Tag: M.W=100-150

Kunz, Peter C.; Thiel, Indre; Noffke, Anna Louisa; Reiss, Guido J.; Mohr, Fabian; Spingler, Bernhard published the artcile< Ruthenium piano-stool complexes bearing imidazole-based PN ligands>, Electric Literature of 36947-69-0, the main research area is crystal structure imidazolylphosphine ruthenium half sandwich preparation catalyst hydration; mol structure imidazolylphosphine ruthenium half sandwich preparation catalyst hydration; imidazole imidazolylphosphine ruthenium preparation phosphorus NMR structure; alkyne hydration catalyst imidazolylphosphine ruthenium half sandwich.

A variety of piano-stool complexes of cyclopentadienyl Ru(II) with imidazole-based PN ligands were synthesized starting from the precursor complexes [CpRu(C10H8)]PF6, [CpRu(NCMe)3]PF6 and [CpRu(PPh3)2Cl]. PN ligands used are imidazol-2-yl, -4-yl and -5-yl phosphines. Depending on the ligand and precursor different types of coordination modes were observed; in the case of polyimidazolyl PN ligands these were κ1P-monodentate, κ2P,N-, κ2N,N- and κ3N,N,N-chelating and μ-κP:κ2N,N-bridging. The solid-state structures of [CpRu(1a)2Cl]·H2O (5·H2O, 1a = imidazol-2-yldiphenylphosphine), [{CpRu(μ-κP:κ2N,N-2b)}2](C6H5PO3H)2(C6H5PO3H2)2 (2b = bis(1-methylimidazol-2-yl)phenylphosphine), a hydrolysis product of the as well determined [{CpRu(μ-κP:κ2N,N-2b)}2](PF6)2·2MeCN (7b·2MeCN), [CpRu(κ1P-3a)(PPh3)]Cl·CH2Cl2 (9·CH2Cl2, 3a = tris(imidazol-2-yl)phosphine) and [CpRu(PPh3)2Cl]·CHCl3 were determined Furthermore, [CpRu(L)2]PF6 (L = imidazol-2-yl or imidazol-4-yl phosphine) were screened for their catalytic activity in the hydration of 1-octyne.

Journal of Organometallic Chemistry published new progress about Aromatic nitrogen heterocycles Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 36947-69-0 belongs to class imidazoles-derivatives, and the molecular formula is C7H12N2, Electric Literature of 36947-69-0.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Takahashi, Shogo; Togo, Hideo published the artcile< Efficient preparation of 2-imidazolines from aldehydes and ethylenediamines with 1,3-diiodo-5,5-dimethylhydantoin>, Application In Synthesis of 36947-69-0, the main research area is aldehyde ethylenediamine cyclization iodohydantoin; imidazoline preparation.

Various 2-imidazolines were prepared in high yields by reacting aldehydes and ethylenediamines with 1,3-diiodo-5,5-dimethylhydantoin. Moreover, chiral 1,3-diimidazolin-2-ylbenzene and 2,6-diimidazolin-2-ylpyridines, which function as a chiral ligand, could be directly obtained from corresponding dialdehydes in high yields.

Heterocycles published new progress about Aldehydes Role: RCT (Reactant), RACT (Reactant or Reagent). 36947-69-0 belongs to class imidazoles-derivatives, and the molecular formula is C7H12N2, Application In Synthesis of 36947-69-0.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Bandela, Anil Kumar; Wagner, Nathaniel; Sadihov, Hava; Morales-Reina, Sara; Chotera-Ouda, Agata; Basu, Kingshuk; Cohen-Luria, Rivka; de la Escosura, Andres; Ashkenasy, Gonen published the artcile< Primitive selection of the fittest emerging through functional synergy in nucleopeptide networks>, Formula: C5H5N5, the main research area is functional synergy nucleopeptide network; chemical evolution; molecular networks; nucleic-acid–peptide conjugates; self-replication.

