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Tryptophan Metabolism: A New Look at the Role of Tryptophan Derivatives in the Human Body

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Abstract—

In modern scientific literature, close attention is paid to the biological role of tryptophan catabolites both in normal conditions and in various pathologies. There are more and more reports that tryptophan metabolism catabolites play a signaling role in the human body and in the intestinal microbial community. Receptors and signaling pathways in the human body, the so-called tryptophan signaling molecules (TrpSM), their cellular targets, and their physiological and metabolic effects are being actively studied. It has now been established that almost all catabolites of tryptophan metabolism are signaling molecules. Many of them realize their signaling role through arylhydrocarbon receptors (АhR). The dominant pathway of tryptophan metabolism for the human body is the kynurenine pathway, which is the source of universal the signaling molecules—kynurenine, quinolinic and kynurenic acids. The indole pathway of tryptophan catabolism, the main pathway for the microbiota, with the exception of indole formation reactions in immunocompetent cells, is a source of interregional and interspecies signaling molecules—indole and its derivatives: indole-3-pyruvate, indole-3-lactate, indole-3-acetate, indole-3-propionate, indole-3-acrylate, indole-3-butyrate and indole-3-acetaldehyde. Serotonin and melatonin are also universal signaling molecules and have been widely studied in various diseases of the nervous system.

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REFERENCES

  1. Abbott, N.J., Inflammatory mediators and modulation of blood-brain barrier permeability, cellular and molecular neurobiology, Cell Mol. Neirobiol., 2000, vol. 20, pp. 131–147. https://doi.org/10.1023/a:1007074420772

    Article  CAS  Google Scholar 

  2. Agus, A., Planchais, J., and Sokol, H., Gut microbiota regulation of tryptophan metabolism in health and disease, Cell Host Microbe, 2018, vol. 23, pp. 716–724. https://doi.org/10.1016/j.chom.2018.05.003

    Article  CAS  PubMed  Google Scholar 

  3. Badawy, A.A., Tryptophan metabolism: A versatile area providing multiple targets for pharmacological intervention, Egypt. J. Basic Clin. Pharmacol., 2019, vol. 9.https://doi.org/10.32527/2019/101415

  4. Barthelemy, A., Sencio, V., Soulard, D., et al., Interleukin-22 immunotherapy during severe influenza enhances lung tissue integrity and reduces secondary bacterial systemic invasion, Infect. Immun., 2018, vol. 86, p. e00706-17. https://doi.org/10.1128/IAI.00706-17

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  5. Behl, T., Kaur, I., Sehgal, A., et al., The footprint of kynurenine pathway in neurodegeneration: Janus-faced role in Parkinson’s disorder and therapeutic implications, Int. J. Mol. Sci., 2021, vol. 22, p. 6737. https://doi.org/10.3390/ijms22136737

  6. Blum, K., Gold, M., Lianos-Gomez, L., et al., Hypothesizing nutrigenomic-based precision anti-obesity treatment and prophylaxis: Should we be targeting sarcopenia induced brain dysfunction?, Int. J. Environ. Res. Public Health, 2021, vol. 18, p. 9774. https://doi.org/10.3390/ijerph18189774

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Bock, K.W., Human and rodent aryl hydrocarbon receptor (AHR): From mediator of dioxin toxicity to physiologic AHR functions and therapeutic options, Biol. Chem., 2017, vol. 398, pp. 455–464. https://doi.org/10.1515/hsz-2016-0303

    Article  CAS  PubMed  Google Scholar 

  8. Carbonnelle-Puscian, A., Copie-Bergman, C., Baia, M., et al., The novel immunosuppressive enzyme IL4I1 is expressed by neoplastic cells of several B-cell lymphomas and by tumor-associated macrophages, Leukemia, 2009, vol. 23, pp. 952–960. https://doi.org/10.1038/leu.2008.380

