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Solid Phase Extraction of (+)-Catechin from Cocoa Shell Waste Using Dual Ionic Liquid@ZIF8 Covered Silica. SEPARATIONS 2022. [DOI: 10.3390/separations9120441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
(+)-catechin is one category of flavonoids in cocoa shell waste and it has been reported to have many health benefits. In order to isolate it from aqueous extracted solution of cocoa shell waste by solid phase extraction (SPE), a series of dual ionic liquids@ZIF8-covered silica were prepared as the sorbents. Regarding the operation conditions of SPE and the characteristic structure of (+)-catechin, ZIF8-covered silica was synthesized to establish a stable and porous substrate, and various dual ionic liquids with multiple properties were immobilized on substrate to obtain a high adsorption capacity. Different adsorption conditions were investigated and the highest adsorption capacity (58.0 mg/g) was obtained on Sil@ZIF8@EIM-EIM at 30 °C during 60.0 min. When the sorbent was applied in the SPE process, 96.0% of the total amount of (+)-catechin from cocoa shell waste can be isolated after several washing and elution steps. The satisfactory recoveries of 97.5–100.2% and RSDs of 1.3–3.2% revealed that the SPE process was accurate and precise. The stability of Sil@ZIF8@EIM-EIM was tested in water and the reusability was tested using repeated adsorption/desorption process. The results revealed that Sil@ZIF8@EIM-EIM as an efficient sorbent can isolate (+)-catechin from cocoa shell waste.
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Shao J, Wang C, Shen Y, Shi J, Ding D. Electrochemical Sensors and Biosensors for the Analysis of Tea Components: A Bibliometric Review. Front Chem 2022; 9:818461. [PMID: 35096777 PMCID: PMC8795770 DOI: 10.3389/fchem.2021.818461] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 12/28/2021] [Indexed: 12/25/2022] Open
Abstract
Tea is a popular beverage all around the world. Tea composition, quality monitoring, and tea identification have all been the subject of extensive research due to concerns about the nutritional value and safety of tea intake. In the last 2 decades, research into tea employing electrochemical biosensing technologies has received a lot of interest. Despite the fact that electrochemical biosensing is not yet the most widely utilized approach for tea analysis, it has emerged as a promising technology due to its high sensitivity, speed, and low cost. Through bibliometric analysis, we give a systematic survey of the literature on electrochemical analysis of tea from 1994 to 2021 in this study. Electrochemical analysis in the study of tea can be split into three distinct stages, according to the bibliometric analysis. After chromatographic separation of materials, electrochemical techniques were initially used only as a detection tool. Many key components of tea, including as tea polyphenols, gallic acid, caffeic acid, and others, have electrochemical activity, and their electrochemical behavior is being investigated. High-performance electrochemical sensors have steadily become a hot research issue as materials science, particularly nanomaterials, and has progressed. This review not only highlights these processes, but also analyzes and contrasts the relevant literature. This evaluation also provides future views in this area based on the bibliometric findings.
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Affiliation(s)
- Jinhua Shao
- School of Chemistry and Bioengineering, Hunan University of Science and Engineering, Yongzhou, China
| | - Chao Wang
- School of Chemistry and Bioengineering, Hunan University of Science and Engineering, Yongzhou, China
| | - Yiling Shen
- School of Chemistry and Bioengineering, Hunan University of Science and Engineering, Yongzhou, China
| | - Jinlei Shi
- School of Chemistry and Bioengineering, Hunan University of Science and Engineering, Yongzhou, China
| | - Dongqing Ding
- School of Chemistry and Bioengineering, Hunan University of Science and Engineering, Yongzhou, China
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Pico J, Pismag RY, Laudouze M, Martinez MM. Systematic evaluation of the Folin–Ciocalteu and Fast Blue BB reactions during the analysis of total phenolics in legumes, nuts and plant seeds. Food Funct 2020; 11:9868-9880. [DOI: 10.1039/d0fo01857k] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Solid Phase Extraction (SPE) is highly advised for the analysis of total phenolics in legumes and nuts, even using Fast Blue BB (FBBB), which in turn displayed better performance over SPE-Folin Ciocalteu (FC).
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Affiliation(s)
- Joana Pico
- School of Engineering
- University of Guelph
- Guelph
- Canada
| | - Remigio Y. Pismag
- School of Engineering
- University of Guelph
- Guelph
- Canada
- Food Engineering School
| | | | - Mario M. Martinez
- School of Engineering
- University of Guelph
- Guelph
- Canada
- Department of Food Science
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Mawson DH, Jeffrey KL, Teale P, Grace PB. Development and validation of a high-throughput assay for the quantification of multiple green tea-derived catechins in human plasma. Biomed Chromatogr 2018; 32:e4319. [PMID: 29920704 DOI: 10.1002/bmc.4319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/24/2018] [Accepted: 06/06/2018] [Indexed: 11/10/2022]
Abstract
A rapid, accurate and robust method for the determination of catechin (C), epicatechin (EC), gallocatechin (GC), epigallocatechin (EGC), catechin gallate (Cg), epicatechin gallate (ECg), gallocatechin gallate (GCg) and epigallocatechin gallate (EGCg) concentrations in human plasma has been developed. The method utilizes protein precipitation following enzyme hydrolysis, with chromatographic separation and detection using reversed-phase liquid chromatography-tandem mass spectrometry (LC-MS/MS). Traditional issues such as lengthy chromatographic runtimes, sample and extract stability, and lack of suitable internal standards have been addressed. The method has been evaluated using a comprehensive validation procedure, confirming linearity over appropriate concentration ranges, and inter/intra-batch precision and accuracies within suitable thresholds (precisions within 13.8% and accuracies within 12.4%). Recoveries of analytes were found to be consistent between different matrix samples, compensated for using suitable internal markers and within the performance of the instrumentation used. Similarly, chromatographic interferences have been corrected using the internal markers selected. Stability of all analytes in matrix is demonstrated over 32 days and throughout extraction conditions. This method is suitable for high-throughput sample analysis studies.
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Abd-ElSalam HAH, Al-Ghobashy MA, Zaazaa HE, Ibrahim MA. On-column decaffeination and HPLC analysis of epigallocatechin gallate in green tea nutraceuticals. SEP SCI TECHNOL 2015. [DOI: 10.1080/01496395.2015.1116571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Chu KO, Chan KP, Yang YP, Qin YJ, Li WY, Chan SO, Wang CC, Pang CP. Effects of EGCG content in green tea extract on pharmacokinetics, oxidative status and expression of inflammatory and apoptotic genes in the rat ocular tissues. J Nutr Biochem 2015; 26:1357-67. [PMID: 26362107 DOI: 10.1016/j.jnutbio.2015.07.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 05/21/2015] [Accepted: 07/06/2015] [Indexed: 12/31/2022]
Abstract
Green tea extract (GTE) exerts antioxidative activities in ocular tissues of rats, but high levels of (-)-epigallocatechin gallate (EGCG) can induce oxidative stress. In this study, pharmacokinetics, diurnal variation of oxidative status, antioxidation and transcription factors changes in ocular tissues of rats were investigated. Rats were fed intragastrically with GTE and catechin mixtures containing different amounts of EGCG. Plasma and various ocular tissues were taken for pharmacokinetic analysis, oxidation marker testings and gene expression assays. Effects of EGCG on ocular oxidation status were assessed by 8-isoprostane level and reduced/oxidized glutathione ratio. Oxidation, inflammation and apoptosis regulations in retina were evaluated by real-time polymerase chain reaction. Epicatechin, epigallocatechin and EGCG were dominant in various ocular tissues except vitreous humor, where gallocatechin was predominant. Diurnal variation of oxidative status was found in some compartments. GTE caused oxidative stress increase in the plasma, aqueous humor, vitreous humor, cornea and retina but decrease in the lens and choroid-sclera. Catechins mixture containing half dose of EGCG lowered 8-isoprostane in the retina and lens. GTE treatment induced superoxide dismutase 1 and glutathione peroxidase-3 expressions but suppressed catalase in the retina. Our results reveal pro-oxidation of GTE with high EGCG content to the ocular tissues. Optimal EGCG level is needed for protection.
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Affiliation(s)
- Kai On Chu
- Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong; Department of Obstetrics and Gynaecology, the Chinese University of Hong Kong
| | - Kwok Ping Chan
- Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong
| | - Ya Ping Yang
- Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong
| | - Yong Jie Qin
- Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong
| | - Wai Ying Li
- Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong
| | - Sun On Chan
- School of Biomedical Sciences, The Chinese University of Hong Kong
| | - Chi Chiu Wang
- Department of Obstetrics and Gynaecology, the Chinese University of Hong Kong
| | - Chi Pui Pang
- Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong.
