53 research outputs found

    Sondas fluorescentes e agentes antifúngicos derivados do Nile Blue

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    Dissertação de mestrado em Técnicas de Caracterização e Análise QuímicaAtendendo ao conhecido interesse a nível biológico das sulfonamidas e de benzo[a]fenoxazinas, assim como à experiência do grupo de trabalho nesta última família de compostos, decidiu-se efetuar a síntese de uma nova série de benzo[a]fenoxazinas, derivadas do Nile Blue, possuindo um grupo sulfonamida como substituinte no sistema policíclico. A escolha deste grupo como substituinte teve como base trabalho publicado anteriormente que mostrou que uma benzo[a]fenoxazina com o grupo metilfenilsulfonamido na amina da posição 5 apresentava um interessante potencial antifúngico (MIC 30 μM em S. cerevisiae). A inexistência de outros derivados semelhantes motivou a exploração de diferentes combinações deste grupo com outros substituintes para otimização da atividade desta classe de compostos. Por outro lado, benzo[a]fenoxazinas possuindo nas aminas das posições 5 e 9 diferentes combinações de substituintes apresentam propriedades fotofísicas que permitem a sua aplicação como sondas de fluorescência na região do infravermelho próximo, designadamente em meio biológico, pelo que se torna fundamental conhecer o comportamento destes compostos em meio aquoso, especificamente em condições fisiológicas simuladas. Assim, neste trabalho efetuou-se a síntese de seis novas benzo[a]fenoxazinas possuindo como substituintes na amina da posição 5 um grupo sulfonamida e na amina da posição 9 grupos propilo (um ou dois), ou um grupo etilo em simultâneo com um grupo metilo na posição 10 do sistema policíclico para comparação de resultados. Para além disso, foram também sintetizadas as benzo[a]fenoxazinas análogas às anteriores, com o mesmo tipo de substituição na posição 9 mas sem o grupo sulfonamida na posição 5, apenas com o grupo amina (sem substituintes), ou com o grupo (3-aminopropil)amino para avaliação do efeito do grupo sulfonamida na atividade biológica. A caracterização dos compostos sintetizados foi efetuada pelas técnicas espectroscópicas de IV, RMN de 1H e 13C. Foram avaliadas as propriedades fotofísicas dos cloretos de benzo[a]fenoxazínio obtidos pelas técnicas de espectroscopia de UV/Vis e de fluorescência, tendo sido obtidos os espetros de absorção e emissão de fluorescência em etanol, água e a diferentes valores de pH, designadamente 3, 5, 7,4 e 8,5, relevantes a nível fisiológico. A atividade antiproliferativa dos cloretos de benzo[a]fenoxazínio sintetizados foi determinada na levedura Saccharomyces cerevisiae PYCC 4072, utilizando o método de microdiluição descrito para os testes de suscetibilidade antifúngica em leveduras.Considering the known biological interest of sulfonamides and benzo[a]phenoxazines, as well as the experience of the research group in the latter family of compounds, it was decided to synthesize a new series of benzo[a]phenoxazines, Nile Blue derivatives, having a sulfonamide as a substituent in the polycyclic system. The choice of this group was based on previous work showing that a benzo[a]phenoxazine with methylphenylsulfonamido at 5-position displayed an interesting antifungal activity (MIC 30 μm in S. cerevisiae). However, the lack of comparative results motivated the exploitation of different combinations of this group with other substituents for optimization of the activity of this class of compounds. On the other hand, benzo[a]phenoxazines possessing in the 5- and 9- amine positions different combinations of substituents show photophysical properties that allow its application as fluorescence probes in the region of near infrared, namely in biological environment, becoming extremely important to know the behavior of these compounds in aqueous medium, specifically at simulated physiological conditions. Thus, in this work is presented the synthesis of six new benzo[a]phenoxazines having as substituent at the 5-position a sulfonamide group and at the 9-position propyl groups (one or two), or an ethyl group with a methyl group at 10-position of the polycyclic system for the comparison of results. In addition, benzo[a]phenoxazines analogous to the above were also synthesized with the same type of substitution at the 9-position but without sulfonamide group at the 5-position, with only amine group (without substituents), or with (3-aminopropyl)amino group to evaluate the effect of sulfonamide group on biological activity. Full characterization of all compounds was carried out by IR, 1H and 13C NMR spectroscopy. Photophysical properties of synthesized benzo[a]phenoxazinium chlorides were evaluated by UV/Vis and fluorescence spectroscopy. Absorption and fluorescence emission spectra were obtained in ethanol, water, and at different physiologically relevant pH values, namely 3, 5, 7.4 and 8.5. The antiproliferative activity of the synthesized benzo[a]phenoxazinium chlorides was determined using Saccharomyces cerevisiae PYCC 4072 and the microdilution method described for antifungal susceptibility tests in yeast

