… Jin S, Sim WS, Nester EW (1995) Genetic evidence for direct sensing of phenolic compounds
by … Natl Acad Sci USA 92: 12245–12249 Mayer AM, Harel E (1979) Polyphenol oxidases in plants …
Plant Cell Rep 18: 180–186 Mittler R, Herr EH, Orvar BL, van Camp W, Willekens H …

… Friedman et al., 1986) and others (Dudley, 1989; Golan-Goldhirsh and Whitaker, 1984) showed
that sulfhydryl (SH or thiol) compounds such as cysteine, N-acetyl-L-cysteine, and reduced
glutathione are good inhibitors of the enzyme polyphenol oxidase (PPO …

… alleviated by enzymatic and non-enzymatic antioxidant machinery of the plant that vary at … Plants
use a diverse array of enzymes like superoxide dismutase (SOD), ascorbate peroxidase … Cysteine,
thiols and ascorbic acid can directly interact with and detoxify oxygen free radicals …

… and that most dietary phytochemicals possess antioxidant activities, the effects of dietary
polyphenols on NF … non-antioxidant properties.(53) In addi- tion, after screening 34 dietary plants
for their … Instead, as proposed by these authors,(54) the ability of several plant extracts and …

… Oxalic acid is a natural component of a large number of plants, such as asparagus … A possibility
synergistic effect of cysteine and plant polyphenols, such as protocatechuic acid, and its analogues
was … Low pH may also decrease the activity of PPO, so that polyphenols cannot be …

… 249-259. Mayer and Harel, 1979 AM Mayer, E. HarelReview Polyphenol oxidase in plants.
Phytochemistry, 18 … F. Forget-Richard, M. Pabion, F. CadetPartial purification and physicochemical
characterisation of palmito (Acanthophoenix rubra) polyphenol oxidases. Plant Physiol …

… The brown color development is related primarily to the oxidation of phenolic compounds … This
reaction, mainly catalyzed by polyphenol oxidase (EC 1.14.18.1; PPO), results in the formation …
of ascorbic acid and 8-cyclodextrins (Sapers et al., 1989) and plant sulfhydryl proteases …

… the phenylproponaid pathway and are involved in the defence of plants against invading … predicted
and confirmed by kinetic studies that ascorbate regenerates plant phenolic compounds in …
Polyphenols have a higher redox potential than ascorbate and consequently oxidise it …

… Article Navigation. Piceatannol, a catechol-type polyphenol, inhibits phorbol
ester-induced NF-κB activation and cyclooxygenase-2 expression in human breast
epithelial cells: cysteine 179 of IKKβ as a potential target. Pil-Soon …

… INTRODUCTION BROWNING in plant tissue is caused mainly by the oxida- tion of endogenous
phenols by polyphenol oxidase (PPO … Proteins and amino acids can interact with o-quinones
formed by the action of PPO on various phenolic substrates (Weinbach and Garbus …