Showing: 10 from total: 2413 publications
491.
Liver says no: the ongoing search for safe catechol O-methyltransferase inhibitors to replace tolcapone
Silva, TB
; Borges, F
; Serrao, MP
; Soares da Silva, P
in DRUG DISCOVERY TODAY, 2020, ISSN: 1359-6446, Volume: 25,
Review, Indexed in: crossref, scopus, wos
Abstract
Catechol O-methyltransferase (COMT) inhibitors are valuable co-adjuvant drugs in the clinical management of Parkinson's disease (PD), and recent data also suggest therapeutic benefits in other neurological disorders associated with dopamine depletion. However, the relationship between tolcapone administration with fatal cases of drug-induced liver damage gave COMT inhibitors a bad reputation as hepatotoxic drugs. Thus, there is a pressing need to feed the pipeline with safe COMT inhibitors to replace tolcapone, the only currently available COMT inhibitor that effectively reaches the brain. Recent efforts led to promising phenolic and nonphenolic COMT inhibitors, which allow isoform-specific targeting and avoid the toxicological and pharmacokinetic (PK) shortcomings of classic nitrocatechols. Here, we describe advances made in this field over the past 5 years.
492.
Structural coloration based on photonic crystals for coating applications on wood
Nunez Montenegro, A
; Crista, DMA
; da Silva, JCGE
in EUROPEAN JOURNAL OF WOOD AND WOOD PRODUCTS, 2020, ISSN: 0018-3768, Volume: 78,
Article, Indexed in: crossref, scopus, wos
Abstract
This work aims to apply photonic-crystal-based nanocoatings with unusual aesthetical orientation to wood application. Structural colors are currently a formula to achieve those colorful coatings including nonfading properties. They can be produced from self-assembled colloidal spheres into photonic crystals, which possess particular optical properties. Herein, photonic crystals with iridescent structural colors were prepared from the self-assembly of monodispersed nanospheres. Particle sizes can be adjusted from 308 to 196 nm, and well-ordered structures are arranged through self-assembly process into films, which exhibit brilliant colors over a wide visible spectrum, from red to violet. Color varies with the angle of observation of incidence light. The present study provided an effective and simple approach to prepare structural color films and their practical application to wood coating for an aesthetic appeal.
493.
Morphology, Structure, and Dynamics of Pentacene Thin Films and Their Nanocomposites with [C(2)C(1)im][NTf2] and [C(2)C(1)im][OTF] Ionic Liquids
Campos, RM
; Alves, ACPM
; Lima, MAL
; Farinha, AFM
; Cardoso, JPS
; Mendes, A
; Costa, JCS
; Santos, LMNBF
in CHEMPHYSCHEM, 2020, ISSN: 1439-4235, Volume: 21,
Article, Indexed in: crossref, scopus, wos
Abstract
In this study, a homogeneous thin film growth of pentacene onto indium tin oxide (ITO) coated glass surfaces is explored using a high-resolution and reproducible vapor deposition methodology. Moreover, vacuum thermal evaporation of ionic liquids (ILs) ([C(2)C(1)im][NTf2] and [C(2)C(1)im][OTF]) onto ITO, gold/palladium (AuPd) and pentacene surfaces were performed. A greater wettability behavior of ILs is observed for surfaces containing AuPd. Sequential and simultaneous depositions of ILs and pentacene were explored. Simultaneous depositions lead to the formation of nanocomposites films, consisting of IL micro- and nanodroplets covered by pentacene layers. Plasma surface treatment was used to induce the ILs droplets coalescence and explore the dynamics and phase separation of the nanocomposites. The [C(2)C(1)im][OTF] droplets were found to be completely covered with pentacene, which suggests a great affinity between cation-anion pairs and the aromatic moiety. Pentacene films and their nanocomposites with ILs exhibit a typical optical band gap ofE(gap)=1.77 eV, indicating that the nanocomposite phase domains are large enough to behavior as the bulk.
494.