    Novel benzo[α]phenoxazinium chlorides functionalized with sulfonamide groups as NIR fluorescent probes for vacuole, endoplasmic reticulum, and plasma membrane staining

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    The demand for new fluorophores for different biological target imaging is increasing. Benzo[a]phenoxazine derivatives are fluorochromophores that show promising optical properties for bioimaging, namely fluorescent emission at the NIR of the visible region, where biological samples have minimal fluorescence emission. In this study, six new benzo[a]phenoxazinium chlorides possessing sulfonamide groups at 5-amino-positions were synthesized and their optical and biological properties were tested. Compared with previous probes evaluated using fluorescence microscopy, using different S. cerevisiae strains, these probes, with sulfonamide groups, stained the vacuole membrane and/or the perinuclear membrane of the endoplasmic reticulum with great specificity, with some fluorochromophores capable of even staining the plasma membrane. Thus, the addition of a sulfonamide group to the benzo[a]phenoxazinium core increases their specificity and attributes for the fluorescent labeling of cell applications and fractions, highlighting them as quite valid alternatives to commercially available dyes.FCT (Fundação para a Ciência e Tecnologia, Portugal) and FEDER (European Fund for Regional Development)-COMPETEQREN-EU for financial support to the research centers CQ/UM (UID/QUI/00686/2021), and CBMA (Ref. UIDB/04050/2020), as well as a PhD grant to J. C. Ferreira (SFRH/BD/133207/2017 and COVID/BD/151978/2021). The NMR spectrometer Bruker Avance III 400 (part of the National NMR Network) was financed by FCT and FEDER

    Quinoline-based hydrazones for biocide detection: Machine learning-aided design of new TBT chemosensors

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    Antifouling compounds are used as paint components to mitigate biofouling on ships and submerged structures. One of the most known and used antifouling compounds is tributyltin (TBT). However, TBT is toxic to aquatic living beings, causing problems such as reduction of growth and imposex. The development of a TBT chemosensor could be of utter relevance in the building of an in-situ TBT monitoring device. Therefore, this work reports the synthesis of five new quinoline-based hydrazones (HZ) and two new quinoline-based thiosemicarbazones (TSC), with synthesis yields from 17 to 83 %. The compounds were tested in the presence of TBT, and some compounds of the group showed colorimetric or fluorimetric changes. The interaction between these compounds and TBT was tested by spectrophotometric or spectrofluorimetric titrations, which allowed to calculate the limit of detection (LOD) for each interaction. The fluorimetric interaction between HZ 4a and TBT was shown to be the most sensitive chemosensory method, with a LOD value of 1.7 µM. A Ridge classifier model was developed to correlate the ability for TBT detection and the modification of the structure of each molecule. The validity of the proposed model was tested by assessing the TBT-sensing ability of the two novel TSC 5a and 5b, which were synthesized after the development of the model. These two compounds also showed colorimetric changes in the presence of TBT, with LODs of 13.8 and 3.1 µM, respectively, in good accordance with the model’s predictions. Further analysis of the model’s decision process provided some insights on the desirable properties of the novel quinoline-derived TBT optical chemosensors

    Amino-alcohol organic-inorganic hybrid sol-gel materials based on an epoxy bicyclic silane: synthesis and characterization

