Dihydrocapsaicin Oxidation by Capsicum annuum (var. annuum) Peroxidase

Abstract

Oxidation of dihydrocapsaicin (S-methyl-N-vanillyl-6-nonanamide) by peroxidase (EC 1.11.1.7) from Capsicum annuum var. annuum fruits yielded one absorbent oxidation product with eX6* = 4.7 l@ M-' cm-'. Dependence of oxidation rate on dihydrocapsaicin and HzOz concentrations revealed Michaelis-Menten type kinetics with inhibition at high substrate concentrations and optimal pH near 6.0. Dihydrocapsaicin was oxidized by pepper peroxidase, and participation of peroxidase in capsaicinoid metabolism of pepper fruits should be taken into account.

Specific Synthesis of 5,5‘-Dicapsaicin by Cell Suspension Cultures of Capsicum annuum Var. annuum (Chili Jalapeño Chigol) and Their Soluble and NaCl-Extracted Cell Wall Protein Fractions

“…However, these results contrast with our previous study in which exogenous capsaicin was conjugated by cell suspension cultures of C. chinense into a more polar glycoside (10) and with those of Lindsey (29) and Yeoman et al (30), who found that cell suspension cultures of Capsicum frutescens apparently had no action on exogenous capsaicin. On the other hand, as pointed out before, several studies have suggested that capsaicinoids may be transformed into dimeric compounds by peroxidases from both fruits (11)(12)(13) and cell suspension cultures making capsaicinoids (14). Similar dimeric compounds of capsaicinoids have been isolated from air-dried powdered fruits of Capsicum (31).…”

Effects of blanching and storage on capsaicinoid stability and peroxidase activity of hot chili peppers (Capsicum frutescens L.)

“…There is some evidence that peroxidase (POD) isoenzymes may directly be involved in the capsaicinoid metabolism, since the vanillyl moiety of capsaicin is readily oxidized by these enzymes (Zapata, Calderon, Munoz, & Ros Barcelo, 1992). Bernal, Calderón, Pedreno, Munoz, Barceló, & de Cáceres (1993a, 1993b suggested that PODs contribute to capsaicinoid degradation, in particular of capsaicin and dihydrocapsaicin. This hypothesis is corroborated by the fact that PODs are mainly located in the placenta and the outermost epidermal cell layers, where the capsaicinoids are also found (Bernal, de Cáceres, & Barceló, 1994).…”

Role of extensin peroxidase in tomato ( Lycopersicon esculentum Mill.) seedling growth

“…Interestingly, Kutschera (1996) observed that cessation of rye (Secale cereale L.) coleoptile growth was directly attributable to low cell wall plasticity as a result of rigidi®cation of the growthlimiting lateral cell walls rather than loss of turgor pressure. Plant peroxidases can reinforce the cell wall through the deposition of several cell wall components such as lignin, suberin and extensin (Gaspar et al 1991;Bernal et al 1993;Lagrimini 1996). Oxidative crosslinking reactions catalyzed by peroxidases are therefore possible mechanisms for regulating cell wall rigidi®cat-ion.…”