17808-35-4

Usage

InChI:InChI=1/C11H11ClN2O2/c12-7-1-2-8-6(3-9(13)11(15)16)5-14-10(8)4-7/h1-2,4-5,9,14H,3,13H2,(H,15,16)

Upstream product

• 54-12-6 Trp 
• 50517-10-7 N^α-acetyl-6-chloro-D,L-tryptophan 
• 73-22-3 L-Tryptophan 
• 56777-76-5 N^α-acetyl-6-chloro-D-tryptophan 
• 63353-00-4 diethyl-(6-chloro-indol-3-ylmethyl)-amine 
• 50517-12-9 1-(6-chloro-1H-indol-3-yl)-N,N-dimethylmethanamine 
• 17422-33-2 6-chloroindole 
• 57233-85-9 N-Formyl-6-chlortryptophan 
• 1076199-98-8 (6-chloro-indol-3-ylmethyl)-formylamino-malonic acid diethyl ester 
• 56-45-1 L-serin 
• 808145-70-2 6-Chloro-3-((2S,5R)-3,6-diethoxy-5-isopropyl-2,5-dihydro-pyrazin-2-ylmethyl)-2-triethylsilanyl-1H-indole 
• 220906-11-6 (2R,5S)-3,6-diethoxy-2-isopropyl-5-[3-(triethylsilyl)prop-2-ynyl]-2,5-dihydropyrazine 
• 89-63-4 4-Chloro-2-nitroaniline 
• 6828-35-9 5-chloro-2-iodoaniline 

Downstream Products

• 56632-86-1 D-6-chlorotryptophan 
• 175777-22-7 L-4-chlorokynurenine 
• 3670-19-7 2-(6-chloro-1H-indole-3-yl)ethan-1-amine 
• 1219168-45-2 Fmoc-D-6Cl-Trp 
• 1217738-82-3 (S)-N-boc-6-chloro-tryptophan 

Relevant academic research and scientific papers

Synthesis of L-6-chloropyrroloindoline of chloptosin cyclohexapeptide

Chloptosin is an apoptosis-inducing dimeric cyclohexapeptide. Enantio-selective synthesis of L-6-chloropyrroloindoline, as the key chiral synthon of the cyclohexapeptide of chloptosin, was successfully achieved starting from 3-chloroaniline by utilizing F

An Unusual Flavin-Dependent Halogenase from the Metagenome of the Marine Sponge Theonella swinhoei WA

Uncultured bacteria from sponges have been demonstrated to be responsible for the generation of many potent, bioactive natural products including halogenated metabolites.1 The identification of gene clusters from the metagenomes of such bacterial communities enables the discovery of enzymes that mediate new and useful chemistries and allows insight to be gained into the biogenesis of potentially pharmacologically important natural products. Here we report a new pathway to the keramamides (krm); the first functional evidence for the existence of a distinct producer in the Theonella swinhoei WA chemotype is revealed, and a key enzyme on the pathway, a unique flavin-dependent halogenase with a broad substrate specificity, with potential as a useful new biocatalytic tool, is described.

Structure and biocatalytic scope of thermophilic flavin-dependent halogenase and flavin reductase enzymes

Flavin-dependent halogenase (Fl-Hal) enzymes have been shown to halogenate a range of synthetic as well as natural aromatic compounds. The exquisite regioselectively of Fl-Hal enzymes can provide halogenated building blocks which are inaccessible using standard halogenation chemistries. Consequently, Fl-Hal are potentially useful biocatalysts for the chemoenzymatic synthesis of pharmaceuticals and other valuable products, which are derived from haloaromatic precursors. However, the application of Fl-Hal enzymes, in vitro, has been hampered by their poor catalytic activity and lack of stability. To overcome these issues, we identified a thermophilic tryptophan halogenase (Th-Hal), which has significantly improved catalytic activity and stability, compared with other Fl-Hal characterised to date. When used in combination with a thermostable flavin reductase, Th-Hal can efficiently halogenate a number of aromatic substrates. X-ray crystal structures of Th-Hal, and the reductase partner (Th-Fre), provide insights into the factors that contribute to enzyme stability, which could guide the discovery and engineering of more robust and productive halogenase biocatalysts.

Targeted Enzyme Engineering Unveiled Unexpected Patterns of Halogenase Stabilization

Halogenases are valuable biocatalysts for selective C?H activation, but despite recent efforts to broaden their application scope by means of protein engineering, improvement of thermostability and catalytic efficiency is still desired. A directed evoluti

Tuning the Biological Activity of RGD Peptides with Halotryptophans ?

An array of l- and d-halotryptophans with different substituents at the indole moiety was synthesized employing either enzymatic halogenation by halogenases or incorporation of haloindoles using tryptophan synthase. Introduction of these Trp derivatives into RGD peptides as a benchmark system was performed to investigate their influence on bioactivity. Halotryptophan-containing RGD peptides display increased affinity toward integrin αvβ3 and enhanced selectivity over integrin α5β1. In addition, bromotryptophan was exploited as a platform for late-stage diversification by Suzuki-Miyaura cross-coupling (SMC), resulting in new-to-nature biaryl motifs. These peptides show enhanced affinity toward αvβ3, good affinity to αvβ8, and remarkable selectivity over α5β1 and αIIbβ3 while featuring fluorogenic properties. Their feasibility as a probe was demonstrated in vitro. Extensive molecular dynamics simulations were undertaken to elucidate NMR and high-performance liquid chromatography (HPLC) data for these late-stage diversified cyclic RGD peptides and to further characterize their conformational preferences.

