2497-02-1Relevant articles and documents
Synthesis and catalytic activity of histidine-based NHC ruthenium complexes
Monney, Angele,Venkatachalam, Galmari,Albrecht, Martin
, p. 2716 - 2719 (2011)
Main-chain C,N-protected histidine has been successfully alkylated at both side-chain nitrogens. The corresponding histidinium salt was metallated with ruthenium(ii) by a transmetalation procedure, thus providing histidine-derived NHC ruthenium complexes. These bio-inspired complexes show appreciable activity in the catalytic transfer hydrogenation of ketones. The Royal Society of Chemistry 2011.
Chemically Fueled Dissipative Self-Assembly that Exploits Cooperative Catalysis
Bal, Subhajit,Das, Krishnendu,Ahmed, Sahnawaz,Das, Dibyendu
, p. 244 - 247 (2019)
In living systems, dissipative processes are driven by the endergonic hydrolysis of chemical fuels such as nucleoside triphosphates. Now, through a simple model system, a transient self-assembled state is realized by utilizing the catalytic effect of histidine on the formation and breaking of ester bonds. First, histidine facilitates the ester bond formation, which then rapidly co-assembles to form a self-supporting gel. An out-of-equilibrium state is realized owing to the cooperative catalysis by the proximal histidines in the assembled state, driving the second pathway and resulting in disassembly to sol. Cooperative effects that use the dual role of imidazoles as nucleophile and as proton donor is utilized to achieve transient assemblies. This simple system mimics the structural journey seen in microtubule formation where the substrate GTP facilitates the non-covalent assembly and triggers a cooperative catalytic process, leading to substrate hydrolysis and subsequent disassembly.
The study of the effect of histidine derivatives as a novel antinociceptive and anti-inflammatory activity
Ramadhan, Usama H.,Al-Salihi, Niran J.
, p. 1832 - 1842 (2011)
This study explains the biochemical activity of histidine derivatives The compounds were identified by CHN analysis, FT-IR and H1 NMR. The results certified that the chemical structures of the prepared compounds. The anti-inflammatory and antinociceptive activity was studied by two different tests; the hot plate test and writhing test for analgesic activity and two tests for anti-inflammatory activity they are formalin induced inflammation test and carrageen an induced inflammation test. The histidine derivatives were found to have potent activity as anti-inflammatory and antinociceptive. The active compounds were tested to acute toxicity. It was found that they are safety to the dose 5 g/kg orally in mice without any mortality. Copyright E-Journal of Chemistry 2004-2011.
Synthesis, spectroscopic and X-ray characterization of various pyrazine-bridged platinum(II) complexes:1H NMR comparative study of their catalytic abilities in the hydrolysis of methionine- and histidine-containing dipeptides
Rajkovi?, Sne?ana,?ivkovi?, Marija D.,Warzajtis, Beata,Rychlewska, Urszula,Djuran, Milo? I.
, p. 367 - 376 (2016)
Four pyrazine (pz)-bridged Pt(II) complexes, [{Pt(1,3-pd)Cl}2(μ-pz)]Cl2·LiCl (1) (1,3-pd = 1,3-propylenediamine), [{Pt(2,2-diMe-1,3-pd)Cl}2(μ-pz)]Cl2·2[Li(H2O)4]Cl·2H2O (2) (2,2-diMe-1,3-pd = 2,2-dimethyl-1,3-propylenediamine), [{Pt(1,3-pnd)Cl}2(μ-pz)](ClO4)2·H2O (3) (1,3-pnd = (±)-1,3-pentanediamine) and [{Pt(1,3-pnd)Cl}2(μ-pz)]Cl2·2[Pt(1,3-pnd)Cl2]·2H2O (4) have been synthesized. NMR and UV-Vis spectroscopic characterization has been performed for compounds 1-3, while single-crystal X-ray analysis has been carried out for complexes 2 and 4. Atomic distribution in the crystals of 4 indicated a disorder which could be attributed to the presence at the same crystallographic site of four distinct stereoisomers of the [{Pt(1,3-pnd)Cl}2(μ-pz)]2+complex cation. The presence of four stereoisomeric products was also observed in complex 3 by13C NMR spectroscopy. Complexes 1-3 were converted into the corresponding aqua complexes, [{Pt(X)(H2O)}2(μ-pz)]4+(X is 1,3-pd, 2,2-diMe-1,3-pd and 1,3-pnd, respectively), and1H NMR spectroscopy was applied for comparison of their catalytic activities with those of the analogous mononuclear [Pt(X)(H2O)2]2+and pyrazine-bridged [{Pt(en)(H2O)}2(μ-pz)]4+complexes in the hydrolysis of the N-acetylated l-methionylglycine (Ac-l-Met-Gly) and l-histidylglycine (Ac-l-His-Gly). All reactions were performed in the pH range 2.0-2.5 at 37 °C. It was found that all investigated dinuclear Pt(II)-aqua complexes promote selective cleavage of the amide bond involving carboxylic group of the anchoring amino acid methionine in the Ac-l-Met-Gly or histidine in the Ac-l-His-Gly.1H NMR data indicate that neither the size of the chelated diamine ring (five-membered in ethylenediamine and six-membered in 1,3-propylenediamine) nor the bulky substituents incorporated into the 1,3-propylenediamine ligand have significant influence on the rate of hydrolysis of Ac-l-Met-Gly dipeptide. Meanwhile, the rate of hydrolysis of Ac-l-His-Gly depends on both of these factors and decreases in order en > 1,3-pd > 1,3-pnd > 2,2-diMe-1,3-pd. Moreover, it has been shown that all investigated dinuclear Pt(II)-aqua complexes are better catalytic agents in the hydrolysis of the dipeptides than the analogous mononuclear Pt(II)-aqua complexes. The present findings are expected to play a crucial role in the development of new Pt(II) complexes, which can act as effective catalytic reagents for the selective hydrolysis of peptides containing either methionine or histidine residues.
Emergence of a Promiscuous Peroxidase Under Non-Equilibrium Conditions**
Bal, Subhajit,Das, Dibyendu,Pal, Sumit,Reja, Antara,Tikader, Baishakhi
supporting information, (2021/12/06)
Herein, we report the substrate induced generation of a transient catalytic microenvironment from a single amino acid functionalized fatty acid in presence of a cofactor hemin. The catalytic state accessed under non-equilibrium conditions showed acceleration of peroxidase activity resulting in degradation of the substrate and subsequently led to disassembly. Equilibrated systems could not access the three-dimensional microphases and showed substantially lower catalytic activity. Further, the assembled state showed latent catalytic function (promiscuity) to hydrolyze a precursor to yield the same substrate. Consequently, the assembly demonstrated protometabolism by exploiting the peroxidase-hydrolase cascade to augment the lifetime and the mechanical properties of the catalytic state.
Effects of Imidazole and Its Derivatives on Radiation-Induced Dephosphorylation of Glycero-1-Phosphate in Deaerated Aqueous Solutions
Brinkevich,Maliborskii, A. Ya.,Melnichuk,Sverdlov,Grigor’ev, Yu. V.,Shadyro
, p. 155 - 164 (2021/04/22)
Abstract: The effect of imidazole, histamine, histidine, and their nitro derivatives on the radiation-induced transformations of glycero-1-phosphate and ethanol in deaerated aqueous solutions at pH 7 has been studied It has been found that the test substances in equimolar concentrations to glycero-1-phosphate inhibit the radiation-induced dephosphorylation by scavenging the radical products of water radiolysis. At an additive-to-substrate ratio of 1 : 100, the nitro derivatives of histidine and metronidazole efficiently inhibit the radiation-induced dephosphorylation of glycero-1-phosphate due to the interaction with its carbon-centered radicals with constants of (3.1–5.1) × 109 L mol–1 s–1. Using the radiolysis of a 1 M aqueous solution of ethanol, it was demonstrated that 5-nitroimidazoles quantitatively oxidize α-hydroxyethyl radicals; this manifested itself in the absence of 2,3-butanediol among the radiolysis products and a ~20-fold increase in the yield of acetaldehyde, as compared to that in a control experiment. Thus, metronidazole and the nitro derivatives of histidine are capable of suppressing the radiation-induced dephosphorylation of glycero-1-phosphate and, probably, glycerophospholipids due to the oxidation of their α-hydroxylcontaining carbon-centered radicals.
Synthesis of Imidazole and Histidine-Derived Cross-Linkers as Analogues of GOLD and Desmosine
Sch?del, Nicole,Icik, Esra,Martini, Maike,Altevogt, Luca,Ramming, Isabell,Greulich, Andreas,Baro, Angelika,Bilitewski, Ursula,Laschat, Sabine
supporting information, p. 2260 - 2268 (2021/03/04)
Amino acid derivatives with a central cationic heterocyclic core (e.g., imidazolium) are biologically relevant cross-linkers of proteins and advanced glycation end (AGE) products. Here, imidazolium-containing cross-linkers were synthesized from imidazole or histidine by N-alkylation employing aspartate- and glutamate-derived mesylates as key step. Biological investigations were carried out to probe the biocompatibility of these compounds.
Peptide Tyrosinase Activators
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, (2015/06/10)
Peptides that increase melanin synthesis are provided. These peptides include pentapeptides YSSWY, YRSRK, and their variants. The peptides may activate the enzymatic activity of tyrosinase to increase melanin synthesis. The pharmaceutical, cosmetic, and other compositions including the peptides are also provided. The methods of increasing melanin production in epidermis of a subject are provided where the methods include administering compositions comprising an amount of one or more peptides effective to increase the melanin production. The methods also include treating vitiligo or other hypopigmentation disorders with compositions including one or more peptides.
A fundamental study of amadori rearrangement products in reducing sugar-amino acid model system by electrospray ionization mass spectrometry and computation
Zhang,Ruan,Wang,Ruan,Shao,Aalhus,Juárez
, p. 2941 - 2944 (2014/06/09)
It is crucial to characterize Amadori rearrangement products (ARPs) formed in the early stage of Maillard reaction, one of the most important modifications in food science. We setup a reaction model system using six selected amino acids (arginine, asparagines, glutamine, histamine, lysine and tryptophan) and their N-terminal acetylated forms with different reducing sugars for a fundamental study of Amadori rearrangement products. The effects on forming Amadori rearrangement products were studied by using electrospray ionization mass spectrometry (ESI-MS). The reaction rate was affected by reaction temperature, reaction time, property of sugars and amino acids and the fragmentation mechanism of Amadori rearrangement products was illustrated by tandem MS (MS2) with collision-induced dissociation. The proposed fragmentation mechanism of Amadori rearrangement products in MS2 was provided based on MS2 data and it was supported by their computational data of density functional theory (DFT) at the B3LYP/6-31++G(d,p) level.
PH-SENSITIVE IMAGING AGENTS
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Paragraph 0323; 0324, (2014/05/20)
Composition and method for surface-functionalized SPION-based agents. Such agents can provide highly pH-sensitive MRI contrast in tissue.