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  9. Carpenedo, R., Pittaluga, A., Cozzi, A., et al., Presynaptic kynurenate-sensitive receptors inhibit glutamate release, Eur. J. Neurosci., 2001, vol. 13, pp. 2141–2147. https://doi.org/10.1046/j.0953-816X.2001.01592.x

    Article  CAS  PubMed  Google Scholar 

  10. Castro-Portuguez, R. and Sutphin, G.L., Kynurenine pathway, NAD+ synthesis, and mitochondrial function: Targeting tryptophan metabolism to promote longevity and healthspan, Exp. Gerontol., 2020, vol. 132, p. 110841. https://doi.org/10.1016/j.exger.2020.110841

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Cecchi, M., Paccosi, S., Silvano, A., et al., Dexamethasone induces the expression and function of tryptophan-2-3-dioxygenase in sk-mel-28 melanoma cells, Pharmaceuticals, 2021, vol. 14, p. 211. https://doi.org/10.3390/ph14030211

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  12. Cénit, M.C., Matzaraki, V., Tigchelaar, E., et al., Rapidly expanding knowledge on the role of the gut microbiome in health and disease, Biochim. Biophys. Acta, Mol. Basis Dis., 2014, vol. 1842, pp. 1981–1992. https://doi.org/10.1016/j.bbadis.2014.05.023

    Article  CAS  Google Scholar 

  13. Cervenka, I., Agudelo, L.Z., and Ruas, J.L., Kynurenines: Tryptophan’s metabolites in exercise, inflammation, and mental health, Science, 2017, vol. 357, p. eaaf9794. https://doi.org/10.1126/science.aaf9794

  14. Chen, Y. and Guillemin, G.J., Kynurenine pathway metabolites in humans: Disease and healthy states, Int. J. Tryptophan Res., 2009, vol. 2, pp. 1–19. https://doi.org/10.4137/ijtr.s2097

    Article  PubMed  PubMed Central  Google Scholar 

  15. Chen, M., Yang, X., Lai, X., et al., Structural investigation for optimization of anthranilic acid derivatives as partial FXR agonists by in silico approaches, Int. J. Mol. Sci., 2016, vol. 17, p. 536. https://doi.org/10.3390/ijms17040536

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Chimerel, C., Emery, E., Summers, D., et al., Bacterial metabolite indole modulates incretin secretion from intestinal enteroendocrine L cells, Cell Rep., 2014, vol. 9, pp. 1202–1208. https://doi.org/10.1016/j.celrep.2014.10.032

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Connor, T.J., Neasa, S., Sullivan, J., et al., Induction of indolamine 2,3-dioxygenase and kynurenine 3-monooxygenase in rat brain following a systemic inflammatory challenge: A role for IFN-γ?, Neurosci. Lett., 2008, vol. 441, no. 1, pp. 29–34. https://doi.org/10.1016/j.neulet.2008.06.007

    Article  CAS  PubMed  Google Scholar 

  18. de Mello, V.D., Paananen, J., Lindstrom, J., et al., Indolepropionic acid and novel lipid metabolites are associated with a lower risk of type 2 diabetes in the Finnish diabetes prevention study, Sci. Rep., 2017, vol. 7, p. 46337. https://doi.org/10.1038/srep46337

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Deng, Y., Lim, A., Lee, J., et al., Diffusible signal factor (DSF) quorum sensing signal and structurally related molecules enhance the antimicrobial efficacy of antibiotics against some bacterial pathogens, BMC Microbiol., 2014, vol. 14, p. 51. https://doi.org/10.1186/1471-2180-14-51

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Díez-Sainz, E., Lorente-Cebrian, S., Aranaz, P., et al., Potential mechanisms linking food-derived micrornas, gut microbiota and intestinal barrier functions in the context of nutrition and human health, Front. Nutr., 2021, vol. 8, p. 586564. https://doi.org/10.3389/fnut.2021.586564

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Ehrlich, A.M., Pacheco, A., Henrick, B., et al., Indole-3-lactic acid associated with Bifidobacterium-dominated microbiota significantly decreases inflammation in intestinal epithelial cells, BMC Microbiol., 2020, vol. 20, p. 356. https://doi.org/10.1186/s12866-020-02023-y

    Article  CAS  Google Scholar 

  22. Evrensel, A. and Ceylan, M.E., The gut-brain axis: The missing link in depression, Clin. Psychopharmacol. Neurosci., 2015, vol. 13, pp. 239–244. https://doi.org/10.9758/cpn.2015.13.3.239

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Ferreira, F.S., Santos, T., Junior, O., et al., Quinolinic acid impairs redox homeostasis, bioenergetic, and cell signaling in rat striatum slices: Prevention by coenzyme Q10, Neurotox. Res., 2022, vol. 40, pp. 473–484. https://doi.org/10.1007/s12640-022-00484-9

    Article  CAS  PubMed  Google Scholar 

  24. Gao, K., Mu, C., Farzi, A., et al., Tryptophan metabolism: A link between the gut microbiota and brain, Adv. Nutr., 2020, vol. 11, pp. 709–723. https://doi.org/10.1093/advances/nmz127

    Article  PubMed  Google Scholar 

  25. Grifka-Walk, H.M., Jenkins, B.R., and Kominsky, D.J., Amino acid Trp: The far out impacts of host and commensal tryptophan metabolism, Front. Immunol., 2021, vol. 12, p. 653208. https://doi.org/10.3389/fimmu.2021.653208

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Guo, J., Williams, D., Puhl, H., et al., Inhibition of N-type calcium channels by activation of GPR35, an orphan receptor, heterologously expressed in rat sympathetic neurons, J. Pharmacol. Exp. Ther., 2008, vol. 324, pp. 342–351. https://doi.org/10.1124/jpet.107.127266

    Article  CAS  PubMed  Google Scholar 

  27. Gutiérrez-Vázquez, C. and Quintana, F.J., Regulation of the immune response by the aryl hydrocarbon receptor, Immunity, 2018, vol. 48, no. 1, pp. 19–33. https://doi.org/10.1016/j.immuni.2017.12.012

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Hendrikx, T. and Schnabl, B., Indoles: Metabolites produced by intestinal bacteria capable of controlling liver disease manifestation, J. Int. Med., 2019, vol. 286, pp. 32–40. https://doi.org/10.1111/joim.12892

    Article  CAS  Google Scholar 

  29. Jones, S.P., Guillemin, G.J., and Brew, B.J., The kynurenine pathway in stem cell biology, Int. J. Tryptophan Res., 2019, vol. 6, pp. 57–66. https://doi.org/10.4137/IJTR.S12626

    Article  CAS  Google Scholar 

  30. Kita, T., Morrison, P., Heyes, M., et al., Effects of systemic and central nervous system localized inflammation on the contributions of metabolic precursors to the L-kynurenine and quinolinic acid pools in brain, J. Neurochem., 2002, vol. 82, pp. 258–268. https://doi.org/10.1046/j.1471-4159.2002.00955.x

    Article  CAS  PubMed  Google Scholar 

  31. Konopelski, P. and Mogilnicka, I., Biological effects of indole-3-propionic acid, a gut microbiota-derived metabolite, and its precursor tryptophan in mammals’ health and disease, Int. J. Mol. Sci., 2022, vol. 23, p. 1222. https://doi.org/10.3390/ijms23031222

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Krishnan, S., Ding, Y., Saedi, N., et al., Erratum: Gut microbiota-derived tryptophan metabolites modulate inflammatory response in hepatocytes and macrophages, Cell Rep., 2018, vol. 23, pp. 1099–1111. https://doi.org/10.1016/j.celrep.2019.08.080

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Kumar, P., Lee, J.H., and Lee, J., Diverse roles of microbial indole compounds in eukaryotic systems, Biol. Rev., 2021, vol. 96, pp. 2522–2545. https://doi.org/10.1111/brv.12765

