Luminescence spectroscopic studies of trimethinecyanines substituted in polymethine chain with nucleic acids and proteins (original) (raw)
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Spectroscopic Studies of α,γ-Disubstituted Trimethine Cyanine: New Fluorescent Dye for Nucleic Acids
2002
Spectral properties of 3-methyl-2-{3-[3-methyl-1,3-benzothiazolo-2(3H )-ylidene]-1,4-cylopentadien-1-yl}-1,3-benzothiazolo-3-ium tosylate (Cyan-Cpentd) in a free state and in the complexes with nucleic acids and synthetic polynucleotides have been investigated by absorption and fluorescence spectroscopy. Significant fluorescence intensity enhancement of dye-nucleic acids complexes is observed. For the first time Cyan-Cpentd is proposed as a new probe for nucleic acid detection. Binding mechanism of Cyan-Cpentd is discussed in view of the NA-ligand interaction models.
Dyes and Pigments, 2005
A series of homodimer styrylcyanine dyes based on (p-dimethylaminostyryl)pyridinium, (p-dimethylaminostyryl)benzoxazolium, (p-dimethylaminostyryl)benzothiazolium, (p-dimethylaminostyryl)-1,3,3-trimethyl-3H-indolium residues were synthesized. Spectralluminescent properties of the obtained homodimers in free state and in the presence of nucleic acids and BSA were studied. Homodimer styrylcyanines with the length of linkage group of 2 or more carbon atoms demonstrated a DNA-binding preference. Significant long-wave shifts of fluorescence and emission maxima of dyes with short linkage group could be explained by the interaction between chromophores due to the short distance between them, as it is the case for molecular aggregates. Homodimer dyes based on the (p-dimethylaminostyryl)pyridinium residue having linkage group of 5 or more carbon atoms interact with dsDNA with significant emission increase and could be used as DNA specific fluorescent probes.
Dyes and Pigments, 2000
Several novel homodimeric asymmetric monomethine cyanine dyes based on the thiazole orange (TO) chromophore were synthesised via an improved synthetic procedure. The two TO chromophores [1-(o-bromoalkyl)-4-[(3-methyl-2-(3H)-benzothiazolilyden)methyl] quinolinium iodide], with dierent chain lengths of the methylene linker between the quinolinium ring and the quaternary ammonium nitrogen, were connected by bisquaternization with N,N,N H ,N H-tetramethyl-1,3-propanediamine, N,N,N H ,N H-tetramethyl-1,6-hexanediamine, 1,4-diazabicyclo-[2,2,2]octane and 1,4 H-bipyridine. The homodimeric dyes have large molar absorptivity (e 130 000±180 000 l mol À1 cm À1) at 505±506 nm. In the presence of ds DNA, their¯uorescence maxima were located at 530±534 nm and the¯uorescence quantum yields were in the range 0.48±0.96. Fluorescence maxima between 560±650 nm and¯uorescence quantum yields of 0.3±0.8 were observed in the presence of ss DNA.
Bioorganic & Medicinal Chemistry Letters, 1999
Spectral properties of newly synthesized cyanine dyes, namely 1-[6-(4-{6-[2,6-dimethyl-4-(3-methyl-2,3-dihydro-1,3benzothiazol-2-ylidenmethyl)-1-pyridiniumyl]hexanoyl}piperazino)-6-oxohexyl]-2,6-dimethyl-4-(3-ethyl-2,3-dihydro--1,3-benzothiazol-2-ylidenmethyl)pyridinium (K-6) (bichromophoric dye) and 1-[5-di(3-{5-[2,6-dimethyl-4-(3-methyl-2,3-dihydro-1,3-benzothiazol-2-ylidenmethyl)-1-pyridiniumyl]pentylcarboxamido}propyl) carbamoylpentyl]-2,6-dimethyl-4-(3-methyl-2,3-dihydro-1,3-benzothiazol-2-ylidenmethyl) pyridinium (K-T) (trichromophoric dye) in solutions in the presence of and without deoxyribonucleic acid (DNA) were studied within a wide concentration range. It has been established that absorption, as well as fluorescence of investigated dye solutions, without DNA are mainly determined by H-aggregates of dye molecules. On the contrary, the fluorescence of dye solutions in the presence of DNA gives an intrinsic dye molecular fluorescence. H-aggregates are broken because of binding dye molecules with DNA. It has been suggested that both K-T and K-6 molecules bind mainly with DNA via the interaction of two chromophores. As the ratio of the number of dye molecules to that of DNA base pairs increases with an increase in dye concentration, a formation of dye molecule H-aggregates on DNA molecules are observed. Such aggregates have a different structure than those formed in the solutions without DNA. On the grounds of the data obtained, it is concluded that it is possible to use a dye aggregation capable of obtaining higher values for fluorescence enhancement of the DNA stains.
6,6'-Disubstituted benzothiazole trimethine cyanines - new fluorescent dyes for DNA detection
Spectrochimica Acta Part A-molecular and Biomolecular Spectroscopy, 2006
The influence of methyl-, 2-hydroxyethyl-, dimethyl-, diethyl-and benzoyl-amino substituents in the 6,6 -positions of benzothiazole heterocycle of trimethine cyanines on their spectral-luminescent properties and behavior in presence of DNA, RNA and BSA was studied. It was shown that incorporation of 6,6 -substituents generally leads to the increase in dyes tendency to aggregation, resulting in the considerable decrease in the emission intensity of the disubstituted dyes as compared to the unsubstituted ones. Emission of the studied 6,6 -disubstited dyes in DNA presence is considerably more intensive than in presence of RNA, that points on the existing of DNA binding preference for the mentioned dyes. Insertion of benzoyl-amino groups into the 6,6 -positions permitted us to design the DNA-sensitive dyes on the basis of symmetric trimethine cyanines with unsubstituted polymethine chain, while typically such dyes slightly respond on the presence of biopolymers. 6,6 -Benzoyl-amino-disubstituted trimethine cyanines are proposed as efficient dyes for DNA detection.
