81-64-1Relevant articles and documents
Clean process for synthesizing 1, 4-dihydroxy anthraquinone
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Paragraph 0020-0023, (2021/07/08)
The invention relates to the technical field of dye intermediates, and especially relates to a clean process for synthesizing 1, 4-dihydroxy anthraquinone. The process comprises the following steps: sequentially adding 98% sulfuric acid, boric anhydride, phthalic anhydride and hydroquinone into a dry reaction container according to a stoichiometric ratio, uniformly stirring, heating to 100-180 DEG C, and carrying out heat preservation reaction for 2-24 hours; after the heat preservation reaction is finished, cooling the materials, and transferring the materials into another reaction container for hydrolysis; and after hydrolysis is completed, cooling, filtering and washing to obtain the 1, 4-dihydroxy anthraquinone. According to the clean process for synthesizing the 1, 4-dihydroxy anthraquinone, provided by the invention, the dosage of the raw material phthalic anhydride can be reduced, the wastewater treatment difficulty is greatly reduced, and the production cost is also reduced; and meanwhile, the yield of the 1, 4-dihydroxy anthraquinone is also improved to a certain extent.
Evaluation of a series of 9,10-anthraquinones as antiplasmodial agents
Osman, Che Puteh,Ismail, Nor Hadiani,Widyawaruyanti, Aty,Imran, Syahrul,Tumewu, Lidya,Choo, Chee Yan,Ideris, Sharinah
, p. 353 - 363 (2019/06/20)
Background: A phytochemical study on medicinal plants used for the treatment of fever and malaria in Africa yielded metabolites with potential antiplasmodial activity, many of which are Anthraquinones (AQ). AQs have similar sub-structure as naphthoquinones and xanthones, which were previously reported as novel antiplasmodial agents. Objective: The present study aimed to investigate the structural requirements of 9,10-anthraquinones with hydroxy, methoxy and methyl substituents to exert strong antiplasmodial activity and to investigate their possible mode of action. Methods: Thirty-one AQs were synthesized through Friedel-Crafts reaction and assayed for antiplasmodial activity in vitro against Plasmodium falciparum (3D7). The selected compounds were tested for toxicity and probed for their mode of action against β-hematin dimerization through HRP2 and lipid catalyses. The most active compounds were subjected to a docking study using AutoDock 4.2. Results: The active AQs have similar common structural characteristics. However, it is difficult to establish a structure-activity relationship as certain compounds are active despite the absence of the structural features exhibited by other active AQs. They have either ortho- or meta-arranged substituents and one free hydroxyl and/or carbonyl groups. When C-6 is substituted with a methyl group, the activity of AQs generally increased. 1,3-DihydroxyAQ (15) showed good antiplasmodial activity with an IC50 value of 1.08 μM, and when C-6 was substituted with a methyl group, 1,3-dihydroxy-6-methylAQ (24) showed stronger antiplasmodial activity with an IC50 value of 0.02μM, with better selectivity index. Compounds 15 and 24 showed strong HRP2 activity and mild toxicity against hepatocyte cells. Molecular docking studies showed that the hydroxyl groups at the ortho (23) and meta (24) positions are able to form hydrogen bonds with heme, of 3.49 A and 3.02 A, respectively. Conclusion: The activity of 1,3-dihydroxy-6-methylAQ (24) could be due to their inhibition against the free heme dimerization by inhibiting the HRP2 protein. It was further observed that the anthraquinone moiety of compound 24 bind in parallel to the heme ring through hydrophobic interactions, thus preventing crystallization of heme into hemozoin.
Monitoring the activity of immobilized lipase with quinizarin diester fluoro-chromogenic probe
Sabatini, Carolina Aparecida,dos Santos, Denis Massucatto,da Silva, Sabrina Matos de Oliveira,Gehlen, Marcelo Henrique
, (2018/01/12)
Ouinizarin diester is used as a fluoro-chromogenic substrate of the activity of lipase supported in poly(methylmetacrylate) beads (CALB, Novozymfi 435) dispersed in organic solvents. The monoester and diester of quinizarin are both non-fluorescent species contrasting with the enzymatic product quinizarin that shows optical absorption in the visible region and strong fluorescence signal. The enzymatic conversion is accomplished by spectroscopic measurements and it follows a sigmoid curve from which the mean reaction time of the enzymatic process can be determined. This parameter indicates the enzyme activity of the immobilized lipase. Its dependency with the amount of lipase allowed the determination of the ratio of the catalytic rate and the Michaelis constant (kc/Km) and the experimental value found was (1.0 ± 0.1) × 10?2 mg?1/min in the case of quinizarin diacetate.