71660-29-2Relevant academic research and scientific papers
Plasmonic Hot Electron-Mediated Hydrodehalogenation Kinetics on Nanostructured Ag Electrodes
Liu, Jia,Cai, Zhuan-Yun,Sun, Wei-Xin,Wang, Jia-Zheng,Shen, Xiao-Ru,Zhan, Chao,Devasenathipathy, Rajkumar,Zhou, Jian-Zhang,Wu, De-Yin,Mao, Bing-Wei,Tian, Zhong-Qun
, p. 17489 - 17498 (2020)
An attractive field of plasmon-mediated chemical reactions (PMCRs) is developing rapidly, but there is still incomplete understanding of how to control the kinetics of such a reaction related to hot carriers. Here, we chose 8-bromoadenine (8BrAd) as a probe molecule of hot electrons to investigate the influence of the electrode potential, laser wavelength, and power on the PMCR kinetics on silver nanoparticle-modified silver electrodes. Plasmonic hot electron-mediated cleavage of the C-Br bond in 8BrAd has been investigated by combining in situ electrochemical surface-enhanced Raman spectroscopy and density functional theory calculations. The experimental and theoretical results reveal that the energy position of plasmon relaxation-generated hot electrons can be modulated conveniently by applied potentials and laser light. This allows the proposal of a mechanism of modulating the matching energy of the hot electron of plasmon relaxation to promote the efficiency of PMCRs in electrochemical interfaces. Our work will be helpful to design surface plasmon resonance photoelectrochemical reactions on metal electrode surfaces of nanostructures with higher efficiency.
Sources of 2,5-diaminoimidazolone lesions in DNA damage initiated by hydroxyl radical attack
Thomas, Caroline Suzanne,Pollard, Hannah Catherine,Razskazovskiy, Yuriy,Roginskaya, Marina
, p. 517 - 524 (2020/09/07)
The present study reports radiation-chemical yields of 2.5-diaminoimidazolone (Iz) derivatives in X-irradiated phosphate-buffered solutions of guanosine and double-stranded DNA. Various gassing conditions (air, N20/O2 (4:1), N2O, vacuum) were employed to elucidate the contribution of several alternative pathways leading to Iz in reactions initiated by hydroxyl radical attack on guanine. In all systems, Iz was identified as the second by abundance guanine degradation product after 8-oxoguanine, formed in 1:5 (guanosine) and 1:3.3 (DNA) ratio to the latter in air-saturated solutions. Experimental data strongly suggest that the addition of molecular oxygen to the neutral guanine radical G(-H)? plays a major in Iz production in oxygenated solutions of double-stranded DNA while in other systems it may compete with recombination of G(-H)? with superoxide and/or alkyl peroxyl radicals. The production of Iz through hydroxyl radical attack on 8-oxoguanine was also shown to take place although the chemical yield of Iz (ca 6%) in this process is too low to compete with the other pathways. The linearity of Iz accumulation with dose also indicates a negligible contribution of this channel to its yield in all systems.
Adenine intermediate pyrimidine-azo compound and preparation method thereof
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Paragraph 0023, (2017/07/14)
The invention relates to an adenine intermediate pyrimidine-azo compound and a preparation method thereof. The preparation method comprises the following steps of: 1) dissolving primary amine in mixed-acid solution, dripping sodium nitrite solution to prepare diazonium salt shown in a formula (3), adding malononitrile for dissolving, and dripping alkaline solution to regulate a pH value of reaction solution and generate coupling reaction, thereby obtaining an intermediate pyrimidine-azo compound (4); 2) adding the intermediate pyrimidine-azo compound (4) prepared in the step 1) into formamide, introducing liquid ammonia, and heating to carry out high-temperature condensation and cyclization reaction, thereby obtaining an adenine intermediate pyrimidine-azo compound (5), wherein a series of derivatives of the adenine intermediate pyrimidine-azo compound can be prepared by selecting different primary amines. The adenine intermediate pyrimidine-azo compound and the preparation method have the advantages that water is used as a solvent in the step 1), and the solvent used in the step 2) can be repeatedly used, so that the 'three wastes' are fewer, and the environment-friendly effect is achieved; and the cost is low, so that the industrialization is easy and the economic benefit is obvious.
Total chemical synthesis method of adenine
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Paragraph 0017; 0020; 0024, (2017/08/29)
The invention relates to a total chemical synthesis method of adenine. The method comprises the following steps of: 1) dissolving primary amine in strong-acid solution, dripping sodium nitrite solution to prepare diazonium salt, adding malononitrile for dissolving, and dripping alkaline solution to regulate a pH value of reaction solution and generate coupling reaction, thereby obtaining an azo compound; 2) adding the azo compound into formamide, and introducing liquid ammonia, heating to carry out high-temperature condensation and cyclization reaction, thereby obtaining a pyrimidine-azo compound; 3) dissolving the pyrimidine-azo compound into water, adding a catalyst, and introducing hydrogen for hydrogenation, thereby obtaining 4,5,6-triamidopyrimidine; and 4) dissolving the 4, 5, 6-triamidopyrimidine into the formamide to carry out high-temperature cyclization with the formamide, thereby obtaining an adenine crude product, and after recrystallization, obtaining white crystalline powder, i.e., a high-purity refined adenine product. The total chemical synthesis method has the advantages that water is used as a solvent in the step 1), and solvents used in the steps 2), 3) and 4) can be repeatedly used, so that the 'three wastes' are fewer, and the environment-friendly effect is achieved; and the total yield is 64.75% (calculated according to the amount of malononitrile), and the cost is low, so that the industrialization is easy and the economic benefit is obvious.
Biosynthesis of 4-aminoheptose 2-epimers, core structural components of the septacidins and spicamycins
Price, Neil P.J.,Furukawa, Takayuki,Cheng, Fang,Qi, Jianzhao,Chen, Wenqing,Crich, David
, p. 405 - 414 (2014/06/10)
Septacidins and spicamycins are acylated 4-aminoheptosyl-β-N- glycosides produced by Streptomyces fimbriatus and S. alanosinicus, respectively. Their structures are highly conserved, but differ in the stereochemistry of the 4-aminoheptosyl residues. The o
Transition state sturcture of 5'-methylthioadenosine/s-adenosylhomocysteine nucleosidases
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Page/Page column 14, (2011/04/25)
Provided are methods of designing a putative inhibitor of a 5′-methylthioadenosine/S-adenosylhomocysteine nucleosidase. The methods comprise designing a chemically stable compound that resembles the charge and geometry of the 5′-methylthioadenosine/S-adenosylhomocysteine nucleosidase transition state. Also provided are methods of inhibiting 5′-methylthioadenosine/S-adenosylhomocysteine nucleosidases using the inhibitors found by the above methods.
Guanine, adenine, and hypoxanthine production in UV-irradiated formamide solutions: Relaxation of the requirements for prebiotic purine nucleobase formation
Barks, Hannah L.,Buckley, Ragan,Grieves, Gregory A.,Di Mauro, Ernesto,Hud, Nicholas V.,Orlando, Thomas M.
experimental part, p. 1240-1243+1159 (2011/04/18)
Relaxed requirements: We demonstrate the formation of adenine, hypoxanthine, and guanine from heated (130 °C), UV-irradiated formamide solutions in the absence of an inorganic catalyst. Evidence is also provided that "classical" HCN pathways for purine nucleobase production are also active in heated and UV-irradiated formamide reactions. (Chemical Equation Presented)
The rate of spontaneous cleavage of the glycosidic bond of adenosine
Stockbridge, Randy B.,Schroeder, Gottfried K.,Wolfenden, Richard
experimental part, p. 224 - 228 (2010/10/01)
Previous estimates of the rate of spontaneous cleavage of the glycosidic bond of adenosine were determined by extrapolating the rates of the acid- and base-catalyzed reactions to neutral pH. Here we show that cleavage also proceeds through a pH-independent mechanism. Rate constants were determined as a function of temperature at pH 7 and a linear Arrhenius plot was constructed. Uncatalyzed cleavage occurs with a rate constant of 3.7 × 10-12 s-1 at 25 °C, and the rate enhancement generated by the corresponding glycoside hydrolase is ～5 × 1012-fold.
Synthesis of 6-substituted 1-deazapurine 2'-deoxyribonucleosides
Wenzel,Seela
, p. 169 - 178 (2007/10/03)
The synthesis of 6-substituted 1-deazapurine 2'-deoxyribonucleosides is described. Glycosylation of the 1-deazapurine (imidazo[4,5-b]pyridine) anions with the α-D-halogenose 5 gives stereoselectively N7- and N9-regioisomers. 1H-NMR NOE and 13C-NMR spectroscopy are used for unambiguous assignment of isomers, and 15N-NMR chemical shifts are correlated with σ(para) Hammett constants and point charges.
