Ion Pairs of Crystal Violet in Sodium Bis(2-ethylhexyl)sulfosuccinate Reverse Micelles

Oliveira, Cristieli Sérgio de Menezes; Bastos, E. L.; Duarte, Evandro L.; Itri, Rosângela; Baptista, Maurı́cio S.

doi:10.1021/la061117p

Cited by 13 publications

(12 citation statements)

References 58 publications

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“…Because the hydrophobic effect is an important driving force for cyclodextrin complex formation,43, 44 in molecular mechanics calculations, the effect of water was considered using periodic boundaries conditions. The resulting geometries of the dyes were optimized at the RM1 semiempirical level 42, 45. Tables S1 and S2 show a comparison of several semiempirical methods in the calculation of some properties of HP and HC.…”

Section: Methodsmentioning

confidence: 99%

Polymethine cyanine dyes in β‐cyclodextrin solution: multiple equilibria and chemical oxidation

Barros

Toma

et al. 2010

J of Physical Organic Chem

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Absorption and fluorescence spectroscopy, electrochemical techniques, and semiempirical calculations were employed to characterize the multiple complexation equilibria between two polymethine cyanine dyes (IR‐786 and Indocyanine green‐ICG, S) and β‐cyclodextrin (β‐CD, L), as well as the chemical reactivity of the complexed and uncomplexed species against the oxidizing agents hypochlorite (HC) and hydrogen peroxide (HP). IR‐786 dimerization is favored with the increase in β‐CD concentration in the form of (SL)2 complexes. In the case of ICG, free dimers (D) and SL complexes are favored. Both IR‐786 and ICG react and discolor in the presence of HC and HP. For IR‐786, the reaction with HP and HC proceeds with observed rate constants of 10−3 and 0.28 s−1 and second‐order rate constants (k2) of ∼10−3 and 104 M−1s−1, respectively. The intermediate species observed in the bleaching reactions of IR‐786 and ICG were shown, by cyclic voltammetry and VIS absorption, to result from one electron oxidation. IR‐786 complexed with β‐CD is protected against bleaching in the presence of HP and HC by factors of 20 and 4, respectively. This protection was not observed in ICG complexes. Superdelocalizability profile of both dyes and frontier orbital analysis indicates that β‐CD does not protect ICG from oxidation by HP or HC, whereas the 2:2 IR‐786/β‐Cd complex is able to avoid the oxidation of IR‐786. We concluded that the decrease in the chemical reactivity of the dyes against oxidant agents in the presence of β‐CD is due to the formation of (SL)2 complexes. Copyright © 2010 John Wiley & Sons, Ltd.

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Section: Methodsmentioning

confidence: 99%

Polymethine cyanine dyes in β‐cyclodextrin solution: multiple equilibria and chemical oxidation

Barros

Toma

et al. 2010

J of Physical Organic Chem

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“…This is another example of the important roles the electrostatic forces and the amphiphilic character play in allowing the interaction of the photosensitizer with membranes. An effect that seems to be important to stabilize photosensitizer in the interfacial region of the membranes is the formation of ion-pairs [38].…”

Section: Sens Binding In Membrane Mimetics Mitochondria and Cellsmentioning

confidence: 99%

“…The interactions of photosensitizers with membranes may occur through several types of forces, including electrostatic, hydrophobic, hydration and coordination [22,25,26,29,30,[33][34][35][36][37][38]. The initial interaction between a sens and a specific type of membrane will take place via electrostatic attraction.…”

Section: Sens Binding In Membrane Mimetics Mitochondria and Cellsmentioning

confidence: 99%

Relationship between structure and photoactivity of porphyrins derived from protoporphyrin IX