METHODS FOR PRODUCING D-TRYPTOPHAN AND SUBSTITUTED D-TRYPTOPHANS

Single-module nonribosomal peptide synthetases (NRPSs) and NRPS-like enzymes activate and transform carboxylic acids in both primary and secondary metabolism; and are of great interest due to their biocatalytic potentials. The single-module NRPS IvoA is essential for fungal pigment biosynthesis. As disclosed herein, we show that IvoA catalyzes ATP-dependent unidirectional stereoinversion of L-tryptophan to D-tryptophan with complete conversion. While the stereoinversion is catalyzed by the epimerization (E) domain, the terminal condensation (C) domain stereoselectively hydrolyzes D-tryptophanyl-S-phosphopantetheine thioester and thus represents a noncanonical C domain function. Using IvoA, we demonstrate a biocatalytic stereoinversion/deracemization route to access a variety of substituted D-tryptophan analogs in high enantiomeric excess.

Biosynthesis of l-4-Chlorokynurenine, an Antidepressant Prodrug and a Non-Proteinogenic Amino Acid Found in Lipopeptide Antibiotics

l-4-Chlorokynurenine (l-4-Cl-Kyn) is a neuropharmaceutical drug candidate that is in development for the treatment of major depressive disorder. Recently, this amino acid was naturally found as a residue in the lipopeptide antibiotic taromycin. Herein, we report the unprecedented conversion of l-tryptophan into l-4-Cl-Kyn catalyzed by four enzymes in the taromycin biosynthetic pathway from the marine bacterium Saccharomonospora sp. CNQ-490. We used genetic, biochemical, structural, and analytical techniques to establish l-4-Cl-Kyn biosynthesis, which is initiated by the flavin-dependent tryptophan chlorinase Tar14 and its flavin reductase partner Tar15. This work revealed the first tryptophan 2,3-dioxygenase (Tar13) and kynurenine formamidase (Tar16) enzymes that are selective for chlorinated substrates. The substrate scope of Tar13, Tar14, and Tar16 was examined and revealed intriguing promiscuity, thereby opening doors for the targeted engineering of these enzymes as useful biocatalysts.

Structure-based switch of regioselectivity in the flavin-dependent tryptophan 6-halogenase Thal

Flavin-dependent halogenases increasingly attract attention as biocatalysts in organic synthesis, facilitating environmentally friendly halogenation strategies that require only FADH2, oxygen, and halide salts. Different flavin-dependent tryptophan halogenases regioselectively chlorinate or brominate tryptophan’s indole moiety at C5, C6, or C7. Here, we present the first substrate-bound structure of a tryptophan 6-halogenase, namely Thal, also known as ThdH, from the bacterium Streptomyces albogriseolus at 2.55 ? resolution. The structure revealed that the C6 of tryptophan is positioned next to the -amino group of a conserved lysine, confirming the hypothesis that proximity to the catalytic residue determines the site of electro-philic aromatic substitution. Although Thal is more similar in sequence and structure to the tryptophan 7-halogenase RebH than to the tryptophan 5-halogenase PyrH, the indole binding pose in the Thal active site more closely resembled that of PyrH than that of RebH. The difference in indole orientation between Thal and RebH appeared to be largely governed by residues positioning the Trp backbone atoms. The sequences of Thal and RebH lining the substrate binding site differ in only few residues. Therefore, we exchanged five amino acids in the Thal active site with the corresponding counterparts in RebH, generating the quintuple variant Thal-RebH5. Overall conversion of L-Trp by the Thal-RebH5 variant resembled that of WT Thal, but its regioselectivity of chlorination and bromination was almost completely switched from C6 to C7 as in RebH. We conclude that structure-based protein engineering with targeted substitution of a few residues is an efficient approach to tailoring flavin-dependent halogenases.

Complete Stereoinversion of l -Tryptophan by a Fungal Single-Module Nonribosomal Peptide Synthetase

Single-module nonribosomal peptide synthetases (NRPSs) and NRPS-like enzymes activate and transform carboxylic acids in both primary and secondary metabolism and are of great interest due to their biocatalytic potentials. The single-module NRPS IvoA is essential for fungal pigment biosynthesis. Here, we show that IvoA catalyzes ATP-dependent unidirectional stereoinversion of l-tryptophan to d-tryptophan with complete conversion. While the stereoinversion is catalyzed by the epimerization (E) domain, the terminal condensation (C) domain stereoselectively hydrolyzes d-tryptophanyl-S-phosphopantetheine thioester and thus represents a noncanonical C domain function. Using IvoA, we demonstrate a biocatalytic stereoinversion/deracemization route to access a variety of substituted d-tryptophan analogs in high enantiomeric excess.

One-Pot Biocatalytic Synthesis of Substituted d -Tryptophans from Indoles Enabled by an Engineered Aminotransferase

d-Tryptophan and its derivatives are important precursors of a wide range of indole-containing pharmaceuticals and natural products. Here, we developed a one-pot biocatalytic process enabling the synthesis of d-tryptophans from indoles in good yields and high enantiomeric excess (91% to >99%). Our method couples the synthesis of l-tryptophans catalyzed by Salmonella enterica tryptophan synthase with a stereoinversion cascade mediated by Proteus myxofaciens l-amino acid deaminase and an aminotransferase variant that we engineered to display native-like activity toward d-tryptophan. Our process is applicable to preparative-scale synthesis of a broad range of d-tryptophan derivatives containing electron-donating or -withdrawing substituents at all benzene-ring positions on the indole group.