In addition to the nitrogen-based heterocycles presented so far, a number of others nitrogen-based scaffolds have also been reported as promising agents for GBM treatment, including pyrazolo-triazole, imidazotetrazine, piperidine, purine, imidazopyrazine, pyrazole, triazole among others.
Incorporation of heterocycles into drug molecules can enhance physical properties and biological activity. Oxadiazoles are a class of five-membered heterocycles containing one oxygen and two nitrogen atoms with special biological activity and thermodynamic properties. 1,2,4- and 1,3,4-oxadiazoles are widely used in the development of bioactive molecules, but 1,2,5-oxadiazoles (furazans) are used relatively sparingly. Compared with 1,2,4- and 1,3,4-isomers, 1,2,5-oxadiazole has unique physicochemical properties and electronic effects. The furazan ring has a strong inductive effect, comparable to that of trifluoromethyl or tetrazolyl. The unique properties of furoxan can confer specific pharmacological activities to drug-like molecules.