Search results for "indoles"
showing 10 items of 251 documents
Variations of acidic functions at position 2 and substituents at positions 4, 5 and 6 of the indole moiety and their effect on NMDA-glycine site affi…
2003
The synthetic procedures to obtain indole derivatives with different acidic functions at position 2 of the indole are reported. The synthesised and tested derivatives comprise 5-tetrazolyl, 1,3,4-oxadiazol-5-yl-2-one, and indole-2-carboxylic acid amides with 5-aminotetrazole, methanesulphonamide and trifluoromethanesulphonamide moieties. The binding affinity was evaluated using [3H]MDL 105,519 and pig cortical brain membranes. In general, compounds with acidic functions different from a carboxylic acid moiety are less potent than indole-2-carboxylic acid derivatives. Also, the 4,6-dichloro substitution pattern was compared to 5-tert-butyl derivatives and compounds not substituted in the ben…
Density Functional Theory Study of the Trans-Trans-Cis (TTC)→Trans-Trans-Trans (TTT) Isomerization of a Photochromic Spiropyran Merocyanine
2008
Density Functional Theory (DFT) calculations have been performed on the TTC→TTT isomerization reaction of the open forms of the 1',3'-dihydro-8-bromo-6-nitro- 1',3',3'-trimethylspiro[2H-1-benzopyran-2,2'-(2H)indole (8-Br-6-nitro-BIPS) system. The calculations were carried out in vacuo and in methylene chloride solution at different temperatures. Results are compared with the available experimental values of free energy difference and activation energy in solution.
Design, Synthesis, and Biological Evaluation of 3,4-Diarylmaleimides as Angiogenesis Inhibitors
2006
The new analogue 2 of combretastatin A-4 was discovered to be an inhibitor of tubulin polymerization with an IC50 of 7.6 microM and reduced angiogenesis in the in vivo chick embryo model. Interestingly, in a series of 2,3-diarylmaleimides closely related to this lead, no other compound was found to be active in the tubulin polymerization assay. However, by screening in the in vivo chick embryo assay 10 was identified as a potent angiogenesis inhibitor indicating an alternative target. Indeed, molecular modeling studies suggest a reasonable binding mode of 10 at the ATP-binding site of the model kinase CDK2. Motivated by these results, analogues of 10 were screened for inhibitory activity in…
Atom-based Stochastic and non-Stochastic 3D-Chiral Bilinear Indices and their Applications to Central Chirality Codification
2006
Abstract Non-stochastic and stochastic 2D bilinear indices have been generalized to codify chemical structure information for chiral drugs, making use of a trigonometric 3D-chirality correction factor. In order to evaluate the effectiveness of this novel approach in drug design we have modeled the angiotensin-converting enzyme inhibitory activity of perindoprilate's σ-stereoisomers combinatorial library. Two linear discriminant analysis models, using non-stochastic and stochastic linear indices, were obtained. The models had shown an accuracy of 95.65% for the training set and 100% for the external prediction set. Next the prediction of the σ-receptor antagonists of chiral 3-(3-hydroxypheny…
Magneto-optical nanomaterials: a SPIO–phthalocyanine scaffold built step-by-step towards bimodal imaging
2013
A SPIO-phthalocyanine nanohybrid is developed as a bimodal contrast agent for Optical and Magnetic Resonance Imaging. The organic coating was covalently attached onto SPIO in a step-by-step approach. Each coated-SPIO was thoroughly characterized. The hydrodynamic size of the SPIO-Pc is ca. 60 nm with a coverage of ca. 690 Pc/SPIO.
A DFT study of [3 + 2] cycloaddition reactions of an azomethine imine with N-vinyl pyrrole and N-vinyl tetrahydroindole
2016
The mechanism and selectivities of the [3+2] cycloaddition (32CA) reactions of azomethine imine (AI) 8 with two N-vinyl five-membered heterocycles (NVFH), 9a and 9b, have been theoretically studied using DFT methods at the MPWB1K/6-31G(d) computational level. The possible ortho/meta regio- and endo/exo stereoselective channels were explored and characterised. The low polar character of these 32CA reactions, which is the consequence of the high nucleophilic character of both reagents, as well as the non-effective reactivity of these NVFH as nucleophiles, accounts for the high calculated activation energies, 16.1 (9a) and 16.8 (9b) kcalmol-1 in chlorobenzene. Analysis of the relative electron…
Interactions of zinc octacarboxyphthalocyanine with selected amino acids and with albumin
2015
Effect of selected amino acids (glycine, l-histidine, l-cysteine, l-serine, l-tryptophan) and albumin on the spectroscopic properties and photostability of zinc octacarboxyphthalocyanine (ZnPcOC) was explored in the phosphate buffer at a pH of 7.0. The photodegradation of ZnPcOC alone and in the presence of amino acids or albumin has been investigated in aqueous phase using UV-366 nm and daylight irradiation. Kinetic analysis showed that the interaction with amino acids or albumin enhances the photostability of ZnPcOC. To answer the question of how zinc phthalocyanine interacts with amino acids extensive DFT calculations were performed. Analysis of the optimized geometry features of ZnPcOC:…
Melatonin and phytomelatonin: Chemistry, biosynthesis, metabolism, distribution and bioactivity in plants and animals—an overview
2021
Melatonin is a ubiquitous indolamine, largely investigated for its key role in the regulation of several physiological processes in both animals and plants. In the last century, it was reported that this molecule may be produced in high concentrations by several species belonging to the plant kingdom and stored in specialized tissues. In this review, the main information related to the chemistry of melatonin and its metabolism has been summarized. Furthermore, the biosynthetic pathway characteristics of animal and plant cells have been compared, and the main differences between the two systems highlighted. Additionally, in order to investigate the distribution of this indolamine in the plan…
Sorafenib, but not sunitinib, affects function of dendritic cells and induction of primary immune responses
2008
AbstractThe tyrosine kinase inhibitors sorafenib and sunitinib are approved for the treatment of patients with malignant diseases. To analyze the possible use of these compounds in combination with immunotherapeutic approaches, we analyzed the effects of both inhibitors on the immunostimulatory capacity of human dendritic cells (DCs) and the induction of primary immune responses in vivo. Sorafenib, but not sunitinib, inhibits function of DCs, characterized by reduced secretion of cytokines and expression of CD1a, major histocompatibility complex, and costimulatory molecules in response to TLR ligands as well as by their impaired ability to migrate and stimulate T-cell responses. These inhib…
Available Lysine in Protein, Assay Using o-Phthalaldehyde/ N-Acetyl-L-cysteine Spectrophotometric Method
1992
An assay was based on reaction of free e-amino groups in proteins with the o-phthalaldehyde/N-acetyl-L-cysteine reagent to form isoindoles, which absorb at 335 nm. The procedure was suitable for proteins or mixtures of proteins with available lysine contents of more than 5 moles lysine/mole protein and required absence of free amino acids and peptides. This method was simpler and more convenient than other methods, since it did not require hydrolysis, amino acid analysis, long heating periods or solvent extraction.