15142-91-3Relevant academic research and scientific papers
Stepwise O-Atom Transfer in Heme-Based Tryptophan Dioxygenase: Role of Substrate Ammonium in Epoxide Ring Opening
Shin, Inchul,Ambler, Brett R.,Wherritt, Daniel,Griffith, Wendell P.,Maldonado, Amanda C.,Altman, Ryan A.,Liu, Aimin
, p. 4372 - 4379 (2018)
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.
Synthesis of CF3-Containing Spirocyclic Indolines via a Red-Light-Mediated Trifluoromethylation/Dearomatization Cascade
Gianetti, Thomas L.,Mei, Liangyong,Moutet, Jules,Stull, Savannah M.
supporting information, p. 10640 - 10653 (2021/07/31)
A red-light-mediated nPr-DMQA+-catalyzed cascade intramolecular trifluoromethylation and dearomatization of indole derivatives with Umemoto's reagent has been developed. This protocol provides a facile and efficient approach for the construction of functionalized and potentially biologically important CF3-containing 3,3-spirocyclic indolines with moderate to high yields and excellent diastereoselectivities under mild conditions. The success of multiple gram-scale (1 and 10 g) experiments further highlights the robustness and practicality of this protocol and the merit of the employment of red light. Mechanistic studies support the formation of a crucial CF3 radical species and a dearomatized benzyl carbocation intermediate.
Enantioselective Enzymatic Reduction of Acrylic Acids
An, Chihui,Shaw, Megan H.,Tharp, Annika,Verma, Deeptak,Li, Hongming,Wang, Heather,Wang, Xiao
supporting information, p. 8320 - 8325 (2020/11/03)
An ene-reductase (ERED 36) with broad substrate specificity was identified, and optimization studies led to the development of an enzymatic protocol for the reduction of α,β-unsaturated acids under mild, aqueous conditions. The substrate scope includes aromatic- A nd aliphatic-substituted acrylic acids, as well as cyclic α,β-substituted acrylic acids, yielding chiral α-substituted acids with exquisite levels of enantioselectivity (>99% ee).
Mechanistic Insights into the Radical S-adenosyl- l -methionine Enzyme NosL from a Substrate Analogue and the Shunt Products
Ji, Xinjian,Li, Yongzhen,Jia, Youli,Ding, Wei,Zhang, Qi
, p. 3334 - 3337 (2016/03/22)
The radical S-adenosyl-l-methionine (SAM) enzyme NosL catalyzes the transformation of l-tryptophan into 3-methyl-2-indolic acid (MIA), which is a key intermediate in the biosynthesis of a clinically interesting antibiotic nosiheptide. NosL catalysis was i
Biosynthesis of violacein, structure and function of L-tryptophan oxidase VioA from chromobacterium violaceum
Füller, Janis J.,R?pke, René,Krausze, Joern,Rennhack, Kim E.,Daniel, Nils P.,Blankenfeldt, Wulf,Schulz, Stefan,Jahn, Dieter,Moser, Jürgen
, p. 20068 - 20084 (2016/11/05)
Violacein is a natural purple pigment of Chromobacterium violaceum with potential medical applications as antimicrobial, antiviral, and anticancer drugs. The initial step of violacein biosynthesis is the oxidative conversion of L-tryptophan into the corresponding α-imine catalyzed by the flavoenzyme L-tryptophan oxidase (VioA). A substrate-related (3-(1H-indol-3-yl)-2-methylpropanoic acid) and a product-related (2-(1H-indol-3-ylmethyl)prop-2-enoic acid) competitive VioA inhibitor was synthesized for subsequent kinetic and x-ray crystallographic investigations. Structures of the binary VioA?FADH2 and of the ternary VioA?FADH2 ?2-(1H-indol-3-ylmethyl)prop-2-enoic acid complex were resolved. VioA forms a "loosely associated" homodimer as indicated by small-angle x-ray scattering experiments. VioA belongs to the glutathione reductase family 2 of FAD-dependent oxidoreductases according to the structurally conserved cofactor binding domain. The substrate-binding domain of VioA is mainly responsible for the specific recognition of L-tryptophan. Other canonical amino acids were efficiently discriminated with a minor conversion of L-phenylalanine. Furthermore, 7-aza-tryptophan, 1-methyl-tryptophan, 5-methyl-tryptophan, and 5-fluoro-tryptophan were efficient substrates of VioA. The ternary product-related VioA structure indicated involvement of protein domain movement during enzyme catalysis. Extensive structure-based mutagenesis in combination with enzyme kinetics (using L-tryptophan and substrate analogs) identified Arg64 , Lys269 , and Tyr309 as key catalytic residues of VioA. An increased enzyme activity of protein variant H163A in the presence of L-phenylalanine indicated a functional role of His163 in substrate binding. The combined structural and mutational analyses lead to the detailed understanding of VioA substrate recognition. Related strategies for the in vivo synthesis of novel violacein derivatives are discussed.
Control of the Bacterial Wilt of Tomato Plants by a Derivative of 3-Indolepropionic Acid Based on Selective Actions on Ralstonia solanacearum
Matsuda, Kazuhiko,Toyoda, Hideyoshi,Nishio, Hitomi,Nishida, Takatsugu,Dohgo, Mitsue,Bingo, Miki,Matsuda, Yoshinori,Yoshida, Satoshi,Harada, Satoshi,Tanaka, Hiroshi,Komai, Koichiro,Ouchi, Seiji
, p. 4416 - 4419 (2007/10/03)
3-Indolepropionic acid (IPA)-related compounds having a benzo[b]thiophene or an indazole ring and derivatives having various substituents in the propionic acid moieties were tested for their antibacterial activity against Ralstonia solanacearum. Substitution of the indole ring for other aromatic rings resulted in lowered activity, whereas addition of a methyl or a trifluoromethyl group to the propionic acid moiety had little effect. Of the derivatives, 3-(3-indolyl)butanoic acid (3-IBA) was as active as IPA, exhibiting a 10-fold higher activity with the S configuration than with the R configuration. In contrast with the strong phytotoxicity of IPA, 3-IBA was able to suppress bacterial wilt without affecting the growth of tomato plants.
