536,537 results match your criteria 269-trisubstituted purine


Purine Nucleoside Derivatives Containing a Sulfa Ethylamine Moiety: Design, Synthesis, Antiviral Activity, and Mechanism.

J Agric Food Chem 2021 May 14. Epub 2021 May 14.

State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, P. R. China.

To find efficient and broad-spectrum viral agents, a series of purine nucleoside derivatives containing sulfa ethylamine moieties was designed and synthesized, and their antiviral activities against tobacco mosaic virus (TMV), cucumber mosaic virus (CMV), and potato virus Y (PVY) were evaluated. Some target compounds displayed good antiviral activities. Among them, compound showed excellent protective activity against CMV and PVY with 50% effective concentration values (EC) of 137 and 209 μg/mL, respectively, which were better than that of the control agent ningnanmycin (508 and 431 μg/mL). Read More

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On the origin of the genetic code: a 27-codon hypothetical precursor of an intricate 64-codon intermediate shaped the modern code.

Authors:
Bernard Dujon

C R Biol 2021 Apr 21;343(4):15-52. Epub 2021 Apr 21.

Institut Pasteur, Dept. Genomes and Genetics, CNRS (UMR3525) and Sorbonne Université (UFR927), Paris, France.

The modern genetic code reveals numerous traces of specific relationships between the early codons which, together with its internal asymmetries, suggest a sequential appearance of the nucleobases in primitive RNA molecules. Keeping the hypothesis of triplet pairings between primitive RNA molecules at the origin of the code, this work systematically examines complete codon-anticodon interaction matrices assuming distinct pairing options at each position of the triplet duplexes. Application of these principles suggests that a 27-codon precursor having a reasonable coding capacity for short peptide synthesis could have started with primitive RNA molecules able to form two distinct pairs with different free energies between a single purine and two pyrimidines (such as G with C and U). Read More

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TSR332 and TSF331 stabilize serum uric acid levels and prevent hyperuricemia in rats.

PeerJ 2021 3;9:e11209. Epub 2021 May 3.

Research and Development Department, Glac Biotech Co., Ltd., Tainan, Taiwan.

Background: Uric acid (UA) is the end product of purine metabolism in the liver and is excreted by the kidneys. When purine metabolism is impaired, the serum UA level will be elevated (hyperuricemia) and eventually lead to gout. During evolution, humans and some primates have lost the gene encoding uricase, which is vital in UA metabolism. Read More

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Recent Understanding and Future Directions of Recurrent Corticotroph Tumors.

Front Endocrinol (Lausanne) 2021 26;12:657382. Epub 2021 Apr 26.

Neuroendocrinology Clinic, Department of Endocrinology and Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.

Corticotroph tumors (CTs) are pituitary neoplasms arising from the Tpit lineage, which may or not express adrenocorticotrophic hormone (ACTH). Functioning CTs cause Cushing's disease (CD), which has high morbidity and mortality due to hypercortisolemia. "Non-functioning" or silent CTs (SCT) and the Crooke's cell subtypes do not cause CD and may be asymptomatic until manifested by compressive symptoms and are more frequently found as macroadenoma. Read More

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Investigating the Role of Guanosine on Human Neuroblastoma Cell Differentiation and the Underlying Molecular Mechanisms.

Front Pharmacol 2021 27;12:658806. Epub 2021 Apr 27.

Department of Medical, Oral and Biotechnological Sciences, "G. D'Annunzio" University of Chieti-Pescara, Chieti, Italy.

Neuroblastoma arises from neural crest cell precursors failing to complete the process of differentiation. Thus, agents helping tumor cells to differentiate into normal cells can represent a valid therapeutic strategy. Here, we evaluated whether guanosine (GUO), a natural purine nucleoside, which is able to induce differentiation of many cell types, may cause the differentiation of human neuroblastoma SH-SY5Y cells and the molecular mechanisms involved. Read More

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Effect of β-carotene supplementation to prepartum Holstein cows on colostrum quality and calf performance.

J Dairy Sci 2021 May 10. Epub 2021 May 10.

Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham 03824. Electronic address:

β-Carotene, a pro-vitamin A carotenoid, acts as an antioxidant, able to scavenge free radicals to prevent oxidative damage. It has also been shown to increase rumen microbial production in vitro. When supplemented prepartum, β-carotene increased colostral fat and protein concentrations. Read More

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[Determination of caffeine content in Ginkgo Folium by ultra high performance liquid chromatography-triple quadrupole mass spectrometry].

