Export 158 results:
Sort by: Author Title Type [ Year  (Desc)]
Submitted
Huang, R, Avo J, Northey T, Chaning-Pearce E, dos Santos PL, Ward JS, Data P, Etherington MK, Fox MA, Penfold TJ, Berberan-Santos MN, Lima JC, Bryce MR, Dias FB.  Submitted.  {The contributions of molecular vibrations and higher triplet levels to the intersystem crossing mechanism in metal-free organic emitters}, {JUL 7}. {JOURNAL OF MATERIALS CHEMISTRY C}. {5}:{6269-6280}., Number {25} Abstract
n/a
2024
Choroba, K, Zowislok B, Kula S, Machura B, Maron AM, Erfurt K, Cordeiro S, Baptista PV, Fernandes {AR}.  2024.  Optimization of Antiproliferative Properties of Triimine Copper(II) Complexes, nov. Journal Of Medicinal Chemistry. 67:19475–19502., Number 21: ACS - American Chemical Society Abstract

Cu(II) complexes with 2,2′:6′,2″-terpyridines (terpy) and 2,6-bis(thiazol-2-yl)pyridines (dtpy) with 1- or 2-naphtyl and methoxy-naphtyl were synthesized to elucidate the impact of the triimine core, naphtyl linking mode, and presence of methoxy groups on the antiproliferative activity of [CuCl2(Ln)]. Their antiproliferative effect was analyzed in ovarian (A2780) and colorectal (HCT116) carcinomas and colorectal carcinoma resistant to doxorubicin (HCT116-DoxR) cell lines and in normal human fibroblasts. Among all complexes, the 1- and 2-naphtyl substituted terpy Cu(II) complexes (Cu1a and Cu1b) showed the strongest cytotoxicity, namely, in HCT116-DoxR 2Dcells and were also capable of inducing the loss of cell viability in 3D HCT116-DoxR spheroids. Their intracellular localization, capability to increase reactive oxygen species (ROS), and interaction with DNA (nonintercalative mode) trigger oxidative DNA cleavage leading to cell death by apoptosis and autophagy. Cu1a and Cu1b do not show in vivo toxicity in a chicken embryo and can interact with bovine serum albumin (BSA).

Choroba, K, Zowiślok B, Kula S, Machura B, Maroń {AM }, Erfurt K, Marques C, Cordeiro S, Baptista {PV}, Fernandes {AR}.  2024.  Optimization of Antiproliferative Properties of Triimine Copper(II) Complexes, nov. Journal Of Medicinal Chemistry. : ACS - American Chemical Society Abstract

Cu(II) complexes with 2,2':6',2″-terpyridines (terpy) and 2,6-bis(thiazol-2-yl)pyridines (dtpy) with 1- or 2-naphtyl and methoxy-naphtyl were synthesized to elucidate the impact of the triimine core, naphtyl linking mode, and presence of methoxy groups on the antiproliferative activity of [CuCl 2(L n )]. Their antiproliferative effect was analyzed in ovarian (A2780) and colorectal (HCT116) carcinomas and colorectal carcinoma resistant to doxorubicin (HCT116-DoxR) cell lines and in normal human fibroblasts. Among all complexes, the 1- and 2-naphtyl substituted terpy Cu(II) complexes ( Cu1a and Cu1b) showed the strongest cytotoxicity, namely, in HCT116-DoxR 2Dcells and were also capable of inducing the loss of cell viability in 3D HCT116-DoxR spheroids. Their intracellular localization, capability to increase reactive oxygen species (ROS), and interaction with DNA (nonintercalative mode) trigger oxidative DNA cleavage leading to cell death by apoptosis and autophagy. Cu1a and Cu1b do not show in vivo toxicity in a chicken embryo and can interact with bovine serum albumin (BSA).

Esmear, T, Twilley D, Thipe {VC}, Katti {KV }, Mandiwana V, Kalombo {ML}, Ray {SS}, Rikhotso-Mbungela R, Bovilla {VR}, Madhunapantula {SR}, Langhanshova L, Roma-Rodrigues C, Fernandes {AR}, Baptista P, Hlati S, Pretorius J, Lall N.  2024.  Anti-inflammatory and antiproliferative activity of Helichrysum odoratissimum sweet. Against lung cancer. South African Journal of Botany. 166:525–538.: Elsevier Abstract

