1. Signaling Pathways
  2. Metabolic Enzyme/Protease
  3. Tryptophan Hydroxylase

Tryptophan Hydroxylase

Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in the biosynthesis of the biogenic monoamine serotonin (5-hydroxytryptamine, 5-HT). TPH belongs to the family of the aromatic amino acid hydroxylases, including phenylalanine hydroxylase (PAH) and tyrosine hydroxylase (TH), which all have a strict requirement for dioxygen, non-heme iron (II) and tetrahydrobiopterin (BH4).Tryptophan hydroxylase is activated by phosphorylating conditions (ATP-Mg2+) in a calcium-dependent, cyclic AMP-independent manner. Two existing TPH isoforms (TPH-1 and TPH-2) are responsible for the generation of two distinct serotonergic systems in vertebrates.

TPH1, predominantly expressed in the gastrointestinal tract and pineal gland, mediates 5-HT biosynthesis in non-neuronal tissues, while TPH2, mainly found in the raphe nuclei of the brain stem, is accountable for the production of 5-HT in the brain. TPH-1, the principal enzyme for peripheral serotonin biosynthesis, provides a novel target to design anabolic agents for osteoporosis. TPH2 is a phenotypic marker for serotonin neurons and is known to be extremely labile to oxidation. As a major modulator of 5-HT neurotransmission and the stress response, TPH2 is of both pathophysiological and pharmacological significance, and is emerging as a new therapeutic target for the treatment of stress disorders.

