Study of the release of gallic acid from (-)-epigallocatechin gallate in old oolong tea by mass spectrometry

2010 ◽  
Vol 24 (7) ◽  
pp. 851-858 ◽  
Author(s):  
Ren-Jye Lee ◽  
Viola S. Y. Lee ◽  
Jason T. C. Tzen ◽  
Maw-Rong Lee
Keyword(s):  
Mass Spectrometry ◽  
Gallic Acid ◽  
Epigallocatechin Gallate ◽  
Oolong Tea

Isolation of Epigallocatechin Gallate from Green Tea and its Effects on Probiotics and Pathogenic Bacteria

2017 ◽  
Vol 17 (1) ◽  
pp. 69-77
Author(s):  
Tu Lijun ◽  
Sun Hanju ◽  
He Shudong ◽  
Zhu Yongsheng ◽  
Yu Ming ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Escherichia Coli ◽  
Green Tea ◽  
Lactobacillus Acidophilus ◽  
Pathogenic Bacteria ◽  
Epigallocatechin Gallate ◽  
Microbial Populations ◽  
Medium Ph ◽  
Bioactive Substance ◽  
Tea Extract

The aim of this study was to investigate epigallocatechin gallate (EGCG) prebiotics activities systematically which was reported as a bioactive substance. Therefore, EGCG was separated by water extraction, resin purification and prep-HPLC. Then the production of EGCG was confirmed by HPLC and mass spectrometry (MS) analysis and its purify was 97.23%. EGCG extractive and green tea extract (GTE) were further incubated with Bifidobacterium infantis, B. adolescentis, B. bifidum and Lactobacillus acidophilus to study its effect on microbial populations and medium pH. Finally, Escherichia coli, Salmonella, Staphylococcus aureus and Candida albicans were employed as pathogenic bacteria to explore the antimicrobial activity of EGCG and GTE. The results demonstrated that EGCG extractive could be beneficial for the proliferation of Bifidobacterium and L. acidophilus and also inhibit some pathogenic bacteria. In conclusion, both EGCG extractive and GTE had prebiotics activities and the effects of EGCG extractive were superior to those of GTE.

scholarly journals Magnesium Supplementation Alters Leaf Metabolic Pathways for Higher Flavor Quality of Oolong Tea

Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 120 ◽  
Author(s):  
Jiuliang Xu ◽  
Liangquan Wu ◽  
Bingxin Tong ◽  
Jiaxu Yin ◽  
Zican Huang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
High Resolution Mass Spectrometry ◽  
Southern China ◽  
Substantial Reduction ◽  
Sugar Accumulation ◽  
Limiting Factor ◽  
Oolong Tea

Oolong tea, one of the most famous tea beverages in China, contains specialized metabolites contributing to rich flavors and human health. Accumulation patterns of such metabolites and underlying regulatory mechanisms significantly vary under different growth conditions. To optimize quality and yield while minimizing environmental effects, three treatments were designed in this study: Conventional fertilization, optimized fertilization, and optimized fertilization supplemented with magnesium (Mg). We investigated the yield, taste quality, primary and secondary metabolites of oolong tea, and found that a substantial reduction in chemical fertilizers (nutrient optimization by reducing 43% N, 58% P2O5 and 55% K2O) did not affect the tea yield in this study. Interestingly, Mg fertilization is an important factor influencing amino acid and sugar accumulation in oolong tea, resulting in higher concentrations of total free amino acids and a lower ratio of tea polyphenols (TP) to free amino acids (FAA). Gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS) and liquid chromatography-high resolution mass spectrometry (LC-HRMS) combined multivariate analyses revealed distinct features of metabolite accumulation in leaves of three different treatments, as indicated by 34 differentially accumulated characteristic compounds. The levels of serine, aspartic acid, isoleucine, phenylalanine, theanine, and proline were reduced by fertilizer optimization and increased by Mg supplementation. Mg particularly promoted theanine accumulation favoring a stronger umami taste of oolong tea, while decreasing astringency and bitter metabolites. Thus, Mg application paves a new path for tea quality improvement in Southern China where Mg deficiency in the soil is a frequent limiting factor for crop production.

