The antiviral activity of 2-substituted and 2,6-disubstituted quinoline-4-carboxylic acids and their derivatives has been studied against orthopoxviruses on Vero and MK-2 cell cultures. High activity has been found for 2-(1,1¢-biphenyl-4-yl)quinoline-4-carboxylic acid.Key words: quinolinecarboxylic acids, acid derivatives, biological activity.Compounds with antibacterial and antifungal properties have been found among 2-mono-and 2,6-disubstituted quinoline-4-carboxylic acids and their derivatives [1,2]. The goal of the present work was to find new antiviral drugs in a series of compounds (I -XIV). 2-Mono-and 2,6-disubstituted quinoline-4-carboxylic acids I, IV, VI, and VIII were prepared by Pfitzinger cyclization of the corresponding methylketones with isatin in basic medium [3,4]. Methyl and ethyl esters II, V, VII, IX, and X were synthesized by esterification of the acids with alcohols in the presence of H 2 SO 4 [4]. Hydrazides III and XIII were prepared from the corresponding esters by refluxing with hydrazine hydrate in alcohol [4]. Compound XI was synthesized by condensation of 2-methyl-6-bromoquinoline-4-carboxylic acid with 4-nitrobenzaldehyde in acetic anhydride in the presence of K 2 CO 3 [5]. Compound XIV was obtained in good yield by Doebner cyclization of 5-acetyl-2,2¢-bithiophene with 2-aminobenaladehyde in alcohol in the presence of base catalyst [6]. The synthesized compounds were crystalline materials that were stable at room temperature and soluble in alcohol, acetone, DMF, and DMSO. Their structures were proven by IR spectral data. Table 1 shows that practically all compounds in the studied series exhibited antiviral activity on cell culture. Thus, the spectrum of activity of acids IV and VI and ester VII extended over a broad range of orthopoxviruses that are pathogenic in humans. Acids IV and VI suppressed multiplication of mousepox virus at a concentration of 0.1 mg/mL. The effective concentration of IV against variolovaccine was 0.03 mg/mL (selectivity index TC 50 /IC 50 = 366). The results of the tests provide hope that the variety of agents with antiviral activity can be expanded.

No abstract

Antiviral agents were sought by using ethyl esters of 2-R-4-quinolinecarboxylic acids to synthesize the corresponding aryl (heteryl) hydrazides. 2-Methyl-4-quinolinecarboxylic acid hydrazide was used to synthesize vinylogs containing a nitro group in the substituent. The resulting compounds were tested for antiviral activity against ECHO virus type 6. 571 0091-150X/08/4210-0571

No abstract