Search results for "Indoles"
showing 10 items of 251 documents
Construction of Spirooxindole Analogues Engrafted with Indole and Pyrazole Scaffolds as Acetylcholinesterase Inhibitors
2021
Twenty-five new hits of spirooxindole analogs 8a–y engrafted with indole and pyrazole scaffolds were designed and constructed via a [3+2]cycloaddition (32CA) reaction starting from three components: new chalcone-based indole and pyrazole scaffolds 5a–d, substituted isatins 6a–c, and secondary amines 7a–d. The potency of the compounds were assessed in modulating cholinesterase (AChE) activity using Ellman’s method. Compounds 8i and 8y showed the strongest acetylcholine esterase inhibition (AChEI) with IC50 values of 24.1 and 27.8 μM, respectively. Molecular docking was used to study their interaction with the active site of hAChE. peerReviewed
Gold(I)-catalysed cascade reactions in the synthesis of 2,3-fused indole derivatives.
2015
A gold(I)-catalysed hydroaminative/arylative cascade for the efficient synthesis of a variety of indole-fused skeletons has been developed. Factors controlling the catalyst loading required in these transformations involving 1,3-unsubstituted indole intermediates have been revealed, allowing isolation of an unprecedented 1,3-dimetallated 3H-indole gold complex characterized by X-ray diffraction.
NMR Spectroscopic Characterization and DFT Calculations of Zirconium(IV)-3,3′-Br2–BINOLate and Related Complexes Used in an Enantioselective Friedel–…
2012
Experimental and theoretical studies on the structure of several complexes based on (R)-3,3'-Br-2-BINOL ligand and group (IV) metals used as catalysts in an enantioselective Friedel-Crafts alkylation of indoles with alpha,beta-unsaturated ketones have been carried out. NMR spectroscopic studies of these catalysts have been performed, which suggested that at room temperature the catalysts would form a monomeric structure in the case of Ti-IV and a dimeric structure in the cases of Zr-IV and Hf-IV. Density functional theory (DFT) calculations clearly corroborate the conclusions of these experimental spectroscopic studies. The dimeric structure with a doubly bridged motif [Zr-2(IV)(mu-(R)-3,3'…
L-Tryptophan on Cu(111): engineering a molecular labyrinth driven by indole groups
2015
The present article investigates the adsorption and molecular orientation of L-Tryptophan, which is both an essential amino acid important for protein synthesis and of particular interest for the development of chiral molecular electronics and biocompatible processes and devices, on Cu(111) using scanning tunneling microscopy and spectroscopy at 55 K and at room temperature. The arrangement of chemisorbed L-Tryptophan on the copper surface varies with both temperature and surface coverage. At low coverage, small clusters form on the surface irrespective of temperature, while at high coverage an ordered chain structure emerges at room temperature, and a tightly packed structure forms a molec…
Profile and molecular modeling of 3-(indole-3-yl)-4-(3,4,5-trimethoxyphenyl)-1 H-pyrrole-2,5-dione (1) as a highly selective VEGF-R2/3 inhibitor.
2006
We report on selectivity profiling of 1 in a panel of 20 protein kinases and molecular modeling indicating 1 to be highly active and selective for VEGF-R2/3. Sequence alignment analysis and detailed insights into the ATP binding pockets of targeted protein kinases from the panel result in a unique structural architecture of VEGF-R2 mainly caused by the hydrophobic pocket I, determining the molecular basis for activity and selectivity of 1.
Two-Step Route to Indoles and Analogues from Haloarenes: A Variation on the Fischer Indole Synthesis
2012
In a new variation on the Fischer indole synthesis, readily available haloarenes are converted into a wide range of indoles in just two steps by halogen-magnesium exchange and quenching with di-tert-butyl azodicarboxylate, followed by reaction with aldehydes or ketones under acidic conditions. The protocol, which is readily extended to the preparation of indole isosteres, 4- and 6-azaindoles and thienopyrroles, obviates the need to prepare potentially toxic aryl hydrazines, simultaneously avoiding undesirable anilines such as naphthylamines.
Redox intermediates of plant and mammalian peroxidases: a comparative transient-kinetic study of their reactivity toward indole derivatives.
2002
Abstract A comparative study on the reactivity of five indole derivatives (tryptamine, N-acetyltryptamine, tryptophan, melatonin, and serotonin), with the redox intermediates compound I (k2) and compound II (k3) of the plant enzyme horseradish peroxidase (HRP) and the two mammalian enzymes lactoperoxidase (LPO) and myeloperoxidase (MPO), was performed using the sequential-mixing stopped-flow technique. The calculated bimolecular rate constants (k2, k3) revealed substantial differences regarding the oxidizability of the substrates by redox intermediates at pH 7.0 and 25°C. With HRP it was shown that k2 and k3 are mainly determined by the reduction potential (E°′) of the substrate with k2 bei…
Diels-Alder reaction between indoles and cyclohexadienes photocatalyzed by a (thia)pyrylium salt
2007
"Thiapyrylium salt 1 is an efficient photocatalyst in the Diels-Alder reaction between indoles (InHs) and 1,3-cyclohexadienes (CHDs). For instance, irradiation of deaerated dichloromethane solutions containing 1 (1 mM), indole (20 mM) and cyclohexadiene (40 mM), in the presence of an acylating agent, led to the Diels-Alder cycloadduct in 62% yield (endo:exo ratio of 1.8:1). Taking into account the very high intersystem crossing yield (Φisc = 0.97) of thiapyrylium salt 1, involvement of its triplet excited state in this Diels-Alder reaction has been studied using steadystate and time-resolved experiments; the results are compared with those previously obtained for pyrylium salts, which exhib…
1,2,4-Oxadiazole topsentin analogs as staphylococcal biofilm inhibitors targeting the bacterial transpeptidase sortase A
2020
The inhibition or prevention of biofilm formation represents an emerging strategy in the war against antibiotic resistance, interfering with key players in bacterial virulence. This approach includes the inhibition of the catalytic activity of transpeptidase sortase A (Srt A), a membrane enzyme responsible for covalently attaching a wide variety of adhesive matrix molecules to the peptidoglycan cell wall in Gram-positive strains. A new series of seventeen 1,2,4-oxadiazole derivatives was efficiently synthesized and screened as potential new anti-virulence agents. The ability of inhibiting biofilm formation was evaluated against both Gram-positive and Gram-negative pathogens. Remarkably, all…
2,6-Disubstituted imidazo[2,1-b][1,3,4]thiadiazole derivatives as potent staphylococcal biofilm inhibitors.
2019
Abstract A class of 36 new 2-(6-phenylimidazo[2,-1-b][1,3,4]thiadiazol-2-yl)-1H-indoles was efficiently synthesized and evaluated for their anti-biofilm properties against the Gram-positive bacterial reference strains Staphylococcus aureus ATCC 25923, S. aureus ATCC 6538 and Staphylococcus epidermidis ATCC 12228, and the Gram-negative strains Pseudomonas aeruginosa ATCC 15442 and Escherichia coli ATCC 25922. Many of these new compounds, were able to inhibit biofilm formation of the tested staphylococcal strains showing BIC50 lower than 10 μg/ml. In particular, derivatives 9c and 9h showed remarkable anti-biofilm activity against S. aureus ATCC 25923 with BIC50 values of 0.5 and 0.8 μg/ml, r…