Ethyl Vinyl Ketone Research Articles

Ethyl vinyl ketone activates oxidative and calcium burst and CML8-ACA8 participates in calcium recovery in Arabidopsis leaves

Plants produce ethyl vinyl ketone (evk) in response to biotic stress, but the evk's identification and downstream defense response remain unclear. In this paper, it is predicted by docking for the first time that evk can be recognized by RBOH protein and assist the electron transfer of RBOHD/RBOHF by binding to its FAD or NADPH binding site. Surface plasmon resonance (SPR) binding assay shows that evk indeed bind to RBOHD. Here, we show that evk treatment increased H2O2 and intracellular calcium concentrations in Arabidopsis thaliana mesophyll cells, as observed by confocal laser scanning microscopy and non-invasive micro-test technology, and that H2O2 signaling functioned upstream of Ca2+ signaling. Yeast two-hybrid, firefly luciferase complementation imaging, and in vitro pull-down assays demonstrated that the ACA8 (AUTOINHIBITED Ca2+-ATPASE, ISOFORM 8)–CML8 (CALMODULIN-LIKE 8) interaction promoted Ca2+ efflux to return Ca2+ levels to the resting state.

RBOH play regulatory role in the JA pathway induced by the volatile organic compound ethyl vinyl ketone

RBOH play regulatory role in the JA pathway induced by the volatile organic compound ethyl vinyl ketone

Robinson Annulation Applied to the Total Synthesis of Natural Products

AbstractThe Robinson annulation is a significant reaction for the synthesis of α,β‐unsaturated ketone ring including the generation of two C−C bonds. It involves a Michael addition of a ketone and a methyl or ethyl vinyl ketone with subsequent intramolecular aldol condensation. Natural products and their structurally related analogues have historically made a major contribution to pharmacotherapy, particularly for cancer and infectious diseases. The Robinson annulation has frequently been employed as a vital step in the total synthesis of these important naturally occurring compounds and related complex biologically active products. In this review, we try to underscore the applications of the Robinson annulation in the total synthesis of biologically active natural products.

DORN1 and GORK regulate stomatal closure in Arabidopsis mediated by volatile organic compound ethyl vinyl ketone

Evk (ethyl vinyl ketone) is a signal substance for plant defense, but little is known about how evk mediates stomatal closure. Through stomatal biology experiments, we found that evk can mediate stomatal closure, and stomatal closure is weakened when DORN1 (DOES NOT RESPOND TO NUCLEOTIDES 1) and GORK (GATED OUTWARDLY-RECTIFYING K+ CHANNEL) are mutated. In addition, it was found by non-invasive micro-test technology (NMT) that the K+ efflux mediated by evk was significantly weakened when DORN and GORK were mutated. Yeast two-hybrid (Y2H), firefly luciferase complementation imaging (LCI), and in vitro pull-down assays demonstrated that DORN1 and GORK could interact in vitro and in vivo. It was found by molecular docking that evk could combine with MRP (Multidrug Resistance-associated Protein), thus affecting ATP transport, promoting eATP (extracellular ATP) concentration increase and realizing downstream signal transduction. Through inoculation of botrytis cinerea, it was found that evk improved the antibacterial activity of Arabidopsis thaliana. As revealed by reverse transcription quantitative PCR (RT-qPCR), the expression of defense related genes was enhanced by evk treatment. Evk is a potential green antibacterial drug.

Organic acid formation in the gas-phase ozonolysis of α,β-unsaturated ketones.