Cat. No. Product Name Effect Purity Chemical Structure
  • HY-B1368
    Fenclonine
    Inhibitor 99.92%
    Fenclonine is a selective and irreversible tryptophan hydroxylase inhibitor, which is a rate-limiting enzyme in the biosynthesis of serotonin. Fenclonine can be used in carcinoid syndrome research.
    Fenclonine
  • HY-101456
    PCPA methyl ester hydrochloride
    Inhibitor 99.89%
    PCPA methyl ester hydrochloride (4-Chloro-DL-phenylalanine methyl ester hydrochloride), a reversible tryptophan hydroxylase inhibitor, is a serotonin (5-HT) synthesis inhibitor. PCPA methyl ester hydrochloride crosses the blood brain barrier and reduces 5-HT central availability.
    PCPA methyl ester hydrochloride
  • HY-13055
    Telotristat etiprate
    Inhibitor 99.89%
    Telotristat etiprate (LX1606 Hippurate) is a novel, orally-delivered inhibitor of tryptophan hydroxylase that reduces serotonin production.
    Telotristat etiprate
  • HY-13041
    LX-1031
    Inhibitor 98.32%
    LX-1031 is a potent, orally available tryptophan 5-hydroxylase (TPH) inhibitor that reduces serotonin (5-HT) synthesis peripherally.
    LX-1031
  • HY-15849A
    LP-533401 hydrochloride
    Inhibitor 98.02%
    LP-533401 hydrochloride is a tryptophan hydroxylase 1 inhibitor that regulates serotonin production in the gut.
    LP-533401 hydrochloride
  • HY-13055E
    Telotristat besilate
    Inhibitor
    Telotristat besilate is a potent tryptophan hydroxylase inhibitor with an in vivo IC50 of 0.028 μM.
    Telotristat besilate
  • HY-W772850
    Fenclonine hydrochloride
    Inhibitor
    Fenclonine hydrochloride is a selective and irreversible tryptophan hydroxylase inhibitor, which is a rate-limiting enzyme in the biosynthesis of serotonin. Fenclonine hydrochloride can be used in carcinoid syndrome research.
    Fenclonine hydrochloride
  • HY-13055B
    Telotristat
    Inhibitor 99.76%
    Telotristat (LP-778902) is a potent tryptophan hydroxylase inhibitor with an in vivo IC50 of 0.028 μM.
    Telotristat
  • HY-13055A
    Telotristat ethyl
    Inhibitor 99.79%
    Telotristat ethyl (LX1032) is a novel, orally-delivered inhibitor of tryptophan hydroxylase that reduces serotonin production.
    Telotristat ethyl
  • HY-W019599
    4-Chloro-L-phenylalanine
    Inhibitor ≥98.0%
    4-Chloro-L-phenylalanine (L-PCPA) is a 5-HT biosynthesis inhibitor. 4-Chloro-L-phenylalanine is also a nonspecific antagonist of both isoforms of tryptophan hydroxylase (TPH1 and TPH2).
    4-Chloro-L-phenylalanine
  • HY-15849
    LP-533401
    Inhibitor 98.68%
    LP-533401 is a Tryptophan hydroxylase 1 inhibitor that regulates serotonin production in the gut.
    LP-533401
  • HY-23460
    p-Ethynylphenylalanine
    Inhibitor 99.93%
    p-Ethynylphenylalanine (4-Ethynyl-L-phenylalanine) is a potent, selective, reversible and competitive inhibitor of tryptophan hydroxylase (TPH), with a Ki of 32.6 μM. p-Ethynylphenylalanine is a click chemistry reagent, it contains an Alkyne group and can undergo copper-catalyzed azide-alkyne cycloaddition (CuAAc) with molecules containing Azide groups.
    p-Ethynylphenylalanine
  • HY-23460A
    p-Ethynylphenylalanine hydrochloride
    Inhibitor 99.42%
    p-Ethynylphenylalanine hydrochloride (4-Ethynyl-L-phenylalanine hydrochloride) is a potent, selective, reversible and competitive inhibitor of tryptophan hydroxylase (TPH), with a Ki of 32.6 μM. p-Ethynylphenylalanine (hydrochloride) is a click chemistry reagent, it contains an Alkyne group and can undergo copper-catalyzed azide-alkyne cycloaddition (CuAAc) with molecules containing Azide groups.
    p-Ethynylphenylalanine hydrochloride
  • HY-120083
    Rodatristat
    Inhibitor 99.11%
    Rodatristat (KAR5417) is a potent tryptophan hydroxylase 1 (TPH1) and TPH2 inhibitor with IC50s value of 33 nM and 7 nM, respectively, and shows robust reduction of intestinal serotonin (5-HT) levels in mice.
    Rodatristat
  • HY-101124
    Rodatristat ethyl
    Inhibitor ≥98.0%
    Rodatristat ethyl (KAR5585) is a first-in-class oral tryptophan hydroxylase 1 (TPH1) Inhibitor with nanomolar in vitro potency. Rodatristat ethyl reduces the level of 5-HT and significantly reduces pulmonary arterial hypertension (PAH).
    Rodatristat ethyl
  • HY-W092533
    6-Fluorotryptophan
    Inhibitor 99.37%
    6-Fluorotryptophan, a competitive inhibitor of tryptophan hydroxylase, produced a transient disruption of sleep in rats chronically implanted with EEG recording electrodes.
    6-Fluorotryptophan
  • HY-157014
    TPT-004
    Inhibitor
    TPT-004 is a TPH inhibitor. TPT-004 has superior pharmacokinetic and pharmacodynamic properties. TPT-004 also has good efficacy in preclinical models of peripheral serotonin attenuation and colorectal tumor growth.
    TPT-004
  • HY-156093
    TPH1-IN-1
    Inhibitor
    TPH1-IN-1 (compound 40) is a xanthine derivative and an inhibitor of tryptophan hydroxylase TPH1 (IC50: 110.1 nM). TPH1-IN-1 has good in vitro activity and liver microsome stability, and effectively inhibits adipocyte differentiation of T3-L1 cells.
    TPH1-IN-1
  • HY-19572
    ACT-678689
    Inhibitor 99.91%
    ACT-678689 (Compound Example 1.53.4) is a tryptophan hydroxylase (TPH) inhibitor with an IC50 of 8 nM.
    ACT-678689
  • HY-13055BR
    Telotristat (Standard)
    Inhibitor
    Telotristat (Standard) is the analytical standard of Telotristat. This product is intended for research and analytical applications. Telotristat (LP-778902) is a potent tryptophan hydroxylase inhibitor with an in vivo IC50 of 0.028 μM.
    Telotristat (Standard)
Cat. No. Product Name / Synonyms Application Reactivity