Comparison of in vitro antioxidant and antiradical activities of L-tyrosine and L-Dopa.
Amino Acids. 2007; 32(3):431-8.AA

Abstract

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), alpha-tocopherol and trolox, a water-soluble analogue of tocopherol, were used as the reference antioxidant compounds. At the same concentration (20 microg/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, alpha-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.

Authors+Show Affiliations

Gülçin I

Department of Chemistry, College of Arts and Sciences, Atatürk University, Erzurum, Turkey. igulcin@atauni.edu.tr

MeSH

Free Radical ScavengersLevodopaReactive Oxygen SpeciesTyrosine

Pub Type(s)

Comparative Study

Journal Article

Language

eng

PubMed ID

16932840

Citation

Gülçin, I. "Comparison of in Vitro Antioxidant and Antiradical Activities of L-tyrosine and L-Dopa." Amino Acids, vol. 32, no. 3, 2007, pp. 431-8.

Gülçin I. Comparison of in vitro antioxidant and antiradical activities of L-tyrosine and L-Dopa. Amino Acids. 2007;32(3):431-8.

Gülçin, I. (2007). Comparison of in vitro antioxidant and antiradical activities of L-tyrosine and L-Dopa. Amino Acids, 32(3), 431-8.

Gülçin I. Comparison of in Vitro Antioxidant and Antiradical Activities of L-tyrosine and L-Dopa. Amino Acids. 2007;32(3):431-8. PubMed PMID: 16932840.

* Article titles in AMA citation format should be in sentence-case

TY - JOUR T1 - Comparison of in vitro antioxidant and antiradical activities of L-tyrosine and L-Dopa. A1 - Gülçin,I, Y1 - 2006/08/21/ PY - 2005/10/05/received PY - 2006/01/17/accepted PY - 2006/8/26/pubmed PY - 2007/9/15/medline PY - 2006/8/26/entrez SP - 431 EP - 8 JF - Amino acids JO - Amino Acids VL - 32 IS - 3 N2 - 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), alpha-tocopherol and trolox, a water-soluble analogue of tocopherol, were used as the reference antioxidant compounds. At the same concentration (20 microg/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, alpha-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. SN - 0939-4451 UR - https://www.unboundmedicine.com/medline/citation/16932840/Comparison_of_in_vitro_antioxidant_and_antiradical_activities_of_L_tyrosine_and_L_Dopa_ DB - PRIME DP - Unbound Medicine ER -

Tags

Comparison of in vitro antioxidant and antiradical activities of L-tyrosine and L-Dopa.Amino Acids. 2007; 32(3):431-8.AA