Abstract
Herein we compared antioxidative activities (AA) of 25 free L-amino acids (FAA) against Fenton system-mediated hydroxyl radical (HO(•)) production in aqueous solution, and examined the relation between AA and a set of physicochemical properties. The rank order according to AA was: Trp > norleucine > Phe, Leu > Ile > His >3,4-dihydroxyphenylalanine, Arg > Val > Lys, Tyr, Pro > hydroxyproline > α-aminobutyric acid > Gln, Thr, Ser > Glu, Ala, Gly, Asn, Asp. Sulfur-containing FAA generated different secondary reactive products, which were discriminated by the means of electron paramagnetic resonance spin-trapping spectroscopy. AA showed a general positive correlation with hydrophobicity. However, when taken separately, uncharged FAA exhibited strong positive correlation of AA with hydrophobicity whereas charged FAA showed negative or no significant correlation depending on the scale applied. A general strong negative correlation was found between AA and polarity. Steric parameters and hydration numbers correlated positively with AA of nonpolar side-chain FAA. In addition, a decrease of temperature which promotes hydrophobic hydration resulted in increased AA. This implies that HO(•)-provoked oxidation of FAA is strongly affected by hydrophobic hydration. Our findings are important for the understanding of oxidation processes in natural and waste waters.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
