556-08-1Relevant articles and documents
Interaction of human arylamine n-acetyltransferase 1 with different nanomaterials
Deng, Zhou J.,Butcher, Neville J.,Mortimer, Gysell M.,Jia, Zhongfan,Monteiro, Michael J.,Martin, Darren J.,Minchin, Rodney F.
, p. 377 - 383 (2014)
Humans are exposed to nanoparticles in the environment as well as those in nanomaterials developed for biomedical applications. However, the safety and biologic effects of many nanoparticles remain to be elucidated. Over the past decade, our understanding of the interaction of proteins with various nanomaterials has grown. The protein corona can determine not only how nanoparticles interact with cells but also their biologic effects and toxicity. In this study, we describe the effects that several different classes of nanoparticles exert on the enzymatic activity of the cytosolic protein human arylamine N-acetyltransferase 1 (NAT1), a drug-metabolizing enzyme widely distributed in the body that is also responsible for the activation and detoxification of known carcinogens. We investigated three metal oxides (zinc oxide, titanium dioxide, and silicon dioxide), two synthetic clay nanoparticles (layered double hydroxide and layered silicate nanoparticles), and a self-assembling thermoresponsive polymeric nanoparticle that differ in size and surface characteristics. We found that the different nanoparticles induced very different responses, ranging from inhibition to marked enhancement of enzyme activity. The layered silicates did not directly inactivate NAT1, but was found to enhance substrate-dependent inhibition. These differing effects demonstrate the multiplicity of nanoparticle-protein interactions and suggest that enzyme activity may be compromised in organs exposed to nanoparticles, such as the lungs or reticulo-endothelial system. Copyright
Metal-Free, Rapid, and Highly Chemoselective Reduction of Aromatic Nitro Compounds at Room Temperature
Han, Min Su,Jang, Mingyeong,Lim, Taeho,Park, Byoung Yong
, p. 910 - 919 (2022/01/20)
In this study, we developed a metal-free and highly chemoselective method for the reduction of aromatic nitro compounds. This reduction was performed using tetrahydroxydiboron [B2(OH)4] as the reductant and 4,4′-bipyridine as the organocatalyst and could be completed within 5 min at room temperature. Under optimal conditions, nitroarenes with sensitive functional groups, such as vinyl, ethynyl, carbonyl, and halogen, were converted into the corresponding anilines with excellent selectivity while avoiding the undesirable reduction of the sensitive functional groups.
Paracetamol and other acetanilide analogs as inter-molecular hydrogen bonding assisted diamagnetic CEST MRI contrast agents
Chakraborty, Subhayan,Peruncheralathan,Ghosh, Arindam
, p. 6526 - 6534 (2021/02/21)
Paracetamol and a few other acetanilide derivatives are reported as a special class of diamagnetic Chemical Exchange Saturation Transfer (diaCEST) MRI contrast agents, that exhibit contrast only when the molecules form inter-molecular hydrogen bonding mediated molecular chains or sheets. Without the protection of the hydrogen bonding their contrast producing labile proton exchanges too quickly with the solvent to produce any appreciable contrast. Through a number of variable temperature experiments we demonstrate that under the conditions when the hydrogen bond network breaks and the high exchange returns back, the contrast drops quickly. The well-known analgesic drug paracetamol shows 12% contrast at a concentration of 15 mM at physiological conditions. With the proven safety track-record for human consumption and appreciable physiological contrast, paracetamol shows promise as a diaCEST agent forin vivostudies.
Synthetic method of 4-(5-nitrobenzo [d] oxazole-2-yl) aniline
-
Paragraph 0025-0029; 0044; 0045; 0048; 0049; 0052; 0053, (2020/05/01)
The invention discloses a synthetic method of 4-(5-nitrobenzo [d] oxazole-2-yl) aniline. The method comprises the following steps: mixing a substrate p-aminobenzoic acid with a reaction solvent; raising the temperature to a reaction temperature of 70-100 DEG C while stirring; dropping acetic anhydride after dissolution of the substrate, reacting for 0.5-1.5 hours after dropwise adding and then performing post-treatment of the reaction liquid to obtain p-acetaminobenzoic acid; mixing the p-acetaminobenzoic acid with 2-amino-4-nitrophenol and polyphosphoric acid, heating to 50-120 DEG C while stirring, carrying out a constant temperature reaction for 2-7 h and then performing post-treatment of the reaction liquid to obtain N-(4-(5-nitrobenzo [d] oxazole-2-yl) phenyl) acetamide; and mixing the N-(4-(5-nitrobenzo [d] oxazole-2-yl) phenyl) acetamide with the reaction solvent, heating to 80-110 DEG C while stirring and reacting for 3-5 h and then performing post-treatment of the reaction liquid to obtain the target product. The reaction process parameters are easy to control, the energy consumption is low, the yield is good, the purity is high and the industrial feasibility is high.