Organic acids are key species in determining the radiative properties of the atmosphere due to their contribution to particle formation. Reported discrepancies between field measurements and modelling suggest significant missing sources. Herein, we present a mechanistic investigation on the gas-phase ozonolysis of ethyl vinyl ketone (EVK, 1-penten-3-one), which we chose as a model compound for α,β-unsaturated ketones. Experiments were performed in a 1080 L quartz-glass reaction chamber (QUAREC) at 990 ± 15 mbar and 298 ± 2 K (r. h. ≪ 0.1%) and analysed via long-path FTIR spectrometry and PTR-ToF-MS. The experiments were performed in the presence of an excess of CO to suppress the chemistry of OH radicals. For a comprehensive picture, in selected experiments, SO2 was also added to the reaction system to scavenge the stabilized Criegee intermediates (sCIs) and to investigate their formation yield. Combining the results of both set-ups allowed us to quantify 2-oxobutanal, for which we report vapour-phase FTIR spectra. In addition, we introduce the first-ever infrared spectra of perpropionic acid, which was also positively identified in the EVK + O3 system. A detailed analysis of the experimental findings allowed us to link the identified reaction products (acetaldehyde, ethyl hydroperoxide, and perpropionic acid) to known bimolecular reactions of RO2 radicals. Thereby, it is shown that the EVK + O3 reaction yields formic acid, HC(O)OH, and propionic acid, C2H5C(O)OH, and their formation is not covered by mechanisms reported in the literature. Three different pathways accounting for their formation from chemically activated CIs are proposed and possible implications for the ozonolysis of α,β-unsaturated ketones in the atmosphere are discussed.

Ethyl Vinyl Ketone Activates K+ Efflux to Regulate Stomatal Closure by MRP4-Dependent eATP Accumulation Working Upstream of H2O2 Burst in Arabidopsis.

Plants regulate stomatal mobility to limit water loss and improve pathogen resistance. Ethyl vinyl ketone (evk) is referred to as a reactive electrophilic substance (RES). In this paper, we found that evk can mediate stomatal closure and that evk-induced stomatal closure by increasing guard cell K+ efflux. To investigate the role of eATP, and H2O2 in evk-regulated K+ efflux, we used Arabidopsis wild-type (WT), mutant lines of mrp4, mrp5, dorn1.3 and rbohd/f. Non-invasive micro-test technology (NMT) data showed that evk-induced K+ efflux was diminished in mrp4, rbohd/f, and dorn1.3 mutant, which means eATP and H2O2 work upstream of evk-induced K+ efflux. According to the eATP content assay, evk stimulated eATP production mainly by MRP4. In mrp4 and mrp5 mutant groups and the ABC transporter inhibitor glibenclamide (Gli)-pretreated group, evk-regulated stomatal closure and eATP buildup were diminished, especially in the mrp4 group. According to qRT-PCR and eATP concentration results, evk regulates both relative gene expressions of MRP4/5 and eATP concentration in rbohd/f and WT group. According to the confocal data, evk-induced H2O2 production was lower in mrp4, mrp5 mutants, which implied that eATP works upstream of H2O2. Moreover, NADPH-dependent H2O2 burst is regulated by DORN1. A yeast two-hybrid assay, firefly luciferase complementation imaging assay, bimolecular fluorescence complementation assay, and pulldown assay showed that the interaction between DORN1 and RBOHF can be realized, which means DORN1 may control H2O2 burst by regulating RBOHF through interaction. This study reveals that evk-induced stomatal closure requires MRP4-dependent eATP accumulation and subsequent H2O2 accumulation to regulate K+ efflux.

Atmospheric degradation, mechanism and kinetics of ethyl vinyl ketone (CH2=CHCOCH2CH3) initiated by Cl atom: an insight from DFT study

The mechanism and kinetics of the H-abstractions of ethylvinylketone (CH2=CHCOCH2CH3) with Cl atom have been carried out using density functional theory (DFT). The electronic structures and frequencies of reaction species are carried out at M06-2X/6-31+G(d,p) level. The energy calculation is performed for optimised species at the same functionality but using a 6-311++G(d,p) basis set. We characterised transition states (TSs) in each H-abstraction channel and explored reaction species along with TS involved in CH2=CHCOCH2CH3+Cl reaction on the potential energy diagram. Among the various H-abstraction channels, H-abstraction from the methylene group (–CH2–) of CH2=CHCOCH2CH3 is found to be a more dominant reaction channel which is further confirmed by thermochemical analysis. The rate constants of all H-abstraction reaction channels and overall rate constant are calculated using canonical transition state theory (TST) within the temperature range of 200–400 K. The value of the overall rate constant at 298.15 K and 1atm pressure is found to be 0.94 × 10−10 cm3 mol−1 s−1, which is in close with the experimental reported rate constant value, i.e. (2.91 ± 1.10) × 10−10 cm3 mol−1 s−1. The percentage branching ratios of each H-abstraction reaction channel, as well as the lifetime of the titled compound, are also reported herein.