Journal of Fluorescence, 2005
A series of pentamethine cyanine dyes with cyclohexene or cyclopentene group in polymethyne chain, assumed as DNA groove-binders, were studied as fluorescent probes for nucleic acids as well as for native and denatured proteins. It was revealed that the presence of methyl or dimethyl substituent in 5 position of the cyclohexene group hinders the formation of dye-DNA fluorescent complex, while the methyl substituent in 2 position leads to the increasing of the dye-DNA complex fluorescence intensity. The dyes SL-251, SL-1041, and SL-1046 containing methyl group in the 2 position of the cyclic group, are reported as bright DNA-sensitive dyes. The study of the dyes DNA-binding specificity demonstrated significant AT-preference that points to the groove-binding interaction mode. At the same time, the dyes SL-251, SL-377, and SL-957 with the 2-methyl substituted cyclohexene group were shown to be sensitive fluorescent dyes both for nonspecific (in SDS presence) proteins detection and for native BSA.
Biomolecules
New analogs of the commercial asymmetric monomethine cyanine dyes thiazole orange (TO) and thiazole orange homodimer (TOTO) with hydroxypropyl functionality were synthesized and their properties in the presence of different nucleic acids were studied. The novel compounds showed strong, micromolar and submicromolar affinities to all examined DNA ds-polynucleotides and poly rA–poly rU. The compounds studied showed selectivity towards GC-DNA base pairs over AT-DNA, which included both binding affinity and a strong fluorescence response. CD titrations showed aggregation along the polynucleotide with well-defined supramolecular chirality. The single dipyridinium-bridged dimer showed intercalation at low dye-DNA/RNA ratios. All new cyanine dyes showed potent micromolar antiproliferative activity against cancer cell lines, making them promising theranostic agents.
Spectrochimica Acta Part A-molecular and Biomolecular Spectroscopy, 2001
Absorption, fluorescence emission and excitation spectra of benzothiazole cyanine dyes -thiazole orange (TO) and 7-methyl-6-(3-methyl-2,3-dihydro-1,3-benzothiazol-2-ylidenmethyl) [1,3] dioxolo [4%,5%:4,5] benzo [d] [1,3] thiazolium methylmethosulfate (Cyan 13) -were investigated over a wide concentration range. The dyes form aggregates with a 'sandwich'-like structure in water solution. At low dye to DNA concentrations ratios, Cyan 13 and TO monomers appear to interact with the DNA. On increasing the dye to DNA concentrations ratio, free dye molecules aggregate with the DNA-bound ones. The spectra of the free dye aggregates and the aggregates formed on the DNA, are characterized by an anomalously large (more than 100 nm) Stokes shift. This suggests, that the y-electron systems of the aggregates undergo substantial changes in excited state, compared to those of the monomers. The formation of aggregates consisting of the free and DNA-bound dye molecules can be explained using the half-intercalation model of the interaction of the cyanine dye monomers with the DNA.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy
Spectral properties of newly synthesized cyanine dyes, namely 1-[6-(4-{6-[2,6-dimethyl-4-(3-methyl-2,3-dihydro-1,3benzothiazol-2-ylidenmethyl)-1-pyridiniumyl]hexanoyl}piperazino)-6-oxohexyl]-2,6-dimethyl-4-(3-ethyl-2,3-dihydro--1,3-benzothiazol-2-ylidenmethyl)pyridinium (K-6) (bichromophoric dye) and 1-[5-di(3-{5-[2,6-dimethyl-4-(3-methyl-2,3-dihydro-1,3-benzothiazol-2-ylidenmethyl)-1-pyridiniumyl]pentylcarboxamido}propyl) carbamoylpentyl]-2,6-dimethyl-4-(3-methyl-2,3-dihydro-1,3-benzothiazol-2-ylidenmethyl) pyridinium (K-T) (trichromophoric dye) in solutions in the presence of and without deoxyribonucleic acid (DNA) were studied within a wide concentration range. It has been established that absorption, as well as fluorescence of investigated dye solutions, without DNA are mainly determined by H-aggregates of dye molecules. On the contrary, the fluorescence of dye solutions in the presence of DNA gives an intrinsic dye molecular fluorescence. H-aggregates are broken because of binding dye molecules with DNA. It has been suggested that both K-T and K-6 molecules bind mainly with DNA via the interaction of two chromophores. As the ratio of the number of dye molecules to that of DNA base pairs increases with an increase in dye concentration, a formation of dye molecule H-aggregates on DNA molecules are observed. Such aggregates have a different structure than those formed in the solutions without DNA. On the grounds of the data obtained, it is concluded that it is possible to use a dye aggregation capable of obtaining higher values for fluorescence enhancement of the DNA stains.
Dyes and Pigments, 2004
Two new homodimeric asymmetric monomethine cyanine dyes SOSO-1 and TOTO-1-6C bearing four and six positive charges respectively have been synthesized. The longest wavelength absorption maxima of both dyes lie between 495 and 520 nm; the molar absorptivities are between 110,000 and 150,000 l mol À1 cm À1 . SOSO-1 and TOTO-1-6C do not fluoresce in TE buffer and bidistilled water but become strongly fluorescent upon binding to dsDNA. The fluorescence maxima are at 540.4 and 534.4 nm and the fluorescence quantum yields are 0.25 and 0.35, respectively.