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    Organic-inorganic hybrids (OIHs) are a type of material that can be obtained using the sol-gel process and has the advantages of organic and inorganic moieties in a single material. Polyetheramines have been widely used in the preparation of this type of material, particularly in combination with epoxy-based alkoxysilanes. Nevertheless, epoxyciclohexylethyltrimethoxysilane (ECHETMS) is a promising alkoxysilane with an epoxy terminal group that is quite unexplored. In this work, four novel OIH materials were synthesized using the sol-gel method. The OIHs were based on Jeffamines® of different molecular weights (D-230, D-400, ED-600, and ED-900), together with ECHETMS. The materials were characterized using multinuclear solid state NMR, FTIR, BET, UV/Vis spectroscopy, EIS, and TGA. The influence of the Jeffamine molecular weight and the suitability of these materials to act as a supporting matrix for heteroaromatic probes were assessed and discussed. The materials show interesting properties in order to be applied in a wide range of sensing applications.This research was funded by Fundação para a Ciência e Tecnologia (FCT) and FEDER (European Fund for Regional Development)-COMPETE-QRENEU for financial support through the Chemistry Research Centre of the University of Minho (Ref. CQ/UM (UID/QUI/00686/2019 and UID/QUI/00686/2020), project “SolSensors—Development of Advanced Fiber Optic Sensors for Monitoring the Durability of Concrete Structures”, reference POCI-01-0145-FEDER-031220, and a PhD grant to R.P.C.L. Sousa (SFRH/BD/145639/2019). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network (PTNMR) and are partially supported by Infrastructure Project No 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC)

    Hybrid sol-gel matrices doped with colorimetric/fluorimetric imidazole derivatives

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    Organic–inorganic hybrids (OIH) are materials that can be easily synthesized by the sol–gel method and combine the advantages of organic and inorganic moieties within a single polymeric matrix. Imidazole derivatives are versatile organic compounds that can change their optical properties with the variation of pH due to the protonation or deprotonation of the nitrogen atoms. This work reports the preparation of different OIHs doped with different contents of two imidazole compounds (3a,b). The obtained materials were characterized structurally by FTIR, and the dielectric properties were studied by electrochemical impedance spectroscopy. The optical properties were studied by UV-Vis absorption and fluorescence spectroscopies. The FTIR analysis showed that the presence of the imidazole does not change the structural properties of the matrices. The normalized resistance values obtained for the doped matrices ranged between 8.57 and 9.32 Ω cm2, all being higher than the undoped matrix. The σ ranged between 9.49 and 10.28 S cm−1, being all higher than the pure OIH samples. Compound 3a showed a maximum absorption peak at 390 nm, which is present in the OIH spectra, proving the presence of the compound. In the case of compound 3b, a maximum absorption wavelength at 412 nm was found, and the compound peak was not clear, which may indicate that an interaction between the compound and the matrix occurred. A synergetic effect between the intrinsic emission of the matrix and the fluorescence of 3a is found on the OIH-doped matrices.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 (Ref. CQ/UM (UID/QUI/00686/2019 and UID/QUI/00686/2020), project “SolSensors—Development of Advanced Fiber Optic Sensors for Monitoring the Durability of Concrete Structures”, reference POCI-01-0145-FEDER-031220, and a PhD grant to R.P.C.L. Sousa (SFRH/BD/145639/2019). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network (PTNMR) and partially supported by Infrastructure Project No 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC)

    Development of competences while solving real industrial interdisciplinary problems: a successful cooperation with industry

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    The development of projects in industrial context constitutes an exceptional opportunity for engineering students to develop competences expected by the labour market. Therefore, the adoption of this type of interaction within engineering curricula is highly recommended, not only at the end of the degree, but also in the previous years. The main purpose of this paper is to present and analyse a Project-Based Learning (PBL) semester in which six teams of Industrial Engineering and Management (IEM) students integrate different areas of knowledge, while solving real problems of five companies, emphasizing the technical solutions developed by the students and the feedback provided by the companies. Students' feedback will be also addressed. The main outcomes of this study reveal that most of the technical solutions lie in areas of Lean applications and ergonomic improvement of workplaces. Companies were very pleased with the results of this type of University-Business Cooperation (UBC).This work was funded by COMPETE-POCI-01-0145-FEDER-007043 and FCT-UID-CEC-00319-2013info:eu-repo/semantics/publishedVersio

    MAMMALS IN PORTUGAL : A data set of terrestrial, volant, and marine mammal occurrences in P ortugal