Selective Activation of Unstrained C(O)-C Bond in Ketone Suzuki-Miyaura Coupling Reaction Enabled by Hydride-Transfer Strategy.

A Rh(I)-catalyzed ketone Suzuki-Miyaura coupling reaction of benzylacetone with arylboronic acid is developed. Selective C(O)-C bond activation, which employs aminopyridine as a temporary directing group and ethyl vinyl ketone as a hydride acceptor, occurs on the alkyl chain containing a β-position hydrogen. A series of acetophenone products were obtained in yields up to 75%.

Enantioselective Total Synthesis of (+)-Heilonine.

Chemical transformations that rapidly and efficiently construct a high level of molecular complexity in a single step are perhaps the most valuable in total synthesis. Among such transformations is the transition metal catalyzed [2 + 2 + 2] cycloisomerization reaction, which forges three new C–C bonds and one or more rings in a single synthetic operation. We report here a strategy that leverages this transformation to open de novo access to the Veratrum family of alkaloids. The highly convergent approach described herein includes (i) the enantioselective synthesis of a diyne fragment containing the steroidal A/B rings, (ii) the asymmetric synthesis of a propargyl-substituted piperidinone (F ring) unit, (iii) the high-yielding union of the above fragments, and (iv) the intramolecular [2 + 2 + 2] cycloisomerization reaction of the resulting carbon framework to construct in a single step the remaining three rings (C/D/E) of the hexacyclic cevanine skeleton. Efficient late-stage maneuvers culminated in the first total synthesis of heilonine (1), achieved in 21 steps starting from ethyl vinyl ketone.

Silica gel-mediated catalyst-free and solvent-free Michael addition of 1,3-dicarbonyl compounds to highly toxic methyl vinyl ketone without volatilization

Silica gel-mediated Michael addition of 1,3-dicarbonyl compounds to methyl vinyl ketone (MVK) and ethyl vinyl ketone (EVK) was carried out to give the corresponding adducts in quite excellent yields. The reactions could be carried out without any catalysts and solvents. In addition, highly toxic MVK and EVK could be employed without significant volatilization. Silica gel could be recycled five times without the decrease of the yields.

<i>trans</i>-2-Pentenal, an Active Compound in Cigarette Smoke, Identified <i>via</i> Its Ability to Form Adducts with Glutathione

α,β-Unsaturated carbonyl compounds readily form adducts with SH or NH2 residues, which are nucleophilic agents, by Michael addition. Glutathione (GSH) is a tripeptide that contains an SH residue and functions as an antioxidant. We demonstrated previously that acrolein (ACR), crotonaldehyde (CA), and methyl vinyl ketone (MVK) are present in nicotine- and tar-removed cigarette smoke extract (CSE) and reacted with GSH in B16-BL6 mouse melanoma cells to form GSH-ACR, GSH-CA, and GSH-MVK adducts, suggesting a possible mechanism for CSE-induced cytotoxicity. In this study, we searched for novel α,β-unsaturated carbonyl compounds other than ACR, CA, and MVK. We selected candidate compounds in CSE based on accurate mass values generated using LC/MS analysis of products formed between CSE and GSH, and identified these using GC/MS analysis and library screening. As a result, we isolated trans-2-methyl-2-butenal, 2-methyl-2-cyclopenten-1-one, 3-methyl-2-cyclopenten-1-one, and furfural, which were poorly reactive with GSH and only very weakly inhibited growth of Colon-26 mouse carcinoma cells and BALB/3T3 clone A31 mouse normal cells. We also isolated 2-cyclopenten-1-one, trans-2-pentenal, 3-methyl-2-butenal and ethyl vinyl ketone, which were highly reactive with GSH and significantly inhibited the growth of both cell lines. Our data suggest that the reactivity of compounds in CSE with GSH may be positively correlated with the effect on inhibiting cell growth. Notably, trans-2-pentenal showed marked inhibition of carcinoma cells growth, whereas this compound exhibited little inhibitory effect on normal cells. trans-2-Pentenal may be a potent candidate or seed for antitumor agents.

