201
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Diniz AM, Basílio N, Cruz H, Pina F, Parola AJ. Spatiotemporal control over the co-conformational switching in pH-responsive flavylium-based multistate pseudorotaxanes. Faraday Discuss 2015; 185:361-79. [PMID: 26395804 DOI: 10.1039/c5fd00078e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A multistate molecular dyad containing flavylium and viologen units was synthesized and the pH dependent thermodynamics of the network completely characterized by a variety of spectroscopic techniques such as NMR, UV-vis and stopped-flow. The flavylium cation is only stable at acidic pH values. Above pH ≈ 5 the hydration of the flavylium leads to the formation of the hemiketal followed by ring-opening tautomerization to give the cis-chalcone. Finally, this last species isomerizes to give the trans-chalcone. For the present system only the flavylium cation and the trans-chalcone species could be detected as being thermodynamically stable. The hemiketal and the cis-chalcone are kinetic intermediates with negligible concentrations at the equilibrium. All stable species of the network were found to form 1 : 1 and 2 : 1 host : guest complexes with cucurbit[7]uril (CB7) with association constants in the ranges 10(5)-10(8) M(-1) and 10(3)-10(4) M(-1), respectively. The 1 : 1 complexes were particularly interesting to devise pH responsive bistable pseudorotaxanes: at basic pH values (≈12) the flavylium cation interconverts into the deprotonated trans-chalcone in a few minutes and under these conditions the CB7 wheel was found to be located around the viologen unit. A decrease in pH to values around 1 regenerates the flavylium cation in seconds and the macrocycle is translocated to the middle of the axle. On the other hand, if the pH is decreased to 6, the deprotonated trans-chalcone is neutralized to give a metastable species that evolves to the thermodynamically stable flavylium cation in ca. 20 hours. By taking advantage of the pH-dependent kinetics of the trans-chalcone/flavylium interconversion, spatiotemporal control of the molecular organization in pseudorotaxane systems can be achieved.
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Affiliation(s)
- Ana Marta Diniz
- Laboratório Associado para a Química Verde (LAQV), REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal. and Departamento de Química, Escola Superior de Tecnologia da Saúde de Lisboa - Instituto Politécnico de Lisboa, Lisboa, Portugal
| | - Nuno Basílio
- Laboratório Associado para a Química Verde (LAQV), REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal.
| | - Hugo Cruz
- Laboratório Associado para a Química Verde (LAQV), REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal.
| | - Fernando Pina
- Laboratório Associado para a Química Verde (LAQV), REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal.
| | - A Jorge Parola
- Laboratório Associado para a Química Verde (LAQV), REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal.
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202
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Barcena HS, Chen P, Tuachi A. Synthetic anthocyanidins and their antioxidant properties. SPRINGERPLUS 2015; 4:499. [PMID: 26405619 PMCID: PMC4573978 DOI: 10.1186/s40064-015-1250-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 08/14/2015] [Indexed: 01/19/2023]
Abstract
Anthocyanidins were synthesized to study the effect of methoxy substitution on the B ring to their antioxidant property. Comparative FRAP studies show 2'- and 4'-methoxy substituents have higher antioxidant activities, which may be attributed to both resonance and inductive effects.Graphical abstract:Anthocyanidins as reducing agents.
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Affiliation(s)
- Homar S. Barcena
- Physical Sciences, Kingsborough Community College, Brooklyn, NY 11235 USA
| | - Peishan Chen
- Physical Sciences, Kingsborough Community College, Brooklyn, NY 11235 USA
| | - Abraham Tuachi
- Physical Sciences, Kingsborough Community College, Brooklyn, NY 11235 USA
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203
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Basílio N, Cabrita L, Pina F. Mimicking Positive and Negative Copigmentation Effects in Anthocyanin Analogues by Host-Guest Interaction with Cucurbit[7]uril and β-Cyclodextrins. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:7624-7629. [PMID: 25891490 DOI: 10.1021/acs.jafc.5b00765] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Copigmentation and the anti-copigmentation effects can be mimicked by the interaction of anthocyanin's model compounds respectively with cucurbit[7]uril (CB7) and β-cyclodextrin (β-CD). The complex network of chemical reactions displayed by this family of compounds includes the colored flavylium cation, AH(+), and quinoidal base, A, along with the colorless hemiketal, B, cis-chalcone, Cc, and trans-chalcone, Ct. Whereas AH(+) is stable only at very acidic pH values, the remaining species are formed at slightly acidic and neutral conditions. However, under these conditions, for most of the natural and synthetic flavylium salts, the colorless species predominate (B, Cc, and Ct) at the expense of A. The host CB7 was found to improve the color of solutions in two different ways: first, it stabilizes AH(+) at higher pH values by decreasing its acidity and, second, it enhances the mole fraction of A due to selective complexation of this species in the pH range where the flavylium cation is no longer stable. In contrast, β-CD increases the acidity of AH(+), favoring the formation of Ct at the expense of all the other multistate species (Bası́lio et al. New J. Chem. 2013, 37, 3166-3173; Petrov et al. J. Phys. Chem. A 2013, 117, 10692-10701; Gago et al. Dyes Pigments 2014, 110, 106-112; and Lopes-Costa et al. Photochem. Photobiol. Sci. 2014, 13, 1420-1426). Although both hosts have a large effect on the hydration rate and pH domain of the flavylium cation, the effect on the degradation kinetics of anthocyanidins is modest. CB7 decreases the hydration rate and decreases the acid-base (AH(+)/A) equilibrium constant (Ka), leading respectively to a slowing and a speeding of the anthocyanin degradation rate. On the other hand, β-CD increases the hydration rate but increases Ka, both effects acting in opposite directions.