Many fundamental cellular and viral functions, including replication and translation, involve complex ensembles hosting synergistic activity between nucleic acids and proteins/peptides. There is ample evidence indicating that the chem. precursors of both nucleic acids and peptides could be efficiently formed in the prebiotic environment. Yet, studies on nonenzymic replication, a central mechanism driving early chem. evolution, have focused largely on the activity of each class of these mols. sep. We show here that short nucleopeptide chimeras can replicate through autocatalytic and cross-catalytic processes, governed synergistically by the hybridization of the nucleobase motifs and the assembly propensity of the peptide segments. Unequal assembly-dependent replication induces clear selectivity toward the formation of a certain species within small networks of complementary nucleopeptides. The selectivity pattern may be influenced and indeed maximized to the point of almost extinction of the weakest replicator when the system is studied far from equilibrium and manipulated through changes in the phys. (flow) and chem. (template and inhibition) conditions. We postulate that similar processes may have led to the emergence of the first functional nucleic-acid-peptide assemblies prior to the origin of life. Furthermore, spontaneous formation of related replicating complexes could potentially mark the initiation point for information transfer and rapid progression in complexity within primitive environments, which would have facilitated the development of a variety of functions found in extant biol. assemblies.

Proceedings of the National Academy of Sciences of the United States of America published new progress about Autocatalysis. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Formula: C5H5N5.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Boehnke, Hendrik; Roettger, Katharina; Ingle, Rebecca A.; Marroux, Hugo J. B.; Bohnsack, Mats; Schwalb, Nina K.; Orr-Ewing, Andrew J.; Temps, Friedrich published the artcile< Electronic Relaxation Dynamics of UV-Photoexcited 2-Aminopurine-Thymine Base Pairs in Watson-Crick and Hoogsteen Conformations>, Electric Literature of 452-06-2, the main research area is electronic relaxation dynamics UV photoexcited aminopurine thymine base conformation.

The fluorescent analog 2-aminopurine (2AP) of the canonical nucleobase adenine (6-aminopurine) base-pairs with thymine (T) without disrupting the helical structure of DNA. It therefore finds frequent use in mol. biol. for probing DNA and RNA structures and conformational dynamics. However, detailed understanding of the processes responsible for fluorescence quenching remains largely elusive on a fundamental level. Although attempts have been made to ascribe decreased excited-state lifetimes to intrastrand charge-transfer and stacking interactions, possible influences from dynamic interstrand H-bonding have been widely ignored. Here, we investigate the electronic relaxation of UV-excited 2AP·T in Watson-Crick (WC) and Hoogsteen (HS) conformations. Although the WC conformation features slowed-down, monomer-like electronic relaxation in τ ∼ 1.6 ns toward ground-state recovery and triplet formation, the dynamics associated with 2AP·T in the HS motif exhibit faster deactivation in τ ∼ 70 ps. As recent research has revealed abundant transient interstrand H-bonding in the Hoogsteen motif for duplex DNA, the established model for dynamic fluorescence quenching may need to be revised in the light of our results. The underlying supramol. photophys. mechanisms are discussed in terms of a proposed excited-state double-proton transfer as an efficient deactivation channel for recovery of the HS species in the electronic ground state.

Journal of Physical Chemistry B published new progress about Double-stranded DNA Role: BSU (Biological Study, Unclassified), BIOL (Biological Study). 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Electric Literature of 452-06-2.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

D’Souza, Sara; Miller, Justin E.; Ahn, Jenny; Subandi, Raechel; Lozano, Daniel; Ramirez, James; Goff, Marisa; Davidian, Christina; Miller, Jeffrey H. published the artcile< The antibiotic trimethoprim displays strong mutagenic synergy with 2-aminopurine>, Name: 7H-Purin-2-amine, the main research area is antibiotic; mutagenesis; synergy; trimethoprim.

We show that trimethoprim (TMP), an antibiotic in current use, displays a strong synergistic effect on mutagenesis in Escherichia coli when paired with the base analog 2-aminopurine (2AP), resulting in a 35-fold increase in mutation frequencies in the rpoB-Rifr system. Combination therapies are often employed both as antibiotic treatments and in cancer chemotherapy. However, mutagenic effects of these combinations are rarely examined An anal. of the mutational spectra of TMP, 2AP, and their combination indicates that together they trigger a response via an alteration in deoxynucleoside triphosphate (dNTP) ratios that neither compound alone can trigger. A similar, although less strong, response is seen with the frameshift mutagen ICR191 and 2AP. These results underscore the need for testing the effects on mutagenesis of combinations of antibiotics and chemotherapeutics.

