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Gil-Martínez L, Aznar-Ramos MJ, Del Carmen Razola-Diaz M, Mut-Salud N, Falcón-Piñeiro A, Baños A, Guillamón E, Gómez-Caravaca AM, Verardo V. Establishment of a Sonotrode Extraction Method and Evaluation of the Antioxidant, Antimicrobial and Anticancer Potential of an Optimized Vaccinium myrtillus L. Leaves Extract as Functional Ingredient. Foods 2023; 12:foods12081688. [PMID: 37107483 PMCID: PMC10137389 DOI: 10.3390/foods12081688] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/24/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
Vaccinium myrtillus L. (bilberry) leaves are an important by-product of berry production that may be used as a source of phenolic compounds which have a positive effect on human health. Therefore, an ultrasound-assisted extraction via sonotrode has been used for the first time to recover bioactive compounds from bilberry leaves. The extraction has been optimized using a Box-Behnken design. The influence of ethanol:water ratio (v/v), time of extraction (min) and amplitude (%) were evaluated considering total phenolic content (TPC) and antioxidant capacity (DPPH and FRAP assays) as dependent variables in a response surface methodology (RSM). Optimum values for the independent factors were 30:70 ethanol/water (v/v), 5 min of extraction and 55% amplitude. The empirical values of the independent variables using the optimized conditions were 217.03 ± 4.92 mg GAE/g d.w. (TPC), 271.13 ± 5.84 mg TE/g d.w. (DPPH) and 312.21 ± 9.30 mg TE/g d.w. (FRAP). The validity of the experimental design was confirmed using ANOVA and the optimal extract was characterized using HPLC-MS. A total of 53 compounds were tentatively identified, of which 22 were found in bilberry leaves for the first time. Among them, chlorogenic acid was the most abundant molecule, representing 53% of the total phenolic compounds identified. Additionally, the antimicrobial and anticancer activities of the optimum extract were tested. Gram-positive bacteria demonstrated high sensitivity to bilberry leaves extract in vitro, with MBC values of 6.25 mg/mL for Listeria monocytogenes, Listeria innocua and Enterococcus faecalis, and 0.8 mg/mL for Staphylococcus aureus and Bacillus cereus. Furthermore, bilberry leaves extract exerted in vitro antiproliferative activity against HT-29, T-84 and SW-837 colon tumor cells with IC50 values of 213.2 ± 2.5, 1140.3 ± 5.2 and 936.5 ± 4.6 μg/mL, respectively. Thus, this rapid ultrasound-assisted extraction method has demonstrated to be an efficient technique to obtain bilberry leaves extract with in vitro antioxidant, antimicrobial and anticancer capacities that may be useful for the food industry as natural preservative or even for the production of functional foods or nutraceuticals.
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Affiliation(s)
- Lidia Gil-Martínez
- Department of Analytical Chemistry, University of Granada, Avda Fuentenueva, 18071 Granada, Spain
| | - María José Aznar-Ramos
- Department of Nutrition and Food Science, University of Granada, Campus of Cartuja, 18071 Granada, Spain
- Biomedical Research Center, Institute of Nutrition and Food Technology 'José Mataix', University of Granada, Avda del Conocimiento sn., Armilla, 18100 Granada, Spain
| | - Maria Del Carmen Razola-Diaz
- Department of Nutrition and Food Science, University of Granada, Campus of Cartuja, 18071 Granada, Spain
- Biomedical Research Center, Institute of Nutrition and Food Technology 'José Mataix', University of Granada, Avda del Conocimiento sn., Armilla, 18100 Granada, Spain
| | - Nuria Mut-Salud
- Department of Microbiology, University of Granada, Avda Fuentenueva, 18071 Granada, Spain
| | - Ana Falcón-Piñeiro
- Department of Microbiology, University of Granada, Avda Fuentenueva, 18071 Granada, Spain
| | - Alberto Baños
- Department of Microbiology, University of Granada, Avda Fuentenueva, 18071 Granada, Spain
| | - Enrique Guillamón
- Department of Chemical Engineering, University of Granada, Avda Fuentenueva, 18071 Granada, Spain
| | - Ana María Gómez-Caravaca
- Department of Analytical Chemistry, University of Granada, Avda Fuentenueva, 18071 Granada, Spain
- Biomedical Research Center, Institute of Nutrition and Food Technology 'José Mataix', University of Granada, Avda del Conocimiento sn., Armilla, 18100 Granada, Spain
| | - Vito Verardo
- Department of Nutrition and Food Science, University of Granada, Campus of Cartuja, 18071 Granada, Spain
- Biomedical Research Center, Institute of Nutrition and Food Technology 'José Mataix', University of Granada, Avda del Conocimiento sn., Armilla, 18100 Granada, Spain
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Antioxidant and Antibacterial Properties of Extracts and Bioactive Compounds in Bryophytes. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app12010160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Today global health problems such as increased risks of oxidative stress-related diseases and antibiotic resistance are issues of serious concern. Oxidative stress is considered to be the underlying cause of many contemporary pathological conditions such as neurological disorders, ischemia, cancer, etc. Antibiotic-resistant bacteria are a concerning issue in clinical practice, causing an increase in deadly infections. Bryophytes synthesize an outstanding number of secondary metabolites that have shown several potential therapeutic and nutraceutical applications. Research in the field has led to the isolation and characterization of several compounds (flavonoids, terpenoids, and bibenzyls). Some of these compounds have shown promising in vitro antibacterial activities and antioxidant potential comparable to known natural antioxidants such as ascorbic acid and α-tocopherol. However, the process of developing new drugs from naturally occurring molecules is often an impervious path. In this paper, the current state of research of bryophytic antioxidant and antibacterial applications is discussed.
