Search

Spectral-fluorescent properties of benzothiazole styryl monomer (Bos-3) and homodimer (DBos-21) dyes in presence of DNA were studied. The dyes enhance their fluorescence intensity in 2–3 orders of magnitude upon interaction with DNA. Studied styrylcyanines in DNA presence demonstrate rather high values of two-photon absorption (TPA) cross-section, which are comparable with the values of TPA cross section of the rhodamine dyes. An applicability of the styrylcyanines as probes for the fluorescence microscopy of living cells was studied. It was shown that both dyes are cell-permeable but homodimer dye DBos-21 produces noticeably brighter staining of HeLa cells comparing with monomer dye Bos-3. Molecules of DBos-21 initially bind to the nucleic acids- containing cell organelles (presumable mitochondria) and are able to penetrate into the cell nucleus. Thus, homodimer styryl DBos-21 dye is viewed as efficient stain for single-photon and two-photon excitation fluorescence imaging of living cells. [ABSTRACT FROM AUTHOR]

Abstract: 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. [Copyright &y& Elsevier]