Enhanced oxidation of flavan-3-ols and proanthocyanidin accumulation in water-stressed tea plants

Hernández, Iker; Alegre, Leonor; Munné‐Bosch, Sergi

doi:10.1016/j.phytochem.2006.04.002

Cited by 96 publications

(40 citation statements)

References 49 publications

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“…EGCG quinone has been proposed as the key intermediate for the formation of many EGCG oxidation products by us and others [17][18][19], but direct evidence for its existence has been lacking. In the present stud y, we provided for the first time the direct evidence of the formation of EGCG quinone and dimer quinone.…”

Section: Discussionmentioning

confidence: 99%

Autoxidative quinone formation in vitro and metabolite formation in vivo from tea polyphenol (-)-epigallocatechin-3-gallate: Studied by real-time mass spectrometry combined with tandem mass ion mapping

Sang

Yang

Buckley

et al. 2007

Free Radical Biology and Medicine

133

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Abstract(−)-Epigallocatechin-3-gallate (EGCG), the most abundant and biologically active compound in tea, has been proposed to have beneficial health effects, including prevention of cancer and heart disease. Different mechanisms of action of EGCG have been proposed, based mainly on studies in cell line systems, in which EGCG is not stable. It has been proposed that oxidation of EGCG and its production of reactive oxygen species are responsible for the biological activities such as receptor inactivation and telomerase inhibition. It is unclear, however, if this phenomenon occurs in vivo. In the present study, the stability of EGCG and product formation in Tris-HCl buffer was investigated using realtime mass spectrometry combined with tandem mass ion mapping. With real-time mass data acquisition, we demonstrate for the first time the formation of EGCG quinone, EGCG dimer quinone, and other related compounds. The structural information of the major appearing ions was provided by tandem mass analysis of each ion. A mechanism for the autoxidation of EGCG was proposed based on the structural information of these ions. None of these oxidation products were observed in the plasma samples of mice after treatment with 50 mg/kg EGCG, i.p. daily for 3 days. Instead, the methylated and conjugated metabolites of EGCG were observed. Therefore the roles of EGCG autoxidation in the biological activities of this compound in vivo remain to be investigated further.

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Section: Discussionmentioning

confidence: 99%

Autoxidative quinone formation in vitro and metabolite formation in vivo from tea polyphenol (-)-epigallocatechin-3-gallate: Studied by real-time mass spectrometry combined with tandem mass ion mapping

Sang

Yang

Buckley

et al. 2007

Free Radical Biology and Medicine

133

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“…The flavonoids have a protective function in plants exposed to water stress, because of its antioxidant properties by eliminating ROS and maintain turgor and stabilize cell membranes and proteins (Rodziewicz et al, 2014). The oxidation products of flavan-3-ols (flavanols) is increased under drought stress in Camellia sinensis (Hernández et al, 2006). Furthermore, the water stress increases the level of quercetin, rutin, and 1-5-dihidroxixantona in Hypericum brasiliense.…”

Section: Total Antioxidant Activitymentioning

confidence: 99%

Seasonal variability of phenolic compounds and antioxidant activity in prickly pear cladodes of Opuntia and Nopalea genres

et al. 2017

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The prickly pear is a cactaceae that have chemical compounds that act as natural antioxidants. In addition, the prickly pear is a plant widely used in semiarid region as it's considered very important forage for animal feed, especially in the dry season. The objectives of this research were to characterize the main classes of phytochemicals, determine the phenols content, flavonoids and anthocyanins and evaluate the antioxidant activity of the prickly pear cultivars Opuntia and Nopalea grown in the semiarid region of Pernambuco in two collection periods (dry and rainy). In the work crude ethanol extracts from cladodes of cultivars (IPA-20, Elephant Ear Mexican, F-08, V-19, Small palm, F-21 and IPA-Sertânia) were used. As for the class of phytochemical compounds from ethanol extract only the flavonoids and steroids were detected in all prickly pear cultivars, in both periods analyzed. The content of phenolic compounds ranges from 1.24 to 5.41 mg GAE g -1 DM, flavonoids 0.90 to 3.43 mg QE g -1 DM, anthocyanins from 0.05 to 0.34 µg QE 100 g -1 DM and antioxidant activity 39.59 to 217.17 µM TEAC g -1 DM. The occurrence of chemical variability and antioxidant activity were observed, both among the botanical cultivars studied and among the collection periods.Keywords: biodiversity and nutrition; cactus pear; flavonoids; phenolic acids; phytochemicals.Practical Application: Use of cladodes of prickly pear cultivars as functional foods in the diet human and animal.

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“…Flavonoids have protective functions in plants exposed to water deficit because of their antioxidant properties. The oxidation products of flavan-3-ols increased in droughtstressed tea leaves (Hernández et al 2006). Water stress, both waterlogging and drought, increased the level of flavonoids: quercetin and rutin in the medicinal herb Hypericum brasiliense, while temperature treatments cause a varied response (de Abreu and Mazzafera 2005).…”

Section: Phenolic Compoundsmentioning

confidence: 99%

Influence of abiotic stresses on plant proteome and metabolome changes

et al. 2013

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Plant responses to abiotic stresses are very complex phenomena with individual characteristics for various species. Abiotic stresses (e.g. drought, salinity, flooding, cold, heat, UV radiation, heavy metals, etc.) strongly affect plant growth and development. It is estimated that they are the cause of more than 50 % of crop yield losses. Abiotic stresses are known to activate a multigene response resulting in the changes in various proteins and primary and secondary metabolite accumulation. Therefore, proteomic and metabolomic approaches are becoming very important and powerful tools used in studying plants' reaction to various stimuli. Precise analysis of proteome and metabolome is essential for understanding the fundamentals of stress physiology and biochemistry. In this review, we focus on recent reports concerned to the influence of abiotic stresses on changes in the level of different protein groups and metabolite classes. Basic information about physicochemical methods applied to qualitative and quantitative analyses of biopolymers and natural products is also briefly presented.

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Enhanced oxidation of flavan-3-ols and proanthocyanidin accumulation in water-stressed tea plants

Cited by 96 publications

References 49 publications

Autoxidative quinone formation in vitro and metabolite formation in vivo from tea polyphenol (-)-epigallocatechin-3-gallate: Studied by real-time mass spectrometry combined with tandem mass ion mapping

Autoxidative quinone formation in vitro and metabolite formation in vivo from tea polyphenol (-)-epigallocatechin-3-gallate: Studied by real-time mass spectrometry combined with tandem mass ion mapping

Seasonal variability of phenolic compounds and antioxidant activity in prickly pear cladodes of Opuntia and Nopalea genres

Influence of abiotic stresses on plant proteome and metabolome changes

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