111339-51-6Relevant articles and documents
Antiplasmodial 2-thiophenoxy-3-trichloromethyl quinoxalines target the apicoplast of Plasmodium falciparum
Amanzougaghene, Nadia,Amrane, Dyhia,Azas, Nadine,Azqueta, Amaya,Mazier, Dominique,Primas, Nicolas,Sanz-Serrano, Julen,Tajeri, Shahin,Vanelle, Patrice,Verhaeghe, Pierre,Arnold, Christophe-Sébastien,Botté, Cyrille,Hutter, Sébastien,Louis, Béatrice
, (2021/08/09)
The identification of a plant-like Achille's Heel relict, i.e. the apicoplast, that is essential for Plasmodium spp., the causative agent of malaria lead to an attractive drug target for new antimalarials with original mechanism of action. Although it is not photosynthetic, the apicoplast retains several anabolic pathways that are indispensable for the parasite. Based on previously identified antiplasmodial hit-molecules belonging to the 2-trichloromethylquinazoline and 3-trichloromethylquinoxaline series, we report herein an antiplasmodial Structure-Activity Relationships (SAR) study at position two of the quinoxaline ring of 16 newly synthesized compounds. Evaluation of their activity toward the multi-resistant K1 Plasmodium falciparum strain and cytotoxicity on the human hepatocyte HepG2 cell line revealed a hit compound (3k) with a PfK1 EC50 value of 0.3 μM and a HepG2 CC50 value of 56.0 μM (selectivity index = 175). Moreover, hit-compound 3k was not cytotoxic on VERO or CHO cell lines and was not genotoxic in the in vitro comet assay. Activity cliffs were observed when the trichloromethyl group was replaced by CH3, CF3 or H, showing that this group played a key role in the antiplasmodial activity. Biological investigations performed to determine the target and mechanism of action of the compound 3k strongly suggest that the apicoplast is the putative target as showed by severe alteration of apicoplaste biogenesis and delayed death response. Considering that there are very few molecules that affect the Plasmodium apicoplast, our work provides, for the first time, evidence of the biological target of trichloromethylated derivatives.
Studies on the synthesis of 2-phenylsulphonyl-3-styrylquinoxalines
Krishnan,Chowdary,Dubey,Vijaya
, p. 565 - 573 (2007/10/03)
o-Phenylenediamine 1 is condensed with pyruvic acid or sodium pyruvate to yield 3-methylbenzo-1H-dihydropyrazine-2-one 2. The latter on condensation with aromatic aldehydes give 3-styrylquinoxaline-1H-2-one 3. Reaction of 3 with POCl3 in the presence of catalytic amount of DMF yields 2-chloro-3-styrylquinoxaline 4, which on reaction with thiophenol in the presence of triethylamine in methanol gives 2-phenylthio-3-styrylquinoxaline 5. Oxidation of 5 with H2O2 in the presence of acetic anhydride affords 2-phenylsulphonyl-3-styrylquinoxaline 6. 6 has also been prepared directly from 4 by reaction with sodium benzenesulphinate under phase transfer conditions. In an alternate approach to the synthesis of title compound. 2 is treated with POCl3 in DMF to obtain the known 2-chloro-3-methylquinoxaline 7. Reaction of 7 with thiophenol in the presence of triethylamine in methanol gives 2-methyl-3-phenylthioquinoxaline 8. Oxidation of 8 with H2O2 in Ac2O affords 2-methyl-3-phenylsulphonylquinoxaline 9. 9 was also prepared in an alternate method from 7 by reaction with sodium benzenesulphinate, 9 on reaction with aromatic aldehydes yields the title compounds 6.