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7
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Yan SL, Wang QZ, Peng GH. Determination of catechin in lotus rhizomes by high-performance liquid chromatography. Int J Food Sci Nutr 2013; 60:432-8. [PMID: 22519678 DOI: 10.1080/09637480701780062] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
A novel method was developed to analyze lotus rhizome polyphenolic catechin using high-performance liquid chromatography (HPLC). The retain time of catechin was 14.72 min under the optimized condition. Mass spectrometry was further employed to qualify and quantify the purity of the catechin peak. Good linearity (R=0.9997) was obtained within the range of 50-1,000 ng. The coefficient of variance was determined as 5.2%, with a recovery rate of 97%. The detection and quantification limitations of catechin were 23 ng and 50 ng, respectively. The catechin level was 0.0025% in the lotus rhizome, and 0.011% in the knot of the lotus rhizome (Nelumbo nucifera cv. 'damao jie'). The optimized conditions of HPLC for catechin detection in the lotus rhizome matrix were as follows: the SuperlcosIL™ LC-18 analytical column (150 mm×4.6 mm, 5 µm), methanol-water-acetic acid (10:90:1, volume ratio) as the mobile phase, an UV detector at 280 nm, a flow rate of 0.8 ml/min, column temperature at 30°C, and an injection volume of 10 µl.
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Affiliation(s)
- Shou-Lei Yan
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, PR China
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Ananingsih VK, Sharma A, Zhou W. Green tea catechins during food processing and storage: A review on stability and detection. Food Res Int 2013. [DOI: 10.1016/j.foodres.2011.03.004] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Wang CC, Xu H, Man GCW, Zhang T, Chu KO, Chu CY, Cheng JTY, Li G, He YX, Qin L, Lau TS, Kwong J, Chan TH. Prodrug of green tea epigallocatechin-3-gallate (Pro-EGCG) as a potent anti-angiogenesis agent for endometriosis in mice. Angiogenesis 2012; 16:59-69. [PMID: 22948799 DOI: 10.1007/s10456-012-9299-4] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Accepted: 08/22/2012] [Indexed: 01/31/2023]
Abstract
Green tea epigallocatechin-3-gallate (EGCG) can inhibit angiogenesis and development of an experimental endometriosis model in mice, but it suffers from poor bioavailability. A prodrug of EGCG (pro-EGCG, EGCG octaacetate) is utilized to enhance the stability and bioavailability of EGCG in vivo. In this study, the potential of pro-EGCG as a potent anti-angiogenesis agent for endometriosis in mice was investigated. Homologous endometrium was subcutaneously transplanted into mice to receive either saline, vitamin E, EGCG or pro-EGCG treatment for 4 weeks. The growth of the endometrial implants were monitored by IVIS(®) non-invasive in vivo imaging during the interventions. Angiogenesis of the endometriotic lesions was determined by Cellvizio(®) in vivo imaging and SCANCO(®) Microfil microtomography. The bioavailability, anti-oxidation and anti-angiogenesis capacities of the treatments were measured in plasma and lesions. The implants with adjacent outer subcutaneous and inner abdominal muscle layers were collected for histological, microvessel and apoptosis examinations. The result showed that EGCG and pro-EGCG significantly decreased the growth of endometrial implants from the 2nd week to the 4th week of intervention. EGCG and pro-EGCG significantly reduced the lesion size and weight, inhibited functional and structural microvessels in the lesions, and enhanced lesion apoptosis at the end of interventions. The inhibition by pro-EGCG in all the angiogenesis parameters was significantly greater than that by EGCG, and pro-EGCG also had better bioavailability and greater anti-oxidation and anti-angiogenesis capacities than EGCG. Ovarian follicles and uterine endometrial glands were not affected by either EGCG or pro-EGCG. Vitamin E had no effect on endometriosis. In conclusion, pro-EGCG significantly inhibited the development, growth and angiogenesis of experimental endometriosis in mice with high efficacy, bioavailability, anti-oxidation and anti-angiogenesis capacities. Pro-EGCG could be a potent anti-angiogenesis agent for endometriosis.
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Affiliation(s)
- Chi Chiu Wang
- Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong.
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Magiera S, Baranowska I, Kusa J. Development and validation of UHPLC–ESI-MS/MS method for the determination of selected cardiovascular drugs, polyphenols and their metabolites in human urine. Talanta 2012; 89:47-56. [DOI: 10.1016/j.talanta.2011.11.055] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 11/05/2011] [Accepted: 11/13/2011] [Indexed: 01/10/2023]
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11
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Sander LC, Bedner M, Tims MC, Yen JH, Duewer DL, Porter B, Christopher SJ, Day RD, Long SE, Molloy JL, Murphy KE, Lang BE, Lieberman R, Wood LJ, Payne MJ, Roman MC, Betz JM, NguyenPho A, Sharpless KE, Wise SA. Development and certification of green tea-containing standard reference materials. Anal Bioanal Chem 2011; 402:473-87. [PMID: 22127575 DOI: 10.1007/s00216-011-5472-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 09/29/2011] [Accepted: 10/03/2011] [Indexed: 11/25/2022]
Abstract
A suite of three green tea-containing Standard Reference Materials (SRMs) has been issued by the National Institute of Standards and Technology (NIST): SRM 3254 Camellia sinensis (Green Tea) Leaves, SRM 3255 Camellia sinensis (Green Tea) Extract, and SRM 3256 Green Tea-Containing Solid Oral Dosage Form. The materials are characterized for catechins, xanthine alkaloids, theanine, and toxic elements. As many as five methods were used in assigning certified and reference values to the constituents, with measurements carried out at NIST and at collaborating laboratories. The materials are intended for use in the development and validation of new analytical methods, and for use as control materials as a component in the support of claims of metrological traceability.
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Affiliation(s)
- L C Sander
- Analytical Chemistry Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899-8392, USA.
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Gossai D, Lau‐Cam CA. Simple HPLC Method, with Fluorometric Detection, for Studying the Oral Absorption of Monomeric Catechins in a Small Animal Model. J LIQ CHROMATOGR R T 2011. [DOI: 10.1080/10826070600915148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Davekanand Gossai
- a Department of Pharmaceutical Sciences, College of Pharmacy and Allied Health Professions , St. John's University , Jamaica, New York, USA
| | - Cesar A. Lau‐Cam
- a Department of Pharmaceutical Sciences, College of Pharmacy and Allied Health Professions , St. John's University , Jamaica, New York, USA
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Baranowska I, Magiera S, Baranowski J. ULTRA HPLC METHOD FOR THE SIMULTANEOUS ANALYSIS OF DRUGS AND FLAVONOIDS IN HUMAN URINE. J LIQ CHROMATOGR R T 2011. [DOI: 10.1080/10826076.2011.555675] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Irena Baranowska
- a Department of Analytical Chemistry , Silesian University of Technology , Gliwice, Poland
| | - Sylwia Magiera
- a Department of Analytical Chemistry , Silesian University of Technology , Gliwice, Poland
| | - Jacek Baranowski
- b Department of Clinical Physiology , University Hospital , Linköping, Sweden
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Analysis of isoflavones and flavonoids in human urine by UHPLC. Anal Bioanal Chem 2010; 399:3211-9. [PMID: 20936271 PMCID: PMC3044235 DOI: 10.1007/s00216-010-4206-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2010] [Revised: 08/29/2010] [Accepted: 09/07/2010] [Indexed: 11/07/2022]
Abstract
A rapid, ultra high-performance liquid chromatographic (UHPLC) method has been developed and validated for simultaneous identification and analysis of the isoflavones genistein, daidzein, glycitin, puerarin, and biochanin A, and the flavonoids (±)-catechin, (−)-epicatechin, rutin, hesperidin, neohesperidin, quercitrin, and hesperetin in human urine. Urine samples were incubated with β-glucuronidase/sulfatase. UHPLC was performed with a Hypersil Gold (50 × 2.1 mm, 1.9 μm) analytical column. Elution was with a gradient prepared from aqueous trifluoroacetic acid (0.05%) and acetonitrile. UV detection was performed at 254 and 280 nm. The calibration curves were indicative of good linearity (r2 ≥ 0.9992) in the range of interest for each analyte. LODs ranged between 15.4 and 107.0 ng mL−1 and 3.9 and 20.4 ng mL−1 for flavonoids and isoflavones, respectively. Intra-day and inter-day precision (C.V., %) was less than 3.9% and 3.8%, respectively, and accuracy was between 0.03% and 5.0%. Recovery was 70.35–96.58%. The method is very rapid, simple, and reliable, and suitable for pharmacokinetic analysis. It can be routinely used for simultaneous determination of these five isoflavones and seven flavonoids in human urine. The method can also be applied to studies after administration of pharmaceutical preparations containing isoflavones and flavonoids to humans.
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Novak I, Šeruga M, Komorsky-Lovrić Š. Characterisation of catechins in green and black teas using square-wave voltammetry and RP-HPLC-ECD. Food Chem 2010. [DOI: 10.1016/j.foodchem.2010.03.084] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Chiral separation of (+)/(-)-catechin from sulfated and glucuronidated metabolites in human plasma after cocoa consumption. Anal Bioanal Chem 2010; 397:723-30. [PMID: 20213173 DOI: 10.1007/s00216-010-3542-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 02/02/2010] [Accepted: 02/05/2010] [Indexed: 12/20/2022]
Abstract
Cocoa is well-known to be rich in flavan-3-ols. Previous analyses have established that alkaline treatment of cocoa beans results in epimerization of (-)-epicatechin to (-)-catechin and (+)-catechin to (+)-epicatechin. Now, the question is whether both epimers can be absorbed by the human organism. This paper describes sample preparation and an HPLC method for chiral determination of (+)/(-)-catechin from sulfated and glucuronidated metabolites in human plasma. The sample preparation includes enzymatic hydrolysis of the catechin metabolites, and solid-phase extraction (SPE). A PM-gamma-cyclodextrin column is used with a coulometric electrode-array detection (CEAD) system. The recovery of catechin ranges from 89.9 to 96.8%. The limit of detection is 5.9 ng mL(-1) for (-)-catechin and 6.8 ng mL(-1) for (+)-catechin, and the limit of quantification is 12.8 ng mL(-1) for (-)-catechin and 16.9 ng mL(-1) for (+)-catechin. The relative standard deviation of the method ranges from 0.9 to 1.5%. This method was successfully applied to human plasma after consumption of a cocoa drink. In one human self-experiment, (+)-catechin and (-)-catechin were found in human plasma, but metabolism of the two enantiomers differed.
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Chu KO, Chan KP, Wang CC, Chu CY, Li WY, Choy KW, Rogers MS, Pang CP. Green tea catechins and their oxidative protection in the rat eye. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:1523-1534. [PMID: 20085274 DOI: 10.1021/jf9032602] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Catechins, active constituents of green tea, are well-known antioxidative natural products. It was proposed that green tea extract (GTE) consumption could benefit the eye, and the pharmacokinetics of catechins and oxidation status in rat eye were investigated after oral administration. Sprague-Dawley rats were fed GTE and sacrificed at different time intervals. Their eyes were dissected into cornea, lens, retina, choroid-sclera, vitreous humor, and aqueous humor for analysis of catechins and 8-epi-isoprostane by HPLC-ECD and GC-NCI-MS, respectively. Catechins were differentially distributed in eye tissues. Gallocatechin was present at the highest concentration in the retina, 22729.4 +/- 4229.4 pmol/g, and epigallocatechin in aqueous humor at 602.9 +/- 116.7 nM. The corresponding area-under-curves were 207,000 pmol x h/g and 2035.0 +/- 531.7 nM x h, respectively. The time of maximum concentration of the catechins varied from 0.5 to 12.2 h. Significant reductions in 8-epi-isoprostane levels were found in the compartments except the choroid-sclera or plasma, indicating antioxidative activities of catechins in these tissues.
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Affiliation(s)
- Kai On Chu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, Kowloon, Hong Kong
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Guo D, Zheng D, Mo G, Ye J. Adsorptive Stripping Voltammetric Detection of Tea Polyphenols at Multiwalled Carbon Nanotubes-Chitosan Composite Electrode. ELECTROANAL 2009. [DOI: 10.1002/elan.200804475] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Zimmermann BF, Papagiannopoulos M, Brachmann S, Lorenz M, Stangl V, Galensa R. A shortcut from plasma to chromatographic analysis: Straightforward and fast sample preparation for analysis of green tea catechins in human plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2009; 877:823-6. [DOI: 10.1016/j.jchromb.2009.01.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 11/24/2008] [Accepted: 01/13/2009] [Indexed: 01/19/2023]
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20
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Wang CC, Chu KO, Chong WS, Li WY, Pang CP, Shum ASW, Lau TK, Rogers MS. Tea epigallocatechin-3-gallate increases 8-isoprostane level and induces caudal regression in developing rat embryos. Free Radic Biol Med 2007; 43:519-27. [PMID: 17640562 DOI: 10.1016/j.freeradbiomed.2007.04.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2007] [Revised: 04/26/2007] [Accepted: 04/26/2007] [Indexed: 10/23/2022]
Abstract
Tea is the most common beverage after water. Concerns have been raised about the safety of tea during pregnancy, especially for embryo development. We aimed at studying the effects of active tea components on developing embryos by in vitro rat embryo culture. Rat embryos during early organogenesis were cultivated in serum supplemented with one of the tea catechins. Developmental hallmarks and malformations (Mal) in the developing embryos were compared and evaluated by a standard morphological scoring system. The embryotoxicity of each tea catechin was classified according to the European Center for the Validation of Alternative Methods. Cell viability was assessed by supervital dye staining, apoptosis by TUNEL assay, and peroxidation by the 8-isoprostane EIA method. We found that (+)-catechin had the least effect on developing embryos (Mal(50)=715.1 mg/L; IC50(Mal)=435 mg/L), whereas (-)-epigallocatechin gallate had the most adverse effect (Mal(50)=54.2 mg/L; IC50(Mal)=45.8 mg/L). The major malformation in affected embryos included caudal retardation with abnormal axial flexion and delayed hind-limb formation. All catechins were classified as nonembryotoxic except (-)-epigallocatechin gallate, which was classified as weakly embryotoxic. With (-)-epigallocatechin gallate, increased numbers of nonviable and apoptotic cells in the malformed embryos were associated with increased embryo 8-isoprostane.