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Zaid AN, Al Ramahi R. Depigmentation and Anti-aging Treatment by Natural Molecules. Curr Pharm Des 2020; 25:2292-2312. [PMID: 31269882 DOI: 10.2174/1381612825666190703153730] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 06/20/2019] [Indexed: 11/22/2022]
Abstract
Natural molecules are becoming more accepted choices as cosmetic agents, many products in the market today claim to include natural components. Plants include many substances that could be of a value in the whitening of the skin and working as anti-aging agents. A wide range of articles related to natural skin whitening and anti-aging agents have been reviewed. Many plant-derived and natural molecules have shown to affect melanin synthesis by different mechanisms, examples include Arbutin, Ramulus mori extract, Licorice extract, Glabridin, Liquiritin, Kojic acid, Methyl gentisate, Aloesin, Azelaic acid, Vitamin C, Thioctic acid, Soya bean extracts, Niacinamide, α and β-hydroxy acids, Lactic acid, Chamomile extract, and Ellagic acid. Some of the widely used natural anti-aging products as natural antioxidants, collagen, hyaluronic acid, and coenzyme Q can counteract the effects of reactive oxygen species in skin cells and have anti-aging properties on the skin. It was concluded that many natural products including antioxidants can prevent UV-induced skin damage and have whitening and anti-aging effects. It is very important to develop and stabilize appropriate methods for the evaluation of the whitening and anti-aging capacity of natural products and their exact mechanism of action to ensure real efficacy based on evidence-based studies. The attention should be oriented on the formulations and the development of an appropriate vehicle to ensure suitable absorption of these natural products in addition to evaluating the suitable concentration of these molecules required having the desired effects without causing harmful side effects.
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Affiliation(s)
- Abdel Naser Zaid
- Pharmacy Department, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestinian Territory, Occupied
| | - Rowa' Al Ramahi
- Pharmacy Department, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestinian Territory, Occupied
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Asakawa Y, Ludwiczuk A. Chemical Constituents of Bryophytes: Structures and Biological Activity. JOURNAL OF NATURAL PRODUCTS 2018; 81:641-660. [PMID: 29019405 DOI: 10.1021/acs.jnatprod.6b01046] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Comparatively little attention has been paid to the bryophytes for use in the human diet or medicine in spite of the presence of 23 000 species globally. Several hundred new compounds have been isolated from the liverworts (Marchantiophyta), and more than 40 new carbon skeletons of terpenoids and aromatic compounds were found. Most of the liverworts studied elaborate characteristic odiferous, pungent, and bitter-tasting compounds, of which many show antimicrobial, antifungal, antiviral, allergic contact dermatitis, cytotoxic, insecticidal, anti-HIV, plant growth regulatory, neurotrophic, NO production and superoxide anion radical release inhibitory, muscle relaxing, antiobesity, piscicidal, and nematocidal activities. The biological effects ascribed to the liverworts are mainly due to lipophilic sesqui- and diterpenoids, phenolic compounds, and polyketides, which are the principal constituents of their oil bodies. Some mosses and liverworts produce significant levels of vitamin B2 and tocopherols, as well as prostaglandin-like highly unsaturated fatty acids. The most characteristic chemical phenomenon of the liverworts is that most of the sesqui- and diterpenoids are enantiomers of those found in higher plants. In this review, the chemical constituents and potential medicinal uses of bryophytes are discussed.
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Affiliation(s)
- Yoshinori Asakawa
- Faculty of Pharmaceutical Sciences , Tokushima Bunri University , Yamashiro-cho, Tokushima 770-8514 , Japan
| | - Agnieszka Ludwiczuk
- Department of Pharmacognosy with Medicinal Plant Unit , Medical University of Lublin , 20-093 Lublin , Poland
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Zeller WE. Synthesis of 1-O-methylchlorogenic acid: reassignment of structure for MCGA3 isolated from bamboo (Phyllostachys edulis) leaves. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:1860-1865. [PMID: 24460043 DOI: 10.1021/jf4042112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The first synthesis of 1-O-methylchlorogenic acid is described. The short and efficient synthesis of this compound provides laboratory-scale quantities of the material to investigate its biological properties. The synthesis involves C-1 alkylation of the known (-)-4,5-cyclohexylidenequinic acid lactone followed by methoxide opening to the hydroxyl ester. Acylation of the C-5 hydroxyl group followed by sequential removal of protecting groups afforded 1-O-methylchlorogenic acid. The NMR spectroscopic characteristics of this compound do not coincide with those reported for the original isolation from bamboo (Phyllostachys edulis) leaves of the compound designated MCGA3. Comparison of the published spectroscopic data reported for MCGA3, with both reported literature values and spectroscopic data obtained from an authentic sample, leads to the conclusion that the compound isolated from bamboo (Phyllostachys edulis) leaves is instead methyl chlorogenate.
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Affiliation(s)
- Wayne E Zeller
- US Dairy Forage Research Center, Agricultural Research Service, USDA, 1925 Linden Drive, Madison, Wisconsin 53706, United States
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Asakawa Y, Ludwiczuk A, Nagashima F. Phytochemical and biological studies of bryophytes. PHYTOCHEMISTRY 2013; 91:52-80. [PMID: 22652242 DOI: 10.1016/j.phytochem.2012.04.012] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 02/21/2012] [Accepted: 04/18/2012] [Indexed: 05/19/2023]
Abstract
The bryophytes contain the Marchantiophyta (liverworts), Bryophyta (mosses) and Anthocerotophyta (hornworts). Of these, the Marchantiophyta have a cellular oil body which produce a number of mono-, sesqui- and di-terpenoids, aromatic compounds like bibenzyl, bis-bibenzyls and acetogenins. Most sesqui- and di-terpenoids obtained from liverworts are enantiomers of those found in higher plants. Many of these compounds display a characteristic odor, and can have interesting biological activities. These include: allergenic contact dermatitis, antimicrobial, antifungal and antiviral, cytotoxic, insecticidal, insect antifeedant, superoxide anion radical release, 5-lipoxygenase, calmodulin, hyaluronidase, cyclooxygenase, DNA polymerase β, and α-glucosidase and NO production inhibitory, antioxidant, piscicidal, neurotrophic and muscle relaxing activities among others. Each liverwort biosynthesizes unique components, which are valuable for their chemotaxonomic classification. Typical chemical structures and biological activity of the selected liverwort constituents as well as the hemi- and total synthesis of some biologically active compounds are summarized.
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Affiliation(s)
- Yoshinori Asakawa
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima, Japan.
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Affiliation(s)
- Wayne E. Zeller
- a U.S. Dairy Forage Research Center , Madison , Wisconsin , USA
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Dey A, De JN. Antioxidative Potential of Bryophytes: Stress Tolerance and Commercial Perspectives: A Review. ACTA ACUST UNITED AC 2012. [DOI: 10.5567/pharmacologia.2012.151.159] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Lorenz P, Duckstein S, Conrad J, Knödler M, Meyer U, Stintzing FC. An Approach to the Chemotaxonomic Differentiation of Two European Dog's Mercury Species: Mercurialis annua L. and M. perennis L. Chem Biodivers 2012; 9:282-97. [DOI: 10.1002/cbdv.201100341] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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11
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Lee KH, Cho JY, Lee HJ, Ma YK, Kwon J, Park SH, Lee SH, Cho JA, Kim WS, Park KH, Moon JH. Hydroxycinnamoylmalic acids and their methyl esters from pear (Pyrus pyrifolia Nakai) fruit peel. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:10124-10128. [PMID: 21859098 DOI: 10.1021/jf2022868] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Two novel caffeoylmalic acid methyl esters, 2-O-(trans-caffeoyl)malic acid 1-methyl ester (6) and 2-O-(trans-caffeoyl)malic acid 4-methyl ester (7), were isolated from pear (Pyrus pyrifolia Nakai cv. Chuhwangbae) fruit peels. In addition, 5 known hydroxycinnamoylmalic acids and their methyl esters were identified: 2-O-(trans-coumaroyl)malic acid (1), 2-O-(cis-coumaroyl)malic acid (2), 2-O-(cis-coumaroyl)malic acid 1-methyl ester (3), 2-O-(trans-coumaroyl)malic acid 1-methyl ester (4), and 2-O-(trans-caffeoyl)malic acid (phaselic acid, 5). The chemical structures of these compounds were determined by spectroscopic data from ESI MS and NMR. Of all the isolated compounds, five hydroxycinnamoylmalic acids and their methyl esters (2-4, 6, 7) were identified in the pear for the first time.
