Stability and Oxidation Products of Hydrolysable Tannins in Basic Conditions Detected by HPLC/DAD–ESI/QTOF/MS

Tuominen, Anu; Sundman, Terhi

doi:10.1002/pca.2456

Cited by 45 publications

(51 citation statements)

References 34 publications

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“…However, the reduction of ellagitannins (% var) did not correspond to the ellagic acid generation. Considering our results and the low degree of ellagitannin hydrolysis at pH 3 observed by Tuominen and Sundman (2013), the extra amount of free and glycosylated ellagic acid recovered could be explained by the sum of both: ellagitannins degradation and the release of ellagic acid from the food matrix during in vitro gastric digestion. Accordingly, higher recovery of total phenolic compounds was observed after gastric digestion of pomegranate extract (Sengul, Surek, & Nilufer-Erdil, 2014).…”

Section: Stability Of Pomegranate Phenolic Compounds During In Vitro mentioning

confidence: 59%

Application of in vitro gastrointestinal digestion and colonic fermentation models to pomegranate products (juice, pulp and peel extract) to study the stability and catabolism of phenolic compounds

Mosele

Macià

Romero

et al. 2015

Journal of Functional Foods

145

109

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Section: Stability Of Pomegranate Phenolic Compounds During In Vitro mentioning

confidence: 59%

Application of in vitro gastrointestinal digestion and colonic fermentation models to pomegranate products (juice, pulp and peel extract) to study the stability and catabolism of phenolic compounds

Mosele

Macià

Romero

et al. 2015

Journal of Functional Foods

145

109

View full text Add to dashboard Cite

“…24) Tuominen and Sundman also reported the hydrolysable tannins were unstable in basic conditions because of polyphenol oxidation. 28) Therefore, it was estimated that it is advantageous to ensure low pH when manufacturing products or medicines containing green tea.…”

Section: Resultsmentioning

confidence: 99%

Analysis of Green Tea Compounds and Their Stability in Dentifrices of Different pH Levels

Jang

Park

Ahn

et al. 2014

CHEMICAL & PHARMACEUTICAL BULLETIN

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In this study, green tea compounds (flavonoids, alkaloids, and phenolic acids) were analyzed in green tea-containing dentifrices, and their stability at different pH levels was evaluated. The compounds were separated under 0.01% phosphoric acid-acetonitrile gradient conditions and detected by photodiode array detector at 210, 280, 300, 335 nm. Column temperature was set at 20°C based on the results of screening various temperatures. Each compound showed good linearity at optimized wavelength as well as showing good precision and accuracy in dentifrices. Using this method, the stability of compounds was investigated in pH 4, 7, 8, and 10 solutions for 96 h, and in pH 7 and pH 10 solutions for 6 months. The green tea compounds were more stable at low pH levels; purine alkaloids were more stable than flavonoids. In particular, gallocatechin (GC), epigallocatechin (EGC), epigallocatechin gallate (EGCG), gallocatechin gallate (GCG), and myricetin almost disappeared in pH 10 solutions after 96 h. In dentifrices, the compounds were gradually decreased until 6 months in both pH types, while gallic acid was increased because of production of galloyl ester of other green tea compounds. Therefore, it is beneficial to adjust to as low a pH as possible when produce green teacontaining dentifrices.

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“…2a, b). In addition, the frass of larvae consuming A. castaneifolia contained brevifolin carboxylic acid, a hydrolysis product of geraniin (Tuominen and Sundman 2013), and derivatives of ellagic acid that were tentatively identified based on their UV and MS spectra (Fig. 2a).…”

Section: The Fates Of Individual Phenolic Compounds In Vitro and In Vivomentioning

confidence: 99%

Phenolic Compounds and Their Fates In Tropical Lepidopteran Larvae: Modifications In Alkaline Conditions

et al. 2015

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Lepidopteran larvae encounter a variety of phenolic compounds while consuming their host plants. Some phenolics may oxidize under alkaline conditions prevailing in the larval guts, and the oxidation products may cause oxidative stress to the larvae. In this study, we aimed to find new ways to predict how phenolic compounds may be modified in the guts of herbivorous larvae. To do so, we studied the ease of oxidation of phenolic compounds from 12 tropical tree species. The leaf extracts were incubated in vitro in alkaline conditions, and the loss of total phenolics during incubation was used to estimate the oxidizability of extracts. The phenolic profiles of the leaf extracts before and after incubation were compared, revealing that some phenolic compounds were depleted during incubation. The leaves of the 12 tree species were each fed to 12 species of lepidopteran larvae that naturally feed on these trees. The phenolic profiles of larval frass were compared to those of in vitro incubated leaf extracts. These comparisons showed that the phenolic profiles of alkali-treated samples and frass samples were similar in many cases. This suggested that certain phenolics, such as ellagitannins, proanthocyanidins, and galloylquinic acid derivatives were modified by the alkaline pH of the larval gut. In other cases, the chromatographic profiles of frass and in vitro incubated leaf extracts were not similar, and new modifications of phenolics were detected in the frass. We conclude that the actual fates of phenolics in vivo are often more complicated than can be predicted by a simple in vitro method.

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Stability and Oxidation Products of Hydrolysable Tannins in Basic Conditions Detected by HPLC/DAD–ESI/QTOF/MS

Abstract: HPLD/DAD-ESI/QTOF/MS was an efficient method for the identification of polyphenol oxidation products and showed how different pH conditions determine the fate of hydrolysable tannins.

Cited by 45 publications

References 34 publications

Application of in vitro gastrointestinal digestion and colonic fermentation models to pomegranate products (juice, pulp and peel extract) to study the stability and catabolism of phenolic compounds

Application of in vitro gastrointestinal digestion and colonic fermentation models to pomegranate products (juice, pulp and peel extract) to study the stability and catabolism of phenolic compounds

Analysis of Green Tea Compounds and Their Stability in Dentifrices of Different pH Levels

Phenolic Compounds and Their Fates In Tropical Lepidopteran Larvae: Modifications In Alkaline Conditions

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