Zhongguo Zhong Yao Za Zhi 2021 Apr;46(7):1790-1794

School of Chinese Materia Medica, Beijing University of Chinese Medicine Beijing 102488, China.

In this experiment, an ultra-high performance liquid chromatographytandem triple quadrupole mass spectrometry was established for the determination of caffeine in commercially available Ginkgo Folium. The samples were extracted by ultrasonic method with methanol, and separated on Waters CORTECS T3 column(2.1 mm×100 mm, 2. Read More

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[Effect of Dendrobii officinalis superfine powder on overeating greasy-induced metabolic hypertension in rats].

Zhongguo Zhong Yao Za Zhi 2021 Apr;46(7):1658-1666

Zhejiang Chinese Medical University Hangzhou 310053, China.

Dendrobii officinalis, with a definite effect of nourishing Yin and clearing heat, has been a folk habit for drinking after being mixed with water. Because its superfine powder has the advantages of high dissolution and convenient drinking, we observed the effect of D. officinalis superfine powder on metabolic hypertension model rats and its possible mechanism in this experiment, which can be used as a reference for its clinical application for hypertension. Read More

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Is high resolution a strict requirement for mass spectrometry-based cellular DNA adductomics?

Chemosphere 2021 Jul 15;274:129991. Epub 2021 Feb 15.

Department of Occupational Safety and Health, Chung Shan Medical University, Taichung, 402, Taiwan; Department of Occupational Medicine, Chung Shan Medical University Hospital, Taichung, 402, Taiwan. Electronic address:

Exposure to endogenous and exogenous factors can result in the formation of a wide variety of DNA adducts, and these may lead to gene mutations, thereby contributing to the development of cancer. DNA adductomics, a novel tool for exposomics, aims to detect the totality of DNA adducts. Liquid chromatography-high resolution mass spectrometry (LC-HRMS) is the state-of-the-art method for DNA adductomic analysis, although its high cost has limited widespread use. Read More

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Deazapurine Nucleoside Analogues for the Treatment of .

ACS Infect Dis 2021 May 11. Epub 2021 May 11.

Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, U.K.

Trichomoniasis is the most common nonviral sexually transmitted disease in humans, but treatment options are limited. Here, we report a resorufin-based drug sensitivity assay for high-throughput microplate-based screening under hypoxic conditions. A 5203-compound enamine kinase library and several specialized compound series were tested for the inhibition of growth at 10 μM with ' values of >0. Read More

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Cell-surface SLC nucleoside transporters and purine levels modulate BRD4-dependent chromatin states.

Nat Metab 2021 May 10. Epub 2021 May 10.

CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria.

Metabolism negotiates cell-endogenous requirements of energy, nutrients and building blocks with the immediate environment to enable various processes, including growth and differentiation. While there is an increasing number of examples of crosstalk between metabolism and chromatin, few involve uptake of exogenous metabolites. Solute carriers (SLCs) represent the largest group of transporters in the human genome and are responsible for the transport of a wide variety of substrates, including nutrients and metabolites. Read More

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The preliminary investigation of potential response biomarkers to PAHs exposure on childhood asthma.

J Expo Sci Environ Epidemiol 2021 May 10. Epub 2021 May 10.

The Key Laboratory of Modern Toxicology of Ministry of Education and Department of Health Inspection and Quarantine, Nanjing Medical University, Nanjing, China.

Background: Exposure to polycyclic aromatic hydrocarbons (PAHs) is a potential risk factor for asthma prevalence. This study aims to explore whether PAHs exposure is associated with childhood asthma by altering microbial diversity and metabolic profiles.

Methods: Thirty children with asthma and 30 children as control in Nanjing, China were recruited. Read More

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Characterization of pathways involved in colorectal cancer using real-time RT-PCR gene expression data.

Gastroenterol Hepatol Bed Bench 2021 ;14(2):123-131

Department of Clinical Genetic, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran.

Aim: Efforts to explore biomarkers and biological pathways involved in the disease are needed to improve colorectal cancer (CRC) diagnosis and alternative treatments.

Background: The fourth common malignancy in the world is colorectal cancer. The over-all burden is predicted to rise by 2030. Read More

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January 2021

Upregulation of glucosamine-phosphate N-acetyltransferase 1 is a promising diagnostic and predictive indicator for poor survival in patients with lung adenocarcinoma.

Oncol Lett 2021 Jun 22;21(6):488. Epub 2021 Apr 22.

Department of Thoracic and Cardiovascular Surgery, Tongji Hospital, School of Medicine, Tongji University, Shanghai 200065, P.R. China.