Michael addition of cyclic β-oxo ester and α-methyl cyano ester substrates with activated olefins by iron complexes of benzimidazole derived N-heterocyclic carbene ligands

Michael addition reactions of cyclic β-oxo ester and α-methyl cyano ester substrates with acceptor activated olefins were catalyzed by iron N−heterocyclic carbene (NHC) complexes of the type, {Cp[1-benzyl-3-alkyl-benzimidazol-2-ylidene]Fe(CO)2}I, where [alkyl = i-Pr (1) and Et (2)] in the presence of l-proline as chiral auxiliary under ambient conditions. In case of the cyclic β-oxo ester substrates good yields of up to 68% and enantioselectivities of up to 18% were observed while for the α-methyl cyano ester substrates similar yields of up to 82% and enantioselectivities of up to 8% were observed. Notably, for the cyclic β-oxo ester substrates, the five membered ethyl-2-oxocyclopentane-1-carboxylate gave superior yields and enantioselectivities over the six membered ethyl-2-oxocyclohexane-1-carboxylate. In case of α-methyl cyano ester substrates, methyl vinyl ketone gave higher yields as compared to the other acceptor activated olefins namely, ethyl vinyl ketone and acrylonitrile. Based on the mass spectrometry studies, that detected the presence of l-proline adduct species (1–2)A, l-proline and substrate adduct species (1–2)B and l-proline and product adduct species (1–2)C in the catalysis reaction mixture, a mechanistic cycle has been proposed for the Fe−NHC mediated Michael addition reaction.

Quantum mechanical study on the oxidation of ethyl vinyl ketone initiated by an OH radical.

Oxidation of ethyl vinyl ketone (CH2CHCOCH2CH3) by an OH radical was carried out using the M06-2X/6-311++G(d,p) level of theory. For the OH-initiated oxidation of ethyl vinyl ketone (EVK), we have considered six H-atom abstractions and three addition reactions. From the energetic calculation of the species involved therein, the potential energy surface (PES) of all the reaction channels was constructed. From the energy profile, we found that the H-atom abstraction from the methylene group (-CH2-) of CH2CHCOCH2CH3 is energetically more favourable than the other H-abstraction channels. Moreover, we also observed that OH-addition to the α-carbon of the carbon-carbon double bond of the title molecule is energetically and thermodynamically more dominant than β-carbon and carbonyl carbon. The rate coefficients for all the reaction channels were calculated using the canonical transition state theory at the temperature range of 250-450 K and it reveals that among all the reaction channels, OH-addition to α-carbon is kinetically more dominant to the total rate constant. The total rate coefficient for the reaction at 298 K is found to be in good agreement with the reported experimental rate constant. Finally, we have determined the atmospheric lifetime of the title molecule.

Mechanistic Investigation of Visible-Light-Induced Intermolecular [2 + 2] Photocycloaddition Catalyzed with Chiral Thioxanthone.

The recent thioxanthone-sensitizer-catalyzed intermolecular [2 + 2] cycloaddition induced by visible-light irradiation set the stage for the future development of feasible photocycloadditions. Nonetheless, the mechanism of this reaction still remains under debate, especially on the activation mode of the thioxanthone photosensitizer (energy transfer, bielectron exchange, and hydrogen transfer are all possible mechanisms). To settle this issue, systematic density functional theory calculations have been carried out. The results indicate that the energy-transfer pathway is more favorable than the bielectron-exchange and the hydrogen-transfer pathways. Meanwhile, the overall transformations involve the complexation and excitation of photosensitizer, the first C-C bond formation, the dissociation of the sensitizer, the triplet-to-singlet electronic state crossing, and the second C-C bond formation. The first C-C bond formation is the rate- and selectivity-determining step, and synergistic energy and electron transfer from photosensitizer to substrate moieties takes place along this process. On this basis, the effect of olefin substrates (ethyl vinyl ketone vs vinyl acetate) on the stereoselectivity was finally analyzed.

An Adductomic Approach to Identify Electrophiles In Vivo.

