Bright fluorescent dsDNA probes: novel polycationic asymmetric monomethine cyanine dyes based on thiazolopyridine‐quinolinium chromophore

Abstract

Seven tri-and tetracationic monomeric and homodimeric monomethine cyanine dyes based on thiazolo [4, 5-b]pyridinium and quinolinium end groups were synthesised and characterised. The dyes were tested as fluorescent DNA intercalating probes to apply in DNA gel electrophoresis. The DNA samples stained with all dyes from the series demonstrated bright fluorescent signals. DNA fragments were successfully visualised under orange and green filters as well as under standard UV transillumination. Two of the studied dyes revealed higher sensitivity to DNA when compared with the commercial dimeric cyanine dye TOTO-1. Their sensitivity reached that of the commercial dimeric cyanine dye YOYO-1, but the emission was shifted to longer wavelengths. These qualities make the dyes suitable to apply in a wide range of medical and scientific analytical methods.

Halogen-containing thiazole orange analogues – new fluorogenic DNA stains

“…2 . Such a spectral change is generally accepted as evidence for the intercalation of dye molecules into DNA [ 39 – 41 ].…”

“…Hybridization-sensitive fluorescent probes in which TO is tethered to a nucleic acid: DNA [ 22 – 23 33 – 36 ], RNA [ 20 , 36 ] or PNA [ 18 – 19 21 , 31 ]) strands have been constructed by several research groups (the Krull, Kubista, Seitz and Wagenknecht groups). The continued scientific and commercial interest in the preparation and application of cyanine dyes as bio-probes [ 37 – 38 ] and our research in this area [ 39 – 41 ] has led us to search for novel representatives of this interesting family of compounds. The main goal of the study described here was to investigate the influence of different halogen atoms (connected directly to the chromophore or as side groups) on the molar absorptivity and the fluorescence intensity of a series of new TO analogues.…”

(E)-3-Heptyl-2-(4-thiomorpholinostyryl)benzo[d]thiazol-3-ium Iodide as Solvatochromic and Fluorogenic Dye for Spectroscopy Applications

“…Cyanines usually show no intrinsic fluorescence in water solutions, while their fluorescence significantly increases upon polynucleotide binding, which makes them the perfect fluorescent probes for DNA/RNA [3][4][5] visualization and analysis. For more than sixty years, the main application of the styryl cyanine dyes, a large subgroup in the cyanine class, was mainly as sensitizers in photographic emulsions until the systematic work conducted by Yarmoluk and co-workers [6] who demonstrated the ability of the styryl cyanine dyes to bind different nucleic acids (NA) as intercalators or mainly as groove binders [7][8][9]. The investigated styryl dyes demonstrated an increase in their fluorescence in a presence of nucleic acids several times.…”

“…Molbank 2023, 2023, x 2 of 9 years, the main application of the styryl cyanine dyes, a large subgroup in the cyanine class, was mainly as sensitizers in photographic emulsions until the systematic work conducted by Yarmoluk and co-workers [6] who demonstrated the ability of the styryl cyanine dyes to bind different nucleic acids (NA) as intercalators or mainly as groove binders [7][8][9]. The investigated styryl dyes demonstrated an increase in their fluorescence in a presence of nucleic acids several times.…”

Polycationic Monomeric and Homodimeric Asymmetric Monomethine Cyanine Dyes with Hydroxypropyl Functionality—Strong Affinity Nucleic Acids Binders

“…Chloro substitution of the oxazole yellow homodimer (YOYO) resulted in a specific fluorimetric response of ds-RNA compared to ds-DNA, while the chlorinated TOTO analogue revealed specific CD recognition of alternating-DNA sequences concerning homo-DNA and homo-RNA sequences [13]. Monomethine cyanine dyes based on thiazolo [4,5-b]pyridinium and quinolinium chromophores revealed higher sensitivity to DNA when compared to commercial dimeric cyanine dye TOTO-1 [14]. Further, we prepared a new series of monomeric and homodimeric cyanine dyes that represented structural modifications of TO (thiazole orange) and TOTO (thiazole orange homodimer) dyes: thioacetyl substituents and 2-hydroxypropyl substituents [15,16].…”