Browse
Submit Data
Databases
API
Help

Dataset Information

23 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Selective oxidation reactions of natural compounds with hydrogen peroxide mediated by methyltrioxorhenium.

ABSTRACT: We have investigated the oxidative behaviour of natural compounds such as methyl abietate (1), farnesyl acetate (2), ?-ionone (3), ?-ionone (4), methyl linolelaidate (5), methyl linolenate (6) and bergamottin (7) with the oxidant system methyltrioxo-rhenium/ H2O2/pyridine. The reactions, performed in CH2Cl2/H2O at 25 °C, have shown good regio- and stereoselectivity. The oxidation products were isolated by HPLC or silica gel chromatography and characterized by MS(EI), 1H-, 13C-NMR, APT, gCOSY, HSQC, TOCSY and NOESY measurements. The selectivity seems to be controlled by the nucleophilicity of double bonds and by stereoelectronic and steric effects.

SUBMITTER: Amato ME

PROVIDER: S-EPMC6270049 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Selective oxidation reactions of natural compounds with hydrogen peroxide mediated by methyltrioxorhenium.

Amato Maria E ME Ballistreri Francesco P FP Pappalardo Andrea A Tomaselli Gaetano A GA Toscano Rosa M RM Sfrazzetto Giuseppe Trusso GT

Molecules (Basel, Switzerland) 20131107 11

We have investigated the oxidative behaviour of natural compounds such as methyl abietate (1), farnesyl acetate (2), α-ionone (3), β-ionone (4), methyl linolelaidate (5), methyl linolenate (6) and bergamottin (7) with the oxidant system methyltrioxo-rhenium/ H2O2/pyridine. The reactions, performed in CH2Cl2/H2O at 25 °C, have shown good regio- and stereoselectivity. The oxidation products were isolated by HPLC or silica gel chromatography and characterized by MS(EI), 1H-, 13C-NMR, APT, gCOSY, HS ...[more]

PMID: 24213654

Similar Datasets

Urea-hydrogen peroxide prompted the selective and controlled oxidation of thioglycosides into sulfoxides and sulfones.

Project description:A practical method for the selective and controlled oxidation of thioglycosides to corresponding glycosyl sulfoxides and sulfones is reported using urea-hydrogen peroxide (UHP). A wide range of glycosyl sulfoxides are selectively achieved using 1.5 equiv of UHP at 60 °C while corresponding sulfones are achieved using 2.5 equiv of UHP at 80 °C in acetic acid. Remarkably, oxidation susceptible olefin functional groups were found to be stable during the oxidation of sulfide.

| S-EPMC5480342 | biostudies-literature

Staphylococcus aureus PerR Is a Hypersensitive Hydrogen Peroxide Sensor using Iron-mediated Histidine Oxidation.

Project description:In many Gram-positive bacteria PerR is a major peroxide sensor whose repressor activity is dependent on a bound metal cofactor. The prototype for PerR sensors, the Bacillus subtilis PerRBS protein, represses target genes when bound to either Mn(2+) or Fe(2+) as corepressor, but only the Fe(2+)-bound form responds to H2O2. The orthologous protein in the human pathogen Staphylococcus aureus, PerRSA, plays important roles in H2O2 resistance and virulence. However, PerRSA is reported to only respond to Mn(2+) as corepressor, which suggests that it might rely on a distinct, iron-independent mechanism for H2O2 sensing. Here we demonstrate that PerRSA uses either Fe(2+) or Mn(2+) as corepressor, and that, like PerRBS, the Fe(2+)-bound form of PerRSA senses physiological levels of H2O2 by iron-mediated histidine oxidation. Moreover, we show that PerRSA is poised to sense very low levels of endogenous H2O2, which normally cannot be sensed by B. subtilis PerRBS. This hypersensitivity of PerRSA accounts for the apparent lack of Fe(2+)-dependent repressor activity and consequent Mn(2+)-specific repressor activity under aerobic conditions. We also provide evidence that the activity of PerRSA is directly correlated with virulence, whereas it is inversely correlated with H2O2 resistance, suggesting that PerRSA may be an attractive target for the control of S. aureus pathogenesis.

| S-EPMC4536443 | biostudies-literature

Oxidation of deuteroferrihaem by hydrogen peroxide.