Lung cancer remains the top killing cancer worldwide despite advances in treatment. Seven ethanolic plant extracts were selected and evaluated for their antiproliferative activity against the two main types of lung cancers: non-small cell (A549) and small cell lung cancer cells (SHP-77). An ethanolic extract of Helichrysum odoratissimum Sweet (HO) showed significant antiproliferative activity against lung cancer, with a fifty percent inhibitory concentration (IC50) of 83.43 ± 1.60 µg/mL (A549), 49.46 ± 0.48 µg/mL (SHP-77) and 50.71 ± 2.27 µg/mL, against normal lung epithelial cells (MRC-5), resulting in a selectivity index (SI) value of 0.61 on A549 cells and 1.03 on SHP-77 cells, which was compared to the positive drug control, actinomycin D where the SI values were found to be 2 and 0.25 against A549 and SHP-77 cells, respectively. Against murine macrophages (RAW 264.7) and hepatocytes (HepG2), the HO ethanolic extract showed IC50 values of 60.15 ± 1.98 µg/mL and 23.61 ± 1.06 µg/mL, respectively. Microscopy showed that the HO ethanolic extract induced apoptosis in the A549 and HepG2 cells at 50 µg/mL and 300 µg/mL, respectively. The HO ethanolic extract, furthermore, inhibited the pro-inflammatory enzymes, cyclooxygenase 2 (COX-2) and 5-lipoxygenase (5-LOX) with IC50 values of 7.94 ± 3.84 µg/mL and 2.08 ± 1.35 µg/mL, respectively, whereas the positive controls Ibuprofen (COX-2) and Zileuton (5-LOX) showed IC50 values of 0.85 ± 0.14 µg/mL and 0.06 ± 0.05 µg/mL, respectively. The activity of NAD(P)H quinone oxidoreductase-1 (NQO1), which is a direct target of nuclear factor erythroid-2-related factor-2 (NRF2), was significantly inhibited in the A549 cells by the HO ethanolic extract (at 125 µg/mL) when compared to the positive control, brusatol (at 500 nM). Using the ex ovo yolk sac membrane (YSM) assay, the HO ethanolic extract (at 18.5 µg/egg) showed a 31.65 ± 12.80% inhibition of blood vessel formation. This is the first report of the noteworthy antiproliferative activity of the HO ethanolic extract on lung cancer cells including its potential to target several enzymes associated with inflammation and therefore, should be considered for further analysis.

Choroba, K, Machura B, Erfurt K, Casimiro {AR}, Cordeiro S, Baptista {PV}, Fernandes {AR}.  2024.  Copper(II) Complexes with 2,2′:6′,2″-Terpyridine Derivatives Displaying Dimeric Dichloro−μ-Bridged Crystal Structure: Biological Activities from 2D and 3D Tumor Spheroids to In Vivo Models. Journal Of Medicinal Chemistry. 67:5813–5836., Number 7: ACS - American Chemical Society Abstract

Eight 2,2′:6′,2″-terpyridines, substituted at the 4′-position with aromatic groups featuring variations in π-conjugation, ring size, heteroatoms, and methoxy groups, were employed to enhance the antiproliferative potential of [Cu2Cl2(R-terpy)2](PF6)2. Assessing the cytotoxicity in A2780 (ovarian carcinoma), HCT116 (colorectal carcinoma), and HCT116DoxR (colorectal carcinoma resistant to doxorubicin) and normal primary fibroblasts revealed that Cu(II) complexes with 4-quinolinyl, 4-methoxy-1-naphthyl, 2-furanyl, and 2-pyridynyl substituents showed superior therapeutic potential in HCT116DoxR cells with significantly reduced cytotoxicity in normal fibroblasts (42-129× lower). Besides their cytotoxicity, the Cu(II) complexes are able to increase intracellular ROS and interfere with cell cycle progression, leading to cell death by apoptosis and autophagy. Importantly, they demonstrated antimetastatic and antiangiogenic properties without in vivo toxicity. In accordance with their nuclear accumulation, the Cu(II) complexes are able to cleave pDNA and interact with bovine serum albumin, which is a good indication of their ability for internalization and transport toward tumor cells.

Choroba, K, Zowiślok B, Kula S, Machura B, Maroń {AM }, Erfurt K, Marques C, Cordeiro S, Baptista {PV}, Fernandes {AR}.  2024.  Optimization of Antiproliferative Properties of Triimine Copper(II) Complexes. Journal Of Medicinal Chemistry. 67:19475–19502., Number 21: ACS - American Chemical Society Abstract

Cu(II) complexes with 2,2′:6′,2″-terpyridines (terpy) and 2,6-bis(thiazol-2-yl)pyridines (dtpy) with 1- or 2-naphtyl and methoxy-naphtyl were synthesized to elucidate the impact of the triimine core, naphtyl linking mode, and presence of methoxy groups on the antiproliferative activity of [CuCl2(Ln)]. Their antiproliferative effect was analyzed in ovarian (A2780) and colorectal (HCT116) carcinomas and colorectal carcinoma resistant to doxorubicin (HCT116-DoxR) cell lines and in normal human fibroblasts. Among all complexes, the 1- and 2-naphtyl substituted terpy Cu(II) complexes (Cu1a and Cu1b) showed the strongest cytotoxicity, namely, in HCT116-DoxR 2Dcells and were also capable of inducing the loss of cell viability in 3D HCT116-DoxR spheroids. Their intracellular localization, capability to increase reactive oxygen species (ROS), and interaction with DNA (nonintercalative mode) trigger oxidative DNA cleavage leading to cell death by apoptosis and autophagy. Cu1a and Cu1b do not show in vivo toxicity in a chicken embryo and can interact with bovine serum albumin (BSA).