Antimicrobial Agents and Chemotherapy published new progress about 452-06-2. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Name: 7H-Purin-2-amine.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Wang, Kai-Bo; Dickerhoff, Jonathan; Wu, Guanhui; Yang, Danzhou published the artcile< PDGFR-β Promoter Forms a Vacancy G-Quadruplex that Can Be Filled in by dGMP: Solution Structure and Molecular Recognition of Guanine Metabolites and Drugs>, Safety of 7H-Purin-2-amine, the main research area is vacancy G quadruplex PDGFRbeta promoter dGMP conformation guanine drug.

Aberrant expression of PDGFR-β is associated with a number of diseases. The G-quadruplexes (G4s) formed in PDGFR-β gene promoter are transcriptional modulators and amenable to small mol. targeting. The major G4 formed in the PDGFR-β gene promoter was previously shown to have a broken G-strand. Herein, we report that the PDGFR-β gene promoter sequence forms a vacancy G-quadruplex (vG4) which can be filled in and stabilized by physiol. relevant guanine metabolites, such as dGMP, GMP, and cGMP, as well as guanine-derivative drugs. We determined the NMR structure of the dGMP-fill-in PDGFR-β vG4 in K+ solution This is the first structure of a guanine-metabolite-fill-in vG4 based on a human gene promoter sequence. Our structure and systematic anal. elucidate the contributions of Hoogsten hydrogen bonds, sugar, and phosphate moieties to the specific G-vacancy fill-in. Intriguingly, an equilibrium of 3′- and 5′-end vG4s is present in the PDGFR-β promoter sequence, and dGMP favors the 5′-end fill-in. Guanine metabolites and drugs were tested and showed a conserved selectivity for the 5′-vacancy, except for cGMP. CGMP binds both the 3′- and 5′-end vG4s and forms two fill-in G4s with similar population. Significantly, guanine metabolites are involved in many physiol. and pathol. processes in human cells; thus, our results provide a structural basis to understand their potential regulatory functions by interaction with promoter vG4s. Moreover, the NMR structure can guide rational design of ligands that target the PDGFR-β vG4.

Journal of the American Chemical Society published new progress about Drugs. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Safety of 7H-Purin-2-amine.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Tang, Ke; Roca, Jorjethe; Chen, Rong; Ansari, Anjum; Liang, Jie published the artcile< Thermodynamics of unfolding mechanisms of mouse mammary tumor virus pseudoknot from a coarse-grained loop-entropy model>, Category: imidazoles-derivatives, the main research area is mammary tumor virus pseudoknot thermodn entropy model; Energy landscape; Fluorescence spectroscopy; Heat capacity; Loop entropy; PK3D; Pseudoknotted RNA; RNA folding; RNA hairpin; Unfolding mechanism.

Pseudoknotted RNA mols. play important biol. roles that depend on their folded structure. To understand the underlying principles that determine their thermodn. and folding/unfolding mechanisms, we carried out a study on a variant of the mouse mammary tumor virus pseudoknotted RNA (VPK), a widely studied model system for RNA pseudoknots. Our method is based on a coarse-grained discrete-state model and the algorithm of PK3D (pseudoknot structure predictor in three-dimensional space), with RNA loops explicitly constructed and their conformational entropic effects incorporated. Our loop entropy calculations are validated by accurately capturing previously measured melting temperatures of RNA hairpins with varying loop lengths. For each of the hairpins that constitutes the VPK, we identified alternative conformations that are more stable than the hairpin structures at low temperatures and predicted their populations at different temperatures Our predictions were validated by thermodn. experiments on these hairpins. We further computed the heat capacity profiles of VPK, which are in excellent agreement with available exptl. data. Notably, our model provides detailed information on the unfolding mechanisms of pseudoknotted RNA. Anal. of the distribution of base-pairing probability of VPK reveals a cooperative unfolding mechanism instead of a simple sequential unfolding of first one stem and then the other. Specifically, we find a simultaneous “”loosening”” of both stems as the temperature is raised, whereby both stems become partially melted and co-exist during the unfolding process.

Journal of Biological Physics published new progress about Algorithm. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Category: imidazoles-derivatives.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Ilgu, Muslum; Yan, Shuting; Khounlo, Ryan M.; Lamm, Monica H.; Nilsen-Hamilton, Marit published the artcile< Common secondary and tertiary structural features of aptamer-ligand interaction shared by RNA aptamers with different primary sequences>, COA of Formula: C5H5N5, the main research area is secondary tertiary structural feature RNA aptamer ligand interaction; 2-aminopurine (2AP), molecular dynamics; aminoglycoside; isothermal titration calorimetry; neomycin-B RNA aptamer.