Project description:1. The oxidation of deuteroferrihaem by H(2)O(2) to bile pigment and CO was studied both by stopped-flow kinetic spectrophotometry and mass spectrometry, at 25 degrees C, I=0.1m. 2. Spectrophotometric studies imply that, at constant pH, the rate of bile pigment formation is first-order with respect to [H(2)O(2)] and also proportional to [deuteroferrihaem monomer]. The effect of pH on the apparent second-order rate constant suggests that acid-ionization of deuteroferrihaem monomer is important in the reaction mechanism. 3. The relative rates of formation of O(2) (from catalytic decomposition of H(2)O(2)) and CO (from oxidation of ferrihaem) have been measured by mass spectrometry. The results are in excellent agreement with those obtained by combining kinetic data for catalytic decomposition (Jones et al., 1973, preceding paper) with the spectrophotometric results for deuteroferrihaem oxidation.

| S-EPMC1165831 | biostudies-other

Efficient photocatalytic hydrogen peroxide generation coupled with selective benzylamine oxidation over defective ZrS<sub>3</sub> nanobelts.

Project description:Photocatalytic hydrogen peroxide (H2O2) generation represents a promising approach for artificial photosynthesis. However, the sluggish half-reaction of water oxidation significantly limits the efficiency of H2O2 generation. Here, a benzylamine oxidation with more favorable thermodynamics is employed as the half-reaction to couple with H2O2 generation in water by using defective zirconium trisulfide (ZrS3) nanobelts as a photocatalyst. The ZrS3 nanobelts with disulfide (S22-) and sulfide anion (S2-) vacancies exhibit an excellent photocatalytic performance for H2O2 generation and simultaneous oxidation of benzylamine to benzonitrile with a high selectivity of >99%. More importantly, the S22- and S2- vacancies can be separately introduced into ZrS3 nanobelts in a controlled manner. The S22- vacancies are further revealed to facilitate the separation of photogenerated charge carriers. The S2- vacancies can significantly improve the electron conduction, hole extraction, and kinetics of benzylamine oxidation. As a result, the use of defective ZrS3 nanobelts yields a high production rate of 78.1 ± 1.5 and 32.0 ± 1.2 μmol h-1 for H2O2 and benzonitrile, respectively, under a simulated sunlight irradiation.

| S-EPMC8016833 | biostudies-literature

Sustainable Approach for Peroxygenase-Catalyzed Oxidation Reactions Using Hydrogen Peroxide Generated from Spent Coffee Grounds and Tea Leaf Residues.

Project description:Peroxygenases are promising catalysts for use in the oxidation of chemicals as they catalyze the direct oxidation of a variety of compounds under ambient conditions using hydrogen peroxide (H2O2) as an oxidant. Although the use of peroxygenases provides a simple method for oxidation of chemicals, the anthraquinone process currently used to produce H2O2 requires significant energy input and generates considerable waste, which negatively affects process sustainability and production costs. Thus, generating H2O2 for peroxygenases on site using an environmentally benign method would be advantageous. Here, we utilized spent coffee grounds (SCGs) and tea leaf residues (TLRs) for the production of H2O2. These waste biomass products reacted with molecular oxygen and effectively generated H2O2 in sodium phosphate buffer. The resulting H2O2 was utilized by the bacterial P450 peroxygenase, CYP152A1. Both SCG-derived and TLR-derived H2O2 promoted the CYP152A1-catalyzed oxidation of 4-methoxy-1-naphthol to Russig's blue as a model reaction. In addition, when CYP152A1 was incubated with styrene, the SCG and TLR solutions enabled the synthesis of styrene oxide and phenylacetaldehyde. This new approach using waste biomass provides a simple, cost-effective, and sustainable oxidation method that should be readily applicable to other peroxygenases for the synthesis of a variety of valuable chemicals.

| S-EPMC9201881 | biostudies-literature

Substrate oxidation enhances the electrochemical production of hydrogen peroxide.

Project description:Hydrogen peroxide (H2O2) is electrochemically produced via oxygen (O2) reduction on a carbon cathode surface. In order to enhance the production of H2O2, anodic loss pathways, which significantly reduce the overall H2O2 production rate, should be inhibited. In this study, we investigate the effects of organic electron donors (i.e., typical chemical contaminants) on the anodic loss pathways of H2O2 in a single-cell electrochemical reactor that employs an anode composed of TiO2 over-coated on a mixed-metal oxide ohmic contact catalyst, Ir0.7Ta0.3O2, deposited on a Ti-metal that is coupled with a graphite rod cathode in a sodium sulfate (Na2SO4) electrolyte that is saturated with oxygen (O2). Organic electron donors are shown to enhance the electrochemical production of H2O2, while simultaneously undergoing oxidative degradation. The observed positive effect of organic electron donors on the electrochemical production of H2O2 is due in part to a preferential adsorption of organic substrates on the TiO2 outer layer of the anode. The sorption of the organic electron donors inhibits the formation of surficial titanium hydroperoxo species ([bond, triple bond]Ti-OOH) on the anode surface. The organic sorbates also act as scavengers of surface-bound hydroxyl radical [bond, triple bond]Ti-OH. As a result, the decomposition of H2O2 on the anode surface is significantly reduced. The cathodic production rate of H2O2 at low pH is enhanced due to proton coupled electron transfer (PCET) to O2, while the anodic decomposition of H2O2 is inhibited due to electrostatic interactions between negatively-charged organic substrates and a positively-charged outer surface of the anode (TiO2 pHzpc = 5.8) at low pH.

| S-EPMC6686209 | biostudies-literature

Modular advanced oxidation process enabled by cathodic hydrogen peroxide production.

Project description:Hydrogen peroxide (H2O2) is frequently used in combination with ultraviolet (UV) light to treat trace organic contaminants in advanced oxidation processes (AOPs). In small-scale applications, such as wellhead and point-of-entry water treatment systems, the need to maintain a stock solution of concentrated H2O2 increases the operational cost and complicates the operation of AOPs. To avoid the need for replenishing a stock solution of H2O2, a gas diffusion electrode was used to generate low concentrations of H2O2 directly in the water prior to its exposure to UV light. Following the AOP, the solution was passed through an anodic chamber to lower the solution pH and remove the residual H2O2. The effectiveness of the technology was evaluated using a suite of trace contaminants that spanned a range of reactivity with UV light and hydroxyl radical (HO(•)) in three different types of source waters (i.e., simulated groundwater, simulated surface water, and municipal wastewater effluent) as well as a sodium chloride solution. Irrespective of the source water, the system produced enough H2O2 to treat up to 120 L water d(-1). The extent of transformation of trace organic contaminants was affected by the current density and the concentrations of HO(•) scavengers in the source water. The electrical energy per order (EEO) ranged from 1 to 3 kWh m(-3), with the UV lamp accounting for most of the energy consumption. The gas diffusion electrode exhibited high efficiency for H2O2 production over extended periods and did not show a diminution in performance in any of the matrices.

| S-EPMC4473729 | biostudies-literature

N6-Hydroperoxymethyladenosine: a new intermediate of chemical oxidation of N6-methyladenosine mediated by bicarbonate-activated hydrogen peroxide.

Project description:N6-Methyladenosine (m6A) represents a relatively abundant modification in eukaryotic RNA. Because m6A has similar properties to adenosine and a low reactivity, limited research has been focused on this nucleoside. In this study, we revealed an important intermediate in the oxidation of m6A through the bicarbonate-activated peroxide system. Over the course of oxidation, we found a new mechanism in which N6-hydroxymethyladenosine (hm6A), N6-formyladenosine (f6A) and N6-hydroperoxymethyladenosine (oxm6A) were intermediate products, and adenosine was the final product. In this study, oxm6A was isolated using HPLC and characterized by mass spectrometry, NMR and diphenyl-1-pyrenylphosphine (DPPP) fluorescence detection. This study provides a new modified nucleoside and demonstrates oxidative demethylation of m6A by reactive oxygen species at the nucleobase level and in RNA strands.

| S-EPMC5657413 | biostudies-literature

Understanding activity trends in electrochemical water oxidation to form hydrogen peroxide.

Project description:Electrochemical production of hydrogen peroxide (H2O2) from water oxidation could provide a very attractive route to locally produce a chemically valuable product from an abundant resource. Herein using density functional theory calculations, we predict trends in activity for water oxidation towards H2O2 evolution on four different metal oxides, i.e., WO3, SnO2, TiO2 and BiVO4. The density functional theory predicted trend for H2O2 evolution is further confirmed by our experimental measurements. Moreover, we identify that BiVO4 has the best H2O2 generation amount of those oxides and can achieve a Faraday efficiency of about 98% for H2O2 production.Producing hydrogen peroxide via electrochemical oxidation of water is an attractive route to this valuable product. Here the authors theoretically and experimentally investigate hydrogen peroxide production activity trends for a range of metal oxides and identify the optimal bias ranges for high Faraday efficiencies.

| S-EPMC5615073 | biostudies-literature

Quantification of hydrogen peroxide during the low-temperature oxidation of alkanes.

Project description:The first reliable quantification of hydrogen peroxide (H(2)O(2)) formed during the low-temperature oxidation of an organic compound has been achieved thanks to a new system that couples a jet stirred reactor to a detection by continuous wave cavity ring-down spectroscopy (cw-CRDS) in the near-infrared. The quantification of this key compound for hydrocarbon low-temperature oxidation regime has been obtained under conditions close to those actually observed before the autoignition. The studied hydrocarbon was n-butane, the smallest alkane which has an oxidation behavior close to that of the species present in gasoline and diesel fuels.

| S-EPMC3586669 | 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