China
Africa
Explore chapters and articles related to this topic
Toxic Responses of the Blood
Published in Stephen K. Hall, Joana Chakraborty, Randall J. Ruch, Chemical Exposure and Toxic Responses, 2020
Hemolytic anemia is due to an increased rate of red blood cell destruction. Frequently, there is shortened life span or an increased fragility of red blood cells. Chemicals cause hemolytic anemia by at least three mechanisms: those that produce hemolysis directly in all persons if a sufficient dose is given (e.g., arsine, benzene, lead, methyl chloride, phenylhydrazine, and trinitrotoluene); those that produce hemolysis by an immune mechanism (e.g., quinine and quinidine); and those that affect people with certain genetic defects such as glucose–6-phosphate dehydrogenase deficiency (e.g., acetanilide, naphthalene, phenylhydrazine, potassium perchlorate, and sulfanilamide). Clinical tests that are available for the determination of hemolytic anemia are blood smears, cell counts, cell morphology, Heinz body accumulation, and urinary levels of erythrocyte breakdown products.
Biofabrication of Graphene Oxide Nanosheets
Published in Klaus D. Sattler, st Century Nanoscience – A Handbook, 2019
Also, we used Terminalia bellirica fruit aqueous extract for the synthesis of rGO sheets (TBG) (Maddinedi and Mandal, 2016) (Figure 16.4). Figure 16.5 shows the proposed stabilization mechanism of TBG using the T. bellirica polyphenols. It suggests that π–π interactions between the oxidized polyphenols and rGO sheets which protects the agglomeration of RGO sheets with higher stability than rGO synthesized by chemical method using sodium borohy-dride, hydrazine and phenylhydrazine due to lack of stabilization. In addition, Ag-rGO nanocomposites synthesized by T. bellirica fruit aqueous extract showed very good catalytic activity at a dose of 75 mg/L towards complete reduction of 4-nitrophenol (0.3 mM) to 4-aminophenol in the presence of NaBH4 as reducing agent within 5 min (Kadiyala and Mandal, 2016). Similar type of catalytic reduction of 4-nitrophenol to 4-aminophenol was performed by Ag/rGO nanocomposites which was synthesized by using protein tyrosine (Figure 16.6) (Maddinedi et al., 2017a).
in vivo evaluation of some bromonaphthyl pyrazolines as new anti-inflammatory agents
Published in Yuli Rahmawati, Peter Charles Taylor, Empowering Science and Mathematics for Global Competitiveness, 2019
Jasril, H.Y. Teruna, N. Frimayanti, S. Hasti, I. Ikhtiarudin
The second step is the synthesis of bromonaphthyl pyrazolines (Compounds 2a and 3a) via Michael addition, followed by intramolecular cyclization (Jasril et al., 2016) using the following procedure: an amount of Compound 1a (1 mmol) was dissolved in absolute ethanol (15 ml) in a closed reaction vessel using an ultrasonicator. Then, hydrazine hydrate or phenylhydrazine (5 mmol) and glacial acetic acid (five drops) were added to the solution. The mixture was irradiated using a domestic microwave (180 W) for 2 min. The reaction progress was observed by TLC analysis. After the reaction was complete, the mixture was cooled in an ice bath to afford the precipitate. This precipitate was filtered in vacuo, washed with cold n-hexane, dried in a desiccator and recrystallized in a mixture of ethyl acetate and n-hexane to obtain pure Compound 2a and Compound 3a.
Advances in the synthesis and chemical transformations of 5-acetyl-1,3,4-thiadiazolines
Published in Journal of Sulfur Chemistry, 2021
Samir Bondock, Tallah Albarqi, Mohamed Abboud
Treatment of 2,2′-terphthaloyl bis(N-phenylhydrazine carbothioamide) (81) with two equivalent amounts of C-acetylhydrazonoyl chlorides 1a,b,d,h,i in boiling ethanol and in the presence of triethylamine as a base afforded the respective N′1,N′4-bis(5-acetyl-3-aryl-1,3,4-thiadiazol-2(3H)-ylidene)terephthalohydrazides 84a–e (Scheme 20) [43]. Compounds 84a–e have exhibited promising antihypertensive α-blocking activities with values IC50 = 6.15–6.53 µg/cm3. The results of structural activity relationship study revealed that the presence of electron donating group such as (–CH3 group, IC50 = 6.15µg/cm3) at the position 4 of aryl substituent of the 1,3,4-thiadiazole ring induced has higher activity than electron withdrawing group (Cl- group, IC50 = 6.53µg/cm3).
Competent inhibitor for the corrosion of zinc in hydrochloric acid based on 2,6-bis-[1-(2-phenylhydrazono)ethyl]pyridine
Published in Chemical Engineering Communications, 2019
M. Abdallah, S. A. Ahmed, H. M. Altass, I. A. Zaafarany, M. Salem, A. I. Aly, E. M. Hussein
A mixture of 2,6-diacetylpyridine (1 g, 6.1 mmol) and freshly distilled phenylhydrazine (1.32 g, 12.2 mmol) in a small volume of absolute ethanol (10 mL) containing a catalytic amount of glacial acetic acid (0.1 mL) was gently stirred at room temperature for 1 h. After cooling the red solution to room temperature, the resulting yellow crystals were collected by filtration, washed twice with cold ethanol (5 mL each), and dried under vacuum to provide 2.01 g (96% yield) of 2,6-bis[(Z)-1-(2-phenylhydrazono)ethyl]pyridine [Lit18 94%] (Thummel and Hegda, 1989): mp 210–211 °C [Lit18 208–211 °C]. 1H NMR (DMSO, 500 MHz): 2.44 (s, 6H, CH3), 6.81 (t, 2H, He, J = 5.0), 7.26 (t, 4H, Hd, J = 10.0), 7.32 (t, 4H, Hc, J = 10.0), 7.76 (t, 1H, Hb, J = 5.0), 8.01 (d, 2H, Ha, J = 10.0), 9.51 (s, 2H, NH). 13C NMR (DMSO, 125 MHz): 11.53 (CH3), 113.48 (CH), 117.93 (CH), 119.83 (CH), 129.44 (CH), 136.72 (CH), 141.95 (C), 146.05 (C = N), and 155.39 (C = N).
Assessment of amination reactions via nucleophilic aromatic substitution using conventional and eco-friendly energies
Published in Green Chemistry Letters and Reviews, 2018
Ricardo A. Luna-Mora, Ángeles Torres-Reyes, Oscar A. González-Cruz, Fernando Ortega-Jiménez, Hulme Ríos-Guerra, Jessica V. González-Carrillo, Francisco Barrera-Téllez, Javier Perez-Flores, José G. Penieres-Carrillo
Interestingly, we observed that when either 1a-d or 4a-d reacted with phenylhydrazine 2d, the unexpected N-[2-nitro-5-(phenyldiazenyl)phenyl]acetamide 3d (Table 2, entries 4, 8, 12 and 16) and 2-nitro-5-(phenyldiazenyl)aniline 5d (Table 3, entries 20, 24, 28 and 32) were isolated as the main products in moderate yields through an oxidative SNAr-based amination reaction. This reaction by an unusual oxidation of the 2-phenylhydrazinyl derivative III through its reaction with DMSO can be explained, which allegedly led to the formation of the species IV, which finally decomposed into the phenyldiazenyl derivative 3d/5d, dimethyl sulfide and water (Scheme 2).