Chemical structure of tryptophol
CAS number  YesY
Jmol-3D images Image 1
Molecular formula C10H11NO
Molar mass 161.20 g mol−1
Melting point 59 °C
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
UV visible spectrum of tryptophol.

Tryptophol is an aromatic alcohol that induces sleep in humans. It is formed in the liver after disulfiram treatment.[1] It is also produced by the trypanosomal parasite in sleeping sickness.

It is also found in wine as a secondary product of alcoholic fermentation. It has been first described by Felix Ehrlich in 1912.

Natural occurrences

Tryptophol can be found in Pinus sylvestris needles[2] or seeds.[3]

It is produced by the trypanosomal parasite (Trypanosoma brucei) in sleeping sickness (African trypanosomiasis).[1][4]

It is found in wine[5] or in beer (although at levels of <23 mg/L in Canadian beers[6] as a secondary product of alcoholic fermentation[7] (a product also known as congener) by Saccharomyces cerevisiae.

It is also an autoantibiotic produced by the fungus Candida albicans.[8]

It can also be isolated from the marine sponge Ircinia spiculosa.[9]



It has been first described by Felix Ehrlich in 1912. Ehrlich demonstrated that yeast attacks the natural amino acids essentially by splitting off carbon dioxide and re-placing the amino group with hydroxyl. By this reaction, tryptophan gives rise to tryptophol.[10] Tryptophan is first deaminated to 3-indolepyruvate. It is then decarboxylated[11] to indole acetaldehyde by indolepyruvate decarboxylase. This latter compound is transformed to tryptophol by alcohol dehydrogenase.[12]

It is formed from tryptophan, along with indole-3-acetic acid in rats infected by Trypanosoma brucei gambiense.[13]

An efficient conversion of tryptophan to indole-3-acetic acid and/or tryptophol can be achieved by some species of fungi in the genus Rhizoctonia.[14]


In Cucumis sativus (cucumber), the enzymes indole-3-acetaldehyde reductase (NADH) and indole-3-acetaldehyde reductase (NADPH) use tryptophol to form (indol-3-yl)acetaldehyde.[15]


The unicellular alga Euglena gracilis converts exogenous trytophol to two major metabolites: tryptophol galactoside and an unknown compound (a tryptophol ester), and to minor amounts of indole-3-acetic acid, tryptophol acetate and tryptophol glucoside.[16]

Biological effects

Tryptophol and its derivatives 5-hydroxytryptophol and 5-methoxytryptophol, induce sleep in mice. It induces a sleep-like state that lasts less than an hour at the 250 mg/kg dose.[17] These compounds may play a role in physiological sleep mechanisms.[18] It may be a functional analog of serotonin or melatonin, compounds involved in sleep regulation.

Tryptophol shows genotoxicity in vitro.[19]

Tryptophol is a quorum sensing molecule for the yeast Saccharomyces cerevisiae.[20] It is also found in the bloodstream of patients with chronic trypanosomiasis. For that reason, it may be a quorum sensing molecule for the trypanosome parasite.[19]

In the case of trypanosome infection, tryptophol decreases the immune response of the host.[21]

As it is formed in the liver after ethanol ingestion or disulfiram treatment, it is also associated with the study of alcoholism.[1][17] Pyrazole and ethanol have been shown to inhibit the conversion of exogenous tryptophol to indole-3-acetic acid and to potentiate the sleep-inducing hypothermic effects of tryptophol in mice.[22]

It is a growth promoter of cucumber hypocotyl segments.[23] The auxinic action in terms of embryo formation is even better for tryptophol arabinoside on Cucurbita pepo hypocotyl fragments.[24]

Precursor for synthesis of other compounds

Tryptophol have been used as precursor in the synthesis of tryptamines like DMT.[25]

It is used in the synthesis of the drug indoramin.

