Antibacterial activity of CTBT (7-chlorotetrazolo[5,1-c]benzo[1,2,4]triazine) generating reactive oxygen species

Abstract

CTBT (7-chlorotetrazolo[5,1-c]benzo[1,2,4]triazine) is an antifungal and chemosensitizing agent that induces oxidative stress in yeast and filamentous fungi and enhances the cytotoxic activity of 5-fluorocytosine and azole antimycotics. This study reports the effect of CTBT on bacterial cells. CTBT inhibited the growth of both Gram-positive and Gram-negative bacterial species. The action of CTBT was bactericidal. In Escherichia coli, CTBT induced an increased formation of reactive oxygen species (ROS), as determined with a ROS specific probe 2',7'-dichlorodihydrofluorescein diacetate. In zone inhibition assays, bacterial cells were more sensitive to CTBT compared with paraquat, menadione and hydrogen peroxide. The deletion of oxidative stress related genes resulted in increased susceptibility of E. coli mutant strains to CTBT treatment. Exogenous antioxidants such as ascorbic acid, cysteine and glutathione exhibited a protective effect against the growth inhibition induced by CTBT. CTBT may be a useful tool in the studies of ROS generation, oxidant sensing and oxidative stress response in different bacterial species.

One-Pot Acid-Catalyzed Ring-Opening/Cyclization/Oxidation of Aziridines with N-Tosylhydrazones: Access to 1,2,4-Triazines

“…1,2,4-Triazine derivatives represent an important class of nitrogen heterocycles: they possess a wide range of applications from ligands for transition-metal complexes to agrochemistry and medicine. They have been shown to exhibit a broad spectrum of biological activities with anti-inflammatory, antitumor, antibacterial, anticonvulsant, and antiviral properties being reported. They are also widely used as key synthetic building blocks for the preparation of heterocyclic systems via hetero-Diels–Alder cycloadditions …”

Synthesis and anticancer evaluation of some novel pyrimido[5,4-e][1,2,4]triazines and pyrazolo[3,4-d]pyrimidine using DMF-DMA as methylating and cyclizing agent

“…It possess the motif part of naturally and synthetic pharmaceutical products [ 1 – 9 ]. They exhibit a broad spectrum biological effects [ 10 ] with antibacterial [ 11 , 12 ], antitumor [ 13 , 14 ], anticonvulsant [ 15 ], anti-inflammatory [ 16 ], and antiviral properties [ 17 ]. 6-Azacytosine and 6-azauracil are used as effective antiviral and antitumor activities [ 18 – 21 ].…”