Human beings are exposed to many reactive electrophiles, both formed endogenously and from exogenous exposures. Such compounds could react with cellular biomolecules and form stable reaction products, adducts, at nucleophilic sites in proteins and DNA, constituting a risk for toxic effects. Adductomic approaches aim to study the totality of adducts, to specific biomolecules, by mass spectrometric screening. This Mini-Review focuses on the development and application of an adductomic approach for the screening of unknown adducts to N-terminal valine (Val) in haemoglobin (Hb) by liquid chromatography tandem mass spectrometry (LC-MS/MS). The approach is based on the FIRE procedure, a modified Edman procedure for the analysis of adducts to N-terminal Val in Hb by LC-MS/MS. In the first application of the approach, samples from 12 smokers/non-smokers were screened for Hb adducts, and six previously identified adducts and 20 unknown adducts were detected. To confirm the observation of the detected unknown adducts, targeted screenings were performed in larger sets of blood samples (n = 50-120) from human cohorts. The majority of the previously detected unknown adducts was found in all analysed samples, with large interindividual variations in adduct levels. For structural identification of unknown adducts, a strategy using adductome LC-MS/MS data was formulated and applied. Six identified adducts correspond to ethylation and the precursor electrophiles ethyl vinyl ketone, glyoxal, methylglyoxal, acrylic acid and 1-octen-3-one. The observation of these adducts in human blood motivate further studies to evaluate possible contributions to health risks, as well as their potential as biomarkers of exposure.

Ruthenium Lewis Acid‐Catalyzed Asymmetric Diels–Alder Reactions: Reverse‐Face Selectivity for α,β‐Unsaturated Aldehydes and Ketones

Acrolein, methacrolein, methyl vinyl ketone, ethyl vinyl ketone, 3‐methyl‐3‐en‐2‐one, and divinyl ketone were coordinated to a cationic cyclopentadienyl ruthenium(II) Lewis acid incorporating the electron‐poor bidentate BIPHOP–F ligand. Analysis by NOESY and ROESY NMR techniques allowed the determination of conformations of enals and enones present in solution in CD2Cl2. The results were compared to solid‐state structures and to the facial selectivities of catalytic asymmetric Diels–Alder reactions with cyclopentadiene. X‐Ray structures of four Ru‐enal and Ru‐enone complexes show the α,β‐unsaturated C=O compounds to adopt an anti‐s‐trans conformation. In solution, enals assume both anti‐s‐trans and anti‐s‐cis conformations. An additional conformation, syn‐s‐trans, is present in enone complexes. Enantioface selectivity in the cycloaddition reactions differs for enals and enones. Reaction products indicate enals to react exclusively in the anti‐s‐trans conformation, whereas with enones, the major product results from the syn‐s‐trans conformation. The alkene in s‐cis conformations, while present in solution, is shielded and cannot undergo cycloaddition. A syn‐s‐trans conformation is found in the solid state of the bulky 6,6‐dimethyl cyclohexanone‐Ru(II) complex. The X‐ray structure of divinyl ketone is unique in that the Ru(II) center binds the enone via a η2 bond to one of the alkene moieties. In solution, coordination to Ru–C=O oxygen is adopted. A comparison of facial preference is also made to the corresponding indenyl Lewis acids.

Reactivity of Biliatresone, a Natural Biliary Toxin, with Glutathione, Histamine, and Amino Acids.

In our previous work, we identified a natural toxin, biliatresone, from Dysphania glomulifera and D. littoralis, endemic plants associated with outbreaks of biliary atresia in Australian neonatal livestock. Biliatresone is a very rare isoflavonoid with an α-methylene ketone between two phenyls, 1,2-diaryl-2-propenone, along with methylenedioxy, dimethoxyl, and hydroxyl functional groups, that causes extrahepatic biliary toxicity in zebrafish. The toxic core of biliatresone is a methylene in the α-position relative to the ketone of 1,2-diaryl-2-propenone that serves as an electrophilic Michael acceptor. The α-methylene of biliatresone spontaneously conjugated with water and methanol (MeOH), respectively, via Michael addition in a reverse phase high-performance liquid chromatography (RP-HPLC) analysis. We here report the reactivity of biliatresone toward glutathione (GSH), several amino acids, and other thiol- or imidazole-containing biomolecules. LC-MS and HPLC analysis of the conjugation reaction showed the reactivity of biliatresone to be in the order histidine > N-acetyl-d-cysteine (D-NAC) = N-acetyl-l-cysteine (L-NAC) > histamine > glutathione ≥ cysteine ≫ glycine > glutamate > phenylalanine, while serine and adenine had no reactivity due to intramolecular hydrogen bonding in the protic solvents. The reactivity of ethyl vinyl ketone (EVK, 1-penten-3-one), an example of a highly reactive α,ß-unsaturated ketone, toward GSH gave a 6.7-fold lower reaction rate constant than that of biliatresone. The reaction rate constant of synthetic 1,2-diaryl-2-propen-1-one (DP), a core structure of the toxic molecule, was 10-fold and 1.5-fold weaker in potency compared to the reaction rate constants of biliatresone and EVK, respectively. These results demostrated that the methylenedioxy, dimethoxyl, and hydroxyl functional groups of biliatresone contribute to the stronger reactivity of the Michael acceptor α-methylene ketone toward nucleophiles compared to that of DP and EVK.