Nash, BW, Fernandes TM, Burton JAJ, Morgado L, van Wonderen JH, Svistunenko DA, Edwards MJ, Salgueiro CA, Butt JN, Clarke TA.  2024.  Tethered heme domains in a triheme cytochrome allow for increased electron transport distances. Protein Science. 33:e5200., Number 11 AbstractWebsite

Abstract Decades of research describe myriad redox enzymes that contain cofactors arranged in tightly packed chains facilitating rapid and controlled intra-protein electron transfer. Many such enzymes participate in extracellular electron transfer (EET), a process which allows microorganisms to conserve energy in anoxic environments by exploiting mineral oxides and other extracellular substrates as terminal electron acceptors. In this work, we describe the properties of the triheme cytochrome PgcA from Geobacter sulfurreducens. PgcA has been shown to play an important role in EET but is unusual in containing three CXXCH heme binding motifs that are separated by repeated (PT)x motifs, suggested to enhance binding to mineral surfaces. Using a combination of structural, electrochemical, and biophysical techniques, we experimentally demonstrate that PgcA adopts numerous conformations stretching as far as 180 Å between the ends of domains I and III, without a tightly packed cofactor chain. Furthermore, we demonstrate a distinct role for its domain III as a mineral reductase that is recharged by domains I and II. These findings show PgcA to be the first of a new class of electron transfer proteins, with redox centers separated by some nanometers but tethered together by flexible linkers, facilitating electron transfer through a tethered diffusion mechanism rather than a fixed, closely packed electron transfer chain.

2023
Engrola, F, Correia MAS, Watson C, Romão CC, Veiros LF, Romão MJ, Santos-Silva T, Santini JM.  2023.  Arsenite oxidase in complex with antimonite and arsenite oxyanions: Insights into the catalytic mechanism, 2023. Journal of Biological ChemistryJournal of Biological Chemistry. 299(8): Elsevier AbstractWebsite

Arsenic contamination of groundwater is among one of the biggest health threats affecting millions of people in the world. There is an urgent need for efficient arsenic biosensors where the use of arsenic metabolizing enzymes can be explored. In this work, we have solved four crystal structures of arsenite oxidase (Aio) in complex with arsenic and antimony oxyanions and the structures determined correspond to intermediate states of the enzymatic mechanism. These structural data were complemented with density-functional theory calculations providing a unique view of the molybdenum active site at different time points that, together with mutagenesis data, enabled to clarify the enzymatic mechanism and the molecular determinants for the oxidation of As(III) to the less toxic As(V) species.Arsenic contamination of groundwater is among one of the biggest health threats affecting millions of people in the world. There is an urgent need for efficient arsenic biosensors where the use of arsenic metabolizing enzymes can be explored. In this work, we have solved four crystal structures of arsenite oxidase (Aio) in complex with arsenic and antimony oxyanions and the structures determined correspond to intermediate states of the enzymatic mechanism. These structural data were complemented with density-functional theory calculations providing a unique view of the molybdenum active site at different time points that, together with mutagenesis data, enabled to clarify the enzymatic mechanism and the molecular determinants for the oxidation of As(III) to the less toxic As(V) species.

Pimenta, AI, Paquete CM, Morgado L, Edwards MJ, Clarke TA, Salgueiro CA, Pereira IAC, Duarte AG.  2023.  Characterization of the inner membrane cytochrome ImcH from Geobacter reveals its importance for extracellular electron transfer and energy conservation. Protein Science. 32:e4796., Number 11 AbstractWebsite

Abstract Electroactive bacteria combine the oxidation of carbon substrates with an extracellular electron transfer (EET) process that discharges electrons to an electron acceptor outside the cell. This process involves electron transfer through consecutive redox proteins that efficiently connect the inner membrane to the cell exterior. In this study, we isolated and characterized the quinone-interacting membrane cytochrome c ImcH from Geobacter sulfurreducens, which is involved in the EET process to high redox potential acceptors. Spectroscopic and electrochemical studies show that ImcH hemes have low midpoint redox potentials, ranging from −150 to −358 mV, and connect the oxidation of the quinol-pool to EET, transferring electrons to the highly abundant periplasmic cytochrome PpcA with higher affinity than to its homologues. Despite the larger number of hemes and transmembrane helices, the ImcH structural model has similarities with the NapC/NirT/NrfH superfamily, namely the presence of a quinone-binding site on the P-side of the membrane. In addition, the first heme, likely involved on the quinol oxidation, has apparently an unusual His/Gln coordination. Our work suggests that ImcH is electroneutral and transfers electrons and protons to the same side of the membrane, contributing to the maintenance of a proton motive force and playing a central role in recycling the menaquinone pool.

