Hydrocaffeic acid oxidation by a peroxidase homogenate from onion solid wastes

Agha, Ayman El; Makris, Dimitris P.; Kefalas, Panagiotis

doi:10.1007/s00217-008-0854-6

Cited by 12 publications

(12 citation statements)

References 40 publications

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“…Contrary to that, favorable temperatures were found to lie between 5 and 20°C, which is significantly lower than that found for quercetin (Osman et al 2008) and hydrocaffeic acid (40°C;El Agha et al 2008a) and also lower than those observed for ferulic and CA (30°C; El Agha et al 2008bAgha et al , 2009.…”

Section: Effect Of Ph and Temperaturecontrasting

confidence: 78%

“…In the case of CGA, the molar ratio found was 1.6, which is higher than those reported for structurally similar hydroxycinnamate derivatives, including hydrocaffeic acid (El Agha et al 2008a) and CA (El Agha et al 2009), where the H 2 O 2 /substrate ratios determined were 1.33 and 0.8, respectively. However, this value is lower than that reported for FA, which was 2.56 (El Agha et al 2008b).…”

Section: Cga/h 2 O 2 Concentration Ratiocontrasting

confidence: 71%

“…The waste consisted of the apical trimmings of the bulbs, as well as the outer dry and semidry layers (Khiari et al 2008). The cell-free, POD-active extract was prepared as previously described (El Agha et al 2008a). …”

Section: Crude Peroxidase Preparationmentioning

confidence: 99%

“…The ability of POD to form ferulic and caffeic acid (CA) dimers has been shown using an enzyme preparation from Bupleurum salicifolium callus cultures (Luis et al 2005), but more recently, the generation of FA (El Agha et al 2008a) and hydrocaffeic acid (El Agha et al 2008b) dimers, as well as CA tetramers (El Agha et al 2009), has been possible using a POD preparation from onion solid wastes.…”

Section: Introductionmentioning

confidence: 98%

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Chlorogenic Acid Oxidation by a Crude Peroxidase Preparation: Biocatalytic Characteristics and Oxidation Products

Osman

Agha

Makris

et al. 2009

Food Bioprocess Technol

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Section: Effect Of Ph and Temperaturecontrasting

confidence: 78%

Section: Cga/h 2 O 2 Concentration Ratiocontrasting

confidence: 71%

Section: Crude Peroxidase Preparationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

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Chlorogenic Acid Oxidation by a Crude Peroxidase Preparation: Biocatalytic Characteristics and Oxidation Products

Osman

Agha

Makris

et al. 2009

Food Bioprocess Technol

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“…Recently, another group described the oxidative coupling of free dihydrocaffeic acid (14, Fig. 6) by a peroxidase homogenate from onion solid wastes (El Agha et al 2008). They tentatively identified three dehydrodimers by using LC-MS. Again, unambiguous characterization of these structures by NMR still needs to be performed.…”

Section: Other Dehydrodihydroxycinnamatesmentioning

confidence: 98%

Chemistry and occurrence of hydroxycinnamate oligomers

2009

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Hydroxycinnamates such as ferulic acid, sinapic acid and p-coumaric acid ester-linked to plant cell wall polymers may act as cross-links between polysaccharides to each other, but also to proteins and lignin. Although sinapates and p-coumarates also form cell wall cross-links by the formation of radically or photochemically formed dimers, ferulate derivatives are the quantitatively most important cross-links in the plant cell wall. While the first radically generated ferulate dimer was already identified almost 40 years ago, the spectrum of known ferulate dimers was considerably broadened within the last 15 years. Higher ferulate oligomers were generated in model systems, but also isolated from plant materials. Different model systems using either free hydroxycinnamic acids or their esters are reviewed, highlighting a discussion of the relevance of these models for the plant cell wall. The first ferulate trimer from plant material was discovered in 2003 and seven dehydrotrimers of ferulic acid were isolated from maize bran since. Some of these trimers were also identified in other plant materials such as wheat and rye grains, corn stover, sugar beet and asparagus. Formation mechanisms of ferulate trimers and implications for the plant cell wall are discussed. Ferulate tetramers are the highest oligomers isolated from plant materials so far. These compounds can theoretically cross-link up to four polysaccharide chains, assuming all cross-links are formed intermolecularly. Formation of intramolecular versus intermolecular polysaccharide crosslinks is a key question to be answered in the future if we want to judge properly the importance of hydroxycinnamate cross-links in the plant cell wall.

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