Synthesis and Biological Activity of 1H-benzotriazole and 1H-benzimidazole Analogues — Inhibitors of the NTPase/Helicase of HCV and of Some Related Flaviviridae

Abstract

To improve anti-helical activity of analogues of 1H-benzotriazole and 1H-benzimidazole their N-alkyl derivatives were synthesized and tested for antihelicase activity against enzymes of selected Flaviviridae including hepatitis C virus (HCV), West Nile virus (WNV), Dengue virus (DENV) and Japanese encephalitis virus (JEV). 1- and 2-alkyl derivatives of 4,5,6,7-tetrabromo-1H-benzotriazole were obtained by direct alkylation of 4,5,6,7-tetrabromo-1H-benzotriazole with the use of respective alkyl halides in the presence of KOH in methanol, to give a mixture of 1- and 2- isomers, which was separated by flash column chromatography in good yield. The proportion of isomers strongly depended on the reaction time and temperature. 1- and 2-hydroxyethyl and 1- and 2-chloroethyl derivatives of the tetrabromobenzo-triazole were synthesized with the use of 2-bromoethanol and 1-bromo-2-chloroethane respectively as alkylating agents. N-alkylation of this benzotriazole compound enhanced inhibitory activity and selectivity towards the helicase activity of HCV NTPase/helicase. The most active were the 2-methyl, 2-ethyl and 2-propyl derivatives (IC50 approximately 6.5 microM in the presence of DNA as a substrate). Derivatives of the benzotriazole in which hydroxyethyl or chloroethyl replaced the alkyl substituents lost their inhibitory activity. Brominated or methylated benzotriazole N(1) ribosides also did not exert helicase inhibitory activity. Although a number of N(1) and N(2) alkyl derivatives exerted good HCV and WNV helicase inhibitory activity when DNA was used as substrate, the activity was strongly decreased or even disappeared when RNA was used as substrate. The cytotoxicity tests in Vero and HeLa Tat cells showed a substantial decrease of cytotoxicity of N-alkyl derivatives as compared to the parent benzotriazole.

White Spot Syndrome Virus Proteins and Differentially Expressed Host Proteins Identified in Shrimp Epithelium by Shotgun Proteomics and Cleavable Isotope-Coded Affinity Tag

“…Targeted reduction or point mutants of NTPase inhibit Toxoplasma gondii proliferation (31) and viral DNA replication (20). Small molecules designed to inhibit NTPase function may be promising antiviral drugs (3,8,34,38).…”

Synthesis of some 1- and 2-carboxyalkyl substituted benzimidazoles and their derivatives

“…The hydrazones 8-12 were synthesized by condensation of carbohydrazide 7 with aromatic aldehydes or ketones-acetone and ethylmethylketone. Analysis of 1 H NMR spectra of 1-aryl-3-arylidenehydrazinocarbonyl-5-oxopyrrolidines [8][9][10][11][12] showed that a mixture of E/Z rotamers exists in DMSO-d 6 solutions in which Z isomer predominates due to a hindered rotation around the CO-NH bond [20,21].…”

“…Benzimidazole derivatives are distinguished for antimicrobial [1][2][3][4], antifungal [5][6][7], antiviral [8], anthelmintic [9,10], antihypertensive [11], antihistaminic [12], analgesic [13], and anti-HIV [14] actions. Also, some of benzimidazoles are used in coordination chemistry [15,16], in optoelectronics [17], etc.…”

Nucleophilic ring opening of 1,4-disubstituted 2-pyrrolidones with hydrazine. Synthesis of azoles with a high antibacterial activity

“…The synthesis of substituted benzimidazole derivatives is of considerable importance, because most of these compounds have a promising biological activity [1][2][3][4][5][6][7][8][9][10]. Also, the compounds whose molecules possess an azole ring, such as pyrrole [11][12][13], 1,3,4-oxadiazole [14][15][16][17][18][19] and 1,2,4-triazole [19][20][21][22][23], are often characterized as good antimicrobial agents.…”