Heterocyclic aromatic amines are dietary carcinogens possibly involved in human carcinogenesis, DNA-adduct formation being an obligatory step in this multistage process. Heterocyclic amine binding to DNA largely depends on the balance between metabolic activation and detoxification pathways and DNA repair efficiency. Several genes coding for metabolic enzymes are polymorphic, which affects gene expression and/or enzyme activity. This paper briefly reviews the effect of polymorphisms of activating/detoxifying enzymes on the metabolism of heterocyclic amines. Despite some epidemiological evidence of an association between genetic polymorphisms and susceptibility to cancer possibly resulting from dietary exposure to heterocyclic aromatic amines (HA), the genetic polymorphisms had only slight effects on biomarker levels, suggesting the existence of further unknown factors.
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http://dx.doi.org/10.1016/j.jchromb.2003.10.055 | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada.
N-heterocyclic carbene (NHC)-protected gold nanoclusters display high stability and high photoluminescence, making them well-suited for fluorescence imaging and photodynamic therapeutic applications. We report herein the synthesis of two bisNHC-protected Au nanoclusters with π-extended aromatic systems. Depending on the position of the π-extended aromatic system, changes to the structure of the ligand shell in the cluster are observed, with the ability to correlate increases in rigidity with increases in fluorescence quantum yield.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Faculty of Pharmaceutical Sciences, Shenzhen University of Advanced Technology, Shenzhen 518107, China.
The synthesis of chiral tetrahydroquinolines (THQs) has garnered significant interest from medicinal chemists due to their frequent presence as pharmacophores in bioactive compounds. While existing synthetic methods have primarily focused on THQs with single or multiple endocyclic chiral centers, the selective construction of THQs with both and cyclic chiral centers remains a significant challenge that requires further development. This study introduces a dynamic kinetic resolution (DKR)-based transfer hydrogenation of racemic 2-substituted quinolines, which yields structurally novel chiral THQs with consecutive and cyclic chiral centers in excellent yields and stereoselectivities (59 examples, with generally >20:1 dr and >90% ee, up to three consecutive stereocenters).
View Article and Find Full Text PDFMed Chem
January 2025
Institute of Pharmaceutical Research, GLA University, Mathura, UP 281406, India.
The five-membered oxazole motif heterocyclic aromatic ring has been gaining considerable attention due to its bioisosterism property and unusually wide range of desired biological properties. Thus, it is a perfect pre-built platform for the discovery of new scaffold development in medicinal chemistry. In recent years, the potential of oxazoles has garnered significant attention from medicinal chemists, resulting in the development of several synthetic and plant-based drugs currently in the market.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Instituto Universitario de Tecnología Química, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, Universitat Politècnica de València, Av. De los Naranjos s/n, 46022 Valencia, Spain.
Due to their conductive properties and optoelectronic tunability, MXenes have revolutionized the area of electrocatalysis and active materials in supercapacitors. In comparison, there are only a few reports on MXenes as thermal catalysts for general organic reactions. Herein, the unprecedented catalytic activity of TiC MXene for the hydroamination of alkynes is reported, overcoming the limitations of poor activity, lack of selectivity, and stability, which are generally encountered in the solid catalysts known so far.
View Article and Find Full Text PDFChemphyschem
January 2025
The University of Sheffield, school of mathematical and physical sciences, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.
Pentalene (C8H6) and NN- and BB-bridged heterocyclic analogues (BN)4H6, derived by replacement of CC pairs with BN, are taken as paradigms for tuning of ring-current (anti)aromaticity by variation of π charge, electronegativity and substitution pattern. Ab initio calculation of maps for the π current density induced in these model systems by a perpendicular external magnetic field exhibits the full range of tropicity, from diatropic aromatic to nonaromatic to paratropic antiaromatic, with a ready rationalisation in terms of an orbital model. Further calculations on systems of varying charge in which these motifs are embedded in extended PAH systems with naphthalene and phenanthrene 'clamps' show promise for switching between current patterns and related opto-electronic properties.
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