Oxidation of Capsaicin and Capsaicin Phenolic Precursors by the Basic Peroxidase Isoenzyme B6 from Hot Pepper

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

“…The 13 Thus, as for the photochemical and autoxidation of capsaicin, but in contrast with the transformation of capsaicin by peroxidases (15), in the present study the oxidation product of capsaicin was exclusively 5,5′-dicapsaicin. To our knowledge, this is the first report of this dimeric compound being detected in in vitro cultures of Capsicum.…”

“…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).…”

Differential effect of organic cultivation on the levels of phenolics, peroxidase and capsidiol in sweet peppers

“…Peroxidases are heme‐containing enzymes that perform single‐electron oxidation of phenolic compounds in the presence of hydrogen peroxide 24. They have been implicated in numerous processes, namely the control of plant cell growth and differentiation, due to their participation in the catabolism of auxins, the polymerisation of cinnamoyl alcohols to lignin, the hydrogen peroxide‐detoxifying reactions25 and the capsaicinoid metabolism 26–28…”

Content of Capsaicinoids and Capsiate in “Filius” Pepper Varieties as Affected by Ripening

“…The arguments that support a relevant role by peroxidase in the degradation of capsaicin are based on the unique location of peroxidase in the placental epidermal cells of hot pepper fruits. Furthermore, this evidence is supported by the strong oxidizing activity of capsaicin on basic peroxidase isoenzyme [ 49 , 50 ]. Finally, during the last stages of fruit ripening, the total capsaicinoid content remains practically constant until the end of their maturation.…”

“…Finally, over the last stages of maturation, a considerably greater drop of around 35% was observed in the total content of capsaicinoids. These decreases in capsaicinoids content could be due to both the action of the peroxidases and the reduced synthesis of capsaicinoids in the peppers due to the specific cultivation conditions in the greenhouse [ 49 ]. Comparable capsaicinoid accumulation patterns, with maximum capsaicinoid content during the last developmental stage, have been previously described for a number of cultivars such as Habanero, which exhibited maximum content levels on the 63th dpa [ 51 ], Habanero Roxo, with maximum levels on the 62nd dpa [ 34 ], and Malagueta on the 68th dpa [ 33 ].…”