Ultraviolet and Light Absorption Spectrometry
Adorjan Aszalos in Modern Analysis of Antibiotics, 2020
Of the antibiotics not in the groups already described, chloramphenicol (112), which has the structure D-threo-l-p-nitrophenyl-2-dichloroacetamidopropan-1,3-diol and is produced industrially on large scale by synthesis, is the practically most important. Due to its aromatic nitro group it has nearly identical UV absorption λmax = 278 nm (ε, 117 m2/mol) in water as in nitrobenzene.
Nitrogen compounds
Bev-Lorraine True, Robert H. Dreisbach in Dreisbach’s HANDBOOK of POISONING, 2001
Ingestion of 1 g of aniline has caused death, although recovery has followed ingestion of 30 g. The toxicity of nitrobenzene is similar. The fatal dose (LD50) in animals for aniline is 400 mg/kg, and for nitrobenzene it is 700 mg/kg. The toxicities of aniline derivatives are given in Table 9.1. Infant deaths have been caused by absorption of aniline from diapers stenciled with cloth-marking ink containing aniline as the vehicle for dyes. The residual pigment is safe after washing.
Green-Synthesized Nanoparticles as Potential Sensors for Health Hazardous Compounds
Richard L. K. Glover, Daniel Nyanganyura, Rofhiwa Bridget Mulaudzi, Maluta Steven Mufamadi in Green Synthesis in Nanomedicine and Human Health, 2021
One additional hazardous chemical to human health is nitrobenzene (Fig. 13.2), a toxic nitroaromatic compound used in the production of many commercially appropriate chemicals. Commercially, nitrobenzene and its derivatives are widely used in the manufacturing of dyes, explosives, perfumes, pesticides and pharmaceuticals. Conversely, the growth of these industries produces a large quantity of wastewater comprising of nitrobenzene, which brings toxicological inferences to human health such as anaemia, cancer and skin irritation (Li et al., 2020). Additionally, when inhaled, nitrobenzene is carcinogenic in humans and presents with symptoms such a cyanosis, dizziness, nausea, restlessness and vomiting. Other studies (e.g. Villegas et al., 2020) have reported additional symptoms such as a burning sensation in the mouth and throat, coordination disorders, a smell of bitter almonds in the exhaled air, signs of paralysis, tachycardia, a drop in blood pressure and unconsciousness. Despite its carcinogenic and toxic nature, the USEPA has certified nitrobenzene as group 2B carcinogen and has detailed a minimum threshold limit of 5 ppb for humans. Furthermore, nitrobenzene groundwater aquifer and soil pollution have become a serious issue resulting from its toxicity and potential harmful health impacts on humans. This is caused by the fact that these compounds are resistant to oxidative degradation resultant from the stability of the benzene rings and effects of the electron-withdrawing nitro groups making its quantification and detection a priority in most countries (Liu et al., 2020). Structure of nitrobenzene.
Small Molecule Inhibitors of Programmed Cell Death Ligand 1 (PD-L1): A Patent Review (2019–2021)
Published in Expert Opinion on Therapeutic Patents, 2022
Jingjing Deng, Zhengqi Cheng, Juyang Long, Alexander Dömling, Micky Tortorella, Yuanze Wang
Later, chemists from Shanghai Institute of Materia Medica (Chinese Academy of Sciences) described 156 1,3-dihydroxy phenyl derivatives. (Figure 3) [24] In this series of compounds different types of soluble groups were used, for example, sulfonic acids and polyalcohols were introduced for the tail group. One of the most potent molecules, 2 exhibited an IC50 of 0.88 nM in the in vitro PD-1/PD-L1 binding assay. Meanwhile, in an efficacy experiment at a concentration of 40 mg/kg, 2 was able to significantly inhibit tumor growth in a melanoma model. In another patent, the Shanghai Institute of Organic Chemistry (Chinese Academy of Sciences) disclosed 106 compounds with similar structures [25]. In an HTRF binding assay, at a dose of 1 μΜ, compound 3 showed 99.94% inhibition of PD-1/PD-L1 interaction. China Pharmaceutical University has filed a patent with 49 molecules that use nitrobenzene as the aryl moiety [26]. 4 displayed an IC50 of 2.7 nM in blocking the binding of the PD-1/PD-L1 interaction in vitro without any cytotoxicity against Lewis lung carcinoma (LLC) cells. In addition, 4 was able to dose-dependently elevate interferon-γ production and counteract PD-1/PD-L1 induced immunosuppression.
Conformational restriction of a type II FMS inhibitor leading to discovery of 5-methyl-N-(2-aryl-1H-benzo[d]imidazo-5-yl)isoxazole-4-carboxamide analogues as selective FLT3 inhibitors
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2019
Daseul Im, Hyungwoo Moon, Jingwoong Kim, Youri Oh, Miyoung Jang, Jung-Mi Hah
The general synthesis of 3-carbonyl-1H-benzimidazolyl isoxazole-4-carboxamide (5a–g, 6a–c) is shown in Scheme 1 (See Supplementary Material). A solution of 4-nitro-1,2-phenylenediamine (1a) and substituted benzoic acid or pyrazole carboxylic acid in phosphorus oxychloride was reacted under microwave irradiation at 192 °C for 10 min to give the core intermediate benzimidazoles (3a-g)15. For 1,2-diamino-3-nitrobenzene (1b), the core structure was synthesised in two sequential steps. First, benzamide (2a-c) formation was achieved using triethylamine and benzoyl chloride in a mixture of CH2Cl2/acetonitrile (2:1), which was reacted in a solution of concentrated aqueous HCl (35%) and acetic acid under microwave irradiation at 150 °C to give the core intermediates 3h–j16. The nitro group of benzimidazole was then reduced to amines 4a–j and coupled with isoxazole chloride to produce carboxamides (5a–g, 6a–c).
Tetrahydroquinazole-based secondary sulphonamides as carbonic anhydrase inhibitors: synthesis, biological evaluation against isoforms I, II, IV, and IX, and computational studies
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2021
Emma Baglini, Rahul Ravichandran, Emanuela Berrino, Silvia Salerno, Elisabetta Barresi, Anna Maria Marini, Monica Viviano, Sabrina Castellano, Federico Da Settimo, Claudiu T. Supuran, Sandro Cosconati, Sabrina Taliani
Compound 7 was obtained as a solid (0.14 g, 30%) starting from compound 16b (0.37 g) and 1-iodo-4-nitrobenzene (0.28 g); m.p. 118–120 °C. 1H NMR (400 MHz, DMSO-d6): δ 2.67–2.73 (m, 2H), 2.97–3.04 (m, 2H), 3.54–3.56 (m, 1H), 7.26–7.30 (m, 2H), 7.34–7.40 (m, 3H), 7.82 (d, J= 8.8 Hz, 2H), 7.96–8.07 (m, 4H), 8.12 (d, J= 9.2 Hz, 2H), 8.91 (s, 1H), 10.82 (s, 1H), 11.21 (s, 1H). 13C NMR (100 MHz, DMSO-d6): δ 38.3, 44.9, 104.5, 118.0 (2C), 118.7, 119.6 (2C), 125.2 (2C), 125.6 (2C), 127.0, 127.1 (2C), 128.2, 128.9 (2C), 139.0, 143.3, 144.0, 157.9, 160.6, 173.0, 194.8.
Related Knowledge Centers
- Almond
- Aniline
- Benzene
- Nitric Acid
- Organic Compound
- Phenyl Group
- Reagent
- Sulfuric Acid
- Chemical Formula
- Nitro Compound