Oxindole (2-indolone) is an aromaticheterocyclicorganic compound with the formula C6H4CHC(O)NH. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing ring. Oxindole is a modified indoline with a substituted carbonyl at the second position of the 5-member indoline ring. Classified as a cyclic amide, it is a pale yellow solid.
Formation and reactions
Oxindole is derived in nature from tryptophan, formed by gut bacteria ("normal flora"). It is normally metabolized and detoxified from the body by the liver. In excess, it can cause sedation, muscle weakness, hypotension, and coma. Patients with hepatic encephalopathy have been recorded to have elevated serum oxindole levels.[1]
Beyond the parent compound, the oxindole structure is present in many compounds,[3] for example 3-methyloxindole[4] and semaxanib.[5]
References
^Riggio, Oliviero; Mannaioni, Guido; Ridola, Lorenzo; Angeloni, Stefania; Merli, Manuela; Carlà, Vincenzo; Salvatori, Filippo Maria; Moroni, Flavio (2 February 2010). "Peripheral and Splanchnic Indole and Oxindole Levels in Cirrhotic Patients: A Study on the Pathophysiology of Hepatic Encephalopathy". The American Journal of Gastroenterology. 105 (6): 1374–1381. doi:10.1038/ajg.2009.738. PMID20125128. S2CID20633097.
^Kang TH, Murakami Y, Matsumoto K, Takayama H, Kitajima M, Aimi N, Watanabe H (2002). "Rhynchophylline and Isorhynchophylline Inhibit NMDA Receptors Expressed in Xenopus Oocytes". European Journal of Pharmacology. 455 (1): 27–34. doi:10.1016/S0014-2999(02)02581-5. PMID12433591.
^Trost, Barry; Brennan, Megan (2009). "Asymmetric Syntheses of Oxindole and Indole Spirocyclic Alkaloid Natural Products". Synthesis. 2009 (18): 3003–3025. doi:10.1055/s-0029-1216975.
^Abraham S. Endler and Ernest I. Becker (1957). "3-Methyloxindole". Org. Synth. 37: 60. doi:10.15227/orgsyn.037.0060.
^Lubkoll, Jana; Millemaggi, Alessia; Perry, Alexis; Taylor, Richard J.K. (2010). "Tandem Horner–Wadsworth–Emmons/Heck procedures for the preparation of 3-alkenyl-oxindoles: The synthesis of Semaxanib and GW441756". Tetrahedron. 66 (33): 6606–6612. doi:10.1016/j.tet.2010.03.018.