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Spectroscopic study of porphyrin-caffeine interactions.

Makarska-Bialokoz M - J Fluoresc (2012)

Bottom Line: The association constants were calculated using curve-fitting procedure (K(AC) of the order of magnitude of 10(3) mol(-1)).Whereas the emission spectra point at the presence of the fluorescence quenching effect testifying for the partial inactivation of the porphyrin molecule.The fluorescence quenching constants were calculated from Stern-Volmer plots.

View Article: PubMed Central - PubMed

Affiliation: Department of Inorganic Chemistry, Maria Curie-Sklodowska University, Lublin, Poland. makarska@hektor.umcs.lublin.pl

ABSTRACT
The association between water-soluble porphyrins: 4,4',4″,4'''-(21 H,23 H-porphine-5,10,15,20-tetrayl)tetrakis-(benzoic acid) (H(2)TCPP), 5,10,15,20-tetrakis(4-sulfonatophenyl)-21 H,23 H-porphine (H(2)TPPS(4)), 5,10,15,20-tetrakis[4-(trimethylammonio)phenyl]-21 H,23 H-porphine tetra-p-tosylate (H(2)TTMePP), 5,10,15,20-tetrakis(1-methyl-4-pyridyl)-21 H,23 H-porphine tetra-p-tosylate (H(2)TMePyP), the Cu(II) complexes of H(2)TTMePP and H(2)TMePyP, as well as chlorophyll a with caffeine (1,3,7-trimethylxanthine) has been studied analysing their absorption and emission spectra in aqueous (or acetone in case of chlorophyll a) solution. During the titration by caffeine the porphyrins absorption spectra undergo the evolution - the bathochromic effect can be observed as well as the hypochromicity of the Soret maximum. The association constants were calculated using curve-fitting procedure (K(AC) of the order of magnitude of 10(3) mol(-1)). Whereas the emission spectra point at the presence of the fluorescence quenching effect testifying for the partial inactivation of the porphyrin molecule. The fluorescence quenching constants were calculated from Stern-Volmer plots. The results obtained show that caffeine can interact with water-soluble porphyrins and through formation of stacking complexes is able to quench their ability to emission.

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The molecular structures of (a) caffeine(1,3,7-trimethylxanthine), (b) chlorophyll a and (c) H2TTMePP (5,10,15,20-tetrakis[4-(trimethylammonio)phenyl]-21 H,23 H-porphine)
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Fig1: The molecular structures of (a) caffeine(1,3,7-trimethylxanthine), (b) chlorophyll a and (c) H2TTMePP (5,10,15,20-tetrakis[4-(trimethylammonio)phenyl]-21 H,23 H-porphine)

Mentions: Studies described in this paper concern the spectroscopic analysis of interactions between biologically important macromolecules. The primary objective of presented research was to specify the mechanism of interactions of the chosen compounds from the class of water-soluble porphyrins with caffeine and verify as well their usefulness as chemical indicators of caffeine. The water-soluble porphyrins are the compounds with the specific spectroscopic and redox properties, as well as the ability to electron transfer, very sensitive to the subtle changes of pH, porphyrins and ligands concentration or form of complexing with metal ions proceeding in a reaction environment, what can be utilized among other things in their interactions with DNA [23–27], nucleic bases [28, M. Makarska-Bialokoz - unpublished results] and, what is equally important, in biomimetic catalysis [29–31] as well as in monitoring of the porphyrins interactions with different kinds of toxic substances [32, 33]. The secondary objective was to compare the behaviour of chlorophyll a (the porphyrin compound which is not soluble in water), during interaction with caffeine, to the results obtained for water-soluble porphyrins. To determine the caffeine - porphyrins relations the absorption and emission spectra evolution was observed during the titration by caffeine a series of water-soluble synthetic porphyrins: 5,10,15,20-tetrakis[4-(trimethylammonio)phenyl]porphine (H2TTMePP), 5,10,15,20-tetrakis(1-methyl-4-pyridyl)porphine (H2TMePyP), their complexes with Cu(II) (CuTTMePP and CuTMePyP), 4,4′,4″’,4‴-(21 H,23 H-porphine-5,10,15,20-tetrayl)tetrakis-(benzoic acid) (H2TCPP), 5,10,15,20-tetrakis(4-sulfonatophenyl)porphine) (H2TPPS4) and chlorophyll a (commercial reagent) (Fig. 1).Fig. 1


Spectroscopic study of porphyrin-caffeine interactions.

Makarska-Bialokoz M - J Fluoresc (2012)

The molecular structures of (a) caffeine(1,3,7-trimethylxanthine), (b) chlorophyll a and (c) H2TTMePP (5,10,15,20-tetrakis[4-(trimethylammonio)phenyl]-21 H,23 H-porphine)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3473192&req=5

Fig1: The molecular structures of (a) caffeine(1,3,7-trimethylxanthine), (b) chlorophyll a and (c) H2TTMePP (5,10,15,20-tetrakis[4-(trimethylammonio)phenyl]-21 H,23 H-porphine)
Mentions: Studies described in this paper concern the spectroscopic analysis of interactions between biologically important macromolecules. The primary objective of presented research was to specify the mechanism of interactions of the chosen compounds from the class of water-soluble porphyrins with caffeine and verify as well their usefulness as chemical indicators of caffeine. The water-soluble porphyrins are the compounds with the specific spectroscopic and redox properties, as well as the ability to electron transfer, very sensitive to the subtle changes of pH, porphyrins and ligands concentration or form of complexing with metal ions proceeding in a reaction environment, what can be utilized among other things in their interactions with DNA [23–27], nucleic bases [28, M. Makarska-Bialokoz - unpublished results] and, what is equally important, in biomimetic catalysis [29–31] as well as in monitoring of the porphyrins interactions with different kinds of toxic substances [32, 33]. The secondary objective was to compare the behaviour of chlorophyll a (the porphyrin compound which is not soluble in water), during interaction with caffeine, to the results obtained for water-soluble porphyrins. To determine the caffeine - porphyrins relations the absorption and emission spectra evolution was observed during the titration by caffeine a series of water-soluble synthetic porphyrins: 5,10,15,20-tetrakis[4-(trimethylammonio)phenyl]porphine (H2TTMePP), 5,10,15,20-tetrakis(1-methyl-4-pyridyl)porphine (H2TMePyP), their complexes with Cu(II) (CuTTMePP and CuTMePyP), 4,4′,4″’,4‴-(21 H,23 H-porphine-5,10,15,20-tetrayl)tetrakis-(benzoic acid) (H2TCPP), 5,10,15,20-tetrakis(4-sulfonatophenyl)porphine) (H2TPPS4) and chlorophyll a (commercial reagent) (Fig. 1).Fig. 1

Bottom Line: The association constants were calculated using curve-fitting procedure (K(AC) of the order of magnitude of 10(3) mol(-1)).Whereas the emission spectra point at the presence of the fluorescence quenching effect testifying for the partial inactivation of the porphyrin molecule.The fluorescence quenching constants were calculated from Stern-Volmer plots.

View Article: PubMed Central - PubMed

Affiliation: Department of Inorganic Chemistry, Maria Curie-Sklodowska University, Lublin, Poland. makarska@hektor.umcs.lublin.pl

ABSTRACT
The association between water-soluble porphyrins: 4,4',4″,4'''-(21 H,23 H-porphine-5,10,15,20-tetrayl)tetrakis-(benzoic acid) (H(2)TCPP), 5,10,15,20-tetrakis(4-sulfonatophenyl)-21 H,23 H-porphine (H(2)TPPS(4)), 5,10,15,20-tetrakis[4-(trimethylammonio)phenyl]-21 H,23 H-porphine tetra-p-tosylate (H(2)TTMePP), 5,10,15,20-tetrakis(1-methyl-4-pyridyl)-21 H,23 H-porphine tetra-p-tosylate (H(2)TMePyP), the Cu(II) complexes of H(2)TTMePP and H(2)TMePyP, as well as chlorophyll a with caffeine (1,3,7-trimethylxanthine) has been studied analysing their absorption and emission spectra in aqueous (or acetone in case of chlorophyll a) solution. During the titration by caffeine the porphyrins absorption spectra undergo the evolution - the bathochromic effect can be observed as well as the hypochromicity of the Soret maximum. The association constants were calculated using curve-fitting procedure (K(AC) of the order of magnitude of 10(3) mol(-1)). Whereas the emission spectra point at the presence of the fluorescence quenching effect testifying for the partial inactivation of the porphyrin molecule. The fluorescence quenching constants were calculated from Stern-Volmer plots. The results obtained show that caffeine can interact with water-soluble porphyrins and through formation of stacking complexes is able to quench their ability to emission.

Show MeSH
Related in: MedlinePlus