Fernandes

Oliveira

Baptista

2010

J. Porphyrins Phthalocyanines

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Protoporphyrin (Pp IX) derivatives were prepared to study the relationship between photosensitizer structure and photoactivity, with an emphasis on understanding the role of membrane interactions in the efficiency of photosensitizers used in photodynamic therapy (PDT). The synthetic strategies described here aimed at changing protoporphyrin periferic groups, varying overall charge and oil/water partition, while maintaining their photochemical properties. Three synthetic routes were used: (1) modification of Pp IX at positions 31 and 81 by addition of alkyl amine groups of different lengths (compounds 2–5), (2) change of Pp IX at positions 133 and 173, generating alkyl amines (compounds 6 and 7, a phosphate amine (compound 8, and quarternary ammonium compounds (compounds 9 and 10), and (3) amine-alkylation of Hematoporphyrin IX (Hp IX) at positions 31, 81, 133 and 173(compound 12). Strategy 1 leads to hydrophobic compounds with low photocytotoxicity. Strategy 2 leads to compounds 6–10 that have high levels of binding/incorporation in vesicles, mitochondria and cells, which are indicative of high bioavailability. Addition of the phosphate group (compound 8), generates an anionic compound that has low liposome and cell incorporation, plus low photocytotoxicity. Compound 12 has intermediate incorporation and photocytotoxic properties. Compound modification is also associated with changes in their sub-cellular localization: 30% of 8 (anionic) is found in mitochondria as compared to 95% of compound 10 (cationic). Photocytotoxicity was shown to be highly correlated with membrane affinity, which depends on the asymmetrical and amphiphilic characters of sens, as well as with sub-cellular localization.

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“…30 Also, structural parameters of E/Z isomers of bis-fenchylidene obtained at the PBE1PBE/6-311+G(d,p) level are in good agreement with both X-ray data as well as theoretical calculations (see Supplementary Information). [31][32][33][34][35] The optimized structures of E/Z , 1a and 1b are depicted in Figure 1 and relevant geometry parameters are given in Table S1 (see Supplementary Information). The isotropic chemical shielding at H and C nuclei of 1a, 1b and TMS were calculated at the GIAO/IEFPCM/W04P/cc-pVDZ// pbe1pbe/6-311+G(d,p) level.…”

Section: Resultsmentioning

confidence: 99%

“…34 This approach allowed us to calculate 1 H and 13 C chemical shifts of 1a and 1b, which were compared to the experimental data ( Figure S8). 35 The adjusted coefficients of determination (adj-R 2 …”

Section: Resultsmentioning

confidence: 99%

Synthesis of some fenchyl-substituted alkenes and enol-ethers containing 3-oxyphenyl substituents by the Barton-Kellogg reaction

Ciscato¹,

Bastos²,

Bartoloni

et al. 2010

J. Braz. Chem. Soc.

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Usando-se a reação de Barton-Kellogg, foram sintetizados um alceno e dois enóis-éteres fenchyl-substituídos, contendo grupos 3-oxifenila como substituintes. O fenchil-alceno aromático tri-substituído 1a foi preparado com rendimento de 53% a partir de tiofenchona e um diazoanisol. A abordagem inversa, baseada no acoplamento entre diazofenchona e tionoésteres aromáticos, foi utilizada para produzir os enóis-éteres 1b e 1c (rendimentos 95 e 75%, respectivamente). Em todos os casos foi obtida uma mistura dos isômeros E e Z; a atribuição e quantificação destes isômeros foram realizadas pela análise dos dados de espectroscopia de RMN assistida por cálculos teóricos (relação E/Z 1a = 0,72, 1b = 2,2, 1c = 1,8). A reação ocorre com baixa estereosseletividade, levando à formação preferencial dos diastereoisômeros das olefinas e enóis-éteres, nos quais o substituinte aromático está localizado ao lado dos dois grupos metila da porção fenchila.The synthesis of one fenchyl-substituted alkene and two enol-ethers, containing 3-oxyphenyl substituents by the Barton-Kellogg reaction is described. The tri-substituted aromatic fenchylalkene 1a was prepared in 53% yield from thiofenchone and a diazoanisole; whereas enol-ethers 1b and 1c were obtained (95 and 75% yield, respectively) using an inverse approach based on diazofenchone and aromatic thionoesters. A mixture of Z and E isomers was obtained in all cases; isomer attribution and quantification has been carried out by analysis of NMR spectroscopic data assisted by theoretical calculations (E/Z ratio: 1a = 0.72, 1b = 2.2, 1c = 1.8). Reaction proceeds with low stereoselectivity leading to the preferential formation of diastereoisomeric olefins and enol-ethers where the aromatic substituent resides at the side of the two fenchyl methyl groups.

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Ion Pairs of Crystal Violet in Sodium Bis(2-ethylhexyl)sulfosuccinate Reverse Micelles

Cited by 13 publications

References 58 publications

Polymethine cyanine dyes in β‐cyclodextrin solution: multiple equilibria and chemical oxidation

Polymethine cyanine dyes in β‐cyclodextrin solution: multiple equilibria and chemical oxidation

Relationship between structure and photoactivity of porphyrins derived from protoporphyrin IX

Synthesis of some fenchyl-substituted alkenes and enol-ethers containing 3-oxyphenyl substituents by the Barton-Kellogg reaction

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