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Affiliation(s)
- Chi Chiu Wang
- Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Shatin, New Territories, Hong Kong.
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Huang J, Huang K, Liu S, Luo Q, Xu M. Adsorption properties of tea polyphenols onto three polymeric adsorbents with amide group. J Colloid Interface Sci 2007; 315:407-14. [PMID: 17681514 DOI: 10.1016/j.jcis.2007.07.005] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 07/02/2007] [Accepted: 07/02/2007] [Indexed: 10/23/2022]
Abstract
Macroporous crosslinked poly(N-methyl-N-p-vinylbenzylacetamide) (PMVBA), poly(N-methyl-N-p-vinylbenzylurea) (PMVBU), and poly(N-methylacrylamide) (PMA) were prepared and their adsorption behaviors for tea polyphenols (TP) were investigated in aqueous solution. The results indicated that their adsorption capacities for TP followed an order as: PMVBU>PMVBA>PMA. The adsorption isotherms were fitted to Freundlich isotherm and adsorption enthalpies were calculated. It was found that Freundlich isotherm was suitable to characterize the adsorption process and their adsorption enthalpies for TP gave the same order as: PMVBU>PMVBA>PMA. Surface energy heterogeneity was analyzed by Do's model and the surface of PMVBU was shown to be the most homogeneous. Analysis of adsorption mechanism suggested that multiple hydrogen bonding, hydrophobic interaction, and pi-pi stacking were responsible for the adsorption of TP onto the adsorbents.
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Affiliation(s)
- Jianhan Huang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China.
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Chu KO, Wang CC, Chu CY, Chan KP, Rogers MS, Choy KW, Pang CP. Pharmacokinetic studies of green tea catechins in maternal plasma and fetuses in rats. J Pharm Sci 2006; 95:1372-81. [PMID: 16625654 DOI: 10.1002/jps.20594] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We carried out a pharmacokinetic study to determine the levels and profiles of catechins in pregnant rats and their fetuses after ingestion of green tea extract (GTE). We measured total catechin levels after enzyme digestions. Dams, at 15.5 days of gestation, were fed with GTE and catechins were measured in the maternal plasma, placenta, and fetus 0, 0.5, 1, 2, 3, 5, 8, 10, 12, 16, and 20 h after maternal GTE intake. The pharmacokinetic changes were analyzed by non compartmental models. We found that maternal plasma concentrations of catechins were about 10 times higher than in placenta and 50-100 times higher than in the fetus. AUC and Cmax levels of (-)-epicatechin (EC) were the highest in plasma while the levels of (-)-epigallocatechin gallate (EGCG) were the highest in the placenta and the fetus. The exposure level of catechin derivatives was higher than the gallate derivatives in maternal plasma after normalization but reversed in the placenta and fetus. The absorption of epi-isomers in plasma was found to be more favorable than their non epi-isomer counterparts. EGCG had the highest level of exposure (AUC) and the highest Cmax in the fetus, implying it may have potential for in utero antioxidant protection.
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Affiliation(s)
- Kai On Chu
- Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, 3/F, Hong Kong Eye Hospital, 147K, Argyle Street, Kowloon, Hong Kong
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Goodwin A, Banks C, Compton R. Electroanalytical Sensing of Green Tea Anticarcinogenic Catechin Compounds: Epigallocatechin Gallate and Epigallocatechin. ELECTROANAL 2006. [DOI: 10.1002/elan.200603485] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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