5-hydroxytryptophan (5-HTP)   中文名称: DL-5-羟基色氨酸

L-5-羟色氨酸（5-HTP）是一种药物，也是一些膳食补充剂的天然成分。5-HTP由色氨酸通过色氨酸羟化酶（TPH）产生，其存在于两种异构体（TPH1和TPH2）中。5-HTP的脱羧作用产生血清素（5-羟色胺，5-HT），其进一步转化为褪黑素（N-乙酰基-5-甲氧基色胺）。5-HTP在神经和代谢疾病中起着重要作用，其由色氨酸合成是血清素和褪黑素生物合成的限制步骤。在这篇综述中，在了解了5-羟色胺的主要天然来源后，将描述分子工程对5-羟色胺的化学分析和合成、生物合成以及微生物生产。5-HTP的生理作用在动物研究和人体临床试验中都有讨论。还讨论了5-HTP在治疗抑郁、焦虑、恐慌、睡眠障碍、肥胖、肌阵挛和血清素综合征中的生理作用。还讨论了5-羟色胺的毒性以及色氨酸和5-羟色胺制剂中存在的有毒杂质的出现。[2]

5-羟色胺前体5-羟基-L-色氨酸（5-HTP）剂量依赖性地（30-100mg/kg腹腔注射）增加雄性大鼠的血浆泌乳素和促肾上腺皮质激素。催乳素和促肾上腺皮质激素对5-HTP（100 mg/kg）的反应通过用非选择性5-HT受体拮抗剂美特戈林（0.5 mg/kg）和选择性5-HT2受体拮抗剂利坦色林（0.4 mg/kg）、酮色林（2.5 mg/kg）、ICI（5.0 mg/kg）和司匹酮（1.0 mg/kg）预处理而减弱。5-HT1受体拮抗剂普萘洛尔（40 mg/kg）和品多醇（4.0 mg/kg）不能拮抗催乳素和促肾上腺皮质激素对5-HTP（100 mg/kg）的反应，选择性5-HT3受体拮抗剂BRL 43694（1.0 mg/kg）也是如此。结果表明，雄性大鼠对5-HTP的催乳素和促肾上腺皮质激素反应是由5-HT2受体介导的。[1]

Absorption, Distribution and Excretion
The immediate precursor in the serotonin synthetic route, 5-hydroxytryptophan (5-HTP), labeled with 11C in the beta position, has become available for studies using positron emission tomography (PET) to examine serotonin formation in human brain. Normalized uptake and intracerebral utilization of tracer amounts of (beta-11C)5-HTP were studied twice in six healthy male volunteers, three of them before and after pharmacological pretreatments ... Pretreatments with benserazide, p-chlorophenylalanine (PCPA), and unlabeled 5-HTP all significantly increased uptake of (beta-11C)5-HTP. The utilization rates in both striatal and frontal cortex were higher than those in the surrounding brain, indicating that PET studies using (beta-11C)5-HTP as a ligand quantitate selective processes in the utilization of 5-HTP.
The efficiency of absorption of 5HTP, as well as its decarboxylation product serotonin, is approximately 47% to 84%. Absorption of 5-HTP occurs by an active transport process. 5-HTP is transported by the portal circulation to the liver where approximately 25% of an administered dose is metabolized ... . 5-HTP that is not metabolized in the liver is transported by the general circulation to the various tissues of the body, including the brain. 5-HTP readily crosses the blood-brain barrier, and is converted to serotonin in brain cells.

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Metabolism / Metabolites
5-HTP is transported by the portal circulation to the liver where approximately 25% of an administered dose is metabolized via vitamin B6-dependent L-aromatic amino acid decarboxylase to 5-hydroxytryptamine (5-HT) /serotonin/. 5-HT is subsequently metabolized to 5-hydroxyindole acetaldehyde which is rapidly metabolized to 5-hydroxyindole acetaldehyde which is rapidly metabolized to 5-hydroxyindoleacetic acid (5-HIAA).
5-Hydroxytryptophan is decarboxylated to serotonin (5-hydroxytryptamine or 5-HT) by the enzyme aromatic-L-amino-acid decarboxylase with the help of vitamin B6. This reaction occurs both in nervous tissue and in the liver.