Portela, PC, Morgado L, Silva MA, Denkhaus L, Einsle O, Salgueiro CA.  2023.  Exploring oxidative stress pathways in Geobacter sulfurreducens: the redox network between MacA peroxidase and triheme periplasmic cytochromes. Frontiers in Microbiology. 14 AbstractWebsite

The recent reclassification of the strict anaerobe Geobacter sulfurreducens bacterium as aerotolerant brought attention for oxidative stress protection pathways. Although the electron transfer pathways for oxygen detoxification are not well established, evidence was obtained for the formation of a redox complex between the periplasmic triheme cytochrome PpcA and the diheme cytochrome peroxidase MacA. In the latter, the reduction of the high-potential heme triggers a conformational change that displaces the axial histidine of the low-potential heme with peroxidase activity. More recently, a possible involvement of the triheme periplasmic cytochrome family (PpcA-E) in the protection from oxidative stress in G. sulfurreducens was suggested. To evaluate this hypothesis, we investigated the electron transfer reaction and the biomolecular interaction between each PpcA-E cytochrome and MacA. Using a newly developed method that relies on the different NMR spectral signatures of the heme proteins, we directly monitored the electron transfer reaction from reduced PpcA-E cytochromes to oxidized MacA. The results obtained showed a complete electron transfer from the cytochromes to the high-potential heme of MacA. This highlights PpcA-E cytochromes’ efficient role in providing the necessary reducing power to mitigate oxidative stress situations, hence contributing to a better knowledge of oxidative stress protection pathways in G. sulfurreducens.

2022
Esteves, C, Palma S, Costa H, Alves C, Santos G, Ramou E, Roque AC.  2022.  VOC Sensing in Humid and Dry Environments, may. 2022 IEEE International Symposium on Olfaction and Electronic Nose (ISOEN). :1–3.: IEEE AbstractPDFWebsite

We report the development of gas-sensing multicomponent hybrid materials to be used under humidified and dried environments without the need of sample preconditioning or heavy signal processing. The easy tunability and the unique characteristics presented by the multicomponent hybrid materials suggests their use in nearterm applications in electronic nose systems able to operate in dry or humidified environments.

Moreira, IP, Esteves C, Palma SICJ, Ramou E, Carvalho ALM, Roque ACA.  2022.  Synergy between silk fibroin and ionic liquids for active gas-sensing materials, jun. Materials Today Bio. 15:100290.: Elsevier AbstractPDFWebsite

Silk fibroin is a biobased material with excellent biocompatibility and mechanical properties, but its use in bioelectronics is hampered by the difficult dissolution and low intrinsic conductivity. Some ionic liquids are known to dissolve fibroin but removed after fibroin processing. However, ionic liquids and fibroin can cooperatively give rise to functional materials, and there are untapped opportunities in this combination. The dissolution of fibroin, followed by gelation, in designer ionic liquids from the imidazolium chloride family with varied alkyl chain lengths (2–10 carbons) is shown here. The alkyl chain length of the anion has a large impact on fibroin secondary structure which adopts unconventional arrangements, yielding robust gels with distinct hierarchical organization. Furthermore, and due to their remarkable air-stability and ionic conductivity, fibroin ionogels are exploited as active electrical gas sensors in an electronic nose revealing the unravelled possibilities of fibroin in soft and flexible electronics.

Esteves, C, Palma SICJ, Costa HMA, Alves C, Santos GMC, Ramou E, Carvalho AL, Alves V, Roque ACA.  2022.  Tackling Humidity with Designer Ionic Liquid-Based Gas Sensing Soft Materials, dec. Advanced Materials. 34:2107205., Number 8: John Wiley & Sons, Ltd AbstractPDFWebsite

