Hydrogen bonding plays a major role in the selective recognition of guanidinium groups by receptor molecules. The present NMR investigation provides direct experimental evidence of hydrogen bonds in an artificial arginine receptor complex consisting of alpha-N-benzoylarginine ethyl ester and a bisphosphonate tweezers molecule. trans-Hydrogen bond 2hJHP couplings between the phosphonate moieties and individual guanidinium protons as well as the amide proton have been detected by [1H,31P]-HMBC and [31P,1H]-INEPT experiments. The detected hydrogen bonding network in the investigated artificial arginine receptor shows a symmetrical end-on interaction of the guanidinium moiety, which enables concerted rotations and deviates from the structure proposed for the biological arginine fork.
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Animals (Basel)
December 2024
College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109, China.
Sex-controlled sperm combined with artificial insemination allows animals to reproduce offspring according to the desired sex, accelerates the process of animal genetics and breeding and promotes the development of animal husbandry. However, the molecular markers for sexual sperm sorting are unusual. To identify the molecular markers of boar sperm sorting, proteomics and metabolomics techniques were applied to analyze the differences in proteins and metabolism between X and Y sperm.
View Article and Find Full Text PDFSmall
January 2025
Department of Chemistry, Key Laboratory of Biomedical Functional Materials, School of Science, China Pharmaceutical University, Nanjing, 211198, P. R. China.
Ulcerative colitis (UC) involves persistent inflammation in the colon and rectum, with excessive reactive oxygen species (ROS) accumulation. This ROS buildup damages colonic epithelial cells and disrupts intestinal flora, worsening disease progression. Current antioxidant therapies are limited due to their instability in the gut and lack of targeting, hindering precise intervention at the lesion site.
View Article and Find Full Text PDFFront Pharmacol
December 2024
College of Pharmacy, Anhui University of Chinese Medicine, Hefei, China.
Introduction: Pharmacological studies have shown that the rhizome of Atractylodes macrocephala Koidz. (Compositae), commonly known as atractylodes macrocephala rhizome (AMR), can modulate immunity. Nevertheless, its resources have been largely depleted, and the pharmacological activity of artificial AMR is relatively modest.
View Article and Find Full Text PDFJ Environ Manage
January 2025
State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), Harbin Institute of Technology, Harbin, 150090, China.
BMC Oral Health
December 2024
Faculty of Dentistry, Department of Restorative Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
Background: The increase in the prevalence of erosion lesions worldwide has led researchers to develop effective toothpastes with different ingredients to prevent erosion that can protect the tooth surface against acid attacks. There remains a lack of consensus in the literature regarding which toothpaste formulation exhibits the most effective preventive action against erosive tooth wear, highlighting the necessity for further investigation in this field. This study aimed to evaluate the preventive effect of brushing with toothpastes with different ingredients on enamel and dentine erosion.
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