[1]. Mediation of ACTH and prolactin responses to 5-HTP by 5-HT2 receptors. Eur J Pharmacol. 1990 Apr 10;179(1-2):103-9.

[2]. Placebo-controlled comparison of three dose-regimens of 5-hydroxytryptophan challenge test in healthy volunteers. J Clin Psychopharmacol. 2002 Apr;22(2):183-9.

[3]. Acute L-5-hydroxytryptophan administration inhibits carbon dioxide-induced panic in panic disorder patients. Psychiatry Res. 2002 Dec 30;113(3):237-43.

5-hydroxytryptophan is a tryptophan derivative that is tryptophan substituted by a hydroxy group at position 5. It has a role as a human metabolite and a neurotransmitter.
5-Hydroxytryptophan has been reported in Panaeolus semiovatus and Solanum lycopersicum with data available.
5-Hydroxytryptophan, DL- is a racemic mixture of 5-hydroxytryptophan (5-HTP), a precursor to the neurotransmitter serotonin with anti-depressant, analgesic and appetite-suppressant activities. DL-5-HTP is decarboxylated to serotonin by aromatic-L-amino-acid decarboxylase, and results in increased serotonin levels within the brain. Mediated through serotonin receptors, elevated levels of serotonin causes increased serotonin neurotransmissions, hence leading to release of depression, pain and appetite.
5-Hydroxy-L-tryptophan is an aromatic amino acid naturally produced by the body from the essential amino acid l-tryptophan. 5-Hydroxy-L-tryptophan is the immediate precursor of the neurotransmitter serotonin. The conversion to serotonin is catalyzed by the enzyme aromatic l-amino acid decarboxylase (EC 4.1.1.28, AADC1 also known as dopa decarboxylase), an essential enzyme in the metabolism of the monoamine neurotransmitters. An accumulation of 5-Hydroxy-L-tryptophan in cerebrospinal fluid occurs in Aromatic l-amino acid decarboxylase deficiency (OMIM 608643), accompanied by an increased excretion in the urine of the patients, which are indicative of the disorder but not specific 5-Hydroxy-L-tryptophan is also increased in other disorders such as in Parkinson's patients with severe postural instability and gait disorders. Confirmation of the diagnosis AADC deficiency is then required by enzyme activity measurement or genetic analysis. The amount of endogenous 5-Hydroxy-L-tryptophan available for serotonin synthesis depends on the availability of tryptophan and on the activity of various enzymes, especially tryptophan hydroxylase (EC 1.14.16.4), indoleamine 2,3-dioxygenase (EC 1.13.11.52), and tryptophan 2,3-dioxygenase. (EC 1.13.11.11, TDO). 5-Hydroxy-L-tryptophan has been used clinically for over 30 years. In addition to depression, the therapeutic administration of 5-Hydroxy-L-tryptophan has been shown to be effective in treating a wide variety of conditions, including fibromyalgia, insomnia, binge eating associated with obesity, cerebellar ataxia, and chronic headaches. 5-Hydroxy-L-tryptophan easily crosses the blood-brain barrier and effectively increases central nervous system (CNS) synthesis of serotonin. Supplementation with 5-Hydroxy-L-tryptophan is hypothesized to normalize serotonin synthesis, which is putatively related to its antidepressant properties. (A3384, A3385, A3386).
The immediate precursor in the biosynthesis of SEROTONIN from tryptophan. It is used as an antiepileptic and antidepressant.
See also: Oxitriptan (annotation moved to).

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Mechanism of Action
The possible analgesic effect of 5-HTP may be accounted for, in part, by its conversion to serotonin. 5-HTP has also been found to increase plasma beta-endorphin and platelet met-enkephalin levels, which may signify a reinforcing effect upon an endogenous analgesic effect.
The mechanism of the possible antidepressant activity of 5-HTP is accounted for by its conversion to the neurotransmitter serotonin which plays a central role in the affective state. Antidepressants may work by either binding to one or more of the family of serotonin 5-HT receptors (5-HT1 - 5-HT7) or by inhibiting the reuptake of serotonin. ...

C11H12N2O3

220.23

220.084

56-69-9

144

White to off-white solid

1.5±0.1 g/cm3

520.6±50.0 °C at 760 mmHg

298-300ºC

268.7±30.1 °C

0.0±1.4 mmHg at 25°C

1.737

-0.14

99.34

4

4

3

16

272

0

O([H])C1C([H])=C([H])C2=C(C=1[H])C(=C([H])N2[H])C([H])([H])C([H])(C(=O)O[H])N([H])[H]

LDCYZAJDBXYCGN-UHFFFAOYSA-N

InChI=1S/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)

2-amino-3-(5-hydroxy-1H-indol-3-yl)propanoic acid; 5-hydroxy-DL-tryptophan

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

配方 1 中的溶解度: ≥ 2.08 mg/mL (9.45 mM) (饱和度未知) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将100 μL 20.8 mg/mL澄清DMSO储备液加入400 μL PEG300中，混匀；然后向上述溶液中加入50 μL Tween-80，混匀；加入450 μL生理盐水定容至1 mL。
*生理盐水的制备：将 0.9 g 氯化钠溶解在 100 mL ddH₂O中，得到澄清溶液。

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配方 2 中的溶解度: ≥ 2.08 mg/mL (9.45 mM) (饱和度未知) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将 100 μL 20.8 mg/mL澄清DMSO储备液加入900 μL 20% SBE-β-CD生理盐水溶液中，混匀。
*20% SBE-β-CD 生理盐水溶液的制备（4°C，1 周）：将 2 g SBE-β-CD 溶解于 10 mL 生理盐水中，得到澄清溶液。

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配方 3 中的溶解度: 2.08 mg/mL (9.45 mM) in 10% DMSO + 90% Corn Oil (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液; 超声助溶.
例如，若需制备1 mL的工作液，可将 100 μL 20.8 mg/mL 澄清 DMSO 储备液添加到 900 μL 玉米油中并混合均匀。

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配方 4 中的溶解度: ≥ 2.0 mg/mL (9.4 mM) in 10% DMSO + 40% PEG300 + 5% Tween80 + + 45% Saline
≥ 2.0 mg/mL (9.4 mM) in 10% DMSO + 90% (20% SBE-β-CD in saline)
≥ 2.0 mg/mL (9.4 mM) in 10% DMSO + 90% Corn oil
5.8 mg/mL (26.0 mM) in PBS, 澄清溶液
20 mg/mL (90.8 mM) in 0.5% CMC-Na/saline water, suspension

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配方 5 中的溶解度: 5.88 mg/mL (26.70 mM) in PBS (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液; 超声助溶 (<60°C).

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配方 6 中的溶解度: 20 mg/mL (90.82 mM) in 0.5% CMC-Na/saline water (这些助溶剂从左到右依次添加，逐一添加), 悬浊液; 超声助溶。
*生理盐水的制备：将 0.9 g 氯化钠溶解在 100 mL ddH₂O中，得到澄清溶液。

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请根据您的实验动物和给药方式选择适当的溶解配方/方案：
1、请先配制澄清的储备液(如：用DMSO配置50 或 100 mg/mL母液(储备液));
2、取适量母液，按从左到右的顺序依次添加助溶剂，澄清后再加入下一助溶剂。以 下列配方为例说明 (注意此配方只用于说明，并不一定代表此产品 的实际溶解配方):
10% DMSO → 40% PEG300 → 5% Tween-80 → 45% ddH2O (或 saline);
假设最终工作液的体积为 1 mL, 浓度为5 mg/mL: 取 100 μL 50 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀/澄清；向上述体系中加入50 μL Tween-80，混合均匀/澄清；然后继续加入450 μL ddH2O (或 saline)定容至 1 mL；
3、溶剂前显示的百分比是指该溶剂在最终溶液/工作液中的体积所占比例;
4、 如产品在配制过程中出现沉淀/析出，可通过加热(≤50℃)或超声的方式助溶;
5、为保证最佳实验结果，工作液请现配现用！
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7、 以上所有助溶剂都可在 Invivochem.cn网站购买。