resources and Interactions with Environment, Shantou University, Shantou 515063, China. Electronic address:
Oxidative stress, caused by excessive production of reactive oxygen species (ROS), plays a crucial role in the occurrence and development of various diseases. Monascin can scavenge ROS and alleviate oxidative stress but with a low fermentation rate and bioavailability. Here, we optimized the fermentation process to increase the production of monascin (508.
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