We present here the synthesis and characterization of four photolabile derivatives of urea in which alpha-substituted 2-nitrobenzyl groups are covalently attached to the urea nitrogen. These derivatives photolyze readily in aqueous solution to release free urea. The alpha-substituents of the 2-nitrobenzyl group strongly influence the rate of the photolysis reaction measured with transient absorption spectroscopy. Rates of photolysis at pH 7.5 and room temperature (approximately 22 degrees C) for N-(2-nitrobenzyl)urea, N-(alpha-methyl-2-nitrobenzyl)urea, N-(alpha-carboxymethyl-2-nitrobenzyl)urea, and N-(alpha-carboxy-2-nitrobenzyl)urea are, respectively, 1.7 x 10(4), 8.5 x 10(4), 4.0 x 10(4), and 1.1 x 10(5) s(-)(1). The quantum yields determined by measurement of free urea following irradiation by a single laser pulse at 308 nm were 0.81 for N-(2-nitrobenzyl)urea, 0.64 for N-(alpha-methyl-2-nitrobenzyl)urea, and 0.56 for N-(alpha-carboxy-2-nitrobenzyl)urea. The caged N-(alpha-carboxy-2-nitrobenzyl)urea is not a substrate of the enzyme urease, while the photolytically released urea is. Also, neither this caged urea nor its photolytic side products inhibit hydrolysis of free urea by urease. Thus, the alpha-carboxy-2-nitrobenzyl derivative of urea is suitable for mechanistic investigations of the enzyme urease.
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BMJ Open
January 2025
School of Cardiovascular and Metabolic Health, University of Glasgow, Glasgow, UK.
Objective: Physical activity (PA) has been generally recognised as beneficial for health. The effect of a change in PA on kidney biomarkers in healthy individuals without kidney disease remains unclear. This manuscript synthesised the evidence of the association of changes in PA with kidney biomarkers in the general population free from kidney disease.
View Article and Find Full Text PDFActa Cir Bras
January 2025
Universidad Nacional de La Plata - Faculty of Medicine - Organ Transplant Laboratory - La Plata - Argentina.
Purpose: To mitigate ischemia-reperfusion injury (IRI) triggered in solid organ transplant procedures, we aimed to evaluate the effects of multi-organ abdominal ischemic preconditioning (MAIP) in the context of renal IRI.
Methods: An experimental kidney transplant model was conducted. Rats were divided into three groups: an intervention free basal group from which physiological data was collected; a control group (CT), which consisted of transplanted animals without MAIP; and a treated group, in which a MAIP protocol was implemented in the donor during the procurement of the left kidney, monitoring the recipient for 24 hours.
J Phys Chem B
January 2025
Department of Chemistry, National Institute of Technology Nagaland, Chumukedima, Nagaland 797103, India.
As one of nature's most fundamental blueprints and due to its critical role in life processes, DNA has naturally become the cornerstone of numerous research efforts. One particularly intriguing area of study is understanding how small molecules interact with nucleic acids. In this study, we investigated the interaction between the plant-derived indole alkaloid Raubasine (Ajmalicine; AJM) and Salmon Testes (ST) DNA using biophysical and computational techniques.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Mechanical Engineering, Research Institute for Smart Energy, The Hong Kong Polytechnic University, Hong Kong, China.
The multielectron conversion electrochemistry of I/I/I enables high specific capacity and voltage in zinc-iodine batteries. Unfortunately, the I ions are thermodynamically unstable and are highly susceptible to hydrolysis. Current endeavors primarily focus on exploring interhalogen chemistry to activate the I/I couple.
View Article and Find Full Text PDFBiology (Basel)
November 2024
Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia.
This study tested the ISL against renal damage induced by a high-fat diet (HFD) and explored its underlying mechanisms. Adult male rats were assigned to four groups: (1) control on a standard diet (STD), (2) ISL on STD (30 mg/kg), (3) HFD, and (4) HFD + ISL (30 mg/kg). After 12 weeks of dietary intervention, ISL treatment led to significant reductions in body weight gain, visceral fat, and glucose and insulin levels in HFD-fed rats.
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