Analysis Of Reaction Products Research Articles

Reaction Pathways and Current Efficiency for Electrooxidation of Ethylene Glycol at Intermediate Temperatures

Electrocatalytic reforming (ECR) of ethylene glycol (EG) was studied in an effort to determine the feasibility of ECR for hydrogen production from biomass. Measurements were made in a proton exchange membrane (PEM) reactor with Pt/C anode and cathode and Nafion electrolyte. Electrooxidation of EG in aqueous phase was studied over the temperature range of 40--137°C. Reaction progress was followed by cyclic voltammetry, potential-step chronoamperometry, and chromatographic analysis of reaction products. Sustained reaction occurred at an overpotential as low as 0.49 V at 137°C. A variety of partial oxidation products were observed; glycolaldehyde, glycolic acid, and traces of oxalic acid; mostly at low temperatures. The results were interpreted according to the dual pathways mechanism, in which path A involves a series reaction through a CO intermediate, and path B is parallel route to CO2 that bypasses CO ads . Reaction progression towards complete oxidation increased with temperature, from an average number of electrons transferred of 5.1 at 40°C to 9.0 at 137°C. Activation energies of 18 and 43 kJ/mol were measured for EG conversion and CO2 production. The lower value is attributed to formation of partial oxidation products, and the higher value to CO ads electrooxidation in path A. The sustained reaction at low overpotential along with near complete oxidation, both of which occur at high temperature, show that ECR can be a viable process in biomass reforming, and that further studies must be conducted at higher temperatures for a more complete understanding of this process.

ConcomitantBRAFV600EMutation andRET/PTCRearrangement Is a Frequent Occurrence in Papillary Thyroid Carcinoma

The tyrosine kinase receptors/RAS/RAF/MAPK cascade is a site of mutational events associated with thyroid carcinogenesis. Some studies suggest the reciprocal exclusion of different oncogenes in the mitogen-activated protein kinase cascade, whereas others suggest that BRAF mutations and RET rearrangements can simultaneously occur in sporadic cases. The aim of this study was to determine the prevalence of concomitant BRAF(V600E) mutation and RET/PTC rearrangements in the same tumor and its association with some clinicopathological features. The percentage of mutant BRAF alleles and the presence of RET/PTC rearrangements were determined by means of pyrosequencing and Southern blot analysis of reverse transcription polymerase chain reaction products in a series of 72 conventional papillary thyroid carcinomas (PTCs). Then, the associations between clinicopathological characteristics and mutation status were assessed. BRAF(V600E) alleles were present in 32 out of 72 PTCs (44.4%) in the range of 5.1-44.7% of total BRAF alleles. RET/PTC was present in 26 tumors (36.1%). Concomitant subclonal BRAF and RET/PTC were demonstrated in 14 PTCs (19.4%), and none of the oncogenes was detected in 22 tumors (30.5%). Only BRAF(V600E) was associated with a more advanced tumor staging. The present study demonstrates that concomitant BRAF mutation and RET/PTC rearrangement is a frequent event in PTC.

Reaction mechanism of NOx removal from flue gas with pyrolusite slurry

Pyrolusite slurry was used as absorbent to remove NOx from flue gas. Reaction mechanism of NOx removal was theoretically analyzed based on E-pH diagram of Mn–NOx–H2O system and then verified by experiments via both the qualitative and quantitative analysis of reaction products. Main reaction and byproduct were also investigated in depth. Results showed that NOx in flue gas dissolved into liquid phase first and then were oxidized into NO3- by MnO2 and O2. NO2 was more easily removed than NO because of its high solubility. NOx removal efficiency was depended strongly on the molar ratio of NO2 to NOx (NO2/NOx ratio). When NO2/NOx ratio at 75%, NOx removal efficiency remained between 60% and 64% within 11h and manganese extraction rate reached 92%. Manganese nitrate, meeting the needs of national industry grade standards, could be produced using purified absorption solution.

Eprobe mediated real-time PCR monitoring and melting curve analysis.

Real-time monitoring of PCR is one of the most important methods for DNA and RNA detection widely used in research and medical diagnostics. Here we describe a new approach for combined real-time PCR monitoring and melting curve analysis using a 3′ end-blocked Exciton-Controlled Hybridization-sensitive fluorescent Oligonucleotide (ECHO) called Eprobe. Eprobes contain two dye moieties attached to the same nucleotide and their fluorescent signal is strongly suppressed as single-stranded oligonucleotides by an excitonic interaction between the dyes. Upon hybridization to a complementary DNA strand, the dyes are separated and intercalate into the double-strand leading to strong fluorescence signals. Intercalation of dyes can further stabilize the DNA/DNA hybrid and increase the melting temperature compared to standard DNA oligonucleotides. Eprobes allow for specific real-time monitoring of amplification reactions by hybridizing to the amplicon in a sequence-dependent manner. Similarly, Eprobes allow for analysis of reaction products by melting curve analysis. The function of different Eprobes was studied using the L858R mutation in the human epidermal growth factor receptor (EGFR) gene, and multiplex detection was demonstrated for the human EGFR and KRAS genes using Eprobes with two different dyes. Combining amplification and melting curve analysis in a single-tube reaction provides powerful means for new mutation detection assays. Functioning as “sequence-specific dyes”, Eprobes hold great promises for future applications not only in PCR but also as hybridization probes in other applications.

Thermolysis of trifluoromethyl-containing vinyldiazocarbonyl compounds and X-ray crystal structure analysis of unexpected reaction products

Two unusual compounds, 1,3a,6,6a-tetrahydro-3a,6a-bis(trifluoromethyl)-cyclopenta[c]pyrazol-3,4,5,6-tetracarboxylic acid tetramethyl ester (C16H14N2O8F6) (3) and 2-acetyl-5,7-bis(trifluoromethyl)-4-methyl-3-methoxy-2,4,6-cycloheptatrienecarboxylic acid methyl ester (C14H11F6O3) (4), were obtained from thermolysis of 3-trifluoromethyl-substituted vinyldiazocarbonyl compounds. The crystal structures of the products were determined as part of a larger comparison study on the thermal and Rh(II)-catalyzed reactions of F- and H-vinyldiazocarbonyl compounds. The resulting structures provide the first crystallographic characterization of bis(trifluoromethyl)substituted compounds of this kind. The pure compounds with all-carbon (4) and half-heterocyclic (3) skeletons are composed of a seven- and two-annulated five-membered rings in folded butterfly and envelope conformations, respectively.

MtnBD Is a Multifunctional Fusion Enzyme in the Methionine Salvage Pathway of Tetrahymena thermophila

To recycle reduced sulfur to methionine in the methionine salvage pathway (MSP), 5-methylthioribulose-1-phosphate is converted to 2-keto-4-methylthiobutyrate, the methionine precursor, by four steps; dehydratase, enolase, phosphatase, and dioxygenase reactions (catalyzed by MtnB, MtnW, MtnX and MtnD, respectively, in Bacillus subtilis). It has been proposed that the MtnBD fusion enzyme in Tetrahymena thermophila catalyzes four sequential reactions from the dehydratase to dioxygenase steps, based on the results of molecular biological analyses of mutant yeast strains with knocked-out MSP genes, suggesting that new catalytic function can be acquired by fusion of enzymes. This result raises the question of how the MtnBD fusion enzyme can catalyze four very different reactions, especially since there are no homologous domains for enolase and phosphatase (MtnW and MtnX, respectively, in B. subtilis) in the peptide. Here, we tried to identify the domains responsible for catalyzing the four reactions using recombinant proteins of full-length MtnBD and each domain alone. UV-visible and 1H-NMR spectral analyses of reaction products revealed that the MtnB domain catalyzes dehydration and enolization and the MtnD domain catalyzes dioxygenation. Contrary to a previous report, conversion of 5-methylthioribulose-1-phosphate to 2-keto-4-methylthiobutyrate was dependent on addition of an exogenous phosphatase from B. subtilis. This was observed for both the MtnB domain and full-length MtnBD, suggesting that MtnBD does not catalyze the phosphatase reaction. Our results suggest that the MtnB domain of T. thermophila MtnBD acquired the new function to catalyze both the dehydratase and enolase reactions through evolutionary gene mutations, rather than fusion of MSP genes.

Functional expression of Brassica juncea oleate desaturase gene (Bjfad2) in Escherichia coli

The synthesis of polyunsaturated fatty acids, the most abundant fatty acids in plants, begins with a reaction catalyzed by fatty acid desaturase-2 (FAD2; EC 1.3.1.35), also called as microsomal Δ12 oleate desaturase. The gene (Bjfad2; GenBank accession No. EF639848) coding for this enzyme from Brassica juncea was previously isolated and characterized. However, functional identity of Bjfad2 was not established. Utilizing the known Bjfad2 cDNA sequence, the ORF of Bjfad2 gene was cloned into the pMAL C2X Escherichia coli expression vector and produced recombinant plasmid by insertion of isolated ORF downstream to the maltose-binding protein coding sequence. The pMALC2X-Bjfad2 vector was used to transform the TB1 strain of E. coli. Induced expression of pMAL-BJFAD2 fused product resulted in the synthesis of a polypeptide with an apparent molecular mass of 80 kDa, which was 8 kDa less than calculated mass as determined by SDS-PAGE, since the fused MalE-Bjfad2 gene contains eight additional codons located between the MalE and Bjfad2 gene. In vitro activity assay of oleate desaturase using the corresponding bacterial crude extracts confirmed that the polypeptide was the product of the Bjfad2 gene. The reaction products analysis of the fatty acid methyl esters by gas chromatography showed the presence of a new peak with a similar retention time to linoleic acid, which was absent in the control activity assay without electron donors. Thus, B. juncea gene has been functionally identified since it encodes the enzyme that catalyzed the desaturation of oleate to linoleate.

Hydroisomerization and hydrocracking of linear and multibranched long model alkanes on hierarchical Pt/ZSM-22 zeolite

Hydroisomerization and hydrocracking using bifunctional zeolite catalysts with hydrogenation-dehydrogenation next to the Brønsted acid functionality are at the heart of key refinery processes converting heavy petroleum fractions to high grade lubricants and fuels. Hierarchical zeolites presenting a network of auxiliary mesoporosity in addition to their native microporosity are known to improve accessibility to their active sites. In this paper we assess the impact of hierarchization by demetallation of the well-established hydroisomerization catalyst Pt/ZSM-22 on the reaction pathways of the n-decane, n-nonadecane and pristane (2,6,10,14-tetramethylpentadecane) model molecules. Detailed analysis of reaction products and assessment of acid site accessibility in conventional and hierarchical ZSM-22 samples highlight the contributions of acid sites in pore mouths and micropores to the skeletal rearrangement and cracking reactions.

Kinetics and Modeling of Degradation of Ionophore Antibiotics by UV and UV/H2O2

Ionophore antibiotics (IPAs), one of the major groups of pharmaceuticals used in livestock industry, have been found to contaminate agricultural runoff and surface waters via land application of animal manures as fertilizers. However, limited research has investigated the means to remove IPAs from water sources. This study investigates the degradation of IPAs by using ultraviolet (UV) photolysis and UV combined with hydrogen peroxide (UV/H2O2) advanced oxidation process (AOP) under low-pressure (LP) UV lamps in various water matrices. Three widely used (monensin, salinomycin, and narasin) and one model (nigericin) IPAs exhibit low light absorption in the UV range and degrade slowly at the light intensity of 3.36 × 10(-6) Einstein·L(-1)·s(-1) under UV photolysis conditions. However, IPAs react with hydroxyl radicals produced by UV/H2O2 at fast reaction rates, with second-order reaction rate constants at (3.49-4.00) × 10(9) M(-1)·s(-1). Water matrix constituents enhanced the removal of IPAs by UV photolysis but inhibited UV/H2O2 process. A steady-state kinetic model successfully predicts the impact of water constituents on IPA degradation by UV/H2O2 and determines the optimal H2O2 dose by considering both energy consumption and IPA removal. LC/MS analysis of reaction products reveals the initial transformation pathways of IPAs via hydrogen atom abstraction and peroxidation during UV/H2O2. This study is among the first to provide a comprehensive understanding of the degradation of IPAs via UV/H2O2 AOP.

UGT74D1 Is a Novel Auxin Glycosyltransferase from Arabidopsis thaliana

Auxin is one type of phytohormones that plays important roles in nearly all aspects of plant growth and developmental processes. The glycosylation of auxins is considered to be an essential mechanism to control the level of active auxins. Thus, the identification of auxin glycosyltransferases is of great significance for further understanding the auxin regulation. In this study, we biochemically screened the group L of Arabidopsis thaliana glycosyltransferase superfamily for enzymatic activity toward auxins. UGT74D1 was identified to be a novel auxin glycosyltransferase. Through HPLC and LC-MS analysis of reaction products in vitro by testing eight substrates including auxins and other compounds, we found that UGT74D1 had a strong glucosylating activity toward indole-3-butyric acid [IBA], indole-3-propionic acid [IPA], indole-3-acetic acid [IAA] and naphthaleneacetic acid [NAA], catalyzing them to form corresponding glucose esters. Biochemical characterization showed that this enzyme had a maximum activity in HEPES buffer at pH 6.0 and 37°C. In addition, the enzymatic activity analysis of crude protein and the IBA metabolite analysis from transgenic Arabidopsis plants overexpressing UGT74D1 gene were also carried out. Experimental results indicated that over-production of the UGT74D1 in plants indeed led to increased level of the glucose conjugate of IBA. Moreover, UGT74D1 overexpression lines displayed curling leaf phenotype, suggesting a physiological role of UGT74D1 in affecting the activity of auxins. Our current data provide a new target gene for further genetic studies to understand the auxin regulation by glycosylation in plants.

Reaction Analysis of Alcohol Electro-Oxidation at Intermediate Temperatures

Comprehensive analysis of electro-oxidation kinetics of alcohols such as methanol, ethanol, ethylene glycol and glycerol was performed at intermediate temperatures of around 250 oC, combining an electrochemical measurement with a reaction product analysis. Through the observations, following common features for the examined alcohols were found: (1) high oxidation current and high selectivity of CO2 were obtained; (2) hydrogen production via thermal decomposition and/or steam reforming of the alcohols (indirect path) and direct electro-oxidation of the alcohols (direct path) proceed in parallel. Based on the findings, a detailed reaction kinetic model was also discussed, considering the possible rate-determining step in direct alcohol electro-oxidation at intermediate temperatures.

Creation of a novel imprinting locus

Background Much work has been done to elucidate the frans-acting proteins that lay down different epigenetic modifications; however, very little is known about the cis regulatory regions that direct the modifications to their targets. To investigate this question we use imprinting, parental-specific methylation which results in monoallelic expression, as a model system. The Rasgrf1 imprinting locus in particular stands out as a tractable system because of the depth of detail to which the DNA methylation mechanism has been described. Previous work in the lab has shown that the Rasgrf1 gene is regulated by an imprinting control region (ICR) that lies 30kb upstream of the gene’s promoter in between the gene and its enhancer. This ICR consists of a differentially methylated region (DMR) just 5’ of a repetitive element. Data suggest that CTCF binding to enhancer blocking sequences within the DMR is modulated by methylation status, which results in differential interference of enhancer-promoter communication. In somatic tissue the maternal DMR is unmethylated with CTCF bound, disrupting the interaction between the Rasgrf1 enhancer and promoter and subsequently inhibiting transcriptional activation. The paternal DMR, however, is methylated with no CTCF binding, which allows for the enhancer interaction and consequent transcription. Previous studies have shown the elements which are necessary for imprinting, however, no study has demonstrated what is sufficient for the imprinting phenotype. To test to see whether we understand what is sufficient for imprinting at this locus, we have inserted the Rasgrf1 ICR between a non-imprinted gene and its enhancer to see if we can create an ectopic imprinting site. Materials and methods Due to its dependence on its well-defined enhancer and haplosuffkiency, the Wnt1 gene was chosen as the target for ICR insertion between its enhancer and promoter. Bisulfite sequencing was used to assess DNA methylation for both germline and somatic tissue. Differential restriction analysis of reverse transcription polymerase chain reaction products was used to determine gene expression from the two alleles. Results We find that somatic methylation on the construct has been laid down as expected: when passed through the maternal germline it is not methylated and when passed through the paternal germline it is fully methylated. Also as expected, the Wnt1 allele under the control of the imprinting locus is expressed during paternal transmission. More characterization must be done to assess the expression of a maternally transmitted allele. Ongoing studies will also investigate the methylation in both the male and female gametes. Conclusions

Accurate Analysis of Formose Reaction Products by LC–UV: An Analytical Challenge

This study presents a liquid chromatography-ultraviolet (LC-UV) method for the accurate analysis of formose reaction products with regard to sum parameters. Limitations encountered in gas chromatography (e.g., thermal stability of analytes) were overcome. First, alditols are O-benzoylated and subjected to reversed-phase chromatography. They are then detected by UV and by electrospray ionization-mass spectrometry (ESI-MS) for validation purposes. Compared with standard 2,4-dinitrophenylhydrazine labeling, the accuracy of results from LC-UV is dramatically improved due to enhanced chromatographic resolution and validation by ESI-MS. For the first time ever, LC-UV may be used to accurately quantify 2-hydroxymethylglycerol, a branched chain alditol, D,L-glyceraldehyde, D,L-galactose, which represents the group of D,L-iditol/galactose/glucose/mannose and D,L-erythrose in formose reaction products.

PREPARATION OF BOVINE SERUM ALBUMIN MONOMER FOR CONJUGATION EXPERIMENTS BY USING DIFFERENT TYPES OF CHROMATOGRAPHY MEDIA

The presence of some sugar contaminants and high molecular mass (HMW) derivatives detected in commercially available bovine serum albumin (BSA) preparations precluded the use of such reagents for basic molecular biology experiments. In this study the effectiveness of three separation methods of monomeric BSA from contaminants were examined: gel filtration on Sephadex G-200, HW-55S resin, and ion-exchange chromatography on DEAE-Sephadex A-50. Only chromatography on HW-55S allowed obtaining protein lacking HMW derivates and freeing of sugar contaminants, which was confirmed in SDS/PAGE and phenol/sulfuric acid analysis, respectively. Moreover, the determination of protein particle size by dynamic light scattering (DLS) at a level of 7 nm was in accordance with data for BSA monomeric molecules previously reported. Finally, the monomer BSA was subjected to modification with natural core oligosaccharide derived from Shigella lipopolysaccharide. The SDS/PAGE analysis of reaction products demonstrated different amounts of glycoconjugates compared to values obtained for commercial BSA. Only the pure protein modification permitted correct appraisal of obtained products. We propose gel filtration chromatography on HW-55S resin as simple and effective method of monomer BSA separation from commercial reagent before basic and applied research.

Desorption Electrospray Ionization Imaging Mass Spectrometry as a Tool for Investigating Model Prebiotic Reactions on Mineral Surfaces.

Mineral-assisted thermal decomposition of formamide (HCONH(2)) is a heavily studied model prebiotic reaction that has offered valuable insights into the plausible pathways leading to the chemical building blocks of primordial informational polymers. To date, most efforts have focused on the analysis of formamide reaction products released in solution, although several studies have examined the role of mineral catalysts in promoting this chemistry. We show here that the direct investigation of reactive mineral surfaces by desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) gives a new perspective on the important role of the mineral surface in the formation of reaction products. As a proof-of-principle example, we show that DESI-MSI allows interrogation of the molecular products produced on heterogeneous granite samples with minimal sample preparation. Purine and pyrimidine nucleobases and their derivatives are successfully detected by DESI-MSI, with a strong correlation of the spatial product distribution with the mineral microenvironment. To our knowledge, this study is the first application of DESI-MSI to the study of complex and porous mineral surfaces and their roles in chemical evolution. This DESI-MSI approach is generally applicable to a wide range of reactions or other processes involving minerals.

Experimental Study on CO2 Solubility in Aqueous Piperazine/Alkanolamines Solutions at Stripper Conditions

Vapor liquid equilibrium (VLE) experiments using pressurized vessel operated at wide range of temperatures from 40°C to 120°C were conducted with four binary solutions of Piperazine (PZ) and alkanolamines, which are 2- Isopropylaminoethanol (IPAE), Monoethanolamine (MEA), Diethanolamine (DEA) and Methyldiethanolamine (MDEA). Effective CO2 loadings of some PZ based binary solutions, which meant the difference between the CO2 loadings at the consistent absorber and stripper conditions, increased in comparison with the PZ only solution and especially, PZ/MDEA showed the largest effective CO2 loading. CO2 loadings at the stripper condition did not depend on additive amount of MDEA to PZ and was the same CO2 loading as PZ only solution, while those increased with increase in MDEA concentration at the absorber condition. According to the reaction products analysis for PZ/MDEA samples operated at different temperature by using 13C-NMR spectroscopy, the bicarbonate in the solution decreased significantly with increase in temperature, but the PZ carbamate dissociated CO2 much less than the carbamate even at 120°C.

A versatile high-resolution magnetic spectrometer for energy compression, reaction studies and nuclear spectroscopy

The Super-FRS in-flight fragment separator at FAIR will be used to produce exotic nuclei at relativistic energies. High resolution experiments in ion traps with the separated fragments will be performed after they are slowed-down in matter and quickly extracted from a gas-filled stopping cell. Such experiments require an effective range bunching with a high-resolution magnetic spectrometer in combination with a wedge-shaped degrader at the dispersive focal plane. The ion-optical system of the spectrometer proposed here is rather versatile because it consists of several dipole and quadrupole magnets arranged such to serve as an energy-buncher and also as a large-acceptance spectrometer for the analysis of secondary reaction products. The performance and the experimental potential of such a multi-purpose spectrometer are described.

Toxicological analysis of limonene reaction products using an in vitro exposure system

Epidemiological investigations suggest a link between exposure to indoor air chemicals and adverse health effects. Consumer products contain reactive chemicals which can form secondary pollutants which may contribute to these effects. The reaction of limonene and ozone is a well characterized example of this type of indoor air chemistry. The studies described here characterize an in vitro model using an epithelial cell line (A549) or differentiated epithelial tissue (MucilAir™). The model is used to investigate adverse effects following exposure to combinations of limonene and ozone. In A549 cells, exposure to both the parent compounds and reaction products resulted in alterations in inflammatory cytokine production. A one hour exposure to limonene+ozone resulted in decreased proliferation when compared to cells exposed to limonene alone. Repeated dose exposures of limonene or limonene+ozone were conducted on MucilAir™ tissue. No change in proliferation was observed but increases in cytokine production were observed for both the parent compounds and reaction products. Factors such as exposure duration, chemical concentration, and sampling time point were identified to influence result outcome. These findings suggest that exposure to reaction products may produce more severe effects compared to the parent compound.

Bio-based thermosetting resins composed of cardanol novolac and bismaleimide

Cardanol novolac (CDN) was synthesized by the reaction of cardanol (CD) and paraformaldehyde in the presence of oxalic acid. The prepolymerized compounds of CD/4,4′-bismaleimidediphenylmethane (BMI) and CDN/BMI with CD/maleimide unit ratios 1/2, 1/4 and 1/6 at 200 °C were finally compression-molded at 250 °C for 5 h to produce cured CD/BMI (cCD/BMI) and cured CDN/BMI (cCDN/BMI) resins. Although the proton nuclear magnetic resonance (1H-NMR) and Fourier transform infrared spectroscopy (FTIR) analyses of the model reaction product of CD and N-phenylmaleimide (PMI) at 200 °C for 8 h suggested the occurrence of the ene reaction and subsequent Diels–Alder reaction, the FTIR analysis of cCD/BMI and cCDN/BMI suggested the occurrence of the ene reaction and addition copolymerization. The cCD/BMI and cCDN/BMI with CD/maleimide ratio lower than 1/2 did not show glass transition until 300 °C and had a 5% weight loss temperature higher than 450 °C. The cCD/BMI and cCDN/BMI with CD/maleimide ratio 1/4 showed the most balanced flexural properties (flexural strength 60–80 MPa, flexural modulus 2.0–2.5 GPa). 4,4′-Bismaleimidediphenylmethane (BMI) was cured finally at 250 °C with cardanol (CD) or CD novolac (CDN) prepared by the reaction of CD and paraformaldehyde with CD/maleimide unit ratios 1/2, 1/4 and 1/6. The obtained cured resins with CD/maleimide ratio lower than 1/2 did not show glass transition until 300°C and had 5% weight loss temperature higher than 450°C. The curing mechanism was elucidated by means of the proton nuclear magnetic resonance (1H-NMR) and Fourier transform infrared spectroscopy (FTIR) analyses of the model reaction products of CD and N-phenylmaleimide (PMI) and the cured resins.

Biobased thermosetting resins composed of terpene and bismaleimide

AbstractPrepolymers prepared by reactions of 1,1′‐(methylenedi‐4,1‐phenylene)bismaleimide (BMI) with myrcene (Myr) and limonene (Lim) in 1,3‐dimethyl‐2‐imidazolidinone (DMI) at 150°C were compressed at 250°C to produce crosslinked Myr/BMI [molar ratio = 2:2–2:5 (MB22–MB25)] and Lim/BMI [molar ratio = 1:1 (LB11)] resins. The 1H‐NMR analysis of the model reaction products of Lim and Myr with N‐phenyl maleimide (PMI) in DMI at 150°C revealed that a Diels–Alder reaction for Myr/PMI and a vinyl copolymerization for Lim/PMI preferentially proceeded in addition to the occurrence of the ene reaction to some extent. The Fourier transform infrared data of the cured resins were consistent with the results of the model reactions. All of the cured resins, except for MB22, showed tan δ peak values and 10% weight loss temperatures that were higher than 330 and 440°C, respectively. The flexural strength and modulus values of the MBs were higher than those of LB11. Field emission scanning electron microscopy analysis revealed that MB22–MB24 were homogeneous, whereas some combined particles appeared in LB11. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013