5-羥色氨酸

5-羥色氨酸（英語：5-Hydroxytryptophan，簡稱5-HTP），也叫歐西曲坦（INN：oxitriptan），是一種天然的氨基酸代謝中間產物，同時也是血清素與褪黑素的生物合成前體。

提示：此條目的主題不是血清素（5-羥色胺，5-HT）。

5-羥色氨酸
IUPAC名 2-amino-3- (5-hydroxy-1H-indol-3-yl) propanoic acid
識別
CAS編號	56-69-9  Y
PubChem	144
ChemSpider	388413
SMILES	O=C(O)[C@@H](N)Cc2c1cc(O)ccc1nc2
InChI	1/C11H12N2O3/c12-9(11(15)16)3-6-5-13-10-2-1-7(14)4-8(6)10/h1-2,4-5,9,13-14H,3,12H2,(H,15,16)/t9-/m0/s1
InChIKey	LDCYZAJDBXYCGN-VIFPVBQEBZ
ChEBI	17780
KEGG	D07339
MeSH	5-Hydroxytryptophan
性質
化學式	C11H12N2O3
摩爾質量	220.23 g/mol g·mol⁻¹
密度	1.484 g/mL
熔點	298-300 °C（571-573 K）
沸點	520.6 °C（794 K）
若非註明，所有數據均出自標準狀態（25 ℃，100 kPa）下。

5-羥色氨酸作為給抑鬱症、厭食症及失眠患者服用的膳食補充劑，在美國、英國和加拿大以非處方方式出售；同時也作為治療重性抑鬱障礙的藥物在歐洲許多國家銷售。^[1][2]幾個安慰劑雙盲臨床試驗已證明5-HTP有治療抑鬱症的效果^[1]，但缺乏極顯著性^[3]，需要更進一步的臨床對照研究^[4]。

代謝

在神經組織和肝細胞中^[5]，5-羥色氨酸在芳香族L-氨基酸脫羧酶、維生素B6幫助下脫羧生成血清素（5-羥色胺）^[6]。 5-羥色氨酸可以穿過血腦屏障^[7]，但血清素不能。過量的5-羥色氨酸會被代謝排出體外，體內的維生素B6會促進這種代謝。^[8][9]

5-HTP	AAAD		血清素
	PLP

藥理學

5-羥色氨酸可促進中樞神經系統分泌血清素^[10]。

Metabolic pathway from tryptophan to serotonin.

另見

• 褪黑素
• N-乙酰血清素
• 血清素
• 色氨酸

參考文獻

1. Turner EH, Blackwell AD. 5-Hydroxytryptophan plus SSRIs for interferon-induced depression: synergistic mechanisms for normalizing synaptic serotonin. Medical Hypotheses. 2005, 65 (1): 138–44 [2013-08-14]. PMID 15893130. doi:10.1016/j.mehy.2005.01.026. （原始內容存檔於2018-10-13）.
2. Swiss Pharmaceutical Society. Index Nominum 2000: International Drug Directory (Book with CD-ROM). Boca Raton: Medpharm Scientific Publishers. 2000. ISBN 3-88763-075-0.
3. Shaw K, Turner J, Del Mar C. Shaw, Kelly A , 編. Tryptophan and 5-hydroxytryptophan for depression. Cochrane Database of Systematic Reviews (Online). 2002, (1): CD003198. PMID 11869656. doi:10.1002/14651858.CD003198.
4. 5-Hydroxytryptophan (5-HTP) （頁面存檔備份，存於互聯網檔案館） University of Maryland Medical Center. 2011. Accessed: 9 January 2012.
5. Bouchard, S; Bousquet, C; Roberge, AG. Characteristics of dihydroxyphenylalanine/5-hydroxytryptophan decarboxylase activity in brain and liver of cat. Journal of Neurochemistry. 1981, 37 (3): 781–7. PMID 6974228. doi:10.1111/j.1471-4159.1982.tb12555.x.
6. Rahman MK, Nagatsu T, Sakurai T, Hori S, Abe M, Matsuda M. Effect of pyridoxal phosphate deficiency on aromatic L-amino acid decarboxylase activity with L-DOPA and L-5-hydroxytryptophan as substrates in rats. Jpn. J. Pharmacol. 1982, 32 (5): 803–11. PMID 6983619. doi:10.1254/jjp.32.803.
7. Gomes P, Soares-da-Silva P. L-DOPA transport properties in an immortalised cell line of rat capillary cerebral endothelial cells, RBE 4. Brain Res. 1999, 829 (1–2): 143–150. PMID 18445233. doi:10.1016/S0006-8993(99)01387-6.
8. Bouchard S, Roberge AG. Biochemical properties and kinetic parameters of dihydroxyphenylalanine--5-hydroxytryptophan decarboxylase in brain, liver, and adrenals of cat. Can. J. Biochem. 1979, 57 (7): 1014–8. PMID 39668. doi:10.1139/o79-126.
9. Amamoto T, Sarai K. On the tryptophan-serotonin metabolism in manic-depressive disorders. Changes in plasma 5-HT and 5-HIAA levels and urinary 5-HIAA excretion following oral loading of L-5HTP in patients with depression. Hiroshima J. Med. Sci. 1976, 25 (2–3): 135–40. PMID 1088369.
10. 5-HTP: Uses, Side Effects, Interactions and Warnings - WebMD. [2009-10-05]. （原始內容存檔於2009-11-16）.

延伸閱讀

• den Boer JA, Westenberg HG. Behavioral, neuroendocrine, and biochemical effects of 5-hydroxytryptophan administration in panic disorder. Psychiatry Research. 1990, 31 (3): 267–78. PMID 2139731. doi:10.1016/0165-1781(90)90096-N.
• Angst J, Woggon B, Schoepf J. The treatment of depression with L-5-hydroxytryptophan versus imipramine. Results of two open and one double-blind study. Archiv für Psychiatrie und Nervenkrankheiten. 1977, 224 (2): 175–86. PMID 336002.
• article at Psychology Today（英語：Psychology Today）
• Turner EH, Loftis JM, Blackwell AD. Serotonin a la carte: supplementation with the serotonin precursor 5-hydroxytryptophan. Pharmacol. Ther. 2006, 109 (3): 325–38. PMID 16023217. doi:10.1016/j.pharmthera.2005.06.004.
• 5-Hydroxytryptophan (5-HTP) Supplement Information（頁面存檔備份，存於互聯網檔案館） at University of Maryland（英語：University of Maryland, Baltimore） Medical Center

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