Simultaneous Determination of Medicinal Drugs with Overlapping Profiles Contained in Low Chromatographic Resolution Data using HPLC-DAD and Multivariate Curve Resolution
Mazivila, SJ
; da Silva, JCGE
; Pascoa, RNMJ
; Leitao, JMM
in CURRENT ANALYTICAL CHEMISTRY, 2020, ISSN: 1573-4110, Volume: 16,
Article, Indexed in: crossref, scopus, wos
Abstract
Background: The increasing demand of effective pharmaceutical products directed to fight against malaria lead to the combination of at least two antimalarial drugs. This combination aims to minimize the Plasmodium falciparum resistance which is found when the most frequently used drugs are taken individually. Within this context, proguanil hydrochloride and chloroquine phosphate which have independent modes of action are taken together to prevent malaria. This paper aims to develop a fast and powerful analytical method for the simultaneous determination of proguanil hydrochloride and chloroquine phosphate in the commercial Paludrine/Avloclor dosage forms using a multi-way chromatographic calibration based on high-performance liquid chromatography with diode array detection (HPLC-DAD) and multivariate curve resolution - alternating least-squares (MCR-ALS). Methods: A rapid and powerful analytical method based on HPLC-DAD and MCR-ALS was developed for the simultaneous quantification of proguanil hydrochloride and chloroquine phosphate in the commercial Paludrine/Avloclor antimalarial drugs. An isocratic mobile phase composed by 0.2 M ammonium acetate, acetonitrile, and methanol (40:25:35) and a flow rate of 1.2 mL min(-1) were employed in the chromatographic runs with an elution time about 5 min. Results: This approach demonstrates that chromatographic analysis may become considerably simpler and economical in terms of time, cost, and organic solvent consumption when coupled to multiway calibration models such as MCR-ALS. In fact, this multi-way chromatographic calibration based on second-order HPLC-DAD data matrices (with extremely low chromatographic resolution) and MCR-ALS allows the development of greener analytical methods for complex samples. The proposed analytical method allowed the simultaneous quantification of two antimalarial APIs present in the commercial Paludrine/Avloclor drugs with low REP values below 8% for the simultaneous determination of proguanil hydrochloride and chloroquine phosphate. Conclusion: The proposed multi-way chromatographic strategy can be used for routine control of pharmaceutical dosage forms. It should be highlighted that MCR-ALS allowed to: (a) achieve the second-order advantage and the quantification of analytes in the presence of uncalibrated compounds such as coeluted profile measured in different magnitude of the signal in each successive chromatographic run and significant overlapping profiles and (b) separate the contribution of several components from chromatographic runs with extremely low separation of peaks through the deconvolution of the signal obtained, performing the so-called mathematical chromatography.
495.
Biofilm control with enzymes
Borges A.
; Meireles A.
; Mergulhão F.
; Melo L.
; Simões M.
in Recent Trends in Biofilm Science and Technology, 2020,
Book Chapter, Indexed in: crossref, scopus
Abstract
Microorganisms have the ability to multiply, attach to wet surfaces, and produce a matrix of extracellular polymeric substances (EPS), forming biofilms. The development of biofilms occurs on almost all surfaces (inanimate and living) and can cause serious problems in medical field, food industry, and systems. The multiple layers of cells and EPS confer to biofilms a complex and compact structure that hinders penetration of antimicrobial agents, decreasing their capacity to reach internal layers, and rendering them ineffective. Thus, when microorganisms form biofilms, the resistance to conventional antimicrobial agents increases significantly, and the control of those biofilms becomes hard to achieve. Besides, due to the complexity/heterogeneity of sessile communities, the application of a single strategy is considered insufficient. In this context, there is a need for new strategies, new antimicrobials, and biofilm prevention/control techniques. An ideal antibiofilm strategy should involve approaches to prevent biofilm formation, disintegrate biofilm structure, or remove preformed biofilms. Promising approaches can be based on the application of “green” and biological-based products, such as enzymes. Enzymes are applied in many fields of investigation and are known to be capable of degrading key components of the biofilm matrix. Moreover, it is recognized that the combination of enzymes with other biofilm control agents can enhance their activity. However, enzymes are specific, and to degrade the complex matrix that involves the biofilm, a mixture of enzymes is often necessary. In this chapter, the factors that play a crucial role in the resistance of biofilm-associated bacteria will be addressed. In addition, emergent strategies for biofilm control and eradication will be highlighted. As the use of biofilm-disrupting enzymes appears to be a very promising option to effectively control and eradicate microbial biofilms, a literature review for this strategy will be presented.
496.
