Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Short-Chained Anthracene Strapped Porphyrins and their Endoperoxides.

ABSTRACT: The syntheses of short-chained anthracene-strapped porphyrins and their Zn(II)complexes are reported. The key synthetic step is a [2+2] condensation between a dipyrromethane and an anthracene bisaldehyde, 2,2'-((anthracene-9,10-diylbis(methylene))bis(oxy))dibenzaldehyde. Following exposure to white light, self-sensitized singlet oxygen and the anthracene moieties underwent [4+2] cycloaddition reactions to yield the corresponding endoperoxides. 1H NMR studies demonstrate that the endoperoxide readily formed in [D]chloroform and decayed at 85 °C. X-ray crystallography and absorption spectroscopy were used to confirm macrocyclic distortion in the parent strapped porphyrins and endoperoxides. Additionally, X-ray crystallography indicated that endoperoxide formation occurred exclusively on the outside face of the anthracene moiety.

SUBMITTER: Callaghan S

PROVIDER: S-EPMC7319435 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Short-Chained Anthracene Strapped Porphyrins and their Endoperoxides.

Callaghan Susan S Flanagan Keith J KJ O'Brien John E JE Senge Mathias O MO

European journal of organic chemistry 20200420 18

The syntheses of short-chained anthracene-strapped porphyrins and their Zn(II)complexes are reported. The key synthetic step is a [2+2] condensation between a dipyrromethane and an anthracene bisaldehyde, 2,2'-((anthracene-9,10-diylbis(methylene))bis(oxy))dibenzaldehyde. Following exposure to white light, self-sensitized singlet oxygen and the anthracene moieties underwent [4+2] cycloaddition reactions to yield the corresponding endoperoxides. <sup>1</sup>H NMR studies demonstrate that the endop ...[more]

PMID: 32612450

Similar Datasets

Thermally Induced Synthesis of Anthracene-, Pyrene- and Naphthalene-Fused Porphyrins.

Project description:The synthesis of π-extended porphyrins containing anthracenyl moieties still represents an important challenge. Here, we report on the synthesis of a series of unsubstituted naphthyl-, pyrenyl- and anthracenyl-fused zinc porphyrin derivatives. To this aim, meso-substitued porphyrins are synthesized and the fusion of the PAHs (Polycyclic Aromatic Hydrocarbon) on the β-positions are performed through thermally induced dehydro-aromatization. The fused zinc-porphyrin derivatives are fully characterized and their optical absorption and photoluminescence properties are reported. We also demonstrate that zinc can be removed from the porphyrin core, giving rise to pure C, H, N materials. This work constitutes the first step towards the synthesis of the fully-fused tetra-anthracenylporphyrin.

| S-EPMC8495684 | biostudies-literature

Short-chained oligo(ethylene oxide)-functionalized gold nanoparticles: realization of significant protein resistance.

Project description:Protein corona formed on nanomaterial surfaces play an important role in the bioavailability and cellular uptake of nanomaterials. Modification of surfaces with oligoethylene glycols (OEG) are a common way to improve the resistivity of nanomaterials to protein adsorption. Short-chain ethylene oxide (EO) oligomers have been shown to improve the protein resistance of planar Au surfaces. We describe the application of these EO oligomers for improved protein resistance of 30 nm spherical gold nanoparticles (AuNPs). Functionalized AuNPs were characterized using UV-Vis spectroscopy, dynamic light scattering (DLS), and zeta potential measurements. Capillary electrophoresis (CE) was used for separation and quantitation of AuNPs and AuNP-protein mixtures. Specifically, nonequilibrium capillary electrophoresis of equilibrium mixtures (NECEEM) was employed for the determination of equilibrium and rate constants for binding between citrate-stabilized AuNPs and two model proteins, lysozyme and fibrinogen. Semi-quantitative CE analysis was carried out for mixtures of EO-functionalized AuNPs and proteins, and results demonstrated a 2.5-fold to 10-fold increase in protein binding resistance to lysozyme depending on the AuNP surface functionalization and a 15-fold increase in protein binding resistance to fibrinogen for both EO oligomers examined in this study. Graphical abstract Using capillary electrophoresis, the addition of short-chained oligo(ethylene oxide) ligands to gold nanoparticles was shown to improve protein binding resistance up to 15-fold.

| S-EPMC5763551 | biostudies-other

Short-Chained Platinum Complex Catalyzed Hydrosilylation under Thermomorphic Conditions: Heterogeneous Phase Separation at Ice Temperature.

