3496-11-5Relevant articles and documents
Insight into the esterase like activity demonstrated by an imidazole appended self-assembling hydrogelator
Singh, Nishant,Conte, Maria P.,Ulijn,Miravet, Juan F.,Escuder, Beatriu
, p. 13213 - 13216 (2015)
A low molecular weight hydrogelator with a covalently appended imidazole moiety is reported. Capable of percolating water in the pH range of 6 to 8, it proves to be an efficient catalyst upon self-assembly, showing Michaelis-Menten type kinetics. Activities at different pH values correlated with dramatic structural changes were observed. It can hydrolyse p-nitrophenyl acetate (pNPA) as well as inactivated esters, and l and d-phenylalanine methyl esters. The enhanced activity can be related to the conglomeration of catalytic groups upon aggregation resulting in their close proximity and the formation of hydrophobic pockets.
Coordination behaviour of new open chain and macrocyclic peptidomimetic compounds with copper(ii)
Wadhavane, Prashant D.,Gorla, Lingaraju,Ferrer, Armando,Altava, Belén,Burguete, M. Isabel,Izquierdo, M. ángeles,Luis, Santiago V.
, p. 72579 - 72589 (2015)
Two valine-derived bis(amino amides) ligands have been prepared and fully characterized. Both compounds contain additional functionalities that implement their basicity and their water solubility. Besides, compound 1 is an open chain ligand, while 2 is a macrocycle. Their protonation constants as well as their stability constants for the formation of the corresponding Cu2+ complexes have been determined potentiometrically. Important differences are associated to the macrocyclic effect and to the additional functionalities in the spacer. The presence of an additional amine group and/or the inclusion of a carboxylic side chain in this spacer increase the stabilities of the Cu2+complexes, suggesting its participation in the interaction with the metal. Thus, 2 is the first pseudopeptidic cyclophane of this family displaying the ability to form highly stable metal complexes in water. UV-Vis and ESI-MS were used for analyzing the complex species detected in the speciation diagram.
The synthesis of new fluorescent bichromophoric compounds as ratiometric pH probes for intracellular measurements
Saura, A. Vanessa,Marín, María J.,Burguete, M. Isabel,Russell, David A.,Galindo, Francisco,Luis, Santiago V.
, p. 7736 - 7749 (2015)
Three different bichromophoric compounds (1-3) containing an aminomethyl anthracene moiety linked to a second chromophore (pyrene, 4-nitrobenzo-2-oxa-1,3-diazole (NBD) and dansyl) through a valine-derived pseudopeptidic spacer have been prepared and their fluorescent properties studied. The results obtained show that upon irradiation the photophysical behavior of these probes involves electronic energy transfer from the excited anthracene to the second chromophore and also intramolecular photoinduced electron transfer. The X-ray structure obtained for 3 reveals that the folding associated with the pseudopeptidic spacer favours a close proximity of the two chromophores. The emissive response of 3 is clearly dependent on the pH of the medium, hence this bichromophoric compound was shown to be an excellent ratiometric pH fluorescent sensor. The emission intensity due to the anthracene moiety exhibits a decrease at neutral-basic pH values that is concomitant with an increase in the intensity arising from the dansyl fluorophore. These properties make this compound a good candidate for biological pH sensing as has been confirmed by preliminary studies with RAW 264.7 macrophage cells imaged by means of confocal fluorescence microscopy with an average pH estimation of 5.4-5.8 for acidic organelles.
Discovery of Peptidomimetic Antibody-Drug Conjugate Linkers with Enhanced Protease Specificity
Wei, Binqing,Gunzner-Toste, Janet,Yao, Hui,Wang, Tao,Wang, Jing,Xu, Zijin,Chen, Jinhua,Wai, John,Nonomiya, Jim,Tsai, Siao Ping,Chuh, Josefa,Kozak, Katherine R.,Liu, Yichin,Yu, Shang-Fan,Lau, Jeff,Li, Guangmin,Phillips, Gail D.,Leipold, Doug,Kamath, Amrita,Su, Dian,Xu, Keyang,Eigenbrot, Charles,Steinbacher, Stefan,Ohri, Rachana,Raab, Helga,Staben, Leanna R.,Zhao, Guiling,Flygare, John A.,Pillow, Thomas H.,Verma, Vishal,Masterson, Luke A.,Howard, Philip W.,Safina, Brian
supporting information, p. 989 - 1000 (2018/01/01)
Antibody-drug conjugates (ADCs) have become an important therapeutic modality for oncology, with three approved by the FDA and over 60 others in clinical trials. Despite the progress, improvements in ADC therapeutic index are desired. Peptide-based ADC linkers that are cleaved by lysosomal proteases have shown sufficient stability in serum and effective payload-release in targeted cells. If the linker can be preferentially hydrolyzed by tumor-specific proteases, safety margin may improve. However, the use of peptide-based linkers limits our ability to modulate protease specificity. Here we report the structure-guided discovery of novel, nonpeptidic ADC linkers. We show that a cyclobutane-1,1-dicarboxamide-containing linker is hydrolyzed predominantly by cathepsin B while the valine-citrulline dipeptide linker is not. ADCs bearing the nonpeptidic linker are as efficacious and stable in vivo as those with the dipeptide linker. Our results strongly support the application of the peptidomimetic linker and present new opportunities for improving the selectivity of ADCs.
Novel fluorescent anthracene-bodipy dyads displaying sensitivity to pH and turn-on behaviour towards Cu(II) ions
Vanessa Saura,Isabel Burguete,Galindo, Francisco,Luis, Santiago V.
