Distinct types of new boron fused primary amino amide organocatalysts were designed and synthesized from commercially available amino acids. Their catalytic activities were investigated in asymmetric crossed aldol reaction of ketones with aromatic aldehydes to afford the corresponding chiral -aldol adducts with good chemical yields, moderate diastereoselectivity and good to excellent enantioselectivities (up to 94% yields, up to 90 : 10 dr, up to 94% ee).
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http://dx.doi.org/10.1039/d2ra06272k | DOI Listing |
Mar Drugs
December 2024
Discipline of Dietetics and Nutrition, College of Agriculture, University of KwaZulu-Natal, Durban 3201, South Africa.
Collagen, a critical biomaterial with wide applications in pharmaceuticals, cosmetics, and medical industries, can be sourced sustainably from fish scales. This study optimizes the extraction of collagen using Tris-Glycine buffer from fish scales via the Taguchi method. Various extraction parameters-buffer concentration, temperature, pH, and time-were evaluated to identify optimal conditions.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR 999077, China.
Catalytic enantioselective substitution of the readily available racemic α-halo carbonyl compounds by nitrogen nucleophiles represents one of the most convenient and direct approaches to access enantioenriched α-amino carbonyl compounds. Distinct from the two available strategies involving radicals and enolate ions, herein we have developed a new protocol featuring an electronically opposite way to weaken/cleave the carbon-halogen bond. A suitable chiral anion-based catalyst enables effective asymmetric control over the key positively charged intermediates.
View Article and Find Full Text PDFFood Sci Nutr
December 2024
Department of Biochemistry and Biotechnology, School of Health Sciences University of Thessaly Larissa Greece.
Previous studies have shown that seaweed extracts (HMEs) possess antioxidant properties, but the molecular mechanisms accounting for this activity are not known. Thus, the present study investigated the molecular mechanisms through which HME exerted its antioxidant activity in human mesenchymal stem cells (WJ-MSCs). After the isolation of HME, its chemical composition was analyzed with gas chromatography mass spectrometry, indicating that it contained amino acids, organic acids, organic amides, sugar alcohols, saturated fatty acids, hydrogenated diterpene alcohols, and other organic compounds.
View Article and Find Full Text PDFBioresour Technol
December 2024
Institute of Clean Coal Technology, East China University of Science and Technology, Shanghai 200237, P.R. China.
Hydrothermal pretreatment (HTP) is used to increase the biochemical methane potential (BMP) of food waste (FW). The formation of melanoidins will seriously affect the microbial activity and methane production during anaerobic digestion (AD). Based on spectroscopic methods, similarities and heterogeneity of melanoidins from different sources were investigated, and the wide peak band (260-350 nm) in the ultraviolet region and the differences of amide groups of fructose-amino acid system, fructose-casein system and FW system were revealed.
View Article and Find Full Text PDFHuan Jing Ke Xue
January 2025
Department of Environmental Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617, China.
To explore the effects of the components in the raw materials and by-products of co-pyrolysis on the physicochemical properties of biochar, rice husk (RH, which has a high percentage of lignin and a low content of N) and sawdust (SD, which has a high percentage of both cellulose and N) were used as typical raw materials to prepare co-pyrolysis biochar. The benzene vapor adsorption performance of the obtained biochar was then tested on a fixed-bed device. At the same time, the by-product components generated during pyrolysis were analyzed using thermogravimetric (TG), scanning electron microscopy (SEM), and gas chromatography-mass spectrometry (GC-MS).
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