Looking for new xanthine oxidase inhibitors: 3-Phenylcoumarins versus 2-phenylbenzofurans
Era, B
; Delogu, GL
; Pintus, F
; Fais, A
; Gatto, G
; Uriarte, E
; Borges, F
; Kumar, A
; Matos, MJ
in INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES, 2020, ISSN: 0141-8130, Volume: 162,
Article, Indexed in: crossref, scopus, wos
Abstract
Overproduction of uric acid in the body leads to hyperuricemia, which is also closely related to gout. Uric acid production can be lowered by xanthine oxidase (XO) inhibitors. Inhibition of XO has also been proposed as a mechanism for improving cardiovascular health. Therefore, the search for new efficient XO inhibitors is an interesting topic in drug discovery. 3-Phenylcoumarins and 2-phenylbenzofurans are privileged scaffolds in medicinal chemistry. Their structural similarity makes them interesting molecules for a comparative study. Methoxy and nitro substituents were introduced in both scaffolds. The current study gives some insights into the synthesis and biological activity of these molecules against this important target. For the best compound of the series, the 3-(4-methoxyphenyl)-6-nitrocoumarin (4), the IC50 value, type of inhibition, cytotoxicity on B16F10 cells and ADME theoretical properties, were determined. Docking studies were also performed in order to better understand the interactions of this molecule with the XO binding pocket. This work is a preliminary screening for further design and synthesis of new non-purinergic derivatives as potential compounds involved in the inflammatory suppression, specially related to gout.
497.
Recent Trends in Biofilm Science and Technology
Simoes M.
; Borges A.
; Simoes L.C.
in Recent Trends in Biofilm Science and Technology, 2020,
Book, Indexed in: crossref, openlibrary, scopus
Abstract
Recent Trends in Biofilm Science and Technology helps researchers working on fundamental aspects of biofilm formation and control conduct biofilm studies and interpret results. The book provides a remarkable amount of knowledge on the processes that regulate biofilm formation, the methods used, monitoring characterization and mathematical modeling, the problems/advantages caused by their presence in the food industry, environment and medical fields, and the current and emergent strategies for their control. Research on biofilms has progressed rapidly in the last decade due to the fact that biofilms have required the development of new analytical tools and new collaborations between biologists, engineers and mathematicians.
498.
The potential of drug repurposing to face bacterial and fungal biofilm infections
Oliveira I.M.
; Borges A.
; Simões M.
in Recent Trends in Biofilm Science and Technology, 2020,
Book Chapter, Indexed in: crossref, scopus
Abstract
The emergence of multidrug-resistant microorganisms in persistent biofilm infections represents a public health threat. The limited efficacy of currently available antimicrobials has been imposing the search for new approaches to overcome bacterial and fungal biofilm infections. Drug repurposing arises as an interesting strategy that can reduce time, cost, and risk associated with drug innovation. This can be achieved by finding new applications beyond the original medical indication for approved or investigational drugs. This chapter collects the antimicrobial effects known so far against bacteria and fungi caused by different classes of drugs, including antineoplastic, antipsychotic, antidepressant, and antiinflammatory, among others. Besides the action on microbial growth in vitro and in vivo, some of these drugs are also able to synergize with traditional antibiotics and antifungals. Finally, a special focus on antibiofilm activity was included, reveling the promising drugs for biofilm prevention and control.
499.
Chemistry and Pharmacology of Modulators of Oxidative Stress
Saso, L
; Suzen, S
; Borges, F
; Csont, T
in CURRENT MEDICINAL CHEMISTRY, 2020, ISSN: 0929-8673, Volume: 27,
Editorial Material, Indexed in: crossref, scopus, wos
500.
COVID-19 Pandemic Consequences on Coastal Water Quality Using WST Sentinel-3 Data: Case of Tangier, Morocco
Cherif, E
; Vodopivec, M
; Mejjad, N
; Esteves da Silva, JCGE
; Simonovic, S
; Boulaassal, H
in WATER, 2020, ISSN: 2073-4441, Volume: 12,
Article, Indexed in: crossref, scopus, wos
Abstract
The west coast of Tangier, in northern Morocco, has been affected by industrial wastewater discharge that reaches the ocean through the Boukhalef river. Therefore, the Jbila and Sidikacem beaches near to the Boukhalef river mouth have been classified as polluted for many years. With the aim of determining the COVID-19 pandemic consequences on the Tangier coastal environment, a linear model using Sentinel 3 water surface temperature (WST) has been tested in several locations. Data from April 2019 and April 2020, before and during the COVID-19 pandemic related emergency status in Morocco, were compared. The results from April 2019 showed high WST values and consequently, the poorest water quality in the sites closest to the Boukhalef river mouth. On the other hand, the results from April 2020 showed normal WST values and high water quality in the same study area. These results illustrate the usefulness of Sentinel 3 WST for the estimation of bathing water quality on the west coast of Tangier. The study shows the positive impact of the COVID-19 pandemic consequences on the coastal environment quality in the study area and indicates the importance of decreasing the industrial discharge on the west coast of Tangier. The same methodology could be used in decision-making processes and to reduce cost, time and human resources for coastal monitoring systems. We demonstrate the potential of using the Sentinel 3 data for coastal waters monitoring, as well as the need for stricter controls of pollutant discharges into the world's rivers.