Antiradical and Anti-H2O2 Properties of Polyphenolic Compounds from an Aqueous Peppermint Extract

• Published in: Zeitschrift für Naturforschung C. A journal of biosciences Vol. 60; no. 11; pp. 826 - 832
• Main Authors: Sroka, Zbigniew, Fecka, Izabela, Cisowski, Wojciech
• Format: Journal Article
• Language: English
• Published: Germany Verlag der Zeitschrift für Naturforschung 01.11.2005
• Subjects: Antioxidants - chemistry; Antioxidants - isolation & purification; Antioxidants - pharmacology; Antiradical Activity; Cinnamates - isolation & purification; Depsides; Flavanones - isolation & purification; Flavonoids - chemistry; Flavonoids - isolation & purification; Flavonoids - pharmacology; Free Radical Scavengers; Herbal Medicine; Hesperidin - isolation & purification; Mentha piperita - chemistry; Mentha × piperita; Phenols - chemistry; Phenols - isolation & purification; Phenols - pharmacology; Plant Extracts - chemistry; Plant Leaves - chemistry; Plant Phenolics; Polyphenols; Rosmarinic Acid; Water
• ISSN: 0939-5075; 1865-7125
• DOI: 10.1515/znc-2005-11-1203

Polyphenolic compounds such as eriocitrin, luteolin-7-O-rutinoside, diosmin, hesperidin, narirutin, isorhoifolin, rosmarinic and caffeic acids were identified in an aqueous extract (Ex) obtained from peppermint leaves (Menthae × piperitae folium). The content of polyphenols in Ex was as follows: eriocitrin 38%, luteolin-7-O-rutinoside 3.5%, hesperidin 2.9%, diosmin 0.8%, isorhoifolin 0.6%, narirutin 0.3%, rosmarinic acid 3.7% and caffeic acid 0.05%. The strongest antiradical activity (determined as DPPH scavenging features) was observed for luteolin-7-O-rutinoside, eriocitrin and rosmarinic acid. Caffeic acid and hesperidin revealed a lower antiradical activity while isorhoifolin, narirutin and diosmin showed the lowest activity. The strongest anti-H activity was observed for eriocitrin, a little lower for rosmarinic acid. The rate of hydrogen peroxide scavenging activity displayed by luteolin-7-O-rutinoside and caffeic acid was lower than that of rosmarinic acids. Hesperidin appeared to be a very weak scavenger of hydrogen peroxide. Almost no anti-H activity was demonstrated for diosmin, narirutin and isorhoifolin. Among examined flavonoids, the strongest antiradical and anti-H activity was shown for compounds with two hydroxy groups bound to the Bring in ortho position in relation to each other. Replacement of one hydroxy group in the Bring with a methoxy group or removing one hydroxy group leads to decrease of antiradical and anti-H activity of flavonoids. Our results suggest that eriocitrin is a powerful peppermint antioxidant and a free radical scavenger.