The Experts below are selected from a list of 1836 Experts worldwide ranked by ideXlab platform

Francisco J Hidalgo - One of the best experts on this subject based on the ideXlab platform.

  • reactive carbonyls and the formation of the heterocyclic aromatic amine 2 amino 3 4 dimethylimidazo 4 5 f quinoline meiq
    Food Chemistry, 2020
    Co-Authors: Rosario Zamora, Cristina M Lavadotena, Francisco J Hidalgo
    Abstract:

    Abstract Reactions involving reactive carbonyls, creatinine, and ammonia-producing compounds were investigated in order to clarify the formation of the heterocyclic aromatic amine (HAA) 2-amino-3,4-dimethylimidazo(4,5-f)quinoline (MeIQ). Obtained results showed that MeIQ was only produced when 2-butenal (Crotonaldehyde) was present. Reaction yields depended on the pH, with a maximum around pH 6.5, and on concentrations of Crotonaldehyde and creatinine. Ammonia was also required for MeIQ formation, but ammonia was produced by creatinine decomposition. The amount of MeIQ formed increased with reaction time, temperature, and oxygen content in the reaction atmosphere. Activation energy for MeIQ formation from Crotonaldehyde, creatinine, and glutamine was 72.2 ± 0.4 kJ·mol−1. A reaction pathway that explains MeIQ formation is proposed. Obtained results suggest a main role of reactive carbonyls formed in foods (the food carbonylome) on HAA formation. In addition, they provide scientific basis for the understanding of how HAAs are formed and could be mitigated.

P Mccormac - One of the best experts on this subject based on the ideXlab platform.

Rosario Zamora - One of the best experts on this subject based on the ideXlab platform.

  • reactive carbonyls and the formation of the heterocyclic aromatic amine 2 amino 3 4 dimethylimidazo 4 5 f quinoline meiq
    Food Chemistry, 2020
    Co-Authors: Rosario Zamora, Cristina M Lavadotena, Francisco J Hidalgo
    Abstract:

    Abstract Reactions involving reactive carbonyls, creatinine, and ammonia-producing compounds were investigated in order to clarify the formation of the heterocyclic aromatic amine (HAA) 2-amino-3,4-dimethylimidazo(4,5-f)quinoline (MeIQ). Obtained results showed that MeIQ was only produced when 2-butenal (Crotonaldehyde) was present. Reaction yields depended on the pH, with a maximum around pH 6.5, and on concentrations of Crotonaldehyde and creatinine. Ammonia was also required for MeIQ formation, but ammonia was produced by creatinine decomposition. The amount of MeIQ formed increased with reaction time, temperature, and oxygen content in the reaction atmosphere. Activation energy for MeIQ formation from Crotonaldehyde, creatinine, and glutamine was 72.2 ± 0.4 kJ·mol−1. A reaction pathway that explains MeIQ formation is proposed. Obtained results suggest a main role of reactive carbonyls formed in foods (the food carbonylome) on HAA formation. In addition, they provide scientific basis for the understanding of how HAAs are formed and could be mitigated.

Amol A. Kulkarni - One of the best experts on this subject based on the ideXlab platform.

  • continuous flow doebner miller reaction and isolation using continuous stirred tank reactors
    Organic Process Research & Development, 2016
    Co-Authors: Maruti B Yadav, Sourabh Kulkarni, Ramesh A. Joshi, Amol A. Kulkarni
    Abstract:

    Continuous flow Doebner–Miller synthesis of different quinaldines from respective anilines is demonstrated using sulfuric acid as a homogeneous catalyst. The extent of reaction was monitored for various parameters, namely, temperature, residence time, mole ratio of sulfuric acid to substrate, mole ratio of Crotonaldehyde to substrate, and so forth. Continuous stirred reactors in series were used as a preferred configuration for this rection that generates byproduct in the form of sticky solid material. The approach has been extended for six different anilines, and the results are compared with batch reactions. Continuous stirred reactors in series with distributed dosing of Crotonaldehyde facilitated a continuous flow reaction with lower byproduct formation, increased yields, and continuous workup and is a scalable approach.

  • Continuous Flow Doebner–Miller Reaction and Isolation Using Continuous Stirred Tank Reactors
    2016
    Co-Authors: Maruti B. Yadav, Sourabh Kulkarni, Ramesh A. Joshi, Amol A. Kulkarni
    Abstract:

    Continuous flow Doebner–Miller synthesis of different quinaldines from respective anilines is demonstrated using sulfuric acid as a homogeneous catalyst. The extent of reaction was monitored for various parameters, namely, temperature, residence time, mole ratio of sulfuric acid to substrate, mole ratio of Crotonaldehyde to substrate, and so forth. Continuous stirred reactors in series were used as a preferred configuration for this rection that generates byproduct in the form of sticky solid material. The approach has been extended for six different anilines, and the results are compared with batch reactions. Continuous stirred reactors in series with distributed dosing of Crotonaldehyde facilitated a continuous flow reaction with lower byproduct formation, increased yields, and continuous workup and is a scalable approach

Michael P Stone - One of the best experts on this subject based on the ideXlab platform.

  • chemistry and biology of dna containing 1 n2 deoxyguanosine adducts of the α β unsaturated aldehydes acrolein Crotonaldehyde and 4 hydroxynonenal
    Chemical Research in Toxicology, 2009
    Co-Authors: Irina G Minko, Ivan D Kozekov, Thomas M Harris, Carmelo J Rizzo, Stephen R Lloyd, Michael P Stone
    Abstract:

    The α,β-unsaturated aldehydes (enals) acrolein, Crotonaldehyde, and trans-4-hydroxynonenal (4-HNE) are products of endogenous lipid peroxidation, arising as a consequence of oxidative stress. The addition of enals to dG involves Michael addition of the N2-amine to give N2-(3-oxopropyl)-dG adducts, followed by reversible cyclization of N1 with the aldehyde, yielding 1,N2-dG exocyclic products. The 1,N2-dG exocyclic adducts from acrolein, Crotonaldehyde, and 4-HNE exist in human and rodent DNA. The enal-induced 1,N2-dG lesions are repaired by the nucleotide excision repair pathway in both Escherichia coli and mammalian cells. Oligodeoxynucleotides containing structurally defined 1,N2-dG adducts of acrolein, Crotonaldehyde, and 4-HNE were synthesized via a postsynthetic modification strategy. Site-specific mutagenesis of enal adducts has been carried out in E. coli and various mammalian cells. In all cases, the predominant mutations observed are G→T transversions, but these adducts are not strongly miscoding...

  • rearrangement of the 6s 8r 11s and 6r 8s 11r exocyclic 1 n2 deoxyguanosine adducts of trans 4 hydroxynonenal to n2 deoxyguanosine cyclic hemiacetal adducts when placed complementary to cytosine in duplex dna
    Journal of the American Chemical Society, 2008
    Co-Authors: Hai Huang, Carmelo J Rizzo, Hao Wang, Albena Kozekova, Michael P Stone
    Abstract:

    trans-4-Hydroxynonenal (HNE) is a peroxidation product of ω-6 polyunsaturated fatty acids. The Michael addition of deoxyguanosine to HNE yields four diastereomeric exocyclic 1,N2-dG adducts. The corresponding acrolein- and Crotonaldehyde-derived exocyclic 1,N2-dG adducts undergo ring-opening to N2-dG aldehydes, placing the aldehyde functionalities into the minor groove of DNA. The acrolein- and the 6R-Crotonaldehyde-derived exocyclic 1,N2-dG adducts form interstrand N2-dG:N2-dG cross-links in the 5′-CpG-3′ sequence context. Only the HNE-derived exocyclic 1,N2-dG adduct of (6S,8R,11S) stereochemistry forms interstrand N2-dG:N2-dG cross-links in the 5′-CpG-3′ sequence context. Moreover, as compared to the exocyclic 1,N2-dG adducts of acrolein and Crotonaldehyde, the cross-linking reaction is slow (Wang, H.; Kozekov, I. D.; Harris, T. M.; Rizzo, C. J. J. Am. Chem. Soc. 2003, 125, 5687−5700). Accordingly, the chemistry of the HNE-derived exocyclic 1,N2-dG adduct of (6S,8R,11S) stereochemistry has been compare...