Research Article

Peroxidase as the Major Protein Constituent in Areca Nut and Identification of Its Natural Substrates

Figure 6

Oxidation of catechin and epicatechin. (a) and (b) HPLC analysis of AN peroxidase-mediated oxidation of catechin (a) and epicatechin (b). The dimerized products with the same molecular mass are identified as C-C and EC-EC. (c) and (d) Spectrophotometric activity assay of AN peroxidase at higher pH using catechin (c) and epicatechin (d) as substrates. The spontaneous oxidation of both substrates in the absence of enzyme is also included.