, p. 3013 - 3024 (2017/04/10)
Three bichromophoric compounds containing anthracene and bodipy moieties connected by different spacers have been synthesized and fully characterized. The set of spacers comprises a variety of bridges (short and flexible 1,2-diaminoethane in compound 1a, long and flexible 1,8-diaminooctane in compound 1b and short and rigid piperazine in compound 1c). The new compounds show interchromophoric communication via Electronic Energy Transfer (EET). When anthracene is excited, the energy is efficiently transferred to the bodipy moiety. The emission of the acceptor is partially quenched in dyad 1a but remarkably not in 1b and 1c. In an aqueous environment, the fluorescence of the new compounds display sensitivity to pH (emissive at acidic values and non-emissive at neutral ones), a typical behaviour of photoinduced electron-transfer (PET) probes, but with remarkable differences in the pKa of each compound, attributable to the nature of the linker. Additionally, the behaviour in the presence of several metallic cations (Cu2+, Ni2+, Cd2+, Zn2+) has been studied, and a turn-on response towards Cu2+ in water at neutral pH has been found.
PROCESS FOR THE PREPARATION OF LEDIPASVIR AND INTERMEDIATES THEREOF
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Page/Page column 15-16, (2017/09/02)
The present invention relates to process for preparation of ledipasvir of formula 1 and its novel intermediates. The process involves reaction of compound of formula 2 with compound of formula 3 to yield a compound of formula 4, deprotection of compound of formula 4 to yield compound of formula 5 and conversion of compound of formula 5 to Ledipasvir wherein PG is an amine protecting group provided that amino protecting group is not carbomethyloxy (-COOCH3) group; X and Y are leaving groups.
Structure-CaSR-activity relation of kokumi γ-glutamyl peptides
Amino, Yusuke,Nakazawa, Masakazu,Kaneko, Megumi,Miyaki, Takashi,Miyamura, Naohiro,Maruyama, Yutaka,Eto, Yuzuru
, p. 1181 - 1189 (2016/08/11)
Modulation of the calcium sensing receptor (CaSR) is one of the physiological activities of γ-glutamyl peptides such as glutathione (γ-glutamylcysteinylglycine). γ-Glutamyl peptides also possess a flavoring effect, i.e., sensory activity of kokumi substances, which modifies the five basic tastes when added to food. These activities have been shown to be positively correlated, suggesting that kokumi γ-glutamyl peptides are perceived through CaSRs in humans. Our research is based on the hypothesis that the discovery of highly active CaSR agonist peptides will lead to the creation of practical kokumi peptides. Through continuous study of the structure-CaSR-activity relation of a large number of γ-glutamyl peptides, we have determined that the structural requirements for intense CaSR activity of γ-glutamyl peptides are as follows: existence of an N-terminal γ-L-glutamyl residue; existence of a moderately sized, aliphatic, neutral substituent at the second residue in an L-configuration; and existence of a C-terminal carboxylic acid, preferably with the existence of glycine as the third constituent. By the sensory analysis of γ-glutamyl peptides selected by screening using the CaSR activity assay, γ-glutamylvalylglycine was found to be a potent kokumi peptide. Furthermore, norvaline-containing γ-glutamyl peptides, i.e., γ-glutamylnorvalylglycine and γ-glutamylnorvaline, possessed excellent sensory activity of kokumi substances. A novel, practical industrial synthesis of regiospecific γ-glutamyl peptides is also required for their commercialization, which was achieved through the ring opening reaction of N-α-carbobenzoxy-L-glutamic anhydride and amino acids or peptides in the presence of N-hydroxysuccinimide.
Mechanistic implications of the enantioselective addition of alkylzinc reagents to aldehydes catalyzed by nickel complexes with α-amino amide ligands
Escorihuela, Jorge,Burguete, M. Isabel,Ujaque, Gregori,Lledós, Agustí,Luis, Santiago V.
supporting information, p. 11125 - 11136 (2016/12/07)
The enantioselective alkylation of aldehydes catalysed by nickel(ii)-complexes derived from α-amino amides was studied by means of density functional theory (DFT) and ONIOM (B3LYP:UFF) calculations. A mechanism was proposed in order to investigate the origin of enantioselectivity. The chirality-determining step for the alkylation was the formation of the intermediate complexes with the involvement of a 5/4/4-fused tricyclic transition state. The predominant products predicted theoretically were of (S)-configuration, in good agreement with experimental observations. The scope of the reaction was examined and high yields and enantioselectivities were observed for the enantioselective addition of Et2Zn and Me2Zn to aromatic and aliphatic aldehydes.
PEPTIDOMIMETIC COMPOUNDS AND ANTIBODY-DRUG CONJUGATES THEREOF
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Page/Page column 133, (2015/07/07)
This invention relates to peptidomimetic linkers and anti-body drug conjugates thereof, to pharmaceutical compositions containing them, and to their use in therapy for the prevention or treatment of cancer.
Fluorescent macrocyclic probes with pendant functional groups as markers of acidic organelles within live cells
Wadhavane, Prashant D.,Izquierdo, M. Angeles,Lutters, Dennis,Burguete, M. Isabel,Marin, Maria J.,Russell, David A.,Galindo, Francisco,Luis, Santiago V.
, p. 823 - 831 (2014/01/23)
A new family of acidity sensitive fluorescent macrocycles has been synthesized and fully characterized. Their photophysical properties including emission quantum yield and fluorescence lifetime have been determined. The acid-base properties of the new molecules can be tuned by the incorporation of pendant functional groups. The nature of such functional groups (carboxylic acid or ester) influences dramatically the pKa of the probes, two compounds of which exhibit low values. Preliminary intracellular studies using confocal microscopy together with emission spectra of the probes from the cellular environment have shown that the synthesized fluorescent macrocycles mark the acidic organelles of RAW 264.7 macrophage cells.