See also


  1. ^ a b c Cornford, E. M.; Bocash, W. D.; Braun, L. D.; Crane, P. D.; Oldendorf, W. H.; MacInnis, A. J. (1979). "Rapid distribution of tryptophol (3-indole ethanol) to the brain and other tissues". Journal of Clinical Investigation 63 (6): 1241–1248.  
  2. ^ Sandberg, Göran (1984). "Biosynthesis and metabolism of indole-3-ethanol and indole-3-acetic acid by Pinus sylvestris L. Needles". Planta 161 (5): 398.  
  3. ^ Sandberg, Goran; Ernstsen, Arild; Hamnede, Marianne (1987). "Dynamics of indole-3-acetic acid and indole-3-ethanol during development and germination of Pinus sylvestris seeds". Physiologia Plantarum 71 (4): 411.  
  4. ^ Richard Seed, John; Seed, Thomas M.; Sechelski, John (1978). "The biological effects of tryptophol (indole-3-ethanol): Hemolytic, biochemical and behavior modifying activity". Comparative Biochemistry and Physiology Part C: Comparative Pharmacology 60 (2): 175.  
  5. ^ Gil, C.; Gómez-Cordovés, C. (1986). "Tryptophol content of young wines made from Tempranillo, Garnacha, Viura and Airén grapes". Food Chemistry 22: 59.  
  6. ^ Szlavko, Clara M. (1973). "Tryptophol, Tyrosol and Phenylethanol-The Aromatic Higher Alcohols in Beer". Journal of the Institute of Brewing 79 (4): 283.  
  7. ^ Ribéreau-Gayon, P; Sapis, JC (1965). "On the presence in wine of tyrosol, tryptophol, phenylethyl alcohol and gamma-butyrolactone, secondary products of alcoholic fermentation". Comptes rendus hebdomadaires des seances de l'Academie des sciences. Serie D: Sciences naturelles 261 (8): 1915–6.   (Article in French)
  8. ^ Lingappa, BT; Prasad, M; Lingappa, Y; Hunt, DF; Biemann, K (1969). "Phenethyl alcohol and tryptophol: Autoantibiotics produced by the fungus Candida albicans". Science 163 (3863): 192–4.  
  9. ^ ErdoĞAn i, I; Sener, B; Higa, T (2000). "Tryptophol, a plant auxin isolated from the marine sponge Ircinia spinulosa". Biochemical systematics and ecology 28 (8): 793–794.  
  10. ^ Richard W. Jackson (1930). "A synthesis of tryptophol". Journal of Biological Chemistry 88 (3): 659–662. 
  11. ^ Dickinson, JR; Salgado, LE; Hewlins, MJ (2003). "The catabolism of amino acids to long chain and complex alcohols in Saccharomyces cerevisiae". The Journal of biological chemistry 278 (10): 8028–34.  
  12. ^ Pathway: tryptophan degradation VIII (to tryptophol) at
  13. ^ Stibbs, H. H.; Seed, J. R. (1975). "Short-Term Metabolism of \14C]Tryptophan in Rats Infected with Trypanosoma brucei gambiense". Journal of Infectious Diseases 131 (4): 459–62.  
  14. ^ Toshiko Furukawa, Jinichiro Koga, Takashi Adachi, Kunihei Kishi and Kunihiko Syono (1996). "Efficient Conversion of L-Tryptophan to Indole-3-Acetic Acid and/or Tryptophol by Some Species of Rhizoctonia". Plant Cell Physiol. 37 (7): 899–905.  
  15. ^ Brown HM, Purves WK (1976). "Isolation and characterization of indole-3-acetaldehyde reductases from Cucumis sativus". J. Biol. Chem. 251 (4): 907–13.  
  16. ^ Laćan, G; Magnus, V; Jericević, B; Kunst, L; Iskrić, S (1984). "Formation of Tryptophol Galactoside and an Unknown Tryptophol Ester in Euglena gracilis". Plant physiology 76 (4): 889–93.  
  17. ^ a b Cornford, Eain M.; Crane, Paul D.; Braun, Leon D.; Bocash, William D.; Nyerges, Anthony M.; Oldendorf, William H. (1981). "Reduction in Brain Glucose Utilization Rate after Tryptophol (3-Indole Ethanol) Treatment". Journal of Neurochemistry 36 (5): 1758–65.  
  18. ^ Feldstein, A.; Chang, F.H.; Kucharski, J.M. (1970). "Tryptophol, 5-hydroxytryptophol and 5-methoxytryptophol induced sleep in mice". Life Sciences 9 (6): 323–9.  
  19. ^ a b Kosalec, Ivan; Ramić, Snježana; Jelić, Dubravko; Antolović, Roberto; Pepeljnjak, Stjepan; Kopjar, Nevenka (2011). "Assessment of Tryptophol Genotoxicity in Four Cell Lines in Vitro: A Pilot Study with Alkaline Comet Assay". Archives of Industrial Hygiene and Toxicology 62.  
  20. ^ Wuster, Arthur; Babu, M. Madan (2010). "Transcriptional control of the quorum sensing response in yeast". Molecular BioSystems 6 (1): 134–41.  
  21. ^ Ackerman, S. B.; Seed, J. R. (1976). "The effects of tryptophol on immune responses and its implications toward trypanosome-induced immunosuppression". Experientia 32 (5): 645–7.  
  22. ^ Seed, John Richard; Sechelski, John (1977). "Tryptophol levels in mice injected with pharmacological doses of tryptophol, and the effect of pyrazole and ethanol on these levels". Life Sciences 21 (11): 1603–10.  
  23. ^ Rayle, DL; Purves, WK (1967). "Isolation and Identification of Indole-3-Ethanol (Tryptophol) from Cucumber Seedlings". Plant Physiology 42 (4): 520–524.  
  24. ^ Jelaska, Sibila; Magnus, Volker; Seretin, Mira; Lacan, Goran (1985). "Induction of embryogenic callus in Cucurbita pepo hypocotyl explants by indole-3-ethanol and its sugar conjugates". Physiologia Plantarum 64 (2): 237.  
  25. ^ "Dialkyltryptamines via Tryptophol - []". Retrieved 2013-08-18.