Aptamer selection can yield many oligonucleotides with different sequences and affinities for the target mol. Here, we have combined computational and exptl. approaches to understand if aptamers with different sequences but the same mol. target share structural and dynamical features. NEO1A, with a known NMR-solved structure, displays a flexible loop that interacts differently with individual aminoglycosides, its ligand affinities and specificities are responsive to ionic strength, and it possesses an adenosine in the loop that is critical for high-affinity ligand binding. NEO2A was obtained from the same selection and, although they are only 43% identical in overall sequence, NEO1A and NEO2A share similar loop sequences. Exptl. anal. by 1D NMR and 2-aminopurine reporters combined with mol. dynamics modeling revealed similar structural and dynamical characteristics in both aptamers. These results are consistent with the hypothesis that the target ligand drives aptamer structure and also selects relevant dynamical characteristics for high-affinity aptamer-ligand interaction. Furthermore, they suggest that it might be possible to “”migrate”” structural and dynamical features between aptamer group members with different primary sequences but with the same target ligand.

Molecules published new progress about Affinity. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, COA of Formula: C5H5N5.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Snyder, Joshua A.; Charnay, Aaron P.; Kohl, Forrest R.; Zhang, Yuyuan; Kohler, Bern published the artcile< DNA-like photophysics in self-assembled silver(I)-nucleobase nanofibers>, Recommanded Product: 7H-Purin-2-amine, the main research area is silver nucleobase self assembly nanofiber transient absorption.

Supramol. assemblies form when silver nitrate is added to an aqueous solution of adenine (Ade) or 2-aminopurine (2AP) in a 2:1 mol ratio. Atomic force microscopy images reveal nanofibers that are ∼30 nm in diameter and micrometers in length in the dried film formed from a room-temperature solution Femtosecond broadband transient absorption spectroscopy was used to investigate the dynamics of excited states formed by UV excitation of the nanofibers in room-temperature aqueous solutions in an effort to learn how nonradiative decay pathways of the uncomplexed nucleobases are altered in the silver-ion-mediated assemblies. The changes in the spectroscopy and dynamics of Ade and 2AP upon forming nanofibers with silver ions closely parallel the ones seen when these bases are organized into DNA strands. The similarities strongly suggest that these structures feature extensive π-π stacking interactions between nucleobases. The results show that time-resolved spectroscopy combined with growing understanding of the photophysics of DNA strands can deliver new insights into the properties of metal-nucleobase nanoassemblies.

Journal of Physical Chemistry B published new progress about Luminescence. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Recommanded Product: 7H-Purin-2-amine.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Wamsley, Max; Nawalage, Samadhi; Hu, Juan; Collier, Willard E.; Zhang, Dongmao published the artcile< Back to the Drawing Board: A Unifying First-Principle Model for Correlating Sample UV-Vis Absorption and Fluorescence Emission>, Computed Properties of 452-06-2, the main research area is anthracene fluorescence emission first principle method.

The popular textbook and literature model I(λx,λm) = or its variants for correlating the sample absorption and fluorescence often fails even for the simplest samples where the fluorophore is the only light absorber. Reported is a first-principle model I(λx,λm) = for correlating the sample fluorescence measured with a conventional spectrofluorometer and its UV-vis absorbance quantified with a conventional UV-vis spectrophotometer. This model can be simplified or expanded for a variety of fluorescence analyses. First, it enables curve-fitting fluorescence intensity as a function of the fluorophore or sample absorbance over a sample concentration range impossible with existing models. Second, it provides the theor. foundation for an inner-filter-effect (IFE)-correction method developed earlier and explains math. the linearity between the IFE-corrected fluorescence and the fluorophore concentration or absorbance. Third, this model can be expanded for quant. mechanistic studies of fluorescence intensity variations triggered by stimuli treatments. One demonstrated example is to quantify temperature effects on the emission-wavelength-specific and total fluorescence quantum yield of anthracene. We expect that this first-principle model will be broadly adopted for both student education that promotes evidence-based learning and a variety of fluorescence applications where disentangling sample absorption and emission are critical for reliable data anal.

Analytical Chemistry (Washington, DC, United States) published new progress about Fluorescence. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Computed Properties of 452-06-2.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem