Publications > Cañeque et al

Dyes Pigm. 2017, 144, 17

Azonia aromatic heterocycles as a new acceptor unit in D-π-A%@2B vs D-A%@2B nonlinear optical chromophores.

Tatiana Cañeque¹, Ana M. Cuadro¹, Raúl Custodio¹, Julio Alvarez-Builla¹, Belén Batanero¹, Pilar Gómez-Sal¹, Javier Pérez-Moreno², Koen Clays³, Obis Castaño⁴, José L. Andrés⁴, Thais Carmona⁴, Francisco Mendicuti⁴, Juan J Vaquero¹

1. Departamento de Química Orgánica y Química Inorgánica, Universidad de Alcalá, 28871, Alcalá de Henares, Madrid, Spain.  2. Department of Physics, Skidmore College, Saratoga Springs, NY, United States.  3. Department of Chemistry, University of Leuven, Celestijnenlaan 200 D, 3001, Leuven, Belgium.  4. Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, 28871, Alcalá de Henares, Madrid, Spain.

Abstract

A comparison of D-π-A%@2B and D-A%@2B cationic chromophores based on the quinolizinium system as new acceptor units is reported along with the results of studies into their linear and non-linear optical properties and electrochemical data. Experimental and theoretical data show that quinolizinium-based chromophores may provide a new generation of second-order non-linear materials with enhanced performance. The first hyperpolarizabilities were measured by Hyper-Rayleigh scattering experiments and the experimental data are supported by a theoretical analysis. In some chromophores the absence of a bridge (D-A%@2B) between the donor and acceptor fragments enhances the NLO properties and the single crystal structure of such a material has been determined by X-ray diffraction.

Publications > Bosch et al

Dyes Pigm. 2017, 138, 135

Imidazopyridinium cations: A new family of azonia aromatic heterocycles with applications as DNA intercalators.

Pedro Bosch¹, Verónica García², Başak S. Bilen³, David Sucunza¹, Alberto Domingo², Francisco Mendicuti³, Juan J Vaquero¹

1. Departamento de Química Inorgánica y Química Orgánica, Química Física e Ingeniería Química, Universidad de Alcalá, 28871, Alcalá de Henares, Madrid, Spain.  2. Departamento de Biología de Sistemas, Química Física e Ingeniería Química, Universidad de Alcalá, 28871, Alcalá de Henares, Madrid, Spain.  3. Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, 28871, Alcalá de Henares, Madrid, Spain.

Abstract

Two novel imidazopyridinium cations formed by a hexacyclic azonia aromatic system have been synthesized. Spectrofluorimetric titrations, circular dichroism measurements, theoretical simulations and fluorescence-based thermal denaturation experiments on these materials have shown the interesting fluorescence properties and DNA-binding ability by intercalation, with a marked preference for AT-rich sequences. Compound 2 presents the highest fluorescence quantum yield (0.32 in 5% DMSO/water and 0.46 in MeOH) and affinity for DNA (binding constant of ∼4.5 × 105 M−1). Moreover, the potential of these compounds for cell staining has been investigated in living HeLa cells by confocal microscopy imaging. This analysis showed the remarkable capacity of both compounds for uptake and accumulation by living cells.

Publications > Zacharioudakis et al

Biorg. Med. Chem. Lett. 2017, 27, 203

Quinolizinium as a new fluorescent lysosomotropic probe.

Emmanouil Zacharioudakis¹, Tatiana Cañeque², Raúl Custodio³, Sebastian Müller¹, Ana M. Cuadro², Juan J Vaquero², Raphaël Rodriguez¹

1. Institut Curie, PSL Research University, Organic Synthesis and Cell Biology Group, 26 rue d’Ulm, 75248 Paris Cedex 05, France, CNRS UMR3666, 75005 Paris, France, INSERM U1143, 75005 Paris, France.  2. Departamento de Química Orgánica y Química Inorgánica, Universidad de Alcalá, 28871, Alcalá de Henares, Madrid, Spain.  3. Departamento de Química Orgánica y Química Inorgánica, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid, Spain.

Abstract

We have synthesized a collection of quinolizinium fluorescent dyes for the purpose of cell imaging. Preliminary biological studies in human U2OS osteosarcoma cancer cells have shown that different functional groups appended to the cationic quinolizinium scaffold efficiently modulate photophysical properties but also cellular distribution. While quinolizinium probes are known nuclear staining reagents, we have identified a particular quinolizinium derivative salt that targets the lysosomal compartment. This finding raises the question of predictability of specific organelle targeting from structural features of small molecules.