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Affiliation(s)
- Nuno Basílio
- Laboratório Associado para a Quı́mica Verde (LAQV), REQUIMTE, Departamento de Quı́mica, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa , 2829-516 Monte de Caparica, Portugal
| | - Luis Cabrita
- Laboratório Associado para a Quı́mica Verde (LAQV), REQUIMTE, Departamento de Quı́mica, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa , 2829-516 Monte de Caparica, Portugal
| | - Fernando Pina
- Laboratório Associado para a Quı́mica Verde (LAQV), REQUIMTE, Departamento de Quı́mica, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa , 2829-516 Monte de Caparica, Portugal
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204
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Klimaviciute R, Navikaite V, Jakstas V, Ivanauskas L. Complexes of dextran sulfate and anthocyanins from Vaccinium myrtillus: Formation and stability. Carbohydr Polym 2015; 129:70-8. [DOI: 10.1016/j.carbpol.2015.04.038] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 03/30/2015] [Accepted: 04/15/2015] [Indexed: 11/28/2022]
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205
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Xia L, Cai H, Lee YR. Microwave-assisted catalyst-free synthesis of diversely functionalized 2-amino-2H-chromene-3-carboxylates. Tetrahedron 2015. [DOI: 10.1016/j.tet.2015.07.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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206
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Basílio N, Petrov V, Pina F. Host-Guest Complexes of Flavylium Cations and Cucurbit[7]uril: The Influence of Flavylium Substituents on the Structure and Stability of the Complex. Chempluschem 2015; 80:1779-1785. [PMID: 31973327 DOI: 10.1002/cplu.201500304] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Indexed: 01/09/2023]
Abstract
The host-guest complexes formed from six differently substituted flavylium cations and cucurbit[7]uril (CB7) have been characterized by UV/Vis absorption, fluorescence emission and 1 H NMR spectroscopy. It was observed that all flavylium cations form 1:1 inclusion complexes with association constants that depend on the nature and position of the substituents. The results indicate that CB7 displays higher affinity for more hydrophobic flavylium compounds and for those bearing amino substituents. 1 H NMR spectroscopy was used to elucidate the structure of the complexes. While for 7-hydroxyflavylium and 4-methyl-7-hydroxyflavylium the phenyl group (ring B) is included within the host's cavity leaving the benzopyrilium group (rings A and C) outside, in 4',7-dihydroxyflavylium and 3',4',7-trihydroxyflavylium the macrocycle shuttles between rings A and B. For compounds with amino substituents it was found that CB7 is attracted towards these groups regardless of their position in ring A or B. In addition, it was observed that the dimethylamino group tends to be positioned near the carbonyl-decorated portal while the diethylamino motif prefers the hydrophobic cavity of CB7.
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Affiliation(s)
- Nuno Basílio
- Laboratório Associado para a Química Verde (LAQV), REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Monte de Caparica, Portugal
| | - Vesselin Petrov
- Laboratório Associado para a Química Verde (LAQV), REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Monte de Caparica, Portugal.,Laboratory of Organic Photochemistry, Faculty of Chemistry, University of Sofia, 1 James Bourchier Boulevard, 1164, Sofia, Bulgaria
| | - Fernando Pina
- Laboratório Associado para a Química Verde (LAQV), REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Monte de Caparica, Portugal
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207
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Lopes-Costa T, Basílio N, Pedrosa JM, Pina F. Photochromism of the natural dye 7,4'-dihydroxy-5-methoxyflavylium (dracoflavylium) in the presence of (2-hydroxypropyl)-β-cyclodextrin. Photochem Photobiol Sci 2015; 13:1420-6. [PMID: 25054889 DOI: 10.1039/c4pp00190g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A photochromic system based on dracoflavylium, a natural pigment extracted from Dragon's blood, a resin appearing in the injury parts of the tree Dracaena draco, is studied in water. The photochromism arises from the irradiation of the trans-chalcone, giving a mixture of flavylium cation/quinoidal base as a photoproduct via cis-chalcone and hemiketal. The performance of the photochromic system can be improved in the presence of (2-hydroxypropyl)-β-cyclodextrin. A mathematical model to account for the details of the kinetics and thermodynamics of the system was deduced. The model is general for all the host-guest systems involving the flavylium network of chemical reactions with 1 : 1 stoichiometric association.
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Affiliation(s)
- Tânia Lopes-Costa
- Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Ctra. Utrera km 1, 41013 Sevilla, Spain
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208
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Gago S, Basílio N, Moro AJ, Pina F. Flavylium based dual photochromism: addressing cis-trans isomerization and ring opening-closure by different light inputs. Chem Commun (Camb) 2015; 51:7349-51. [PMID: 25820365 DOI: 10.1039/c5cc01677k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The multistate system of 4',7-dihydroxy-3-methoxyflavylium is constituted by a multiequilibrium involving trans-chalcone, cis-chalcone, hemiketal, flavylium cation and quinoidal base. This system possesses two independently addressable inter-connected photochromic systems based on the cis-trans isomerization and ring opening-closure of the hemiketal.
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Affiliation(s)
- Sandra Gago
- LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
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209
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210
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Chassaing S, Isorez-Mahler G, Kueny-Stotz M, Brouillard R. Aged red wine pigments as a source of inspiration for organic synthesis—the cases of the color-stable pyranoflavylium and flavylium-(4→8)-flavan chromophores. Tetrahedron 2015. [DOI: 10.1016/j.tet.2014.10.058] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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211
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Photochemistry of the hemiketal form of anthocyanins and its potential role in plant protection from UV-B radiation. Tetrahedron 2015. [DOI: 10.1016/j.tet.2014.06.092] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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212
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Trouillas P, Di Meo F, Gierschner J, Linares M, Sancho-García JC, Otyepka M. Optical properties of wine pigments: theoretical guidelines with new methodological perspectives. Tetrahedron 2015. [DOI: 10.1016/j.tet.2014.10.046] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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213
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Zaffino C, Russo B, Bruni S. Surface-enhanced Raman scattering (SERS) study of anthocyanidins. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 149:41-47. [PMID: 25942083 DOI: 10.1016/j.saa.2015.04.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 04/14/2015] [Accepted: 04/20/2015] [Indexed: 06/04/2023]
Abstract
Anthocyanins are an important class of natural compounds responsible for the red, purple and blue colors in a large number of flowers, fruits and cereal grains. They are polyhydroxy- and polymethoxy-derivatives of 2-phenylbenzopyrylium (flavylium) salts, which are present in nature as glycosylated molecules. The aim of the present study is to assess the identification of anthocyanidins, i.e. anthocyanins without the glycosidic moiety, by means of surface-enhanced Raman spectroscopy (SERS), a very chemically-specific technique which is moreover sensitive to subtle changes in molecular structures. These features can lead to elect SERS, among the spectroscopic tools currently at disposal of scientists, as a technique of choice for the identification of anthocyanidins, since: (1) anthocyanidins structurally present the same benzopyrylium moiety and differentiate only for the substitution pattern on their phenyl ring, (2) different species are present in aqueous solution depending on the pH. It will be demonstrated that, while resonance Raman spectra of anthocyanidins are very similar to one another, SER spectra show greater differences, leading to a further step in the identification of such important compounds in diluted solutions by means of vibrational spectroscopy. Moreover, the dependence on the pH of the six most common anthocyanidins, i.e. cyanidin, delphinidin, pelargonidin, peonidin, malvidin and petunidin, is studied. To the best of the authors' knowledge, a complete SERS study of such important molecules is reported in the present work for the first time.
