6548-09-0Relevant articles and documents
An Obligate Peptidyl Brominase Underlies the Discovery of Highly Distributed Biosynthetic Gene Clusters in Marine Sponge Microbiomes
Nguyen, Nguyet A.,Lin, Zhenjian,Mohanty, Ipsita,Garg, Neha,Schmidt, Eric W.,Agarwal, Vinayak
supporting information, p. 10221 - 10231 (2021/07/26)
Marine sponges are prolific sources of bioactive natural products, several of which are produced by bacteria symbiotically associated with the sponge host. Bacteria-derived natural products, and the specialized bacterial symbionts that synthesize them, are not shared among phylogenetically distant sponge hosts. This is in contrast to nonsymbiotic culturable bacteria in which the conservation of natural products and natural product biosynthetic gene clusters (BGCs) is well established. Here, we demonstrate the widespread conservation of a BGC encoding a cryptic ribosomally synthesized and post-translationally modified peptide (RiPP) in microbiomes of phylogenetically and geographically dispersed sponges from the Pacific and Atlantic oceans. Detection of this BGC was enabled by mining for halogenating enzymes in sponge metagenomes, which, in turn, allowed for the description of a broad-spectrum regiospecific peptidyl tryptophan-6-brominase which possessed no chlorination activity. In addition, we demonstrate the cyclodehydrative installation of azoline heterocycles in proteusin RiPPs. This is the first demonstration of halogenation and cyclodehydration for proteusin RiPPs and the enzymes catalyzing these transformations were found to competently interact with other previously described proteusin substrate peptides. Within a sponge microbiome, many different generalized bacterial taxa harbored this BGC with often more than 50 copies of the BGC detected in individual sponge metagenomes. Moreover, the BGC was found in all sponges queried that possess high diversity microbiomes but it was not detected in other marine invertebrate microbiomes. These data shed light on conservation of cryptic natural product biosynthetic potential in marine sponges that was not detected by traditional natural product-to-BGC (meta)genome mining.
Novel Arylindigoids by Late-Stage Derivatization of Biocatalytically Synthesized Dibromoindigo
Schnepel, Christian,Dodero, Veronica I.,Sewald, Norbert
supporting information, p. 5404 - 5411 (2021/03/03)
Indigoids represent natural product-based compounds applicable as organic semiconductors and photoresponsive materials. Yet modified indigo derivatives are difficult to access by chemical synthesis. A biocatalytic approach applying several consecutive selective C?H functionalizations was developed that selectively provides access to various indigoids: Enzymatic halogenation of l-tryptophan followed by indole generation with tryptophanase yields 5-, 6- and 7-bromoindoles. Subsequent hydroxylation using a flavin monooxygenase furnishes dibromoindigo that is derivatized by acylation. This four-step one-pot cascade gives dibromoindigo in good isolated yields. Moreover, the halogen substituent allows for late-stage diversification by cross-coupling directly performed in the crude mixture, thus enabling synthesis of a small set of 6,6’-diarylindigo derivatives. This chemoenzymatic approach provides a modular platform towards novel indigoids with attractive spectral properties.
Biosynthesis of l-4-Chlorokynurenine, an Antidepressant Prodrug and a Non-Proteinogenic Amino Acid Found in Lipopeptide Antibiotics
Luhavaya, Hanna,Sigrist, Renata,Chekan, Jonathan R.,McKinnie, Shaun M. K.,Moore, Bradley S.
supporting information, p. 8394 - 8399 (2019/05/21)
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.
Discovery of 7-[18F]Fluorotryptophan as a Novel Positron Emission Tomography (PET) Probe for the Visualization of Tryptophan Metabolism in Vivo
Zlatopolskiy, Boris D.,Zischler, Johannes,Sch?fer, Dominique,Urusova, Elizaveta A.,Guliyev, Mehrab,Bannykh, Olesia,Endepols, Heike,Neumaier, Bernd
, p. 189 - 206 (2018/02/10)
Tryptophan and its metabolites are involved in different physiological and pathophysiological processes. Consequently, positron emission tomography (PET) tracers addressing tryptophan metabolic pathways should allow the detection of different pathologies like neurological disorders and cancer. Herein we report an efficient method for the preparation of fluorotryptophans labeled in different positions with 18F and their biological evaluation. 4-7-[18F]Fluorotryptophans ([18F]FTrps) were prepared according to a modified protocol of alcohol-enhanced Cu-mediated radiofluorination in 30-53% radiochemical yields. In vitro experiments demonstrated high cellular uptake of 4-7-[18F]FTrps in different tumor cell lines. 4, 5-, and 6-[18F]FTrps, although stable in vitro, suffered from rapid in vivo defluorination. In contrast, 7-[18F]FTrp demonstrated a high in vivo stability and enabled a clear delineation of serotonergic areas and melatonin-producing pineal gland in rat brains. Moreover 7-[18F]FTrp accumulated in different tumor xenografts in a chick embryo CAM model. Thus, 7-[18F]FTrp represents a highly promising PET probe for imaging of Trp metabolism.
Non-natural tryptophan derivative synthesis method
-
Paragraph 0026-0028; 0035-0037, (2017/08/27)
The invention relates to the field of organic synthesis, and discloses a non-natural tryptophan derivative synthesis method. Indole derivatives serve as raw materials. The synthesis method includes the steps: (1) dissolving the indole derivatives, 2-nitrine ethyl acrylate and bismuth trifluoromethanesulfonate in organic solvents, performing reaction for 2-6 hours, performing quenching reaction after complete reaction, extracting reaction liquid, and washing and drying an organic phase to obtain a compound 2; (2) dissolving the compound 2 in alcohol, dripping alkali solution, continuing reaction for 1.5-5 hours, performing concentration after complete reaction, extracting the reaction liquid, adjusting the pH (potential of hydrogen) of an aqueous phase to be 4-5, filtering the aqueous phase and taking solid to obtain a compound 3; (3) dissolving the compound 3 in alcohol, adding palladium carbon catalysts, leading in hydrogen, performing reaction for 6-10 hours, filtering the solution after complete reaction, and concentrating and recrystallizing filtrate. The synthesis method has the advantages that the raw materials are easily obtained, reaction conditions are mild, yield is high, production is easily amplified, and cost can be reduced.
Modular Combination of Enzymatic Halogenation of Tryptophan with Suzuki-Miyaura Cross-Coupling Reactions
Frese, Marcel,Schnepel, Christian,Minges, Hannah,Vo?, Hauke,Feiner, Rebecca,Sewald, Norbert
, p. 1799 - 1803 (2016/06/01)
The combination of the biocatalytic halogenation of l-tryptophan with subsequent chemocatalytic Suzuki-Miyaura cross-coupling reactions leads to the modular synthesis of an array of C5, C6, or C7 aryl-substituted tryptophan derivatives. In a three-step one-pot reaction, the bromo substituent is initially incorporated regioselectively by immobilized tryptophan 5-, 6-, or 7-halogenases, respectively, with concomitant cofactor regeneration. The halogenation proceeds in aqueous media at room temperature in the presence of NaBr and O2. After the separation of the biocatalyst by filtration, a Pd catalyst, base, and boronic acid are added to the aryl halide formed in situ to effect direct Suzuki-Miyaura cross-coupling reactions followed by tert-butoxycarbonyl (Boc) protection. After a single purification step, different Boc-protected aryl tryptophan derivatives are obtained that can, for example, be used for peptide or peptidomimetic synthesis. Putting the pieces together: By combining the enzymatic halogenation of l-tryptophan using flavin adenine dinucleotide dependent halogenases with Pd-catalyzed Suzuki-Miyaura cross-coupling reactions in water, the C5-, C6-, or C7-position of the indole ring can be brominated regioselectively in situ and functionalized chemocatalytically in a stepwise one-pot reaction.
Directed evolution of the tryptophan synthase β-subunit for stand-alone function recapitulates allosteric activation
Buller, Andrew R.,Brinkmann-Chen, Sabine,Romney, David K.,Herger, Michael,Murciano-Calles, Javier,Arnold, Frances H.
, p. 14599 - 14604 (2015/12/05)
Enzymes in heteromeric, allosterically regulated complexes catalyze a rich array of chemical reactions. Separating the subunits of such complexes, however, often severely attenuates their catalytic activities, because they can no longer be activated by their protein partners. We used directed evolution to explore allosteric regulation as a source of latent catalytic potential using the β-subunit of tryptophan synthase from Pyrococcus furiosus (PfTrpB). As part of its native αββα complex, TrpB efficiently produces tryptophan and tryptophan analogs; activity drops considerably when it is used as a stand-alone catalyst without the α-subunit. Kinetic, spectroscopic, and X-ray crystallographic data show that this lost activity can be recovered by mutations that reproduce the effects of complexation with the α-subunit. The engineered PfTrpB is a powerful platform for production of Trp analogs and for further directed evolution to expand substrate and reaction scope.
Synthesis of tripeptides containing d-Trp substituted at the indole ring, assessment of opioid receptor binding and in vivo central antinociception
De Marco, Rossella,Bedini, Andrea,Spampinato, Santi,Gentilucci, Luca
supporting information, p. 6861 - 6866 (2014/10/15)
The noncationizable tripeptide Ac-d-Trp-Phe-GlyNH2 was recently proposed as a novel minimal recognition motif for μ-opioid receptor. The introduction of different substituents (methyl, halogens, nitro, etc.) at the indole of d-Trp significantly influenced receptor affinities and resulted in serum stability and in a measurable effect on central antinociception in mice after ip administration.
Total synthesis of nominal (11S)- and (11R)-cyclocinamide A
Garcia, Jessica M.,Curzon, Stephanie S.,Watts, Katharine R.,Konopelski, Joseph P.
supporting information; experimental part, p. 2054 - 2057 (2012/06/29)
The cyclocinamides possess a unique β2αβ 2α 14-membered tetrapeptide core. The initially reported biological data and intriguing structure, which was without full stereochemical identification, necessitated synthesis of both nominal (all-S) cyclocinamide A and the 11R isomer. The completed synthesis is highlighted by the use of a (cyclo)asparagine-containing dipeptide as a turn inducing fragment. Due to inconsistencies in analytical data between natural and synthetic samples, a re-evaluation of the natural product stereochemistry appears necessary.
Precursor-directed fungal generation of novel halogenated chaetoglobosins with more preferable immunosuppressive action
Ge, Hui Ming,Yan, Wei,Guo, Zhi Kai,Luo, Qiong,Feng, Rui,Zang, Le Yun,Shen, Yan,Jiao, Rui Hua,Xu, Qiang,Tan, Ren Xiang
scheme or table, p. 2321 - 2323 (2011/04/18)
Precursor-fed cultivation of endophytic Chaetomium globosum 1C51 afforded nine novel "unnatural" halogenated chaetoglobosins including those with more preferable immunosuppressive activity.