    Article  CAS  PubMed  Google Scholar 

  34. Labadie, B.W., Bao, R., and Luke, J.J., Reimagining IDO pathway inhibition in cancer immunotherapy via downstream focus on the tryptophan–kynurenine–aryl hydrocarbon axis, Clin. Cancer Res., 2019, vol. 25, pp. 1462–1471. https://doi.org/10.1158/1078-0432.CCR-18-2882

    Article  CAS  PubMed  Google Scholar 

  35. Lee, J.H., Wood, T.K., and Lee, J., Roles of indole as an interspecies and interkingdom signaling molecule, Trends Microbiol., 2015, vol. 23, pp. 707–718. https://doi.org/10.1016/j.tim.2015.08.001

    Article  CAS  PubMed  Google Scholar 

  36. Maffei, M.E., 5-Hydroxytryptophan (5-htp): Natural occurrence, analysis, biosynthesis, biotechnology, physiology and toxicology, Int. J. Mol. Sci., 2021, vol. 22, p. 181. https://doi.org/10.3390/ijms22010181

    Article  CAS  Google Scholar 

  37. Mangge, H., Summers, K., Mrinitzer, A., et al., Obesity-related dysregulation of the tryptophan-kynurenine metabolism: Role of age and parameters of the metabolic syndrome, Obesity, 2014, vol. 22, pp. 195–201. https://doi.org/10.1002/oby.20491

    Article  CAS  PubMed  Google Scholar 

  38. Marszalek-Grabska, M., et al., Kynurenine emerges from the shadows—Current knowledge on its fate and function, Pharmacol. Ther., 2021, vol. 225, p. 107845. https://doi.org/10.1016/j.pharmthera.2021.107845

    Article  CAS  PubMed  Google Scholar 

  39. Marszalek-Grabska, M., Stachniuk, A., Iwaniak, P., et al., Unexpected content of kynurenine in mother’s milk and infant formulas, Sci. Rep., 2022, vol. 12, p. 6464. https://doi.org/10.1038/S41598-022-10075-5

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  40. McCuen-Wurst, C., Ruggieri, M., and Allison, K.C., Disordered eating and obesity: Associations between binge-eating disorder, night-eating syndrome, and weight-related comorbidities, Annal. N. Y. Acad. Sci., 2018, vol. 1411, pp. 96–105. https://doi.org/10.1111/nyas.13467

    Article  Google Scholar 

  41. O’Mahony, S.M., Clarke, G., Borre, Y.E., et al., Serotonin, tryptophan metabolism and the brain-gut-microbiome axis, Behav. Brain Res., 2015, vol. 277, pp. 32–48. https://doi.org/10.1016/j.bbr.2014.07.027

    Article  CAS  PubMed  Google Scholar 

  42. Opitz, C.A., Litzenburger, U., Sahm, F., et al., An endogenous tumour-promoting ligand of the human aryl hydrocarbon receptor, Nature, 2011, vol. 478, pp. 197–203. https://doi.org/10.1038/nature10491

    Article  CAS  PubMed  Google Scholar 

  43. Platten, M., Nollen, E., Rohrig, U., et al., Tryptophan metabolism as a common therapeutic target in cancer, neurodegeneration and beyond, Nat. Rev. Drug Discovery, 2019, vol. 18, pp. 379–401. https://doi.org/10.1038/s41573-019-0016-5

    Article  CAS  PubMed  Google Scholar 

  44. Qiao, P., Zhang, C., Yu, J., et al., Quinolinic acid, a tryptophan metabolite of the skin microbiota, negatively regulates NLRP3 inflammasome through AhR in psoriasis, J. Invest. Dermatol., 2022, vol. 142, pp. 2184–2193. https://doi.org/10.1016/j.jid.2022.01.010

    Article  CAS  PubMed  Google Scholar 

  45. Roager, H.M. and Licht, T.R., Microbial tryptophan catabolites in health and disease, Nat. Commun., 2018, vol. 9, p. 3294. https://doi.org/10.1038/s41467-018-05470-4

