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
Identifiers
CAS Number	1892-21-3 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:50157;
ChemSpider	67261;
IUPHAR/BPS	6634;
KEGG	C05634;
PubChem CID	74688;
UNII	DAE26MT2UK;
CompTox Dashboard (EPA)	DTXSID60172318 ;
	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]

References

^ ^a ^b 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.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l 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.
^ ^a ^b ^c 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.
^ ^a ^b 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.
^ ^a ^b 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.
^ 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.
^ 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.
^ 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.

[JinsmaaCooneySullivan2015-1] 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.

[BortolatoChenShih2010-2] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l 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.

[MatthesMosienkoBashammakh2010-3] 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.

[BortolatoShih2011-4] 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.

[BeckHelander2003-5] 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.

[CagleCrawfordDoorn2019-6] 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.

[MatveychukMacKenzieKumpula2022-7] 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.

[BehlKaurSehgal2021-8] 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.

[2]

[3]

[1]

[4]

[5]

[6]

[7]

[8]

5-Hydroxyindoleacetaldehyde

See also

References