Relative humidity is simultaneously a sensing target and a contaminant in gas and volatile organic compound (VOC) sensing systems, where strategies to control humidity interference are required. An unmet challenge is the creation of gas-sensitive materials where the response to humidity is controlled by the material itself. Here, humidity effects are controlled through the design of gelatin formulations in ionic liquids without and with liquid crystals as electrical and optical sensors, respectively. In this design, the anions [DCA]− and [Cl]− of room temperature ionic liquids from the 1-butyl-3-methylimidazolium family tailor the response to humidity and, subsequently, sensing of VOCs in dry and humid conditions. Due to the combined effect of the materials formulations and sensing mechanisms, changing the anion from [DCA]− to the much more hygroscopic [Cl]−, leads to stronger electrical responses and much weaker optical responses to humidity. Thus, either humidity sensors or humidity-tolerant VOC sensors that do not require sample preconditioning or signal processing to correct humidity impact are obtained. With the wide spread of 3D- and 4D-printing and intelligent devices, the monitoring and tuning of humidity in sustainable biobased materials offers excellent opportunities in e-nose sensing arrays and wearable devices compatible with operation at room conditions.

Moreira, IP, Esteves C, Palma SICJ, Ramou E, Carvalho ALM, Roque ACA.  2022.  Synergy between silk fibroin and ionic liquids for active gas-sensing materials. Materials Today Bio. :100290. AbstractWebsite

Silk fibroin is a biobased material with excellent biocompatibility and mechanical properties, but its use in bioelectronics is hampered by the difficult dissolution and low intrinsic conductivity. Some ionic liquids are known to dissolve fibroin but removed after fibroin processing. However, ionic liquids and fibroin can cooperatively give rise to functional materials, and there are untapped opportunities in this combination. The dissolution of fibroin, followed by gelation, in designer ionic liquids from the imidazolium chloride family with varied alkyl chain lengths (2–10 carbons) is shown here. The alkyl chain length of the anion has a large impact on fibroin secondary structure which adopts unconventional arrangements, yielding robust gels with distinct hierarchical organization. Furthermore, and due to their remarkable air-stability and ionic conductivity, fibroin ionogels are exploited as active electrical gas sensors in an electronic nose revealing the unravelled possibilities of fibroin in soft and flexible electronics.

Esteves, C, Palma SICJ, Costa HMA, Alves C, Santos GMC, Ramou E, Carvalho AL, Alves V, Roque ACA.  2022.  Tackling Humidity with Designer Ionic Liquid-Based Gas Sensing Soft Materials. Advanced Materials. 34:2107205., Number 8 AbstractWebsite

Abstract Relative humidity is simultaneously a sensing target and a contaminant in gas and volatile organic compound (VOC) sensing systems, where strategies to control humidity interference are required. An unmet challenge is the creation of gas-sensitive materials where the response to humidity is controlled by the material itself. Here, humidity effects are controlled through the design of gelatin formulations in ionic liquids without and with liquid crystals as electrical and optical sensors, respectively. In this design, the anions [DCA]− and [Cl]− of room temperature ionic liquids from the 1-butyl-3-methylimidazolium family tailor the response to humidity and, subsequently, sensing of VOCs in dry and humid conditions. Due to the combined effect of the materials formulations and sensing mechanisms, changing the anion from [DCA]− to the much more hygroscopic [Cl]−, leads to stronger electrical responses and much weaker optical responses to humidity. Thus, either humidity sensors or humidity-tolerant VOC sensors that do not require sample preconditioning or signal processing to correct humidity impact are obtained. With the wide spread of 3D- and 4D-printing and intelligent devices, the monitoring and tuning of humidity in sustainable biobased materials offers excellent opportunities in e-nose sensing arrays and wearable devices compatible with operation at room conditions.

2021
Palion-Gazda, J, Luz A, Raposo {LR }, Choroba K, Nycz {JE }, Bieńko A, Lewińska A, Erfurt K, Baptista {PV}, Machura B, Fernandes {AR}, Shul’pina {LS }, Ikonnikov {NS }, Shul’pin {GB }.  2021.  Vanadium(IV) complexes with methyl-substituted 8-hydroxyquinolines: Catalytic potential in the oxidation of hydrocarbons and alcohols with peroxides and biological activity, oct. Molecules. 26, Number 21: MDPI - Multidisciplinary Digital Publishing Institute Abstract

Methyl-substituted 8-hydroxyquinolines (Hquin) were successfully used to synthetize five-coordinated oxovanadium(IV) complexes: [VO(2,6-(Me)2-quin)2 ] (1), [VO(2,5-(Me)2-quin)2 ] (2) and [VO(2-Me-quin)2 ] (3). Complexes 1–3 demonstrated high catalytic activity in the oxidation of hydrocarbons with H2 O2 in acetonitrile at 50◦ C, in the presence of 2-pyrazinecarboxylic acid (PCA) as a cocatalyst. The maximum yield of cyclohexane oxidation products attained was 48%, which is high in the case of the oxidation of saturated hydrocarbons. The reaction leads to the formation of a mixture of cyclohexyl hydroperoxide, cyclohexanol and cyclohexanone. When triphenylphosphine is added, cyclohexyl hydroperoxide is completely converted to cyclohexanol. Consideration of the regioand bond-selectivity in the oxidation of n-heptane and methylcyclohexane, respectively, indicates that the oxidation proceeds with the participation of free hydroxyl radicals. The complexes show moderate activity in the oxidation of alcohols. Complexes 1 and 2 reduce the viability of colorectal (HCT116) and ovarian (A2780) carcinoma cell lines and of normal dermal fibroblasts without showing a specific selectivity for cancer cell lines. Complex 3 on the other hand, shows a higher cytotoxicity in a colorectal carcinoma cell line (HCT116), a lower cytotoxicity towards normal dermal fibroblasts and no effect in an ovarian carcinoma cell line (order of magnitude HCT116 > fibroblasts > A2780).

Jesus, {AR }, Raposo {LR }, Soromenho {MRC }, Agostinho {DAS }, Esperan{\c c}a {JMSS }, Baptista {PV}, Fernandes {AR}, Reis {PM }.  2021.  New non-toxic n-alkyl cholinium-based ionic liquids as excipients to improve the solubility of poorly water-soluble drugs, nov. Symmetry. 13, Number 11: MDPI - Multidisciplinary Digital Publishing Institute Abstract

In this work, we prepared new biocompatible N-alkyl cholinium-based ionic liquids to be used as cosolvents to improve the solubility of poorly water-soluble drugs, namely, sodium diclo-fenac and paracetamol. In this set of ionic liquids, we intend to understand the effect of increasing the asymmetry of the ionic liquid cation/anion by growing the length of one of the alkyl chains attached to the nitrogen center/sulfonate center on the dissolution capacity of the ionic liquid. The addition of these new ionic liquids to water increased the dissolution capacity of the drugs up to four-times that in water, and improved the pharmacodynamic properties of these drugs, especially the case of sodium diclofenac. The intermolecular interactions between the drugs and ionic liquids were investigated by NMR. Two-dimensional1H/1H nuclear overhauser effect spectroscopy (NO-ESY) revealed an interaction between sodium diclofenac and the alaninate anion from the [C2Ch]2[SucAla]. In the case of paracetamol and [C4Ch][C2SO3], it was possible to observe two inter-molecular interactions between the hydroxyl group of paracetamol and two protons from the cation [C4Ch]+. Interestingly, the ionic liquid bearing a succinyl-DL-alaninate anion, [SucAla]2−, and a N-ethyl cholinium cation, [C2Ch]+, which presented the highest ability to dissolve sodium diclofenac, showed no cytotoxicity up to 500 mM. Therefore, this ionic liquid is a potential candidate for drug delivery applications.

Rivas-García, L, Quiles {JL }, Roma-Rodrigues C, Raposo {LR }, Navarro-Hortal {MD }, Romero-Márquez {JM }, Esteban-Muñoz A, Varela-López A, García {LC}, Cianciosi D, {Forbes Hernández} {TY }, Battino M, Llopis J, Fernandes {AR}, Baptista {PV}, Sánchez-González C.  2021.  Rosa x hybrida extracts with dual actions: Antiproliferative effects against tumour cells and inhibitor of Alzheimer disease, mar. Food and Chemical Toxicology. 149: Elsevier Science B.V., Amsterdam. Abstract

Edible flowers are being used as a new ingredient in modern gastronomy. Recently, these products have also gained interest as an important source of phenolic compounds with potential for biomedical applications. The present work studied a methanolic extract of Rosa x hybrida in which 35 individual phenolic compounds were identified. The extract has been evaluated for its antiproliferative properties in ovarian carcinoma cells. Results showed that the antiproliferative effect was associated with the induction of autophagy and apoptosis with the concomitant ROS increase probably related to mitochondria dysfunction. These antiproliferative effects might be associated with some components of the extract such as quercetin. The extract did not induce damage in healthy cells and that it was able to improve the wound healing activity. The present study also evaluated the properties of the mentioned extract in vivo in C. elegans. Tests demonstrated a lack of toxicity in the worm model. Promising results have been obtained in transgenic strains of C. elegans that produce human beta amyloid peptide, suggesting the possible utility of the extract from the point of view of Alzheimer disease. Altogether, results suggest that Rosa x hybrida extracts could be a new tool for the development of functional foods.

Raposo, {LR }, Silva {AR}, Silva D, Roma-Rodrigues C, Espadinha M, Baptista {PV}, Santos {MMM }, Fernandes {AR}.  2021.  Exploiting the antiproliferative potential of spiropyrazoline oxindoles in a human ovarian cancer cell line, jan. Bioorganic and Medicinal Chemistry. 30: Elsevier Science B.V., Amsterdam. Abstract

Cancer is still one of the deadliest diseases worldwide despite the efforts in its early detection and treatment strategies. However, most chemotherapeutic agents still present side effects in normal tissues and acquired resistance that limit their efficacy. Spiropyrazoline oxindoles might be good alternatives as they have shown antiproliferative activity in human breast and colon cancer cell lines, without eliciting cytotoxicity in healthy cells. However, their potential for ovarian cancer was never tested. In this work, the antiproliferative activity of five spiropyrazoline oxindoles was assessed in ovarian cancer cells A2780 and the biological targets and mechanism of action of the most promising compound evaluated. Compound 1a showed the highest antiproliferative effect, as well as the highest selectivity for A2780 cells compared to healthy fibroblasts. This antiproliferative effect results from the induction of cell death by mitochondria-mediated apoptosis and autophagy. In vitro DNA interaction studies demonstrated that 1a interacts with DNA by groove-binding, without triggering genotoxicity. In addition, 1a showed a strong affinity to bovine serum albumin that might be important for further inclusion in drug delivery platforms. Proteomic studies reinforced 1a role in promoting A2780 endoplasmatic reticulum (ER) stress by destabilizing the correct protein folding which triggers cell death via apoptosis and autophagy.

Raposo, LR, Silva A, Silva D, Roma-Rodrigues C, Espadinha M, Baptista PV, Santos MMM, Fernandes AR.  2021.  Exploiting the antiproliferative potential of spiropyrazoline oxindoles in a human ovarian cancer cell line, 2021. Bioorganic & Medicinal Chemistry. 30:115880. AbstractWebsite

Cancer is still one of the deadliest diseases worldwide despite the efforts in its early detection and treatment strategies. However, most chemotherapeutic agents still present side effects in normal tissues and acquired resistance that limit their efficacy. Spiropyrazoline oxindoles might be good alternatives as they have shown antiproliferative activity in human breast and colon cancer cell lines, without eliciting cytotoxicity in healthy cells. However, their potential for ovarian cancer was never tested. In this work, the antiproliferative activity of five spiropyrazoline oxindoles was assessed in ovarian cancer cells A2780 and the biological targets and mechanism of action of the most promising compound evaluated. Compound 1a showed the highest antiproliferative effect, as well as the highest selectivity for A2780 cells compared to healthy fibroblasts. This antiproliferative effect results from the induction of cell death by mitochondria-mediated apoptosis and autophagy. In vitro DNA interaction studies demonstrated that 1a interacts with DNA by groove-binding, without triggering genotoxicity. In addition, 1a showed a strong affinity to bovine serum albumin that might be important for further inclusion in drug delivery platforms. Proteomic studies reinforced 1a role in promoting A2780 endoplasmatic reticulum (ER) stress by destabilizing the correct protein folding which triggers cell death via apoptosis and autophagy.

Mota, C, Diniz A, Coelho C, Santos-Silva T, Esmaeeli M, Leimkühler S, Cabrita EJ, Marcelo F, Romão MJ.  2021.  Interrogating the Inhibition Mechanisms of Human Aldehyde Oxidase by X-ray Crystallography and NMR Spectroscopy: The Raloxifene Case, 2021. Journal of Medicinal ChemistryJournal of Medicinal Chemistry. : American Chemical Society AbstractWebsite

Human aldehyde oxidase (hAOX1) is mainly present in the liver and has an emerging role in drug metabolism, since it accepts a wide range of molecules as substrates and inhibitors. Herein, we employed an integrative approach by combining NMR, X-ray crystallography, and enzyme inhibition kinetics to understand the inhibition modes of three hAOX1 inhibitors—thioridazine, benzamidine, and raloxifene. These integrative data indicate that thioridazine is a noncompetitive inhibitor, while benzamidine presents a mixed type of inhibition. Additionally, we describe the first crystal structure of hAOX1 in complex with raloxifene. Raloxifene binds tightly at the entrance of the substrate tunnel, stabilizing the flexible entrance gates and elucidating an unusual substrate-dependent mechanism of inhibition with potential impact on drug–drug interactions. This study can be considered as a proof-of-concept for an efficient experimental screening of prospective substrates and inhibitors of hAOX1 relevant in drug discovery.Human aldehyde oxidase (hAOX1) is mainly present in the liver and has an emerging role in drug metabolism, since it accepts a wide range of molecules as substrates and inhibitors. Herein, we employed an integrative approach by combining NMR, X-ray crystallography, and enzyme inhibition kinetics to understand the inhibition modes of three hAOX1 inhibitors—thioridazine, benzamidine, and raloxifene. These integrative data indicate that thioridazine is a noncompetitive inhibitor, while benzamidine presents a mixed type of inhibition. Additionally, we describe the first crystal structure of hAOX1 in complex with raloxifene. Raloxifene binds tightly at the entrance of the substrate tunnel, stabilizing the flexible entrance gates and elucidating an unusual substrate-dependent mechanism of inhibition with potential impact on drug–drug interactions. This study can be considered as a proof-of-concept for an efficient experimental screening of prospective substrates and inhibitors of hAOX1 relevant in drug discovery.

Peyroteo, M, Ferreira IA, Elvas LB, Ferreira JC, Lapão LV.  2021.  Remote Monitoring Systems for Patients With Chronic Diseases in Primary Health Care: Systematic Review. JMIR Mhealth and Uhealth. 9(12):1-11.
El-Haouzi, HB, Valette E, Krings B-J, Moniz AB.  2021.  Social Dimensions in CPS & IoT Based Automated Production Systems. Societies. 11(98)Website
2020
Choroba, K, Raposo LR, Palion-Gazda J, Malicka E, Erfurt K, Machura B, Fernandes AR.  2020.  In vitro antiproliferative effect of vanadium complexes bearing 8-hydroxyquinoline-based ligands - the substituent effect, 2020. Dalton Trans. 49(20):6596-6606. AbstractWebsite

This is the first comprehensive study demonstrating the antiproliferative effect of vanadium complexes bearing 8-hydroxyquinoline (quinH) ligands, including the parent and -CH3 (Me), -NO2, -Cl and -I substituted ligands, on HCT116 and A2780 cancer cell lines. To determine the structure-cytotoxicity relationships seven six-coordinate oxovanadium(v) complexes [VO(OMe)(5,7-(Me)2-quin)2] (1), [VO(OMe)(5,7-Cl2-quin)2] (2), [VO(OMe)(5,7-Cl,I-quin)2] (3), [VO(OMe)(5,7-I2-quin)2] (4), [VO(OMe)(5-NO2-quin)2] (5), [VO(OMe)(5-Cl-quin)2] (6), and [VO(OMe)(quin)2] (7) were investigated. The cytotoxicity of 8-hydroxyquinoline oxovanadium(v) complexes is higher in the A2780 cell line (lower IC50) than that observed for the widely used chemotherapeutic agent, cisplatin, while displaying low cytotoxicity for normal human primary fibroblasts. Substituents introduced into the 8-hydroxyquinoline backbone reduced the antiproliferative effect of the vanadium complexes, and the complexes with the ligand substituted only in the 5 position (5 and 6) were more cytotoxic than those with substituents in the 5,7 positions of the quin backbone (1-4). Depending on the substituent type, the cytotoxicity of 1-4 followed the trend: -Cl > -CH3 > -I. Incubation of A2780 cancer cells with IC50 concentrations of complexes 5, 6 and 7 promoted cellular detachment, possibly through membrane destabilization, and triggered apoptosis and necrosis. ROS production might be responsible for the cell death mechanism observed particularly in the A2780 cells exposed to complexes 5 and 6.

dos Santos, LM, Bernard FL, Polesso BB, Pinto IS, Frankenberg CC, Corvo MC, Almeida PL, Cabrita E, Menezes S, Einloft S.  2020.  Designing silica xerogels containing RTIL for CO2 capture and CO2/CH4 separation: Influence of ILs anion, cation and cation side alkyl chain length and ramification. Journal of Environmental Management. 268:110340. AbstractWebsite

CO2 separation from natural gas is considered to be a crucial strategy to mitigate global warming problems, meet product specification, pipeline specs and other application specific requirements. Silica xerogels (SX) are considered to be potential materials for CO2 capture due to their high specific surface area. Thus, a series of silica xerogels functionalized with imidazolium, phosphonium, ammonium and pyridinium-based room-temperature ionic liquids (RTILs) were synthesized. The synthesized silica xerogels were characterized by NMR, helium pycnometry, DTA-TG, BET, SEM and TEM. CO2 sorption, reusability and CO2/CH4 selectivity were assessed by the pressure-decay technique. Silica xerogels containing IL demonstrated advantages compared to RTILs used as separation solvents in CO2 capture processes including higher CO2 sorption capacity and faster sorption/desorption. Using fluorinated anion for functionalization of silica xerogels leads to a higher affinity for CO2 over CH4. The best performance was obtained by SX- [bmim] [TF2N] (223.4 mg CO2/g mg/g at 298.15 K and 20 bar). Moreover, SX- [bmim] [TF2N] showed higher CO2 sorption capacity as compared to other reported sorbents. CO2 sorption and CO2/CH4 selectivity results were submitted to an analysis of variance and the means compared using Tukey's test (5%).

loading