Indolyl Azaspiroketal Mannich Bases Are Potent Antimycobacterial Agents with Selective Membrane Permeabilizing Effects and in Vivo Activity was written by Nyantakyi, Samuel Agyei;Li, Ming;Gopal, Pooja;Zimmerman, Matthew;Dartois, Veronique;Gengenbacher, Martin;Dick, Thomas;Go, Mei-Lin. And the article was included in Journal of Medicinal Chemistry in 2018.Quality Control of 6-Nitro-1H-indole This article mentions the following:
The inclusion of an azaspiroketal Mannich base in the membrane targeting antitubercular 6-methoxy-1-n-octyl-1H-indole scaffold resulted in analogs with improved selectivity and submicromolar activity against Mycobacterium tuberculosis H37Rv. The potency enhancing properties of the spiro-ring fused motif was affirmed by SAR and validated in a mouse model of tuberculosis. As expected for membrane inserting agents, the indolyl azaspiroketal Mannich bases perturbed phospholipid vesicles, permeabilized bacterial cells and induced the mycobacterial cell envelope stress reporter promoter piniBAC. Surprisingly, their membrane disruptive effects did not appear to be associated with bacterial membrane depolarization. This profile was not uniquely associated with azaspiroketal Mannich bases but was characteristic of indolyl Mannich bases as a class. Whereas resistant mycobacteria could not be isolated for a less potent indolyl Mannich base, the more potent azaspiroketal analog displayed low spontaneous resistance mutation frequency of 10-8/CFU. This may indicate involvement of an addnl. envelope-related target in its mechanism of action. In the experiment, the researchers used many compounds, for example, 6-Nitro-1H-indole (cas: 4769-96-4Quality Control of 6-Nitro-1H-indole).
6-Nitro-1H-indole (cas: 4769-96-4) belongs to indole derivatives. Indole, first isolated in 1866, and it is commonly synthesized from phenylhydrazine and pyruvic acid, although several other procedures have been discovered. They are capable of binding to a variety of receptors with high affinity and thus have applications in a wide range of therapeutic areas.Quality Control of 6-Nitro-1H-indole
Referemce:
Indole alkaloid derivatives as building blocks of natural products from Bacillus thuringiensis and Bacillus velezensis and their antibacterial and antifungal activity study,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles