Importance of phenols structure on their activity as antinitrosating agents: A kinetic study

Abstract

Objective:Nitrosative deamination of DNA bases induced by reaction with reactive nitrogen species (RNS) has been pointed out as a probable cause of mutagenesis. (Poly)phenols, present in many food items from the Mediterranean diet, are believed to possess antinitrosating properties due to their RNS scavenging ability, which seems to be related to their structure. It has been suggested that phenolic compounds will react with the above-mentioned species more rapidly than most amino compounds, thus preventing direct nitrosation of the DNA bases and their transnitrosation from endogenous N-nitroso compounds, or most likely from the transient N-nitrosocompounds formed in vivo.Materials and Methods:In order to prove that assumption, a kinetic study of the nitroso group transfer from a N-methyl-N-nitrosobenzenesulfonamide (N-methyl-N-nitroso-4-methylbenzenesulfonamide, MeNMBS) to the DNA bases bearing an amine group and to a series of phenols was carried out. In the transnitrosation of phenols, the formation of nitrosophenol was monitored by Ultraviolet (UV) / Visible spectroscopy, and in the reactions of the DNA bases, the consumption of MeNMBS was followed by high performance liquid chromatography (HPLC).Results:The results obtained point to the transnitrosation of DNA bases being negligible, as well as that of phenols bearing electron-withdrawing groups. Phenols with methoxy substituents in positions 2, 4, and / or 6, although they seemed to react, did not afford the expected product. Phenols with electron-releasing substituents, unless these blocked the oxygen atom, reacted with our model compound at an appreciable rate. O-nitrosation of the phenolate ion followed by rearrangement of the C-nitrosophenol seemed to be involved.Conclusion:This study provided evidence that the above compounds might actually act as antinitrosating agents in vivo.

Mediterranean Diet: Prevention of Colorectal Cancer

“…Approximately 50% of CRC are known to harbor mutated KRAS, namely a G > A transition at codons 12 or 13, which are characteristic of NOC-mediated DNA alkylation ( 77 ). NOCs have also been shown to induce DNA deamination leading to DNA polymerase and mismatch errors, and the formation of abasic sites ( 78 ). Evidence suggests guanine residues are more sensitive to N -nitroso deamination than adenine and cytosine ( 78 ).…”

“…NOCs have also been shown to induce DNA deamination leading to DNA polymerase and mismatch errors, and the formation of abasic sites ( 78 ). Evidence suggests guanine residues are more sensitive to N -nitroso deamination than adenine and cytosine ( 78 ). Cooking of meat at high temperatures generates heterocyclic amines (HCA) and polycyclic aromatic hydrocarbons (PAH) ( 79 , 80 ).…”

Analysis of the potential of cupuaçu husks (Theobroma grandiflorum) as raw material for the synthesis of bioproducts and energy generation

“…Rambo et al (2021), like this study, identified guaiacol (28.7%) and creosol (22.5%) compounds in bio-oil derived from baru hydrolyzed endocarp. Bioproducts observed in this research have a wide range of industrial applications, a high market value, and a suitable use in biorefinery processes (Pessêgo et al, 2011).…”

“…The holocellulosic fraction, which represents the sum of cellulose and hemicellulose contents in cupuaçu husk (59.6%), was significantly higher than others raw biomass found in cocoa shell (38.8%) (Hoyos et al, 2020) and pequi shell (41.6%) (Scapin et al, 2020), for instance, and similar to the baru mesocarp (59.3%) found by Rambo et al (2020). Additionally, complementary methodologies for characterization of alpha-cellulose and hemicellulose (Pedrazzi et al, 2019) Additionally, it is employed in the food, cosmetics, and textile sectors, as well as in the recent synthesis of functional materials (Pessêgo et al, 2011;Albuquerque et al, 2021;Rahim et al, 2019).…”