5-Hydroxyindoleacetaldehyde

5-Hydroxyindoleacetaldehyde
Names
IUPAC name
2-(5-hydroxy-1H-indol-3-yl)acetaldehyde
Other names
5-Hydroxyindole-acetaldehyde; 5-HIAL; 5-HIAAL; 5-Hydroxytryptaldehyde; 5-Hydroxyindole-3-acetaldehyde; Serotonin aldehyde[1]
Identifiers
CAS Number
3D model (JSmol)
ChEBI
ChemSpider
KEGG
PubChem CID
UNII
InChI
  • InChI=1S/C10H9NO2/c12-4-3-7-6-11-10-2-1-8(13)5-9(7)10/h1-2,4-6,11,13H,3H2
    Key: OBFAPCIUSYHFIE-UHFFFAOYSA-N
SMILES
  • C1=CC2=C(C=C1O)C(=CN2)CC=O
Properties
Chemical formula
C10H9NO2
Molar mass 175.18 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

5-Hydroxyindoleacetaldehyde (5-HIAL), also known as 5-hydroxytryptaldehyde or as serotonin aldehyde, is an inactive metabolite and metabolic intermediate of the monoamine neurotransmitter serotonin (5-hydroxytryptamine; 5-HT).[2][3][1]

5-HIAL is formed from serotonin by oxidative deamination via monoamine oxidase (MAO).[2][3] MAO-mediated deamination is the primary metabolic pathway of serotonin inactivation.[2] Monoamine oxidase A (MAO-A) has about 120-fold higher affinity for serotonin than monoamine oxidase B (MAO-B).[2] In relation to this, MAO-A is the main isozyme of MAO involved in serotonin degradation.[2]

Following its formation, 5-HIAL is metabolized by aldehyde dehydrogenase (ALDH) to form 5-hydroxyindoleacetic acid (5-HIAA).[2][3] 5-HIAL can also be converted into small amounts of 5-hydroxytryptophol (5-HTOL; also known as 5-hydroxyindolethanol or 5-HIET) by either aldehyde reductase (ALR/ALDR) or alcohol dehydrogenase (ADH).[2][4] However, brain concentrations of 5-HTOL are only 1 to 5% of those of 5-HIAA.[2][4]

Use of ethanol (alcohol) can dramatically increase 5-HTOL formation by inhibiting ALDH and enhancing ADH activity.[2][5] As a result, the ratio of 5-HTOL to 5-HIAA is a sensitive and reliable marker of recent ethanol ingestion and has been suggested for use in clinical and forensic contexts.[2][5]

Besides oxidative deamination by MAO into 5-HIAL, serotonin can also be conjugated by glucuronidation via glucuronyltransferases, conjugated by sulfation via sulfotransferases, acetylated and then methylated into melatonin (N-acetyl-5-methoxytryptamine) (which occurs mainly in the pineal gland), and converted into certain other metabolites like 5-hydroxyindole thiazoladine carboxylic acid (5-HITCA).[2] However, these secondary metabolic pathways appear to play only a minor role in serotonin metabolism.[2]

5-HIAL has been implicated in producing neurotoxicity and in the development and progression of neurodegenerative diseases.[6][7][8]

See also

References

  1. 1 2 Jinsmaa Y, Cooney A, Sullivan P, Sharabi Y, Goldstein DS (March 2015). "The serotonin aldehyde, 5-HIAL, oligomerizes alpha-synuclein". Neurosci Lett. 590: 134–137. doi:10.1016/j.neulet.2015.01.064. PMC 4755587. PMID 25637699.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 Bortolato, Marco; Chen, Kevin; Shih, Jean C. (2010). "The Degradation of Serotonin: Role of MAO". Handbook of Behavioral Neuroscience. Vol. 21. Elsevier. pp. 203–218. doi:10.1016/s1569-7339(10)70079-5. ISBN 978-0-12-374634-4.
  3. 1 2 3 Matthes S, Mosienko V, Bashammakh S, Alenina N, Bader M (2010). "Tryptophan hydroxylase as novel target for the treatment of depressive disorders". Pharmacology. 85 (2): 95–109. doi:10.1159/000279322. PMID 20130443.
  4. 1 2 Bortolato M, Shih JC (2011). "Behavioral outcomes of monoamine oxidase deficiency: preclinical and clinical evidence". Int Rev Neurobiol. International Review of Neurobiology. 100: 13–42. doi:10.1016/B978-0-12-386467-3.00002-9. ISBN 978-0-12-386467-3. PMC 3371272. PMID 21971001.
  5. 1 2 Beck O, Helander A (December 2003). "5-hydroxytryptophol as a marker for recent alcohol intake". Addiction. 98 Suppl 2: 63–72. doi:10.1046/j.1359-6357.2003.00583.x. PMID 14984243.
  6. Cagle BS, Crawford RA, Doorn JA (February 2019). "Biogenic Aldehyde-Mediated Mechanisms of Toxicity in Neurodegenerative Disease". Curr Opin Toxicol. 13: 16–21. Bibcode:2019COTox..13...16C. doi:10.1016/j.cotox.2018.12.002. PMC 6625780. PMID 31304429.
  7. Matveychuk D, MacKenzie EM, Kumpula D, Song MS, Holt A, Kar S, Todd KG, Wood PL, Baker GB (January 2022). "Overview of the Neuroprotective Effects of the MAO-Inhibiting Antidepressant Phenelzine". Cell Mol Neurobiol. 42 (1): 225–242. doi:10.1007/s10571-021-01078-3. PMC 8732914. PMID 33839994.
  8. Behl T, Kaur D, Sehgal A, Singh S, Sharma N, Zengin G, Andronie-Cioara FL, Toma MM, Bungau S, Bumbu AG (June 2021). "Role of Monoamine Oxidase Activity in Alzheimer's Disease: An Insight into the Therapeutic Potential of Inhibitors". Molecules. 26 (12): 3724. doi:10.3390/molecules26123724. PMC 8234097. PMID 34207264.