Project description:Homogeneous catalysts PtCl2[5,5'-bis-(n-ClCF2(CF2)3CH2OCH2)-2,2'-bpy] (2A) and PtCl2[5,5'-bis-(n-HCF2(CF2)3CH2OCH2)-2,2'-bpy] (2B), which contained short fluorous chains, were synthesized and used in catalysis of hydrosilylation of alkynes. In these reactions the thermomorphic mode was effectively used to recover these catalysts from the reaction mixture up to eight cycles by taking advantage of heterogeneous phase separation at ice temperature. This kind of catalysis had previously been observed in fluorous catalysts of platinum containing about 50% F-content, but in this work the percentage of F-content is decreased to only about 30%, by which we termed them as "very light fluorous". Our new type of catalyst with limited number of F-content is considered as the important discovery in the fluorous technology field as the reduced number of fluorine atoms will help to be able to comply the EPA 8-carbon rule. The metal leaching after the reaction has been examined by ICP-MS, and the testing results show the leaching of residual metal to be minimal. Additionally, comparing these results to our previous work, fluorous chain assisted selectivity has been observed when different fluorous chain lengths of the catalysts are used. It has been found that there exists fluorous chain assisted better selectivity towards β-(E) form in the Pt-catalyzed hydrosilylation of non-symmetric terminal alkyne when the Pt catalyst contains short fluorous chain (i.e., 4 Cs). Phenyl acetylenes showed the opposite regioselectivity due to pi-pi interaction while using the same catalyst via Markovnikov's addition to form terminal vinyl silane, which is then a major product for Pt-catalyzed hydrosilylation of terminal aryl acetylene with triethylsilane. Finally, the kinetic studies indicate that the insertion of alkyne into the Pt-H bond is the rate-determining step.

| S-EPMC7828357 | biostudies-literature

Triphenylphosphine reduction of saturated endoperoxides.

Project description:Triphenylphosphine reduction of saturated endoperoxides derived from 6,6-dimethylfulvene and spiro[2.4]hepta-4,6-diene in the presence of nucleophiles results in the formation of products that mainly stem from deoxygenation followed by carbocation formation. Nucleophilic attack by solvent proceeds by an S(N)1 like mechanism; allyl shifts and cyclopropylcarbinyl-cyclobutyl rearrangements also occur. With the systems lacking carbocation-stabilizing groups, the deoxygenation step is preceded by attack of H(2)O at the phosphorus.

| S-EPMC2760492 | biostudies-literature

Turn-folding in fluorescent anthracene-substituted cyclopenta[<i>d</i>]isoxazoline short peptides.

Project description:Cyclopenta[d]isoxazoline aminols were used for the synthesis of β-turn mimics. The peptide chain choice ascertained the influence of their structural features on the applicability/reliability/robustness of these scaffolds as β-turn inducers and their limitations. The amino acid selection as well as steric demands can favor or disfavor the structure folding and the correct design of the peptide chains deeply influences the potential use of these nitrosocarbonyl-based compounds as turn-inducers.

| S-EPMC9033613 | biostudies-literature

Urinary Medium-Chained Acyl-Carnitines Sign High Caloric Intake whereas Short-Chained Acyl-Carnitines Sign High -Protein Diet within a High-Fat, Hypercaloric Diet in a Randomized Crossover Design Dietary Trial.

Project description:The western dietary pattern is known for its frequent meals rich in saturated fat and protein, resulting in a postprandial state for a large part of the day. Therefore, our aim was to investigate the postprandial glucose and lipid metabolism in response to high (HP) or normal (NP) protein, high-fat hypercaloric diet and to identify early biomarkers of protein intake and hepatic lipid accumulation. In a crossover design, 17 healthy subjects were randomly assigned to consume a HP or NP hypercaloric diet for two weeks. In parallel, a control group (CD; n = 10) consumed a weight-maintaining control diet. Biomarkers of postprandial lipid and glucose metabolism were measured in 24 h urine and in plasma before and following a meal challenge. The metabolic profile of urine but not plasma, showed increased excretion of 13C, carnitine and short chain acyl-carnitines after adaptation to the HP diet. Urinary excretion of decatrienoylcarnitine and octenoylcarnitine increased after adaptation to the NP diet. Our results suggest that the higher excretion of short-chain urinary acyl-carnitines could facilitate the elimination of excess fat of the HP diet and thereby reduce hepatic fat accumulation previously reported, whereas the higher excretion medium-chains acyl-carnitine could be early biomarkers of hepatic lipid accumulation.

| S-EPMC8066704 | biostudies-literature

Short-Chained Alcohols Make Membrane Surfaces Conducive for Melittin Action: Implication for the Physiological Role of Alcohols in Cells