scholarly journals Relevance and Standardization of In Vitro Antioxidant Assays: ABTS, DPPH, and Folin–Ciocalteu

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Helena Abramovič ◽  
Blaž Grobin ◽  
Nataša Poklar Ulrih ◽  
Blaž Cigić
Keyword(s):  
Ascorbic Acid ◽  
Chlorogenic Acid ◽  
Gallic Acid ◽  
Caffeic Acid ◽  
Sulfonic Acid ◽  
Epigallocatechin Gallate ◽  
The Other ◽  
Oh Groups ◽  
Standard Compound

Trolox, gallic acid, chlorogenic acid, caffeic acid, catechin, epigallocatechin gallate, and ascorbic acid are antioxidants used as standards for reaction with chromogenic radicals, 2,2-diphenyl-1-picrylhydrazyl (DPPH⋅) and 2,2′-azino-bis-3-ethylbenzotiazolin-6-sulfonic acid (ABTS⋅+), and Folin–Ciocalteu (FC) reagent. The number of exchanged electrons has been analyzed as function of method and solvent. A majority of compounds exchange more electrons in FC assay than in ABTS and DPPH assays. In reaction with chromogenic radicals, the largest number of electrons was exchanged in buffer (pH 7.4) and the lowest reactivity was in methanol (DPPH) and water (ABTS). At physiological pH, the number of exchanged electrons of polyphenols exceeded the number of OH groups, pointing to the important contribution of partially oxidized antioxidants, formed in the course of reaction, to the antioxidant potential. For Trolox, small impact on the number of exchanged electrons was observed, confirming that it is more suitable as a standard compound than the other antioxidants.

Gallic Acid in Old Oolong Tea

2013 ◽  
pp. 447-456
Author(s):  
Chung-Yu Chen ◽  
Ren-Jye Lee ◽  
Viola S.Y. Lee ◽  
Jianpeng Dou ◽  
Victor R. Preedy ◽  
...  
Keyword(s):  
Gallic Acid ◽  
Oolong Tea

scholarly journals Isolation and Purification of Bioactive Compounds from the Stem Bark of Jatropha podagrica

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 889 ◽  
Author(s):  
Truong Minh ◽  
Tran Xuan ◽  
Hoang-Dung Tran ◽  
Truong Van ◽  
Yusuf Andriana ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ethyl Acetate ◽  
Gallic Acid ◽  
Bioactive Compounds ◽  
Stem Bark ◽  
Ionization Mass ◽  
Methyl Gallate ◽  
Antioxidant Power ◽  
Isolation And Purification ◽  
Chemical Structures

This paper reports the successive isolation and purification of bioactive compounds from the stem bark of Jatropha podagrica, a widely known medicinal plant. The ethyl acetate extract of the stem bark exhibited the strongest antioxidant activity assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and ferric reducing antioxidant power (FRAP) assays (IC50 = 46.7, 66.0, and 492.6, respectively). By column chromatography (CC) with elution of hexane and ethyl acetate at 8:2, 7:3, and 6:4 ratios, the isolation of this active extract yielded five fractions (C1–C5). Chemical structures of the constituents included in C1–C5 were elucidated by gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR) and resolved as methyl gallate (C1, C2, C3, C4), gallic acid (C1, C2), fraxetin (C2, C3, C4, C5), and tomentin (C3). Mixture C2 (IC50 DPPH and ABTS = 2.5 µg/mL) and C3 (IC50 FRAP = 381 µg/mL) showed the highest antioxidant properties. Among the isolated fractions, C4 was the most potential agent in growth inhibition of six bacterial strains including Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Bacillus subtilis, and Proteus mirabilis (MIC = 5, 20, 30, 20, 25, and 20 mg/mL, respectively). All identified constituents exerted an inhibitory activity on the growth of Lactuca sativa, of which the mixture C3 performed the maximal inhibition on shoot (IC50 = 49.4 µg/mL) and root (IC50 = 47.1 µg/mL) growth. Findings of this study suggest that gallic acid, methyl gallate, fraxetin, and tomentin isolated from J. podagrica possessed antioxidant, antibacterial, and growth inhibitory potentials.

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