Luminescence of 5-arylmethylene-2-thioxoimidazolidin-4-ones and their application in the detection of DNA

MARQUEZ, DALMA M.; PEPINO, ANA J.; FAILLACE, MARTIN S.; PELAEZ, WALTER J.; CARRIZO, MARIA ELENA; BURGOS PACI, MAXIMILIANO; ARGUELLO, GUSTAVO A.

Villa Carlos Paz- Cordoba Argentina

Conferencia; 13a Conferencia Latinoamericana de Fisico-quimica organica; 2015

INFIQC, Universidad Nacional de Cordoba, Argentina

Photoisomerization Z/E reactions are elementary processes of fundamental importance in biological photoreceptors1 and in the design of molecular photo-active materials2. Moreover, compounds that can exist in their Z and E conformations are known to exhibit fluorescence in one of their isomeric states. Such molecules have been developed as useful imaging tools which can help visualizing various biological events through the highly sensitive detection of biologically important molecules such as DNA.2 In a previous work3, we studied the mechanism of photoisomerization and thermal reversion of 5-arylmethylene-2-thioxoimidazolidin-4-one (Figure 1, 1a). This compound exists predominantly in its Z form but can be isomerized to the E form by irradiation at 355 nm. In this work, we studied the luminescence of six thioxoimidazolidin-4-one derivatives (1a-f) and their application in the detection of double stranded DNA (dsDNA). The fluorescent profile was examined in the absence and presence of fish dsDNA, and the results for 1a are shown in Figure 2. The compound 1a did not exhibit fluorescence in its Z form, however, in the presence of dsDNA, exhibited fluorescence which gradually increased and reached a maximum after near 4 h (λem: 440 nm). In terms of emission intensity, the behavior of 1a is equivalent to that of ethidium bromide, which is widely used in DNA detection. However, we believe our imidazolidine could perform better not only because its emission appears inside the visible spectrum, but because of its reduced toxicity.