Project description:Alcohols are a part of cellular metabolism, but their physiological roles are not well understood. We investigated the effects of short-chain alcohols on Daphnia pulex and model membranes mimicking the lipid composition of eukaryotic inner mitochondrial membranes. We also studied the synergistic effects of alcohols with the bee venom membrane-active peptide, melittin, which is structurally similar to endogenous membrane-active peptides. The alcohols, from ethanol to octanol, gradually decreased the heart rate and the mitochondrial ATP synthesis of daphnia; in contrast, in combination with melittin, which exerted no sizeable effect, they gradually increased both the heart rate and the ATP synthesis. Lipid packing and the order parameter of oriented films, monitored by EPR spectroscopy of the spin-labeled probe 5-doxylstrearic acid, revealed gradual alcohol-assisted bilayer to non-bilayer transitions in the presence of melittin; further, while the alcohols decreased, in combination with melittin they increased the order parameter of the film, which is attributed to the alcohol-facilitated association of melittin with the membrane. A 1H-NMR spectroscopy of the liposomes confirmed the enhanced induction of a non-bilayer lipid phase that formed around the melittin, without the permeabilization of the liposomal membrane. Our data suggest that short-chain alcohols, in combination with endogenous peptides, regulate protein functions via modulating the lipid polymorphism of membranes.

| S-EPMC9221640 | biostudies-literature

Contextual control of chained instrumental behaviors.

Project description:Recent studies suggest a significant role for context in controlling the acquisition and extinction of simple operant responding. The present experiments examined the contextual control of a heterogeneous behavior chain. Rats first learned a chain in which a discriminative stimulus set the occasion for a procurement response (e.g., pulling a chain), which led to a second discriminative stimulus that occasion-set a consumption response (e.g., pressing a lever) that produced a food-pellet reinforcer. Experiment 1 showed that, after separate extinction of procurement and consumption, each response increased when it was returned to the acquisition context (ABA renewal) or was tested in a new context (AAB renewal). In addition, procurement responding, but not consumption responding, was decreased by changing the context after acquisition. Experiment 2 demonstrated ABA and AAB renewal of procurement and consumption following extinction of the whole chain. This time, the context-switch after acquisition weakened both procurement and consumption. Experiment 3 found that return to the context of the behavior chain renewed a consumption response that had been extinguished separately. Finally, in Experiment 4, rats learned 2 different discriminated heterogeneous chains; consumption extinguished outside its chain was only renewed on return to a chain when it was preceded by its associated procurement response. The results suggest a role for context in the extinction of chained behavior. They also support the view that procurement is influenced by the physical context and that consumption is controlled primarily by the response that precedes it in the chain. (PsycINFO Database Record

| S-EPMC5061624 | biostudies-literature

Anion binding behavior of heterocycle-strapped calix[4]pyrroles.

Project description:A comparative study of the halide and benzoate anion binding properties of a series of phenyl, pyrrole, and furan-strapped calix[4]pyrroles has been carried out. These receptors, which have previously been shown to bind the chloride anion (Yoon et al., Angew. Chem., Int. Ed. 47(27):5038-5042, 2008), were found to bind bromide and benzoate anion (studied as the corresponding tetrabutyl-ammonium salts) with near equal affinity in acetonitrile, albeit less well than chloride, as determined from ITC measurements or NMR spectroscopic titrations. This stands in marked contrast to the parent octamethylcalix[4]pyrrole, where the carboxylate anion affinities are substantially higher than those for bromide anion under identical conditions. This finding is rationalized in terms of tighter binding cavity present in the strapped systems. For all three anions for which quantitative data could be obtained (i.e., Cl(-), Br(-), PhCO(2) (-)), the pyrrole-strapped system displayed the highest affinity, although the relative enhancement was found to depend on the anion in question. In the specific case of fluoride anion binding to the pyrrole-strapped receptor, two modes of interaction are inferred, with the first consisting of binding to the calix[4]pyrrole via NH-anion hydrogen bonds, followed by a process that involves deprotonation of the strapped pyrrolic NH proton. A single crystal X-ray diffraction analysis provides support for the first of these modes and further reveals the presence of a methanol molecule bound to the fluoride anion.

| S-EPMC3016718 | biostudies-literature

Determination of Dodecanol and Short-Chained Ethoxylated Dodecanols by LC-MS/MS (with Electrospray Ionization) After Their Derivatization (with Phenyl Isocyanate).

Project description:AbstractThis report describes the application of LC-MS/MS for the separation of dodecanol (C12OH) and homogenous fatty alcohols ethoxylated (AE) containing a dodecyl moiety and 1-9 ethoxy groups. These ethoxylates and free alcohol were derivatized for LC-MS/MS analysis with phenyl isocyanate (PIC). The derivatives of analytes with PIC were separated using a C18 column. Gradient elution with a mixture of ethyl acetate and acetonitrile (5 mM) was employed. The described determination method is characterized by low detection limits (range from 0.005 µg L-1 for: C12OH, C12EO2-7 to 1 µg L-1 for C12EO1) and quantification limits (range from 0.01 µg L-1 for: C12EO5-7 to 2 µg L-1 for C12EO1). The developed and validated method was used in combination with liquid-liquid extraction (using ethyl acetate) in order to identify and quantitatively determine the C12OH and C12EO1-9 present in environmental samples collected from Warta river water in Poznan.Graphical abstract

| S-EPMC5686276 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data