Oxindole (2-indolone) is an

aromatic In chemistry, aromaticity is a chemical property of cyclic ( ring-shaped), ''typically'' planar (flat) molecular structures with pi bonds in resonance (those containing delocalized electrons) that gives increased stability compared to satur ...

heterocyclic A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and ...

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...

with the formula C6H4CHC(O)NH. It has a bicyclic structure, consisting of a six-membered

benzene Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, ...

ring fused to a five-membered

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

-containing ring. Oxindole is a modified

indoline Indoline is an aromatic heterocyclic organic compound with the chemical formula C8H9N. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing ring. The compound is based on the indole st ...

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 Tryptophan (symbol Trp or W) is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α- carboxylic acid group, and a side chain indole, making it a polar molecule with a non-polar aromatic ...

, 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 Hepatic encephalopathy (HE) is an altered level of consciousness as a result of liver failure. Its onset may be gradual or sudden. Other symptoms may include movement problems, changes in mood, or changes in personality. In the advanced stages ...

have been recorded to have elevated serum oxindole levels. Treatment with

phosphorus pentasulfide Phosphorus pentasulfide is the inorganic compound with the formula (monomer) or (dimer). This yellow solid is the one of two phosphorus sulfides of commercial value. Samples often appear greenish-gray due to impurities. It is soluble in carbon d ...

gives the thione.

Oxindoles

left, Rhynchophylline, a naturally occurring oxindole is a medicinal used as an NMDA antagonist and a calcium channel blocker. Beyond, the parent compound, oxindoles include many compounds. One example is 3-methyloxindole.

References

Indolines Lactams Oxindoles, {{Heterocyclic-stub