Antiviral activity of SK&F 21681 against herpes simplex virus

Functionalised 1,2,4-Triazino[5,6-b]indoles

3-Ethoxycarbonylmethylthio-5 H-1,2,4-triazino[5,6- b]indole (2) and 5-ethoxycarbonylmethyl-3-ethoxycarbonyl-methylthio-5 H-1,2,4-triazino[5,6- b]indole (4) have been prepared from 2,5-dihydro-3 H-1,2,4-triazino[5,6- b]indole-3-thione (1). The reaction of 2 and 4 with hydrazine hydrate gave the respective mono- and bishydrazide derivatives 3 and 5. Reaction of the monohydrazide 3 with acetylacetone, various carbonyl compounds and monosaccharides afforded the respective hydrazones 6 and 8–14. Dehydrative cyclization of 6 and 9 with boiling acetic anhydride afforded the pyrazole and 1,3,4-oxadiazoline derivatives 7 and 15, and reaction of 3 with CS2/KOH followed by hydrazinolysis afforded 16.

Antifungal properties in a novel series of triazino[5,6-b]indoles

GR99060 and GR99062 are representatives of a series of 1,2,4-triazino[5,6-b]indole compounds. This series possessed broad-spectrum antifungal activity in vitro. The MIC ranges of the two compounds were as follows: 0.25 to 4 micrograms/ml for Candida albicans, 0.25 to 16 micrograms/ml for Candida sp., 1 to 8 micrograms/ml for Aspergillus spp., and 0.25 to 16 micrograms/ml for Cryptococcus neoformans. GR99062 was metabolized in vitro by a mouse liver microsomal preparation, while GR99060 was stable. GR99060 was efficacious in a murine model of systemic candidiasis by oral or parenteral administration, although no clear dose-response was achieved, suggesting that other factors adversely affected the compound's in vivo activity.

Selective inhibition of virus multiplication by new acylated 1,2,4-triazole derivatives

Six out of 99 new acylated 1,2,4-triazole derivatives specifically inhibited rubella virus replication in RK 13 cell cultures. These are the following: 3-methylthio-5-(2-chlorobenzamido)-1H-1,2,4-triazole; 3-methylthio-5-(2-bromobenzamido)-1H-1,2,4-triazole; 3-methylthio-5-(2-methylbenzamido)-1H-1,2,4-triazole; 3-methylthio-5-(2-nitrobenzamido)-1H-1,2,4-triazole; 3-methylthio-5-(2-methylthiobenzamido)-1H-1,2,4-triazole and 3-ethylthio-5-(2-methylbenzamido)-1H-1,2,4-triazole. The compounds did not directly interfere with the infectivity of the rubella virus particles and the antiviral effect was demonstrable only within cells infected with rubella virus. The active compounds did not inhibit the replication of herpes simplex virus type 1, influenza virus and adenovirus in cell culture systems. Structure-activity relationships are discussed.