The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Biochemical studies on quinoline derivatives. VII. Metabolic products of 8-quinolinol N-oxide》. Authors are Ito, Ryoji; Otaka, Hajime; Usui, Shigeru; Hashimoto, Yukichi.The article about the compound:8-Hydroxyquinoline 1-oxidecas:1127-45-3,SMILESS:OC1=CC=CC2=CC=C[N+]([O-])=C12).Synthetic Route of C9H7NO2. Through the article, more information about this compound (cas:1127-45-3) is conveyed.
cf. CA 56, 13486h. Main metabolic products of 8-quinolinol N-oxide (I) found in the urine of injected rabbits were 8-hydroxy-2-quinolone (II) and 7,8-dihydroxy-2-quinolone. 8,x-dihydroxy-2-quinolone, a product of further metabolism of 8-hydroxy-4-quinolone, an alkylated derivative of quinoline, and a compound of unknown structure were also found: 8-Quinolinol (III), 7,8-dihydroxyquinoline (IV), IV N-oxide, 8-quinolylsulfuric acid (V), V N-oxide, and I were not present. All other metabolic products, except a part of II, occurred in urine as glucuronides or ethereal sulfates. Metabolic products were in accord with those of II, but very different from those of III. In vitro oxidation of I by quinoline dehydrogenase was very difficult, and oxidation products were not detected.
There is still a lot of research devoted to this compound(SMILES：OC1=CC=CC2=CC=C[N+]([O-])=C12)Synthetic Route of C9H7NO2, and with the development of science, more effects of this compound(1127-45-3) can be discovered.
Reference:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider