all-endo-3-amino-5-hydroxybicyclo[2.2.2]octane-2-carboxylic acid (13) and all-endo-5-amino-6-(hydroxymethyl)bicyclo[2.2.2]octan-2-ol (10) were prepared via dihydro-1,3-oxazine or g-lactone intermediates by the stereoselective functionalization of an N-protected derivative of endo-3-aminobicyclo[2.2.2]oct-5-ene-2-carboxylic acid (2). Ring closure of b-amino ester 4 resulted in tricyclic pyrimidinones 15 and 16. The structures, stereochemistry and relative configurations of the synthesized compounds were determined by IR and NMR.
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http://dx.doi.org/10.3390/molecules16097691 | DOI Listing |
Glob Chang Biol
January 2025
Department of Renewable Resources, University of Alberta, Edmonton, Canada.
Soil microorganisms transform plant-derived C (carbon) into particulate organic C (POC) and mineral-associated C (MAOC) pools. While microbial carbon use efficiency (CUE) is widely recognized in current biogeochemical models as a key predictor of soil organic carbon (SOC) storage, large-scale empirical evidence is limited. In this study, we proposed and experimentally tested two predictors of POC and MAOC pool formation: microbial necromass (using amino sugars as a proxy) and CUE (by O-HO approach).
View Article and Find Full Text PDFMol Cancer
January 2025
Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Background And Aims: Oncogenic KRAS mutations are present in approximately 90% of pancreatic ductal adenocarcinoma (PDAC). However, Kras mutation alone is insufficient to transform precancerous cells into metastatic PDAC. This study investigates how KRAS-mutated epithelial cells acquire the capacity to escape senescence or even immune clearance, thereby progressing to advanced PDAC.
View Article and Find Full Text PDFBMC Plant Biol
January 2025
Center for Eco-Environment Restoration of Hainan Province, School of Ecology, Hainan University, Haikou, 570228, China.
Drought has a significant impact on ecosystem functions, especially on the biogeochemical cycling of phosphorus (P), which is a crucial nutrient for plant growth and productivity. Despite its importance, the effects of different drought scenarios on soil P cycling and availability remain poorly understood in previous studies. This study simulated drought conditions in tropical soils using maize as a test crop under varying field capacity (FC) levels (100%, 80%, 60%, 40%, and 20%) over a 60-day pot experiment.
View Article and Find Full Text PDFCell Mol Biol Lett
January 2025
Department of Analytical Chemistry, Medical University of Bialystok, Kilinskiego 1, 15-069, Bialystok, Poland.
The skin is a barrier that protects the human body against environmental factors (physical, including solar radiation, chemicals, and pathogens). The integrity and, consequently, the effective metabolic activity of skin cells is ensured by the cell membrane, the important structural and metabolic elements of which are phospholipids. Phospholipids are subject to continuous transformation, including enzymatic hydrolysis (with the participation of phospholipases A, C, and D) to free polyunsaturated fatty acids (PUFAs), which under the influence of cyclooxygenases (COX1/2), lipoxygenases (LOXs), and cytochrome P450 (CYPs P450) are metabolized to various classes of oxylipins, depending on the type of PUFA being metabolized and the enzyme acting.
View Article and Find Full Text PDFProbiotics Antimicrob Proteins
January 2025
State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, No. 20 Dongda Street, Beijing, 100071, Fengtai District, China.
Human β-defensin (HBD) has been recognized as a promising antimicrobial agent due to its broad-spectrum antimicrobial activity against various pathogens. In our previous work, we engineered a chimeric human β-defensin, designated H4, by fusing human β-defensin 3 and human β-defensin 4, resulting in enhanced antimicrobial activity and salt stability. However, the high cost of chemical synthesis due to the relatively large number of amino acids in H4 has limited its applications.
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