When CMRP met alkyl vinyl ketone: visible light induced living radical polymerization (LRP) of ethyl vinyl ketone (EVK)

Photo responsive polyethyl vinyl ketone (PEVK) and various block copolymers were prepared through the visible light induced cobalt mediated radical polymerization (CMRP) process. The first order kinetics and linear increase in molecular weight with conversion demonstrated a well-behaved system. Chain extension experiments showed the retention of the living end of PEVK.

Characterization of a Hemoglobin Adduct from Ethyl Vinyl Ketone Detected in Human Blood Samples.

Electrophiles have the ability to form adducts to nucleophilic sites in proteins and DNA. Internal exposure to such compounds thus constitutes a risk for toxic effects. Screening of adducts using mass spectrometric methods by adductomic approaches offers possibilities to detect unknown electrophiles present in tissues. Previously, we employed untargeted adductomics to detect 19 unknown adducts to N-terminal valine in hemoglobin (Hb) in human blood. This article describes the characterization of one of these adducts, which was identified as the adduct from ethyl vinyl ketone (EVK). The mean adduct level was 40 ± 12 pmol/g Hb in 12 human blood samples; adduct levels from acrylamide (AA) and methyl vinyl ketone (MVK) were quantified for comparison. Using l-valine p-nitroanilide (Val-pNA), introduced as a model of the N-terminal valine, the rate of formation of the EVK adduct was studied, and the rate constant determined to 200 M(-1)h(-1) at 37 °C. In blood, the reaction rate was too fast to be feasibly measured, EVK showing a half-life <1 min. Parallel experiments with AA and MVK showed that the two vinyl ketones react approximately 2 × 10(3) times faster than AA. The EVK-Hb adduct was found to be unstable, with a half-life of 7.6 h. From the mean adduct level measured in human blood, a daily dose (area under the concentration-time-curve, AUC) of 7 nMh EVK was estimated. The AUC of AA from intake via food is about 20 times higher. EVK is naturally present in a wide range of foods and is also used as a food additive. Most probably, naturally formed EVK is a major source to observed adducts. Evaluation of available toxicological data and information on occurrence of EVK indicate that further studies of EVK are motivated. This study illustrates a quantitative strategy in the initial evaluation of the significance of an adduct detected through adduct screening.

ChemInform Abstract: Palladium‐Promoted Asymmetric Cycloaddition Reaction of Arsole via an Unusual exo—endo Stereochemically Controlled Method.

Asymmetric cycloaddition reaction between 3,4-dimethyl-1-phenylarsole and ethyl vinyl ketone was promoted by the palladium complex containing ortho-metalated (S)-[1-(dimethylamino)ethyl]naphthalene as the chiral auxiliary. The keto group in the resulting arsanorbornene cycloadducts could be located stereospecifically in the endo or exo position by controlling the electronic properties of the organopalladium promoter. In the intermolecular cycloaddition reaction, a pair of separable diastereomeric palladium complexes was obtained in the ratio of 2:1. In the intramolecular process, however, only one As–O bidentate arsanorbornene palladium complex was produced stereoselectively. The arsenic-elimination reaction was readily observed on the corresponding endo- and exo-ketoarsine ligands. The absolute configuration and the coordination property of the enantiomerically pure endo-cycloadduct had been established by single-crystal X-ray analysis.