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Affiliation(s)
- Chiara Zaffino
- Dipartimento di Chimica, Università degli Studi di Milano, Via C. Golgi 19, 20133 Milano, Italy.
| | - Bianca Russo
- Dipartimento di Chimica, Università degli Studi di Milano, Via C. Golgi 19, 20133 Milano, Italy
| | - Silvia Bruni
- Dipartimento di Chimica, Università degli Studi di Milano, Via C. Golgi 19, 20133 Milano, Italy
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214
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Coutinho IB, Freitas A, Maçanita AL, Lima J. Effect of water content on the acid–base equilibrium of cyanidin-3-glucoside. Food Chem 2015; 172:476-80. [DOI: 10.1016/j.foodchem.2014.09.060] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 08/07/2014] [Accepted: 09/11/2014] [Indexed: 10/24/2022]
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215
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Chen H, Lin W, Jiang W, Dong B, Cui H, Tang Y. Locked-flavylium fluorescent dyes with tunable emission wavelengths based on intramolecular charge transfer for multi-color ratiometric fluorescence imaging. Chem Commun (Camb) 2015; 51:6968-71. [PMID: 25797486 DOI: 10.1039/c5cc01242b] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A new class of locked-flavylium fluorophores with tunable emission wavelengths based on intramolecular charge transfer were designed, synthesized, and evaluated. The optical studies indicate that sensor LF3 can display an intriguing character, fluorescence ratiometric response in three channels by tuning the ICT efficiencies.
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Affiliation(s)
- Hua Chen
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
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216
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Petrov V, Slavcheva S, Stanimirov S, Pina F. Origin of the metastable stability in flavylium multistate systems. J Phys Chem A 2015; 119:2908-18. [PMID: 25715665 DOI: 10.1021/acs.jpca.5b01473] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Metastable states regarding the network of chemical reactions involving flavylium compounds were investigated as well as the role they may play in models for optical memories capable of write-read-erase. A necessary requirement to achieve metastable states in flavylium systems is the existence of a high cis-trans isomerization barrier, as in 4'-hydroxyflavylium described through this paper. In an optical memory, the metastable state could be the signal to be detected upon the write step. In that case the autoerase is prevented by the metastable state. Conversely, the metastable state may be the initial state and prevents the auto and unwanted write step. The compound 4'-hydroxyflavylium offers the possibility of achieving both of these two situations, depending on the sequence of the pH stimuli prior to light absorption. In this work the pH dependent distribution of the flavylium species of the network in the presence of β-cyclodextrin was calculated. Improvement of the performance of the photochromic system in the presence of β-cyclodextrin was observed.
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Affiliation(s)
- Vesselin Petrov
- †Laboratory of Organic Photochemistry, Faculty of Chemistry and Pharmacy, Sofia University, 1164 Sofia, Bulgaria.,‡REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal
| | - Stoyanka Slavcheva
- †Laboratory of Organic Photochemistry, Faculty of Chemistry and Pharmacy, Sofia University, 1164 Sofia, Bulgaria
| | - Stanislav Stanimirov
- †Laboratory of Organic Photochemistry, Faculty of Chemistry and Pharmacy, Sofia University, 1164 Sofia, Bulgaria
| | - Fernando Pina
- ‡REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal
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217
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Cruz L, Basílio N, Mateus N, Pina F, de Freitas V. Characterization of kinetic and thermodynamic parameters of cyanidin-3-glucoside methyl and glucuronyl metabolite conjugates. J Phys Chem B 2015; 119:2010-8. [PMID: 25622073 DOI: 10.1021/jp511537e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The determination of rate and equilibrium constants of anthocyanin metabolites with in vivo occurrence, cyanidin-4'-O-methyl-3-glucoside (Cy4'Me3glc) and cyanidin-7-O-glucuronyl-3-glucoside (Cy7Gluc3glc), was carried out for the first time by means of direct and reverse pH jumps. The thermodynamics and kinetics of these compounds are similar to the anthocyanin monoglucosides in particular for the analogous cyanidin-3-glucoside (Cy3glc) and peonidin-3-glucoside (Peo3glc). The rate and equilibrium constants of metabolites were also compared with malvin (malvidin 3,5-diglucoside) and with a bioinspired compound 3',4'-dihydroxy-7-O-glucopyranosyloxyflavylium (DGF). In Cy4'Me3glc and Cy7Gluc3glc the rate of hydration for a fixed pH value is slower than in DGF and the dominant species at moderately acidic solutions is the hemiketal. Oppositely, in DGF trans-chalcone is the dominant species at moderately acidic solutions.
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Affiliation(s)
- Luís Cruz
- Centro de Investigação em Química e Bioquímica, Departamento de Química, Faculdade de Ciências, Universidade do Porto , Rua do Campo Alegre, 687, 4169-007 Porto, Portugal
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218
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Fernandes A, Brás NF, Mateus N, Freitas VD. A study of anthocyanin self-association by NMR spectroscopy. NEW J CHEM 2015. [DOI: 10.1039/c4nj02339k] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Malvidin-3-O-coumaroylglucoside molecules self-associate, with this interaction occurring mainly by dispersive contacts (direct π–π stacking and van der Waals interactions).
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Affiliation(s)
- Ana Fernandes
- Centro de Investigação em Química (CIQ)
- Departamento de Química e Bioquímica
- Faculdade de Ciências
- Universidade do Porto
- 4169-007 Porto
| | - Natércia F. Brás
- REQUIMTE
- Departamento de Química e Bioquímica
- Faculdade de Ciências
- Universidade do Porto
- 4169-007 Porto
| | - Nuno Mateus
- Centro de Investigação em Química (CIQ)
- Departamento de Química e Bioquímica
- Faculdade de Ciências
- Universidade do Porto
- 4169-007 Porto
| | - Victor de Freitas
- Centro de Investigação em Química (CIQ)
- Departamento de Química e Bioquímica
- Faculdade de Ciências
- Universidade do Porto
- 4169-007 Porto
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219
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Calogero G, Bartolotta A, Di Marco G, Di Carlo A, Bonaccorso F. Vegetable-based dye-sensitized solar cells. Chem Soc Rev 2015; 44:3244-94. [DOI: 10.1039/c4cs00309h] [Citation(s) in RCA: 254] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In this review we provide an overview of vegetable pigments in dye-sensitized solar cells, starting from main limitations of cell performance to cost analysis and scaling-up prospects.
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Affiliation(s)
| | | | - Gaetano Di Marco
- CNR-IPCF
- Istituto per i Processi Chimico-Fisici
- 98158 Messina
- Italy
| | - Aldo Di Carlo
- CHOSE – Centre for Hybrid and Organic Solar Energy – University of Rome “Tor Vergata”
- 00133 Roma
- Italy
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220
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Liazid A, Barbero GF, Azaroual L, Palma M, Barroso CG. Stability of anthocyanins from red grape skins under pressurized liquid extraction and ultrasound-assisted extraction conditions. Molecules 2014; 19:21034-43. [PMID: 25517342 PMCID: PMC6270781 DOI: 10.3390/molecules191221034] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 11/29/2014] [Accepted: 12/09/2014] [Indexed: 11/17/2022] Open
Abstract
The stability of anthocyanins from grape skins after applying different extraction techniques has been determined. The following compounds, previously extracted from real samples, were assessed: delphinidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, peonidin 3-glucoside, malvidin 3-glucoside, peonidin 3-acetylglucoside, malvidin 3-acetylglucoside, malvidin 3-caffeoylglucoside, petunidin 3-p-coumaroylglucoside and malvidin 3-p-coumaroylglucoside (trans). The techniques used were ultrasound-assisted extraction and pressurized liquid extraction. In ultrasound-assisted extraction, temperatures up to 75 °C can be applied without degradation of the aforementioned compounds. In pressurized liquid extraction the anthocyanins were found to be stable up to 100 °C. The relative stabilities of both the glycosidic and acylated forms were evaluated. Acylated derivatives were more stable than non-acylated forms. The differences between the two groups of compounds became more marked on working at higher temperatures and on using extraction techniques with higher levels of oxygen in the extraction media.
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Affiliation(s)
- Ali Liazid
- Department of Analytical Chemistry, University of Cadiz, Puerto Real 11510, Spain.
| | - Gerardo F Barbero
- Department of Analytical Chemistry, University of Cadiz, Puerto Real 11510, Spain.
| | - Latifa Azaroual
- Faculty of Sciences, Abdelmalek Essaâdi University, Tetouan 93000, Morocco.
| | - Miguel Palma
- Department of Analytical Chemistry, University of Cadiz, Puerto Real 11510, Spain.
| | - Carmelo G Barroso
- Department of Analytical Chemistry, University of Cadiz, Puerto Real 11510, Spain.
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221
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Padhi B, Reddy DS, Mohapatra DK. Trimethylsilyl Iodide Mediated One-Pot Synthesis of 2-Allyl-2H-chromenes. European J Org Chem 2014. [DOI: 10.1002/ejoc.201403240] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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222
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Chen W, Xie Z, Zheng H, Lou H, Liu L. Structurally diverse α-substituted benzopyran synthesis through a practical metal-free C(sp3)-H functionalization. Org Lett 2014; 16:5988-91. [PMID: 25386987 DOI: 10.1021/ol503004a] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
A trityl ion-mediated practical C-H functionalization of a variety of benzopyrans with a wide range of nucleophiles (organoboranes and C-H molecules) at ambient temperature has been disclosed. The metal-free reaction has an excellent functional group tolerance and high chemoselectivity and displays a broad scope with respect to both benzopyran and nucleophile partners, efficiently affording a collection of benzopyrans bearing diverse skeletons and α-functionalities in one step.
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Affiliation(s)
- Wenfang Chen
- Key Laboratory of Chemical Biology of Ministry of Education, School of Pharmaceutical Sciences, Shandong University , Jinan 250012, PR China
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223
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Oliveira J, Brás NF, da Silva MA, Mateus N, Parola AJ, de Freitas V. Grape anthocyanin oligomerization: a putative mechanism for red color stabilization? PHYTOCHEMISTRY 2014; 105:178-185. [PMID: 24890388 DOI: 10.1016/j.phytochem.2014.05.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 04/30/2014] [Accepted: 05/04/2014] [Indexed: 06/03/2023]
Abstract
The equilibrium forms of malvidin-3-O-glucoside trimer present in grape skins were studied in aqueous solution at different pH values through UV-Visible spectroscopy. It was observed that the reactivity of this compound is strongly dominated by acid-base chemistry (pKa1=3.61±0.03; pKa2=6.83±0.06), with the reaction sequence hydration-tautomerization-isomerization accounting less than 10% of the overall reactivity. The decrease of hydration of this flavylium cation derivative when compared to the original anthocyanins results from the formation of a cluster of the pigment with a high-energy of solvation that inhibits the access of water molecules to the flavylium cation core preventing by this way the hydration reactions. Overall of these results raise the hypothesis that polymerization may be a natural stabilization mechanism for the red color of anthocyanins.
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Affiliation(s)
- Joana Oliveira
- Centro de Investigação em Química, Departamento de Química, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal
| | - Natércia F Brás
- REQUIMTE, Departamento de Química, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal
| | - Mara Alhinho da Silva
- Centro de Investigação em Química, Departamento de Química, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal
| | - Nuno Mateus
- Centro de Investigação em Química, Departamento de Química, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal
| | - A Jorge Parola
- REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
| | - Victor de Freitas
- Centro de Investigação em Química, Departamento de Química, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal.
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224
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Moro AJ, Pana AM, Cseh L, Costisor O, Parola J, Cunha-Silva L, Puttreddy R, Rissanen K, Pina F. Chemistry and Photochemistry of 2,6-Bis(2-hydroxybenzilidene)cyclohexanone. An Example of a Compound Following the Anthocyanins Network of Chemical Reactions. J Phys Chem A 2014; 118:6208-15. [DOI: 10.1021/jp505533b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Artur J. Moro
- REQUIMTE,
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal
| | - Ana-Maria Pana
- Institute of Chemistry Timisoara of Romanian Academy, 24 MihaiViteazul Bvd, 300223 Timisoara, Romania
| | - Liliana Cseh
- Institute of Chemistry Timisoara of Romanian Academy, 24 MihaiViteazul Bvd, 300223 Timisoara, Romania
| | - Otilia Costisor
- Institute of Chemistry Timisoara of Romanian Academy, 24 MihaiViteazul Bvd, 300223 Timisoara, Romania
| | - Jorge Parola
- REQUIMTE,
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal
| | - L. Cunha-Silva
- REQUIMTE,
Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal
| | - Rakesh Puttreddy
- Department
of Chemistry, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - Kari Rissanen
- Department
of Chemistry, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - Fernando Pina
- REQUIMTE,
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal
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225
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Sousa A, Araújo P, Cruz L, Brás NF, Mateus N, De Freitas V. Evidence for copigmentation interactions between deoxyanthocyanidin derivatives (oaklins) and common copigments in wine model solutions. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:6995-7001. [PMID: 24392836 DOI: 10.1021/jf404640m] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The aim of this study was to investigate interactions possibly taking place in red wine between oaklins, which are deoxyanthocyanidin derivatives (guaiacylcatechin-pyrylium and syringylcatechin-pyrylium), and several copigments: catechin (CP1), epicatechin (CP2), chlorogenic acid (CP3), epigallocatechin (CP4), and procyanidin B3 (CP5). The results show that oaklins, like common anthocyanins, also present copigmentation interactions that further stabilize the flavylium cation in hydroalcoholic solutions. Molecular dynamics simulations were also performed to interpret the binding data, to specify the relative arrangement of the pigment and copigment molecules within the complexes, and to interpret their absorption properties in the visible range.
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Affiliation(s)
- André Sousa
- Departamento de Quı́mica, Faculdade de Ciências, Universidade do Porto , Rua do Campo Alegre 687, 4169-007 Porto, Portugal
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226
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Pina F. Chemical applications of anthocyanins and related compounds. A source of bioinspiration. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:6885-97. [PMID: 24397265 DOI: 10.1021/jf404869m] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Independently of the natural or synthetic origin, flavylium derivatives follow the same network of chemical reactions. Actually, the flavylium cation is stable only at low pH values. Increasing the pH gives rise to the formation of several species: quinoidal bases, hemiketal, cis- and trans-chalcones, and their deprotonated forms. A deep knowledge of the thermodynamics and kinetics of these species is an essential tool to practical applications of these compounds, in particular, in the domain of food chemistry. In this work the network of chemical reactions involving flavylium derivatives is presented, and the respective thermodynamics and kinetics are discussed in detail, including the mathematical expressions and a step-by-step procedure to calculate all of the rate and equilibrium constants of the system. Examples of systems possessing a high or low cis-trans isomerization barrier are shown. Recent practical applications of anthocyanins and related compounds illustrate the potentialities of the flavylium-based family of compounds.
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Affiliation(s)
- Fernando Pina
- REQUIMTE, Departamento de Quı́mica, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa , 2829-516 Monte de Caparica, Portugal
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227
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Fernandes A, Brás NF, Mateus N, de Freitas V. Understanding the molecular mechanism of anthocyanin binding to pectin. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:8516-8527. [PMID: 24991843 DOI: 10.1021/la501879w] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Association between anthocyanins and carbohydrates has drawn attention over the past few years and this interaction is of particularly importance in food chemistry since these compounds are often found together in plants and foodstuffs. This work intended to bring insights on the interaction between ionic carbohydrates (pectin) and two anthocyanins (cyanidin-3-O-glucoside, cy3glc and delphinidin-3-O-glucoside, dp3glc). The interaction between the flavylium cation and hemiketal anthocyanin forms was characterized by saturation transfer difference (STD) NMR spectroscopy and the respective dissociation constant (Kd) was obtained. This binding was also studied by Molecular Dynamics simulation. In the presence of the anthocyanin hemiketal form a weak interaction between anthocyanins and pectin seems to occur. A variation in the extent of this interaction was also noticed for the two anthocyanins with dp3glc bearing three hydroxyl groups, revealing to be a stronger binder to pectin (Kd ≈ 180 μM for dp3glc and Kd ≈ 250 μM for cy3glc). Experiments performed at acidic pH (flavylium cation) revealed a much stronger interaction (Kd ≈ 2 μM). These experimental results were also supported by theoretical studies which also revealed a stronger interaction in the presence of the anthocyanin flavylium cation and also a stronger interaction between pectin and dp3glc than with cy3glc (for the hemiketal form).
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Affiliation(s)
- Ana Fernandes
- Centro de Investigação em Química (CIQ) and ‡REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto , Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
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228
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Gavara R, Gago S, Jordão N, Pina F. 4′-Carboxy-7-hydroxyflavylium. A Multistate System Involving Twelve Species Reversibly Interconverted by pH and Light Stimuli. J Phys Chem A 2014; 118:4723-31. [DOI: 10.1021/jp503790z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Raquel Gavara
- REQUIMTE,
Departamento de
Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal
| | - Sandra Gago
- REQUIMTE,
Departamento de
Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal
| | - Noémi Jordão
- REQUIMTE,
Departamento de
Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal
| | - Fernando Pina
- REQUIMTE,
Departamento de
Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal
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229
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Pana AM, Badea V, Bănică R, Bora A, Dudas Z, Cseh L, Costisor O. Network reaction of 2,6-bis(2-hydroxybenzilidene)cyclohexanone by external stimuli. J Photochem Photobiol A Chem 2014. [DOI: 10.1016/j.jphotochem.2014.03.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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230
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Basílio N, Pina F. Flavylium network of chemical reactions in confined media: modulation of 3',4',7-trihydroxyflavilium reactions by host-guest interactions with cucurbit[7]uril. Chemphyschem 2014; 15:2295-302. [PMID: 24862455 DOI: 10.1002/cphc.201402051] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Indexed: 01/23/2023]
Abstract
In moderately acidic aqueous solutions, flavylium compounds undergo a pH-, and in some cases, light-dependent array of reversible chemical reactions. This network can be described as a single acid-base reaction involving a flavylium cation (acidic form) and a mixture of basic forms (quinoidal base, hemiketal and cis and trans chalcones). The apparent pK'a of the system and the relative mole fractions of the basic forms can be modulated by the interaction with cucurbit[7]uril. The system is studied by using (1) H NMR spectroscopy, UV/Vis spectroscopy, flash photolysis, and steady-state irradiation. Of all the network species, the flavylium cation possesses the highest affinity for cucurbit[7]uril. The rate of interconversion between flavylium cation and the basic species (where trans-chalcone is dominant) is approximately nine times lower inside the cucurbit[7]uril.
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Affiliation(s)
- Nuno Basílio
- REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica (Portugal)
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231
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Carbonneau MA, Cisse M, Mora-Soumille N, Dairi S, Rosa M, Michel F, Lauret C, Cristol JP, Dangles O. Antioxidant properties of 3-deoxyanthocyanidins and polyphenolic extracts from Côte d’Ivoire’s red and white sorghums assessed by ORAC and in vitro LDL oxidisability tests. Food Chem 2014; 145:701-9. [DOI: 10.1016/j.foodchem.2013.07.025] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 06/28/2013] [Accepted: 07/03/2013] [Indexed: 11/17/2022]
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232
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Paul ND, Mandal S, Otte M, Cui X, Zhang XP, de Bruin B. Metalloradical approach to 2H-chromenes. J Am Chem Soc 2014; 136:1090-6. [PMID: 24400781 PMCID: PMC3936204 DOI: 10.1021/ja4111336] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Cobalt(III)-carbene radicals, generated through metalloradical activation of salicyl N-tosylhydrazones by cobalt(II) complexes of porphyrins, readily undergo radical addition to terminal alkynes to produce salicyl-vinyl radical intermediates. Subsequent hydrogen atom transfer (HAT) from the hydroxy group of the salicyl moiety to the vinyl radical leads to the formation of 2H-chromenes. The Co(II)-catalyzed process can tolerate various substitution patterns and produces the corresponding 2H-chromene products in good isolated yields. EPR spectroscopy and radical-trapping experiments with TEMPO are in agreement with the proposed radical mechanism. DFT calculations reveal the formation of the salicyl-vinyl radical intermediate by a metalloradical-mediated process. Unexpectedly, subsequent HAT from the hydroxy moiety to the vinyl radical leads to formation of an o-quinone methide intermediate, which dissociates spontaneously from the cobalt center and easily undergoes an endocyclic, sigmatropic ring-closing reaction to form the final 2H-chromene product.
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Affiliation(s)
- Nanda D. Paul
- Homogeneous Catalysis group, van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Sutanuva Mandal
- Homogeneous Catalysis group, van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Matthias Otte
- Homogeneous Catalysis group, van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Xin Cui
- Department of Chemistry, University of South Florida, Tampa, Florida 33620-5250, United States
| | - X. Peter Zhang
- Department of Chemistry, University of South Florida, Tampa, Florida 33620-5250, United States
| | - Bas de Bruin
- Homogeneous Catalysis group, van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
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233
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Bindu PJ, Mahadevan KM, Naik TRR, Harish BG. Synthesis, DNA binding, docking and photocleavage studies of quinolinyl chalcones. MEDCHEMCOMM 2014. [DOI: 10.1039/c4md00185k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A series of simple quinoline–chalcone conjugates have been synthesized and evaluated for their nucleolytic activity. The compounds 3c and 3d exhibited promising DNA binding and DNA photocleavage studies.
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Affiliation(s)
- P. J. Bindu
- Department of Studies and Research in Chemistry
- Kuvempu University
- , India
| | - K. M. Mahadevan
- Department of Studies and Research in Chemistry
- Kuvempu University
- , India
| | - T. R. Ravikumar Naik
- Department of Center of Nano Science and Engineering
- Indian Institute of Science
- Bangalore 560 012, India
| | - B. G. Harish
- Department of Biotechnology
- M.S. Ramaiah Institute of Technology
- Bengaluru, India
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234
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Sousa A, Cabrita L, Araújo P, Mateus N, Pina F, de Freitas V. Color stability and spectroscopic properties of deoxyvitisins in aqueous solution. NEW J CHEM 2014. [DOI: 10.1039/c3nj01271a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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235
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Abstract
Cyanidin was studied by direct pH jumps (from equilibrated solutions at very low pH values to higher pH values) and reverse pH jumps (from equilibrated or not equilibrated solutions at higher pH values to very low ones).
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Affiliation(s)
- Luis Cabrita
- REQUIMTE
- Departamento de Química
- Faculdade de Ciências e Tecnologia
- Universidade Nova de Lisboa
- , Portugal
| | - Vesselin Petrov
- Laboratory of Organic Photochemistry
- Faculty of Chemistry
- University of Sofia
- Sofia, Bulgaria
| | - Fernando Pina
- REQUIMTE
- Departamento de Química
- Faculdade de Ciências e Tecnologia
- Universidade Nova de Lisboa
- , Portugal
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236
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Fernandes A, Ivanova G, Brás NF, Mateus N, Ramos MJ, Rangel M, de Freitas V. Structural characterization of inclusion complexes between cyanidin-3-O-glucoside and β-cyclodextrin. Carbohydr Polym 2013; 102:269-77. [PMID: 24507282 DOI: 10.1016/j.carbpol.2013.11.037] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 11/06/2013] [Accepted: 11/26/2013] [Indexed: 11/25/2022]
Abstract
Inclusion complex formation between the multiple equilibrium forms of cyanidin-3-O-glucoside (cy3glc) and β-cyclodextrin (β-CD) was investigated using a combined approach of NMR spectroscopy and Molecular Dynamics simulation. Diffusion ordered NMR spectroscopy (DOSY) and study of nuclear Overhauser effects (NOE) were used to determine the selective intermolecular interactions and structure of these complexes in aqueous solution. The observed chemical shift displacements of resonance signals of protons from the interior of β-CD cavity and protons belonging to the hemiketal (B) and cis-chalcone forms (Cc), the diffusion measurements using DOSY and the NOE studies have anticipated the formation of an inclusion complex between these two forms and β-CD. The analysis of the NMR spectral data has shown no evidence of internal interaction between β-CD and the flavylium cation (AH(+)) or trans-chalcone (Ct) forms of cy3glc. The hemiketal formed a 1:1 inclusion complex with β-cyclodextrin in which the pyranic C ring is deeply included inside the β-CD cavity while B ring lies on the plane of the wider rim of β-CD. The structure of the complexes was also clarified through a theoretical approach by Molecular Dynamics simulation.
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Affiliation(s)
- Ana Fernandes
- Centro de Investigação em Química (CIQ), Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal
| | - Galya Ivanova
- REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
| | - Natércia F Brás
- REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
| | - Nuno Mateus
- Centro de Investigação em Química (CIQ), Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal
| | - Maria J Ramos
- REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
| | - Maria Rangel
- REQUIMTE, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Victor de Freitas
- Centro de Investigação em Química (CIQ), Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal.
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237
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García-Estévez I, Gavara R, Alcalde-Eon C, Rivas-Gonzalo JC, Quideau S, Escribano-Bailón MT, Pina F. Thermodynamic and kinetic properties of a new myrtillin-vescalagin hybrid pigment. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:11569-11578. [PMID: 24164407 DOI: 10.1021/jf403319u] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
During red wine maturation in contact with oak wood, C-glucosidic ellagitannins can react with anthocyanins, leading to new pigments. In this work the thermodynamic and kinetic constants of the network pH-dependent equilibrium of a new myrtillin (delphinidin 3-O-glucoside)-vescalagin hybrid pigment (1-deoxyvescalagin-(1β→8)-myrtillin) have been determined by UV-visible absorption and stopped-flow experiments and compared to those determined for myrtillin. The vescalagin substitution at the C-8' center of myrtillin entails important variations in the pigment behavior upon pH changes. The hybrid pigment showed lower pK'a and pKa values and a much higher value of Kt. As a consequence, at moderately acidic pH values (4 < pH < 6), the percentage of the hemiketal is much lower and the quinoidal base and the (E)-chalcone represent higher percentages relative to those for myrtillin. Therefore, the hybrid pigment can provide in slightly acidic or neutral solutions an exceptionally different color compared to that of myrtillin.
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Affiliation(s)
- Ignacio García-Estévez
- Grupo de Investigación en Polifenoles (GIP), Facultad de Farmacia, Universidad de Salamanca , E37007 Salamanca, Spain
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238
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Calogero G, Sinopoli A, Citro I, Di Marco G, Petrov V, Diniz AM, Parola AJ, Pina F. Synthetic analogues of anthocyanins as sensitizers for dye-sensitized solar cells. Photochem Photobiol Sci 2013; 12:883-94. [PMID: 23467482 DOI: 10.1039/c3pp25347c] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Seven flavylium salt dyes were employed for the first time as sensitizers for dye-sensitized solar cells (DSSCs). The theoretical and experimental wavelengths of the maximum absorbances, the HOMO and LUMO energy levels, the coefficients, the oscillator strengths and the dipole moments are calculated for these synthetic dyes. The introduction of a donor group in the flavylium molecular structure was investigated. Photophysical and photoelectrochemical measurements showed that some of these synthetic analogues of anthocyanins are very promising for DSSC applications. The best performance was obtained by a DSSC based on the novel compound 7-(N,N-diethylamino)-3',4'-dihydroxyflavylium which produced a 2.15% solar energy-to-electricity conversion efficiency, under AM 1.5 irradiation (100 mW cm(-2)) with a short-circuit current density (J(sc)) of 12.0 mA cm(-2), a fill factor of 0.5 and an open-circuit voltage (V(oc)) of 0.355 V; its incident photocurrent efficiency of 51% at the peak of the visible absorption band of the dye is remarkable. Our results demonstrated that the substitution of a hydroxylic group with a diethylamine unit in position 7 of ring A of the flavylium backbone expanded the π-conjugation in the dye and thus resulted in a higher absorption in the visible region and is advantageous for effective electron injection from the dye into the conduction band of TiO2.
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Affiliation(s)
- Giuseppe Calogero
- CNR-IPCF, Istituto per i Processi Chimico-Fisici, via F. Stagno D'Alcontres 37, I-98158 Messina, Italy.
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239
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Jordão N, Gavara R, Parola AJ. Flavylium-Supported Poly(N-isopropylacrylamide): A Class of Multistimuli Responsive Polymer. Macromolecules 2013. [DOI: 10.1021/ma401497q] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Noémi Jordão
- REQUIMTE, Departamento de
Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Raquel Gavara
- REQUIMTE, Departamento de
Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - A. Jorge Parola
- REQUIMTE, Departamento de
Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
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240
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Petrov V, Stanimirov S, Petrov IK, Fernandes A, de Freitas V, Pina F. Emptying the β-Cyclodextrin Cavity by Light: Photochemical Removal of the trans-Chalcone of 4′,7-Dihydroxyflavylium. J Phys Chem A 2013; 117:10692-701. [DOI: 10.1021/jp4060582] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Vesselin Petrov
- Laboratory
of Organic Photochemistry, Faculty of Chemistry, University of Sofia, 1 James Bourchier Boulevard, 1164 Sofia, Bulgaria
- REQUIMTE,
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Monte de Caparica, Portugal
| | - Stanislav Stanimirov
- Laboratory
of Organic Photochemistry, Faculty of Chemistry, University of Sofia, 1 James Bourchier Boulevard, 1164 Sofia, Bulgaria
| | - Ivan K. Petrov
- Laboratory
of Organic Photochemistry, Faculty of Chemistry, University of Sofia, 1 James Bourchier Boulevard, 1164 Sofia, Bulgaria
| | - Ana Fernandes
- Centro
de Investigação em Química, Departamento de Química,
Faculdade de Ciências, Universidade do Porto, Rua do Campo
Alegre 687, 4169-007 Porto, Portugal
| | - Victor de Freitas
- Centro
de Investigação em Química, Departamento de Química,
Faculdade de Ciências, Universidade do Porto, Rua do Campo
Alegre 687, 4169-007 Porto, Portugal
| | - Fernando Pina
- REQUIMTE,
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Monte de Caparica, Portugal
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241
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Basílio N, Piñeiro Á, Da Silva JP, García-Río L. Cooperative Assembly of Discrete Stacked Aggregates Driven by Supramolecular Host–Guest Complexation. J Org Chem 2013; 78:9113-9. [DOI: 10.1021/jo401307c] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Nuno Basílio
- Departamento
de Química Física, Centro de Investigación en
Química Biológica y Materiales Moleculares (CIQUS), Universidad de Santiago de Compostela, 15782 Santiago
de Compostela, Spain
| | - Ángel Piñeiro
- Departamento
de Física Aplicada, Facultad de Física, Universidad de Santiago de Compostela, Campus Vida, 15782 Santiago de
Compostela, Spain
| | - José P. Da Silva
- Faculdade
de Ciências e Tecnologia, CIQA, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - Luis García-Río
- Departamento
de Química Física, Centro de Investigación en
Química Biológica y Materiales Moleculares (CIQUS), Universidad de Santiago de Compostela, 15782 Santiago
de Compostela, Spain
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242
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Moro A, Diniz AM, Petrov V, Pina F. Chemistry of 7,8-dihydroxy-2-(4-dimethylaminostyryl)-1-benzopyrylium. A photochromic system switching from yellow to green. J Photochem Photobiol A Chem 2013. [DOI: 10.1016/j.jphotochem.2013.04.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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243
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Characterisation of phenolic compounds in wild fruits from Northeastern Portugal. Food Chem 2013; 141:3721-30. [PMID: 23993541 DOI: 10.1016/j.foodchem.2013.06.071] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 05/26/2013] [Accepted: 06/15/2013] [Indexed: 11/21/2022]
Abstract
This study aimed to analyse the phenolic composition of wild fruits of Arbutus unedo (strawberry-tree), Prunus spinosa (blackthorn), Rosa canina and Rosa micrantha (wild roses). Analyses were performed by HPLC-DAD-ESI/MS. P spinosa fruits presented the highest concentration in phenolic acids (29.78 mg/100 g dry weight), being 3-O-caffeoylquinic acid the most abundant one, and flavone/ols (57.48 mg/100 g), among which quercetin3-O-rutinoside (15.63 mg/100 g) was the majority compound. (+)-Catechin was the most abundant compound in A. unedo (13.51 mg/100 g) and R. canina (3.59 mg/100 g) fruits. A. unedo fruits presented the highest concentration in flavan-3-ols (36.30 mg/100 g). Cyanidin 3-O-glucoside was found in all the studied fruits, being the major anthocyanin in most of them, with the exception of P. spinosa samples, in which cyaniding 3-O-rutinoside and peonidin 3-O-rutinoside predominated; P. spinosa fruit presented the more complex anthocyanin profile among the analysed fruits and also the highest anthocyanin concentrations, which was coherent with its greater pigmentation. All in all, P. spinosa presented the highest levels of phenolic acids and flavonoids, including anthocyanins, flavonols and flavones, although no flavan-3-ols could be identified in its fruits. The present study represents a contribution to the chemical characterisation of phenolic compounds from wild fruits with acknowledged antioxidant activity and traditionally used for several folk medicinal applications.
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244
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Limón PM, Gavara R, Pina F. Thermodynamics and kinetics of cyanidin 3-glucoside and caffeine copigments. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:5245-5251. [PMID: 23697334 DOI: 10.1021/jf4006643] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The multiequilibrium system of reactions of cyanidin 3-glucoside at acidic and mildly acidic pH values was studied in the presence of caffeine as a copigment. The thermodynamic and kinetic constants were determined using the so-called direct and reverse pH jump experiments that were followed by conventional UV-vis spectroscopy or stopped flow coupled to a UV-vis detector, depending on the rate of the monitored process. Compared with that of free anthocyanin, the copigmentation with caffeine extends the domain of the flavylium cation up to less acidic pH values, while in a moderately acidic medium, the quinoidal base becomes more stabilized. As a consequence, the hydration to give the colorless hemiketal is difficult over the entire range of pH values. At pH 1, two adducts were found for the flavylium cation-caffeine interaction, with stoichiometries of 1:1 and 1:2 and association constants of 161 M⁻¹ (K₁) and 21 M⁻¹ (K₂), respectively.
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Affiliation(s)
- Piedad M Limón
- Department of Physical and Analytical Chemistry, Jaén University , EPS of Linares, Alfonso X El Sabio, n° 28, 23700 Linares, Jaén, Spain
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245
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Leydet Y, Batat P, Jonusauskas G, Denisov S, Lima JC, Parola AJ, McClenaghan ND, Pina F. Impact of water on the cis-trans photoisomerization of hydroxychalcones. J Phys Chem A 2013; 117:4167-73. [PMID: 23611019 DOI: 10.1021/jp402761j] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The photochromism of a 2-hydroxychalcone has been studied in CH3CN and H2O/CH3OH (1/1, v/v), as well as in analogous deuterated solvents using steady-state (UV-vis absorption, (1)H and (13)C NMR) and time-resolved (ultrafast transient absorption and nanosecond flow flash photolysis) spectroscopies. Whereas the irradiation of trans-chalcone (Ct) under neutral pH conditions leads to the formation of the same final chromene derivative (B) in both media, two distinct photochemical mechanisms are proposed in agreement with thermodynamic and kinetic properties of the chemical reaction network at the ground state. Following light excitation, the first steps are identical in acetonitrile and aqueous solution: the Franck-Condon excited state rapidly populates the trans-chalcone singlet excited state (1)Ct* (LE), which evolves into a twisted state (1)P*. This excited state is directly responsible for the photochemistry in acetonitrile in the nanosecond time scale (16 ns) leading to the formation of cis-chalcone (Cc) through a simple isomerization process. The resulting cis-chalcone evolves into the chromene B through a tautomerization process in the ground state (τ = 10 ms). Unlike in acetonitrile, in H2O/CH3OH (1/1, v/v), the P* state becomes unstable and evolves into a new state attributed to the tautomer (1)Q*. This state directly evolves into B in one photochemical step through a consecutive ultrafast tautomerization process followed by electrocyclization. This last case represents a new hypothesis in the photochromism of 2-hydroxychalcone derivatives.
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Affiliation(s)
- Yoann Leydet
- REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
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246
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Fernandes A, Sousa A, Azevedo J, Mateus N, de Freitas V. Effect of cyclodextrins on the thermodynamic and kinetic properties of cyanidin-3-O-glucoside. Food Res Int 2013. [DOI: 10.1016/j.foodres.2013.01.037] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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247
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Cruz L, Mateus N, de Freitas V. First chemical synthesis report of an anthocyanin metabolite with in vivo occurrence: cyanidin-4′-O-methyl-3-glucoside. Tetrahedron Lett 2013. [DOI: 10.1016/j.tetlet.2013.03.100] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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248
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Gavara R, Leydet Y, Petrov V, Pina F. Photochemistry of 2-(4-hydroxystyryl)-1-naphthopyrylium. Photochem Photobiol Sci 2013; 11:1691-9. [PMID: 22797713 DOI: 10.1039/c2pp25104c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new photochromic system based on 2-(4-hydroxystyryl)-1-naphthopyrylium encompasses the properties of the previously described naphthoflavylium and styrylflavylium systems. The photoproduct exhibits a colour deep in hue and is red shifted in comparison with the equivalent flavylium system. Reaction of 2-hydroxy-1-naphthaldehyde with p-hydroxystyrylmethylketone in acetic acid in the presence of tetrafluoroboric acid and acetic anhydride as catalysts leads to a mixture of two compounds: the photochromic 2-(4-hydroxystyryl)-1-naphthopyrylium and a second product 2-(4-acetoxystyryl)-1-naphthopyrylium resulting from the acetylation by acetic anhydride of the former. In acidic medium and at room temperature the hydrolysis of the acetoxy derivative leads to the 2-(4-hydroxystyryl)-1-naphthopyrylium, in circa 2 days, [HCl] = 0.25 M. The pH dependent chemical reactions taking place with 2-(4-hydroxystyryl)-1-naphthopyrylium were determined by UV-Vis, stooped flow, flash photolysis and (1)H NMR and follow the same general pattern of flavylium derivatives. In order to rationalize the photochromism, an energy level diagram summarizing all the equilibrium and rate constants of the network was drawn.
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Affiliation(s)
- Raquel Gavara
- REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
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249
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Yamamoto A, Hasegawa T, Hamada T, Hirukawa T, Hisaki I, Miyata M, Tohnai N. Role-Allocated Combination of Two Types of Hydrogen Bonds towards Constructing a Breathing Diamondoid Porous Organic Salt. Chemistry 2013; 19:3006-16. [DOI: 10.1002/chem.201202959] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 11/21/2012] [Indexed: 11/11/2022]
Affiliation(s)
- Atsushi Yamamoto
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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250
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Petrov V, Gavara R, Dangles O, Al Bittar S, Mora-Soumille N, Pina F. A flash photolysis and stopped-flow spectroscopy study of 3',4'-dihydroxy-7-O-β-D-glucopyranosyloxyflavylium chloride, an anthocyanin analogue exhibiting efficient photochromic properties. Photochem Photobiol Sci 2013; 12:576-81. [PMID: 23280153 DOI: 10.1039/c2pp25329a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The complete determination of all rate and equilibrium constants of the network of reversible chemical reactions involving the anthocyanin analogue, 3',4'-dihydroxy-7-O-β-D-glucopyranosyloxyflavylium chloride, was achieved by means of UV-visible spectroscopy, flash photolysis and pH jumps monitored by stopped-flow. An energy level diagram containing all the data was obtained. A detailed step by step procedure illustrating all the calculations is reported.
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Affiliation(s)
- Vesselin Petrov
- REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal
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