Pyrrolidine, also known as tetrahydropyrrole, is a saturated five-membered heterocyclic ring, which is miscible with water. Pyrrolidine exists in many alkaloids and drug molecules, such as kappa opioids, antagonists of dopamine D4 receptors, and HIV reverse transcriptase inhibitors.
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.