Identification of a polyphenol and its antioxidant properties from the roasting reaction of alginic acid

Abstract

The radical scavenging activity of marine polysaccharides was enhanced by their high-temperature treatment (roasting reaction model). The product obtained from alginic acid exhibited maximum activity, and a radical scavenger, alginetin, was identified in the product. Its antioxidant activities were examined by chemical methods, which confirmed that it possessed a stoichiometrically greater antioxidant capacity than that of Trolox.

Isolation and Identification of the Antibacterial Compounds Produced by Maillard Reaction of Xylose with Phenylalanine or Proline

“…29 Compound 2 exhibited strong antioxidant and chelating activities for iron ions. 9,30 The metal chelating activity of compound 2 is consistent with the hypothesis of Ruriań-Henares et al that the antimicrobial mechanism of MRPs is due to the chelation of metal ions inside and outside the bacterial cell. 9,31 Both compounds 1 and 2 showed growth inhibition at lower concentrations (0.25−1.0 mM) compared to the minimum effective concentration (13−20 mM) of antimicrobial smallmolecule MRPs (molecular weight: 217) on bacteria in the previous study.…”

“…Compound 2 has been identified as a product of heating uronic acids, such as alginic acid, glucuronic acid, and galacturonic acid. − The formation pathway toward compound 2 has already been proposed in the previous study . Compound 2 exhibited strong antioxidant and chelating activities for iron ions. , The metal chelating activity of compound 2 is consistent with the hypothesis of Rurián-Henares et al that the antimicrobial mechanism of MRPs is due to the chelation of metal ions inside and outside the bacterial cell. , …”

Identification of Polyphenol and Reductone Antioxidants in the Caramelization Product of N-Acetylglucosamine

“…This antioxidant activity contributes toward the control of both the food quality and redox balance of the human body, which is beneficial to human health . Thermal treatment of saccharides, which involves various types of reactions, such as dehydration, enolization, oxidation, and polymerization, affords caramel products that contain a variety of furans and also enediol products, , including polyphenols in some cases. , Notably, polyphenols are gaining attention as important food functional substances, which can interact with functional cell components . Although the origin of polyphenols has been considered to be limited to higher plants, caramelization should be another source of polyphenols. , Polyphenols have potent radical scavenging antioxidant activity.…”

“…Thermal Treatment of the Monosaccharides and Measurement of Their DPPH Radical Scavenging Activity (Experiment 1). According to the method previously reported, 9 each monosaccharide (glucose, fucose, galacturonic acid, and NAG: 0.24 mmol) was dissolved in 1 mL of phosphate buffer (0.2 mol/L, pH 6.5, a possible pH value of foods) in a test tube [TEST-SCR16-100; outer diameter (o.d. ), 16 mm; length, 100 mm; AGC Techno Glass, Shizuoka, Japan].…”