caa a22 4500 463185471 CHVBK 20180406164851.0 cr unu---uuuuu 170326e20070401xx s 000 0 eng 10.1007/s00726-006-0379-x doi (NATIONALLICENCE)springer-10.1007/s00726-006-0379-x Gülçin İ. Department of Chemistry, College of Arts and Sciences, Atatürk University, Erzurum, Turkey aut Comparison of in vitro antioxidant and antiradical activities of L-tyrosine and L-Dopa [Elektronische Daten] [İ. Gülçin] Summary.: Phenolic compounds are interesting because of their antioxidant properties. In the present study, the antioxidant properties of L-tyrosine as a monophenolic and L-Dopa as a diphenolic amino acid were investigated by using different antioxidant assays: (i) 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH•) scavenging; (ii) 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation decolorization assay; (iii) total antioxidant activity by ferric thiocyanate method; (iv) ferric ions (Fe3+) reducing power; (v) superoxide anion radical (O2 •−) scavenging; (vi) hydrogen peroxide (H2O2) scavenging, and (vii) ferrous ions (Fe2+) chelating activities. Butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and trolox, a water-soluble analogue of tocopherol, were used as the reference antioxidant compounds. At the same concentration (20 µg/mL), L-tyrosine and L-Dopa showed 30.6 and 67.9% inhibition of lipid peroxidation of linoleic acid emulsion, respectively. On the other hand, BHA, BHT, α-tocopherol and trolox indicated inhibitions of 74.4, 71.2, 54.7 and 20.1% on the peroxidation of linoleic acid emulsion, respectively, at the above-mentioned concentration. In addition, L-tyrosine and L-Dopa had an effect on DPPH radical scavenging, ABTS radical scavenging, superoxide anion radical scavenging, H2O2 scavenging, total ferric ions reducing power and metal chelating on ferrous ions activities. Springer-Verlag, 2006 Keywords: Antioxidant activity - L-Tyrosine - L-Dopa - Metal chelating - Amino acids - Radical scavenging nationallicence Amino Acids Springer-Verlag 32/3(2007-04-01), 431-438 0939-4451 32:3<431 2007 32 726 https://doi.org/10.1007/s00726-006-0379-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00726-006-0379-x text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Gülçin İ. Department of Chemistry, College of Arts and Sciences, Atatürk University, Erzurum, Turkey aut NATIONALLICENCE 773 0- Amino Acids Springer-Verlag 32/3(2007-04-01), 431-438 0939-4451 32:3<431 2007 32 726 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer