Carnosine (beta-Ala-L-His) has high antioxidant activity, and it is widely used in biology, chemical engineering, medicine and other fields. Its analogue syntheised in non-aqueous solvent and catalyzed by enzymes is high-effective but low-price, so it has great prospect. Here, we synthesized a carnosine analogue imidazole 4(5)-alanylamide-5(4)-carboxylic acid with imidazole-4,5-dicarboxylic acid and L-Alanine as substrates, alpha-chymotrypsin as catalyst in tetrahydrofuran (THF) solvent. Based on the orthogonal experiments, the optimized synthetic conditions are 4,5-dicarboxylic acid: L-alanine = 1:3 (m/m), alpha-chymotrypsin: substrates (4,5-dicarboxyl acid and L-alanine) = 1:200 (m/m), pH 8 phosphate buffer:THF = 1.6:10 (V/V), reaction temperature 35 degrees C, time 1.5 h. We separated the product with silica gel G60 thin-layer chromatography (TLC), and a new spot appeared at Rf (ratio to front) = 0.81; then the new spot was purified and characterized with UV spectra, high performance liquid chromatogram (HPLC) and 13C NMR (13C nuclear magnetic resonance). The UV spectra shows a new absorption peak at 310 nm, and the peak in 253 nm is largely strengthened; HPLC reserve times are all 4.5 min at 253 nm, 310 nm, 330 nm; 13C NMR shows 8 carbons. Combing with the catalytic mechanism of alpha-chymotrypsin, structure of the analogue is confirmed, i.e., imidazole 4(5)-alanylamide-5(4)-carboxylic acid.
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Sci Rep
January 2025
Department of Zoology, Faculty of Science, Cairo University, Giza, Egypt.
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View Article and Find Full Text PDFPlant Physiol Biochem
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Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Shaanxi Provincial Key Laboratory of Biotechnology, College of Life Sciences, Northwest University, Xi'an, 710069, Shaanxi, People's Republic of China. Electronic address:
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Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
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Probiotics Antimicrob Proteins
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Department of Gastroenterology & Hepatology, Laboratory of Metabolomics and Drug-induced Liver Injury, Frontiers Science Center for Disease-Related Molecular Network, and State Key Laboratory of Respiratory Health and Multimorbidity, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
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View Article and Find Full Text PDFACS Chem Neurosci
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School of Health & Life Sciences, Teesside University, Middlesbrough TS1 3BX, United Kingdom.
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