Lung adenocarcinoma, a type of non-small cell lung cancer, is the leading cause of cancer death worldwide. Great efforts have been made to identify the underlying mechanism of adenocarcinoma, especially in relation to oncogenes. The present study by integrating computational analysis with western blotting, aimed to understand the role of the upregulation of glucosamine-phosphate N-acetyltransferase 1 (GNPNAT1) in carcinogenesis. Read More

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Hepatic Accumulation of Hypoxanthine: A Link Between Hyperuricemia and Nonalcoholic Fatty Liver Disease.

Arch Med Res 2021 May 6. Epub 2021 May 6.

Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México. Ciudad de México, México. Electronic address:

Background: An elevated level of plasma uric acid has been widely recognized as a risk factor for non-alcoholic fatty liver disease (NAFLD), where oxidative stress and inflammation play an important role in the pathophysiology of the disease. Although the complete molecular mechanisms involved remain unknown, while under physiological conditions uric acid presents antioxidant properties, hyperuricemia has been linked to oxidative stress, chronic low-grade inflammation, and insulin resistance, basic signs of NAFLD.

Aim Of Study: Employing in vivo experimentation, we aim to investigate whether a high-fat diet rich in cholesterol (HFD), modifies the metabolism of purines in close relationship to molecular events associated with the development of NAFLD. Read More

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Optical Redox Imaging Differentiates Triple-Negative Breast Cancer Subtypes.

Adv Exp Med Biol 2021 ;1269:253-258

Britton Chance Laboratory of Redox Imaging, Department of Radiology and Johnson Research Foundation, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.

Triple-negative breast cancer (TNBC) is a highly diverse group of cancers with limited treatment options, responsible for about 15% of all breast cancers. TNBC cells differ from each other in many ways such as gene expression, metabolic activity, tumorigenicity, and invasiveness. Recently, many research and clinical efforts have focused on metabolically targeted therapy for TNBC. Read More

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Potential Biomarker for Triple-Negative Breast Cancer Invasiveness by Optical Redox Imaging.

Adv Exp Med Biol 2021 ;1269:247-251

Britton Chance Laboratory of Redox Imaging, Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.

Predicting tumor metastatic potential remains a challenge in cancer research and in clinical diagnosis. Cancer invasion to neighboring tissues is a significant event in cancer progression to metastasis. Optical redox imaging (ORI) is based on detecting the endogenous fluorescence signals of reduced nicotinamide adenine dinucleotide (NADH) and oxidized flavin adenine dinucleotide (FAD). Read More

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Regulation of GC box activity by 8-oxoguanine.

Redox Biol 2021 Apr 30;43:101997. Epub 2021 Apr 30.

Unit "Responses to DNA Lesions", Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, 55131, Germany; Institute of Nutritional Science, University of Jena, Jena, 07743, Germany. Electronic address:

The oxidation-induced DNA modification 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) was recently implicated in the activation and repression of gene transcription. We aimed at a systematic characterisation of the impacts of 8-oxodG on the activity of a GC box placed upstream from the RNA polymerase II core promoter. With the help of reporters carrying single synthetic 8-oxodG residues at four conserved G:C base pairs (underlined) within the 5'-TGGGCGGAGC-3' GC box sequence, we identified two modes of interference of 8-oxodG with the promoter activity. Read More

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Association of serum uric acid levels with COVID-19 severity.

BMC Endocr Disord 2021 May 8;21(1):97. Epub 2021 May 8.

Department of Endocrinology and Metabolism, The Fifth Affiliated Hospital Sun Yat-Sen University, Zhuhai, Guangdong, China.

Aims: Hyperuricemia has attracted increasing attention. However, limited concern has been paid to the potential dangers of lowering serum uric acid (SUA). We observed lower levels of SUA in patients with COVID-19. Read More

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Metabolomics based comprehensive investigation of Gardeniae Fructus induced hepatotoxicity.

Food Chem Toxicol 2021 May 5;153:112250. Epub 2021 May 5.

School of Pharmacy, Second Military Medical University, Shanghai, 200433, China; Shanghai Key Laboratory for Pharmaceutical Metabolite Research, School of Pharmacy, Second Military Medical University, Shanghai, 200433, China. Electronic address:

Gardeniae Fructus (Zhizi in Chinese, ZZ in brief), a commonly used herbal medicine, has aroused wide concern for hepatotoxicity, but the mechanism remains to be investigated. This study was aimed at investigating the mechanism of ZZ-induced liver injury in vivo and in vitro based on metabolomics and evaluating the hepatotoxicity prediction ability of the in vitro model. SD rats were administered with extracted ZZ and HepG2 cells were treated with genipin, the major hepatotoxic metabolite of ZZ. Read More

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A structural intermediate pre-organizes the add adenine riboswitch for ligand recognition.

Nucleic Acids Res 2021 May 8. Epub 2021 May 8.

Department of Biology, Faculty of Science, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada.

Riboswitches are RNA sequences that regulate gene expression by undergoing structural changes upon the specific binding of cellular metabolites. Crystal structures of purine-sensing riboswitches have revealed an intricate network of interactions surrounding the ligand in the bound complex. The mechanistic details about how the aptamer folding pathway is involved in the formation of the metabolite binding site have been previously shown to be highly important for the riboswitch regulatory activity. Read More

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Uncommon presentation and complications of herpes zoster infection involving the cervical, vagus and accessory nerves which caused a delay in diagnosis and treatment.

BMJ Case Rep 2021 May 7;14(5). Epub 2021 May 7.

Department of Community Health and Family Medicine, University of Florida Physicians Family Practice Medical Group, Gainesville, Florida, USA

A 70-year-old man with a history of invasive anal squamous cell carcinoma treated with excision and chemoradiation presented to the emergency department with right-sided neck pain and submandibular lymphadenopathy. CT imaging of the head and neck was unrevealing. The patient eventually developed cranial nerves X and XI dysfunction, manifesting as severe vocal cord paralysis (dysphonia), dysphagia, asymmetric palate elevation/deviation and trapezius muscle atrophy, in addition to scalene muscle atrophy. Read More

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Impact of high dose of baricitinib in severe COVID-19 pneumonia: a prospective cohort study in Bangladesh.

BMC Infect Dis 2021 May 7;21(1):427. Epub 2021 May 7.

Department of Pharmacy, University of Dhaka, Dhaka, Bangladesh.

Purpose: Hyperinflammation in severe COVID-19 infection increases the risk of respiratory failure and one of the cogent reasons of mortality associated with COVID-19. Baricitinib, a janus kinases inhibitor, can potentially suppress inflammatory cascades in severe COVID-19 pneumonia.

Methods: The objective of this study was to compare the clinical outcomes of high dose of baricitinib with its usual dose in patients with severe COVID-19 pneumonia. Read More

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Gout and 'Podagra' in medieval Cambridge, England.

Int J Paleopathol 2021 May 4;33:170-181. Epub 2021 May 4.

Department of Archaeology, University of Cambridge, Cambridge, UK.

Objective: To estimate the prevalence rate of gout and to explore the social factors that contributed to its development in the various sub-populations in medieval Cambridge.

Materials: 177 adult individuals from four medieval cemeteries located in and around Cambridge, UK.

Methods: Lesions were assessed macroscopically and radiographically. Read More

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Insights into the substrate discrimination mechanisms of methyl-CpG-binding domain 4.

Biochem J 2021 May 7. Epub 2021 May 7.

The University of Texas at Austin, Austin, Texas, United States.

G:T mismatches, the major mispairs generated during DNA metabolism, are repaired in part by mismatch-specific DNA glycosylases such as methyl-CpG-binding domain 4 (MBD4) and thymine DNA glycosylase (TDG). Mismatch-specific DNA glycosylases must discriminate the mismatches against million-fold excess correct base pairs. MBD4 efficiently removes thymine opposite guanine but not opposite adenine. Read More

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Management of Locally Excited States for Purine-based TADF Emitters: A Method to Reduce Device Efficiency Roll-Off.

Org Lett 2021 May 7. Epub 2021 May 7.

Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, P. R. China.

The programmed arylation of purine has been developed to construct a series of efficient thermally activated delayed fluorescent (TADF) materials. The corresponding organic light-emitting diodes (OLEDs) exhibit external quantum efficiency as high as 16.0% alongside small efficiency roll-off. Read More

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[Phosphodesterase type 5 inhibitors clinical efficiency and role in therapy for erectile dysfunction].

Urologiia 2021 May(2):135-140

Samarkand State Medical Institute, Samarkand, Uzbekistan.

This article discusses the physiological mechanisms of erection and the pathophysiological basis of erectile dysfunction. Parameters characterizing the features of the pharmacokinetics and pharmacodynamics of drugs from the group of phosphodiesterase type 5 inhibitors (PDE-5i) are presented. The clinical efficacy and possible adverse effects of the most significant PDE-5i are considered. Read More

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