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    Mammals are threatened worldwide, with 26% of all species being includedin the IUCN threatened categories. This overall pattern is primarily associatedwith habitat loss or degradation, and human persecution for terrestrial mam-mals, and pollution, open net fishing, climate change, and prey depletion formarine mammals. Mammals play a key role in maintaining ecosystems func-tionality and resilience, and therefore information on their distribution is cru-cial to delineate and support conservation actions. MAMMALS INPORTUGAL is a publicly available data set compiling unpublishedgeoreferenced occurrence records of 92 terrestrial, volant, and marine mam-mals in mainland Portugal and archipelagos of the Azores and Madeira thatincludes 105,026 data entries between 1873 and 2021 (72% of the data occur-ring in 2000 and 2021). The methods used to collect the data were: live obser-vations/captures (43%), sign surveys (35%), camera trapping (16%),bioacoustics surveys (4%) and radiotracking, and inquiries that represent lessthan 1% of the records. The data set includes 13 types of records: (1) burrowsjsoil moundsjtunnel, (2) capture, (3) colony, (4) dead animaljhairjskullsjjaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8),observation in shelters, (9) photo trappingjvideo, (10) predators dietjpelletsjpine cones/nuts, (11) scatjtrackjditch, (12) telemetry and (13) vocalizationjecholocation. The spatial uncertainty of most records ranges between 0 and100 m (76%). Rodentia (n=31,573) has the highest number of records followedby Chiroptera (n=18,857), Carnivora (n=18,594), Lagomorpha (n=17,496),Cetartiodactyla (n=11,568) and Eulipotyphla (n=7008). The data setincludes records of species classified by the IUCN as threatened(e.g.,Oryctolagus cuniculus[n=12,159],Monachus monachus[n=1,512],andLynx pardinus[n=197]). We believe that this data set may stimulate thepublication of other European countries data sets that would certainly contrib-ute to ecology and conservation-related research, and therefore assisting onthe development of more accurate and tailored conservation managementstrategies for each species. There are no copyright restrictions; please cite thisdata paper when the data are used in publications.info:eu-repo/semantics/publishedVersio

    Mammals in Portugal: a data set of terrestrial, volant, and marine mammal occurrences in Portugal

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    Mammals are threatened worldwide, with ~26% of all species being included in the IUCN threatened categories. This overall pattern is primarily associated with habitat loss or degradation, and human persecution for terrestrial mammals, and pollution, open net fishing, climate change, and prey depletion for marine mammals. Mammals play a key role in maintaining ecosystems functionality and resilience, and therefore information on their distribution is crucial to delineate and support conservation actions. MAMMALS IN PORTUGAL is a publicly available data set compiling unpublished georeferenced occurrence records of 92 terrestrial, volant, and marine mammals in mainland Portugal and archipelagos of the Azores and Madeira that includes 105,026 data entries between 1873 and 2021 (72% of the data occurring in 2000 and 2021). The methods used to collect the data were: live observations/captures (43%), sign surveys (35%), camera trapping (16%), bioacoustics surveys (4%) and radiotracking, and inquiries that represent less than 1% of the records. The data set includes 13 types of records: (1) burrows | soil mounds | tunnel, (2) capture, (3) colony, (4) dead animal | hair | skulls | jaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8), observation in shelters, (9) photo trapping | video, (10) predators diet | pellets | pine cones/nuts, (11) scat | track | ditch, (12) telemetry and (13) vocalization | echolocation. The spatial uncertainty of most records ranges between 0 and 100 m (76%). Rodentia (n =31,573) has the highest number of records followed by Chiroptera (n = 18,857), Carnivora (n = 18,594), Lagomorpha (n = 17,496), Cetartiodactyla (n = 11,568) and Eulipotyphla (n = 7008). The data set includes records of species classified by the IUCN as threatened (e.g., Oryctolagus cuniculus [n = 12,159], Monachus monachus [n = 1,512], and Lynx pardinus [n = 197]). We believe that this data set may stimulate the publication of other European countries data sets that would certainly contribute to ecology and conservation-related research, and therefore assisting on the development of more accurate and tailored conservation management strategies for each species. There are no copyright restrictions; please cite this data paper when the data are used in publications

    Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

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    Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For schoolaged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesit

    Measurement of jet fragmentation in Pb+Pb and pppp collisions at sNN=2.76\sqrt{{s_\mathrm{NN}}} = 2.76 TeV with the ATLAS detector at the LHC

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