STUDIA UBB CHEMIA, LXII, 4, Tom I, 2017 (p. 11-19) (RECOMMENDED CITATION) DOI:10.24193/subbchem.2017.4.01 CATECHIN OXIDATION PRODUCTS: MECHANISTIC ASPECTS AND KINETICS ANCA - RUXANDRA LEONTIEŞ a *, ADINA RĂDUCAN b , IOANA CATALINA GÎFU a , DAN FLORIN ANGHEL a ABSTRACT. The oxidation of catechin in the presence of atmospheric oxygen in a methanol/buffer model solution was studied by investigating generated products using LC/MS and spectrophotometry. It was proved that catechin was slowly converted to dimeric species with similar structures and properties. The catechin autoxidation was investigated spectrophotometrically at different pH ranging between 5 and 10. Using the initial linear dependence of the kinetic curves [Dimers] = f(t) the initial reaction rates were estimated for the autoxidation of catechin in methanol/buffered solutions. It was found that the dimer formation is favored at pH 8. Keywords: catechin, autoxidation, dehydrocatechin INTRODUCTION Polyphenols are widely distributed in plants and in plant-derived products, mostly in wines and teas, where they contribute to food organoleptic properties and oxidative stability [1]. Polyphenols have several health benefits, acting as antioxidant, anticarcinogen, antimicrobial, anti-inflammatory and UV protection agents [2]. One of the most common natural polyphenols from the class of flavanols is catechin (Scheme 1). As polyphenol, catechin is susceptible to enzymatic and non-enzymatic oxidation. The oxidation products are the oxidation dimers. The dimers are linked either by C6 → C8 or C 6→ C6 interflavan linkages a Ilie Murgulescu Institute of Physical Chemistry, Spl. Independentei 202, Bucharest, 060021, Romania b University of Bucharest, Faculty of Chemistry, Bulevardul Regina Elisabeta 4-12, Bucharest, 030018, Romania * Corresponding author: ancaleonties@gmail.com