3978-11-8

Usage

Uses

Formylkynurenine is the impurity of Tryptophan (T947210), which is an essential amino acid.

Upstream product

• 54-12-6 Trp 
• 70938-99-7 3a-hydroperoxy-1,2,3,3a,8,8a-hexahydro-pyrrolo[2,3-b]indole-2-carboxylic acid 
• 73-22-3 L-Tryptophan 
• 153-94-6 D-tryptophan 
• 152071-32-4 methylene blue 
• 79647-52-2 (2S,3aR,8aR)-3a-hydroperoxy-1,2,3,3a,8,8a-hexahydropyrrolo[2,3-b]indole-2-carboxylic acid 
• 64-18-6 formic acid 
• 2922-83-0 L-kynurenine 
• 343-65-7 Kynurenine 
• 70938-99-7 2-carboxy-3a-hydroperoxy-1,2,3,3a,8,8a-hexahydropyrrolo<2,3-b>indole 
• 54-12-6 L(-)-tryptophan 

Relevant academic research and scientific papers

Photooxidation of tryptophan: O2(1Δ(g)) versus electron-transfer pathway

Tris (2,2'-bipyridyl)ruthenium(II)chloride hexahydrate (Ru[bpy]32+) free in solution and adsorbed onto antimony-doped SnO2 colloidal particles was used as a photosensitizer for a comparison of the O2(1/sup

Catalytic activity of human indoleamine 2,3-dioxygenase (hIDO1) at low oxygen

A cytokine-inducible extrahepatic human indoleamine 2,3-dioxygenase (hIDO1) catalyzes the first step of the kynurenine pathway. Immunosuppressive activity of hIDO1 in tumor cells weakens host T-cell immunity, contributing to the progression of cancer. Her

Engineered Biosynthesis of Fungal 4-Quinolone Natural Products

Quinolone-containing natural products are widely found in bacteria, fungi, and plants. The fungal quinolactacins, which are N-methyl-4-quinolones, display a wide spectrum of biological activities. Here we uncovered a concise nonribosomal peptide synthetase pathway involved in quinolactacin A biosynthesis from Penicillium by using heterologous reconstitution and in vitro enzymatic synthesis. The N-desmethyl analog of quinolactacin A was accessed through the construction of a hybrid bacterial and fungi pathway in the heterologous host.

Directed Evolution of a Tryptophan 2,3-Dioxygenase for the Diastereoselective Monooxygenation of Tryptophans

Herein, we report an engineered enzyme that can monooxygenate unprotected tryptophan into the corresponding 3a-hydroxyhexahydropyrrolo[2,3-b]indole-2-carboxylic acid (HPIC) in a single, scalable step with excellent turnover number and diastereoselectivity. Taking advantage of directed evolution, we analyzed the stepwise oxygen-insertion mechanism of tryptophan 2,3-dioxygenases, and transformed tryptophan 2,3-dioxygenase from Xanthomonas campestris into a monooxygenase for oxidative cyclization of tryptophans. It was revealed that residue F51 is vital in determining the product ratio of HPIC to N′-formylkynurenine. Our reactions and purification procedures use no organic solvents, resulting in an eco-friendly method to prepare HPICs for further applications.

Singlet molecular oxygen regulates vascular tone and blood pressure in inflammation

Singlet molecular oxygen (1O2) has well-established roles in photosynthetic plants, bacteria and fungi1–3, but not in mammals. Chemically generated 1O2 oxidizes the amino acid tryptophan to precursors of a key metabolite called N-formylkynurenine4, whereas enzymatic oxidation of tryptophan to N-formylkynurenine is catalysed by a family of dioxygenases, including indoleamine 2,3-dioxygenase 15. Under inflammatory conditions, this haem-containing enzyme is expressed in arterial endothelial cells, where it contributes to the regulation of blood pressure6. However, whether indoleamine 2,3-dioxygenase 1 forms 1O2 and whether this contributes to blood pressure control have remained unknown. Here we show that arterial indoleamine 2,3-dioxygenase 1 regulates blood pressure via formation of 1O2. We observed that in the presence of hydrogen peroxide, the enzyme generates 1O2 and that this is associated with the stereoselective oxidation of l-tryptophan to a tricyclic hydroperoxide via a previously unrecognized oxidative activation of the dioxygenase activity. The tryptophan-derived hydroperoxide acts in vivo as a signalling molecule, inducing arterial relaxation and decreasing blood pressure; this activity is dependent on Cys42 of protein kinase G1α. Our findings demonstrate a pathophysiological role for 1O2 in mammals through formation of an amino?acid-derived hydroperoxide that regulates vascular tone and blood pressure under inflammatory conditions.

Stepwise O-Atom Transfer in Heme-Based Tryptophan Dioxygenase: Role of Substrate Ammonium in Epoxide Ring Opening

Heme-based tryptophan dioxygenases are established immunosuppressive metalloproteins with significant biomedical interest. Here, we synthesized two mechanistic probes to specifically test if the α-amino group of the substrate directly participates in a critical step of the O atom transfer during catalysis in human tryptophan 2,3-dioxygenase (TDO). Substitution of the nitrogen atom of the substrate to a carbon (probe 1) or oxygen (probe 2) slowed the catalytic step following the first O atom transfer such that transferring the second O atom becomes less likely to occur, although the dioxygenated products were observed with both probes. A monooxygenated product was also produced from probe 2 in a significant quantity. Analysis of this new product by HPLC coupled UV-vis spectroscopy, high-resolution mass spectrometry, 1H NMR, 13C NMR, HSQC, HMBC, and infrared (IR) spectroscopies concluded that this monooxygenated product is a furoindoline compound derived from an unstable epoxyindole intermediate. These results prove that small molecules can manipulate the stepwise O atom transfer reaction of TDO and provide a showcase for a tunable mechanism by synthetic compounds. The product analysis results corroborate the presence of a substrate-based epoxyindole intermediate during catalysis and provide the first substantial experimental evidence for the involvement of the substrate α-amino group in the epoxide ring-opening step during catalysis. This combined synthetic, biochemical, and biophysical study establishes the catalytic role of the α-amino group of the substrate during the O atom transfer reactions and thus represents a substantial advance to the mechanistic comprehension of the heme-based tryptophan dioxygenases.

Nitrobenzofurazan derivatives of N′-hydroxyamidines as potent inhibitors of indoleamine-2,3-dioxygenase 1

Tryptophan metabolism through the kynurenine pathway is considered as a crucial mechanism in immune tolerance. Indoleamine 2,3-dioxygenase 1 (IDO1) plays a key role in tryptophan catabolism in the immune system and it is also considered as an important therapeutic target for the treatment of cancer and other diseases that are linked with kynurenine pathway. In this study, a series of nitrobenzofurazan derivatives of N′-hydroxybenzimidamides (1) and N′-hydroxy-2-phenylacetimidamides (2) were synthesized and their inhibitory activities against human IDO1 enzyme were tested using in-vitro and cellular enzyme activity assay. The optimization leads to the identification of potent compounds, 1d, 2i and 2k (IC50 = 39-80 nM), which are either competitive or uncompetitive inhibitors of IDO1 enzyme. These compounds also showed IDO1 inhibition potencies in the nanomolar range (IC50 = 50-71 nM) in MDA-MB-231 cells with no/negligible amount of cytotoxicity. The stronger selectivity of the potent compounds for IDO1 enzyme over tryptophan 2,3-dioxygenase (TDO) enzyme (312-1593-fold) also makes them very attractive for further immunotherapeutic applications.

N 1-fluoroalkyltryptophan analogues: Synthesis and in vitro study as potential substrates for indoleamine 2,3-dioxygenase

Indoleamine 2,3-dioxygenase (hIDO) is an enzyme that catalyzes the oxidative cleavage of the indole ring of l-tryptophan through the kynurenine pathway, thereby exerting immunosuppressive properties in inflammatory and tumoral tissues. The syntheses of 1-(2-fluoroethyl)-tryptophan (1-FETrp) and 1-((1-(2-fluoroethyl)-1H-1,2,3-triazol-4-yl)methyl)-tryptophan, two N1-fluoroalkylated tryptophan derivatives, are described here. In vitro enzymatic assays with these two new potential substrates of hIDO show that 1-FETrp is a good and specific substrate of hIDO. Therefore, its radioactive isotopomer, 1-[18F]FETrp, should be a molecule of choice to visualize tumoral and inflammatory tissues and/or to validate new potential inhibitors.

Associative chemosensing by fluorescent macrocycle-dye complexes-a versatile enzyme assay platform beyond indicator displacement

A label-free in situ method to monitor reactions in real time by using fluorescent supramolecular chemosensors based on cucurbit[8]uril is presented. It allows sensing of enzymatic activity, inhibitor and activator screening, and analyte detection with unprecedented versatility and high sensitivity.

Formation of fluorophores from the kynurenine pathway metabolite N-formylkynurenine and cyclic amines involves transamidation and carbon-carbon bond formation at the 2-position of the amine

Background Tryptophan catabolism along the kynurenine pathway is associated with a number of pathologies including cataract formation and cancer. Whilst the chemical reactions of kynurenine are well studied, less is known about the reactivity of its precu