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  46. Sas, K., Szabó, E., and Vécsei, L., Mitochondria, oxidative stress and the kynurenine system, with a focus on ageing and neuroprotection, Molecules, 2018, vol. 23, p. 191. https://doi.org/10.3390/molecules23010191

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  47. Savitz, J., The kynurenine pathway: A finger in every pie, Mol. Psychiatry, 2020, vol. 25, pp. 131–147. https://doi.org/10.1038/s41380-019-0414-4

    Article  PubMed  Google Scholar 

  48. Shestopalov, A.V., et al., Coupling features of intestinal and serum indole pools in obesity, Probl. Biol., Med. Pharm. Chem., 2021, vol. 24, pp. 3–12. https://doi.org/10.29296/25877313-2021-10-01

    Article  Google Scholar 

  49. Shestopalov, A.V., Shatova, O.P., Komarova, E.F., et al., Features of metabolic coupling in the “superorganism” system (host-microbiota), Crimea J. Exp. Clin. Med., 2020a, vol. 10, pp. 95–103. https://doi.org/10.37279/2224-6444-2020-10-2-95-103

    Article  Google Scholar 

  50. Shestopalov, A.V., Shatova, O.P., Karbyshev, M.S., et al., “Kynurenine switch” and obesity, Bull. Sib. Med., 2020b, vol. 4, pp. 103–111. https://doi.org/10.20538/1682-0363-2021-4-103-111

    Article  Google Scholar 

  51. Silva, S., Shimizu, J., Oliveira, D., et al., A diarylamine derived from anthranilic acid inhibits ZIKV replication, Sci. Rep., 2019, vol. 9, p. 17703. https://doi.org/10.1038/s41598-019-54169-z

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  52. Sittipo, P., Brain profiling in murine colitis and human epilepsy reveals neutrophils and TNFα as mediators of neuronal hyperexcitability, J. Neuroinflammation, 2021, vol. 19, p. 154. https://doi.org/10.1186/s12974-022-02510-1

    Article  Google Scholar 

  53. Song, S., Yin, W., Sun, X., et al., Anthranilic acid from Ralstonia solanacearum plays dual roles in intraspecies signaling and inter-kingdom communication, ISME J., 2020, vol. 14, pp. 2248–2260. https://doi.org/10.1038/s41396-020-0682-7

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  54. Stone, T.W. and Perkins, M.N., Quinolinic acid: A potent endogenous excitant at amino acid receptors in cns, Eur. J. Pharmacol., 1981, vol. 72, pp. 411–412. https://doi.org/10.1016/0014-2999(81)90587-2

    Article  CAS  PubMed  Google Scholar 

  55. Sun, M., Ma, N., He, T., et al., Tryptophan (Trp) modulates gut homeostasis via aryl hydrocarbon receptor (AhR), Crit. Rev. Food Sci. Nutr., 2020, vol. 60, pp. 1760–1768. https://doi.org/10.1080/10408398.2019.1598334

    Article  CAS  PubMed  Google Scholar 

  56. Szelest, M., Walczak, K., and Plech, T., A new insight into the potential role of tryptophan-derived AhR ligands in skin physiological and pathological processes, Int. J. Mol. Sci., 2021, vol. 22, p. 1104. https://doi.org/10.3390/ijms22031104

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  57. Thomas, T., Stefanoni, D., Reisz, J., et al., COVID-19 infection alters kynurenine and fatty acid metabolism, correlating with IL-6 levels and renal status, JCI Insight, 2019, vol. 5, p. e140327. https://doi.org/10.1172/JCI.INSIGHT.140327

    Article  Google Scholar 

  58. Tunaru, S., Kero, J., Schaub, A., et al., PUMA-G and HM74 are receptors for nicotinic acid and mediate its anti-lipolytic effect, Nat. Med., 2003, vol. 9, pp. 352–355. https://doi.org/10.1038/nm824

    Article  CAS  PubMed  Google Scholar 

  59. Vamos, E., Pardutz, A., Klivenyi, P., et al., The role of kynurenines in disorders of the central nervous system: possibilities for neuroprotection, J. Neurol. Sci., 2009, vol. 283, pp. 21–27. https://doi.org/10.1016/j.jns.2009.02.326

    Article  CAS  PubMed  Google Scholar 

  60. van Galen, K.A., Horst, K., Booij, J., et al., The role of central dopamine and serotonin in human obesity: Lessons learned from molecular neuroimaging studies, Metab., Clin. Exp., 2018, vol. 85, pp. 325–339. https://doi.org/10.1016/j.metabol.2017.09.007

    Article  CAS  PubMed  Google Scholar 

  61. van Galen, K.A., Horst, K.W., and Serlie, M.J., Serotonin, food intake, and obesity, Obes. Rev., 2021, vol. 22, p. e13210. https://doi.org/10.1111/obr.13210

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  62. Venkatesh, M., Mukherjee, S., Wang, H., et al., Symbiotic bacterial metabolites regulate gastrointestinal barrier function via the xenobiotic sensor PXR and toll-like receptor 4, Immunity, 2014, vol. 41, pp. 296–310. https://doi.org/10.1016/j.immuni.2014.06.014

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  63. Vyhlídalová, B., Krrasulova, K., Pecinkova, P., et al., Gut microbial catabolites of tryptophan are ligands and agonists of the aryl hydrocarbon receptor: A detailed characterization, Int. J. Mol. Sci., 2020, vol. 21, p. 2614. https://doi.org/10.3390/ijms21072614

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  64. Wang, S.Z., Yu, Y.J., and Adeli, K., Role of gut microbiota in neuroendocrine regulation of carbohydrate and lipid metabolism via the microbiota-gut-brain-liver axis, Microorganisms, 2020, vol. 8, p. 527. https://doi.org/10.3390/microorganisms8040527

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  65. Wei, G.Z., Martin, K.A., Xing, P.Y., et al., Tryptophan-metabolizing gut microbes regulate adult neurogenesis via the aryl hydrocarbon receptor, Proc. Natl. Acad. Sci. U. S. A., 2021, vol. 118, no. 27, p. e2021091118. https://doi.org/10.1073/pnas.2021091118

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  66. Wolf, A.M., Wolf, D., Rumpold, H., et al., Overexpression of indoleamine 2,3-dioxygenase in human inflammatory bowel disease, Clin. Immunol., 2004, vol. 113, pp. 47–55. https://doi.org/10.1016/j.clim.2004.05.004

    Article  CAS  PubMed  Google Scholar 

  67. Zádori, D., Klivenyi, P., Szalardy, L., et al., Mitochondrial disturbances, excitotoxicity, neuroinflammation and kynurenines: Novel therapeutic strategies for neurodegenerative disorders, J. Neurol. Sci., 2012, vol. 322, pp. 187–191. https://doi.org/10.1016/j.jns.2012.06.004

    Article  CAS  PubMed  Google Scholar 

  68. Zunszain, P.A., Anacker, C., Cattaneo, A., et al., Interleukin-1β: A new regulator of the kynurenine pathway affecting human hippocampal neurogenesis, Neuropsychopharmacology, 2012, vol. 37, pp. 939–949. https://doi.org/10.1038/npp.2011.277

    Article  CAS  PubMed  Google Scholar 

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  1. Pirogov Russian National Research Medical University, 117997, Moscow, Russia

    O. P. Shatova & A. V. Shestopalov

  2. Rogachev National Medical Research Center for Pediatric Hematology, Oncology and Immunology, 117198, Moscow, Russia

    A. V. Shestopalov

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Shatova, O.P., Shestopalov, A.V. Tryptophan Metabolism: A New Look at the Role of Tryptophan Derivatives in the Human Body. Biol Bull Rev 13, 81–91 (2023). https://doi.org/10.1134/S2079086423020068

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