Synthesis and characterization of a fluorescent BODIPY derivative

Despite existing for almost a century, fluorescent dyes continue to attract the attention of scientists from an ever expanding multidisciplinary areas. Among the many diverse fluorescent molecules, 3-difluoroborodipyrromethene (BODIPY) derivatives, have become a cornerstone for innovative applications such as biological fluorescent labelling, electroluminescent devices, dye sensitized solar cells (DSSCs), photodynamic therapy (PDT), optical sensors etc. Recently, BODIPYs have received great attention because of their advantageous features: photochemical stability, sharp absorption with high intensity in visible to NIR region and high fluorescence quantum yields. In fact, BODIPY came to be known to the biochemists and biologists as a photostable substitute for fluorescein. Furthermore, the BODIPY core can be chemically modified in order to fine tune the optical properties or add new functionalities, such as receptor groups selective to analytes in the case of sensors. In continuation of the investigation developed in our research group, we report in this work the synthesis and the characterization of a BODIPY derivative using several spectroscopic/spectrophotometric techniques. Evaluation of their optical properties showed its potential application as a novel fluorescent probe for in vivo/in vitro studies.The authors thank FCT for funding through CQUM (Pest-C/QUI/UI0686/2018) and project PTDC/QUI-COL/28052/2017. The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network (REDE/1517/RMN/2005)

Investigating the photophysical properties and biological efficacy of BODIPY derivatives as photosensitizers in photodynamic therapy

The selectivity of photosensitizers for light activation is a key advantage in photodynamic therapy (PDT), allowing for precise targeting while sparing healthy cells. BODIPY derivatives have emerged as promising PDT candidates due to their tunable photophysical properties and versatile synthesis. Herein, we explore the photophysical characterization and the in vitro photodynamic activity of BODIPY analogues meso-substituted with an anthracene moiety and functionalized with iodine atoms or formyl group at 2,6-position. The formylated anthracene-BODIPY derivative exhibited the highest tumor suppression under irradiation, making it a potential candidate as PDT photosensitizer

N,N-Diphenylanilino-heterocyclic aldehyde-based chemosensors for UV-vis/NIR and fluorescence Cu(II) detection

Herein, three N,N-diphenylanilino-heterocyclic aldehyde probes (5, 6 and 7) are synthesized, characterized and their sensing behaviour against metal cations tested. Acetonitrile solutions of the three probes show an intramolecular charge-transfer band in the 360-420 nm range due to the presence of an electron donor N,N-diphenylanilino group and an electron acceptor aldehyde moiety. Besides, all three probes are moderately emissive with bands in the 540-580 nm range in acetronitrile. The chromo-fluorogenic behaviour of the three probes in acetonitrile in the presence of selected metal cations is assessed. Of all the metal cations tested only Cu(ii) induces marked colour and emission changes. In this respect, addition of Cu(ii) cations to solutions of the probes induces the appearance of NIR absorptions at 756 nm for 5, at 852 nm for 6 and at 527, 625 and 1072 nm for 7. Besides, Cu(ii) induces a marked quenching of the emission of the three probes. The observed spectral changes are ascribed to the formation of 1:1 probe-Cu(ii) complexes in which the metal cation interacts with the acceptor part of the chemosensors. In addition, the limits of detection determined using UV-visible and fluorescence titrations are in the 0.21-5.12 M range, which are values lower than the minimum concentration prescribed by the World Health Organization (WHO) guideline for drinking water for copper (30 mM). Besides, probe 7 is used for the detection of Cu(ii) in aqueous environments using SDS anionic surfactant.We thank the Spanish Government (MAT2015-64139-C4-1-R) and Generalitat Valenciana (PROMETEO2018/024). H. E. O. thanks Generalitat Valenciana for his Grisolia fellowship. Thanks are due to Fundação para a Ciência e Tecnologia (FCT) for a PhD grant to R. C. M. Ferreira (SFRH/BD/86408/2012), and FEDER (European Fund for Regional Development)-COMPETE-QREN-EU for financial support through the Chemistry Research Centre of the University of Minho (Ref. PEst-C/QUI/UI0686/2016 and PEst-C/QUI/UI0686/2018). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005 with funds from POCI 2010 (FEDER) and FCT

Polyaromatic bis(indolyl)methane derivatives with antiprolif-erative and antiparasitic activity

Bis(indolyl)methanes (BIM) are a class of compounds that has been recognized as an important core in the design of drugs with important pharmacological properties, such as promising anticancer and antiparasitic activity. Here, we explored the biological activity of the BIM core functionalized with different (hetero)aromatic moieties. We synthesized substituted BIM deriva-tives with triphenylamino, N,N-dimethyl-1-naphthylamino and 8-hydroxylquinolyl groups, studied their photophysical properties and evaluated their in vitro antiproliferative and antiparasitic activity. The triphenylamino BIM derivative 2a displayed an IC50 of 3.21, 3.30 and 3.93 μM against Trypanosoma brucei, Leishmania major and HT-29 cancer cell line, respectively. The selectivity index demonstrated that compound 2a was up to 8-fold more active against the parasites and HT-29 than to the heathy cell line MRC-5. Fluorescence microscopy studies with MRC-5 cells and T. brucei parasites incubated with derivative 2a indicates that the compound seems to accumulate in the cell’s mitochondria and in the parasite’s nucleus. In conclusion, the BIM scaffold functional-ized with the triphenylamino moiety proved to be the most promising antiparasitic and anticancer agent of this series.This research was funded by Fundação para a Ciência e Tecnologia (FCT) and FEDER (European Fund for Regional Development)-COMPETE-QRENEU through the Chemistry Research Centre of the University of Minho CQ-UM (UID/QUI/00686/2020), project PTDC/QUI-OUT/3143/2021 and a PhD grant to R.C.R. Gonçalves (SFRH/BD/05278/2020). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005 with funds from POCI 2010 (FEDER) and FC

Synthesis and characterization of a BODIPY probe for the chromogenic detection of Cu2+ and Fe3+

In recent years, the development of chromo-fluorogenic chemosensors for metal cations has attracted the attention of researchers around the world. Among transition metal cations, Cu2+ is the third most abundant essential element in the human body and plays vital roles in several physiological processes. Nevertheless, abnormal levels of this cation can cause serious health problems on humans. In fact, high concentrations of Cu2+ in cells cause toxicity and different neurodegenerative diseases such as Menkes, Wilson's and Alzheimer. Trivalent metal cations play also crucial roles in biological processes. For instance, iron is the most abundant transition metal in cellular systems. More specifically, Fe3+ is an essential element in the growth and development of living systems and its deficiency is associated with several diseases (anemia, hemochromatosis, diabetes, Parkinson’s, and dysfunction of heart, pancreas, and liver). Therefore, simple and rapid sensing tools to monitor Cu2+ and Fe3+ levels in biological media are of importance. In this respect boron-dipyrromethene (BODIPY) derivatives have received great attention due to their advantageous features, such as fine tuning of the optical properties and facility of functionalization of the BODIPY core in order to be use as selective chromo-fluorogenic chemosensors for various analytes.Thanks are due to Fundação para a Ciência e Tecnologia (FCT) and FEDER for financial support through the Chemistry Research Centre of the University of Minho (Ref. UID/QUI/0686/2019). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005 with funds from POCI 2010 (FEDER) and FCT