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Affiliation(s)
- Ki Hoon Lee
- Department of Food Science and Technology and Functional Food Research Center, Chonnam National University, Gwangju 500-757, Republic of Korea
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Antirheumatoid Arthritis Activities and Chemical Compositions of Phenolic Compounds-Rich Fraction from Urtica atrichocaulis, an Endemic Plant to China. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2011; 2012:818230. [PMID: 21904564 PMCID: PMC3166763 DOI: 10.1155/2012/818230] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 06/20/2011] [Accepted: 06/29/2011] [Indexed: 11/17/2022]
Abstract
Urtica atrichocaulis, an endemic plant to China, is commonly used to treat rheumatoid arthritis even though its pharmaceutical activities and chemical constituents were not studied. Herein, we reported our investigations on the chemical compositions of the phenolic compounds-rich fraction from U. atrichocaulis (TFUA) and their antirheumatoid arthritis activities. We found that the TFUA significantly inhibited the adjuvant-induced rats arthritis, carrageenin-induced rats paw edema, cotton pellet-induced mice granuloma, and the acetic acid-induced mice writhing response. Our phytochemical investigations on the TFUA resulted in the first-time isolation and identification of 17 phenolic constituents and a bis (5-formylfurfuryl) ether. The extensive HPLC analysis also revealed the chemical compositions of TFUA. Our further biological evaluation of the main phenolic components, individually and collectively, indicated that the antirheumatoid arthritis activities of TFUA were the combined effect of multiple phenolic constituents.
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Saviranta NMM, Julkunen-Tiitto R, Oksanen E, Karjalainen RO. Leaf phenolic compounds in red clover (Trifolium pratense L.) induced by exposure to moderately elevated ozone. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2010; 158:440-446. [PMID: 19766367 DOI: 10.1016/j.envpol.2009.08.029] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Revised: 08/11/2009] [Accepted: 08/29/2009] [Indexed: 05/28/2023]
Abstract
Red clover (Trifolium pratense L.), an important feed crop in many parts of the world, is exposed to elevated ozone over large areas. Plants can limit ozone-induced damages by various defence mechanisms. In this work, changes in the concentrations of antioxidant phenolic compounds induced by slightly elevated levels of ozone were determined in red clover leaves by high-performance liquid chromatography and mass spectrometry. 31 different phenolics were identified and the most abundant isoflavones and flavonoids were biochanin A glycoside malonate (G-M), formononetin-G-M and quercetin-G-M. Elevated ozone (mean 32.4 ppb) increased the total phenolic content of leaves and also had minor effects on the concentrations of individual compounds. Elevated ozone increased the net photosynthesis rate of red clover leaves before visible injuries by 21-23%. This study thus suggests that the concentrations of phenolics in red clover leaves change in response to slightly elevated ozone levels.
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Affiliation(s)
- Niina M M Saviranta
- University of Kuopio, Department of Biosciences, Institute of Applied Biotechnology, Box 1627, 70211 Kuopio, Finland
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Arróniz-Crespo M, Núñez-Olivera E, Martínez-Abaigar J, Becker H, Scher J, Zapp J, Tomás R, Beaucourt N. Physiological changes and UV protection in the aquatic liverwort Jungermannia exsertifolia subsp. cordifolia along an altitudinal gradient of UV-B radiation. FUNCTIONAL PLANT BIOLOGY : FPB 2006; 33:1025-1036. [PMID: 32689313 DOI: 10.1071/fp06096] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2006] [Accepted: 07/21/2006] [Indexed: 06/11/2023]
Abstract
Here we report the effects of a natural altitudinal gradient of UV-B radiation, from 1140 to 1816 m altitude, on the physiology of the aquatic liverwort Jungermannia exsertifolia Steph. subsp. cordifolia (Dumort.) Váña collected in mountain streams. Photosynthetic pigments, net photosynthesis and dark respiration rates, chlorophyll fluorescence, protein concentration, sclerophylly, and UV-absorbing compounds [both global UV absorbance of methanol-extractable UV-absorbing compounds (MEUVAC) and concentrations of five individual compounds] were measured. Two new caffeic acid derivatives were discovered: 5″-(7″,8″-dihydroxycoumaroyl)-2-caffeoylmalic acid and 5″-(7″,8″-dihydroxy-7-O-β-glucosyl-coumaroyl)-2-caffeoylmalic acid, whereas three additional compounds were already known in other species: p-coumaroylmalic acid, phaselic acid (both compounds in their cis- and trans- forms) and feruloylmalic acid. Most physiological variables changed considerably along the altitudinal gradient, but only six showed significant linear relationships with altitude: MEUVAC levels, the concentrations of the two new secondary compounds, the maximal apparent electron transport rate through PSII (ETRmax) and the maximal non-photochemical quenching (NPQmax) increased with altitude, whereas photoinhibition percentage decreased. A principal components analysis (PCA) was conducted to rank the values of the physiological and ecological variables obtained along the altitudinal transect, showing that those variables correlated with altitude were responsible for the ordination of the sampling points. The liverwort was not adversely affected by the changing conditions along the altitudinal gradient and, in particular, by the increasing UV-B irradiance, probably because the characteristics shown by high-altitude populations may confer tolerance to high UV-B levels. The response to UV-B of the two new compounds suggests that they could be used as indicators of the spatial changes in UV-B radiation.
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Affiliation(s)
- María Arróniz-Crespo
- Universidad de La Rioja, Complejo Científico-Tecnológico, Avda. Madre de Dios 51, 26006 Logroño (La Rioja), Spain
| | - Encarnación Núñez-Olivera
- Universidad de La Rioja, Complejo Científico-Tecnológico, Avda. Madre de Dios 51, 26006 Logroño (La Rioja), Spain
| | - Javier Martínez-Abaigar
- Universidad de La Rioja, Complejo Científico-Tecnológico, Avda. Madre de Dios 51, 26006 Logroño (La Rioja), Spain
| | - Hans Becker
- Pharmakognosie und Analytische Phytochemie, Universität des Saarlandes, Gebäude C2.2, D-66041 Saarbrücken, Germany
| | - Jochen Scher
- Pharmakognosie und Analytische Phytochemie, Universität des Saarlandes, Gebäude C2.2, D-66041 Saarbrücken, Germany
| | - Josef Zapp
- Pharmakognosie und Analytische Phytochemie, Universität des Saarlandes, Gebäude C2.2, D-66041 Saarbrücken, Germany
| | - Rafael Tomás
- Universidad de La Rioja, Complejo Científico-Tecnológico, Avda. Madre de Dios 51, 26006 Logroño (La Rioja), Spain
| | - Nathalie Beaucourt
- Universidad de La Rioja, Complejo Científico-Tecnológico, Avda. Madre de Dios 51, 26006 Logroño (La Rioja), Spain
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Arakawa R, Yamaguchi M, Hotta H, Osakai T, Kimoto T. Product analysis of caffeic acid oxidation by on-line electrochemistry/electrospray ionization mass spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2004; 15:1228-1236. [PMID: 15276170 DOI: 10.1016/j.jasms.2004.05.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2004] [Revised: 05/05/2004] [Accepted: 05/05/2004] [Indexed: 05/24/2023]
Abstract
On-line electrochemistry/electrospray ionization mass spectrometry (EC/ESI-MS) was developed using a microflow electrolytic cell. This technique was applied to electrochemical oxidation of caffeic acid (CAF) which is known to be a highly antioxidative agent. Effects of electrolytic potentials on ion intensities of product ions and on electrolytic currents were examined at different pHs. Dimer products were detected at electrolytic potentials of E = 0.7 V (vs. Ag/AgCl) and trimer products at 1.0 V at pH 9. Dimer products were distinguished from hydrogen-bonded complexes by MS/MS experiments. Hydrogen/deuterium exchange experiments determined the number of hydroxyl and carboxyl groups in the Dimers formed by electrolysis. The mechanism of oxidative polymerization of CAF is discussed with speculation as to the structure of the dimer product.
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Affiliation(s)
- Ryuichi Arakawa
- Department of Applied Chemistry, Kansai University, Osaka, Japan.
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