FCS (DCM)- Artigos em Revistas Científicas Internacionais com Arbitragem Científica
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- The synthesis, crystal structure and Hirshfeld analysis of 4-(3,4-dimethylanilino)-N-(3,4-dimethylphenyl)quinoline-3-carboxamidePublication . Gomes, Lígia Rebelo; Low, John Nicolson; Borges, Fernanda; Gaspar, Alexandra; Mesiti, FrancescoThe structure of the title quinoline carboxamide derivative, C26H25N3O, is described. The quinoline moiety is not planar as a result of a slight puckering of the pyridine ring. The secondary amine has a slightly pyramidal geometry, certainly not planar. Both intra- and intermolecular hydrogen bonds are present. Hirshfeld surface analysis and lattice energies were used to investigate the intermolecular interactions.
- Phytochemical characterization and biological activities of green tea (Camellia sinensis) produced in the Azores, PortugalPublication . Barreira, Sérgio; Moutinho, Carla; Silva, André M.N.; Neves, José Manuel Gomes da Silva; Seo, Ean-Jeong; Hegazy, Mohamed-Elamir F.; Efferth, Thomas; Gomes, Lígia RebeloBackground: Green tea is not only one of the most widely consumed beverages worldwide, but is also known for its health promoting and therapeutic effects. Green tea is cultivated in areas with high humidity and acidic soils in China, Indonesia and Japan. Those places have well-marked dry and rainy seasons. In opposite, Azores have a climate with constant average annual rainfall and, unlike eastern regions, relatively constant air humidity throughout the year. While a brand implemented on the Portuguese market, the quality of green tea produced in Azores must be guaranteed. Quality control measures based on phytochemical determination of the chemical composition and biological activities are needed in order to address whenever climate changes interferes significantly with composition and biological effects. Purpose: Make the phytochemical characterization of various extracts of green tea leaves coming from Azores and evaluate the anti-cancer activities of the extracts in order to compare the obtained results with those of teas coming from eastern regions. Methods: Phytochemical characterization (catechins, oxyaromatic acids, flavonols, alkaloids and theanine) and total catechins contents (TCC) was performed by using HPLC-DAD analysis, in infusions (5–7 min and 30 min), maceration and methanolic extracts of Camellia sinensis samples coming from Azores, Portugal. The antioxidant activity of extracts was measured by the DPPH assay and the total phenolics contents (TPC) were estimated using the Folin-Ciocalteu colorimetric method. The cytotoxic activity towards drug sensitive and multidrug-resistant leukemia cell lines was determined by the resazurin assay. Results: The TCC was higher in methanolic extracts and lower in maceration, as epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) concentrations were significantly higher in methanolic extracts and were only residual in maceration extracts. Maceration extracts showed the highest content of gallic acid, indicating that methanol extracts contained more flavonols of higher molecular weight and/or that maceration may lead to the degalloylation of catechins. The amount of o-caffeoylquinic acid extracted was significantly higher in methanolic samples. Short-term extraction at high temperatures resulted in high amounts of neochlorogenic acid. The contents of glycosylated quercitin-3-d-galactoside and kaempferol-3-glucoside were small in maceration samples and high in methanolic samples. Caffeine was easily extracted by methanol (99%) compared with water, while extraction of the amino-acid l-theanine was impossible with methanol. TPC values correlated linearly with DPPH• IC50, with infusion samples showing the best antioxidant capacities. The aqueous and the methanol/water extracts were active in multidrug-resistant and drug sensitive cancer cells.
- Effect of extraction methodology on the phytochemical composition for camelia sinensis “Powdered tea extracts” from different provenancesPublication . Barreira, Sérgio; Silva, André M. N.; Moutinho, Carla; Seo, Ean-Jeong; Hegazy, Mohamed-Elamir F.; Efferth, Thomas; Gomes, Lígia RebeloBackground: beverages based on extracts from Camellia sinensis are popular worldwide. Due to an increasing number of processed teas on the market, there is a need to develop unified classification standards based on chemical analysis. Meanwhile, phytochemical characterizations are mainly performed on tea samples from China (~80%). Hence, data on teas of other provenances is recommended. (2) Methods: in the present investigation, we characterized lyophilised extracts obtained by infusion, maceration and methanolic extraction derived from tea samples from China, Japan, Sri Lanka and Portugal by phytochemistry (catechins, oxyaromatic acids, flavonols, alkaloids and theanine). The real benefits of drinking the tea were analysed based on the bioavailability of the determined phytochemicals. (3) Results: the infusions revealed the highest total phenolic contents (TPC) amounts, while methanolic extracts yielded the lowest. The correlation matrix indicated that the levels of phenolic compounds were similar in the infusions and methanolic samples, while extractions made by maceration were significantly different. The differences could be partially explained by the different amounts of (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG) and gallic acids (GA). The catechin percentages were significantly lower in the macerations, especially the quantity of EGCG decreases by 4- to 5-fold after this process. (4) Conclusions: the results highlight the importance of the processing methodology to obtain “instant tea”; the composition of the extracts obtained with the same methodology is not significantly affected by the provenance of the tea. However, attention should be drawn to the specificities of the Japanese samples (the tea analysed in the present work was of Sencha quality). In contrast, the extraction methodology significantly affects the phytochemical composition, especially concerning the content of polyphenols. As such, our results indicate that instant tea classification based on chemical composition is sensible, but there is a need for a standard extraction methodology, namely concerning the temperature and time of contact of the tea leaves with the extraction solvent.
- Determination by ICP-MS of essential and toxic trace elements in gums and carrageenans used as food additives commercially available in the portuguese marketPublication . Azevedo, Rui; Oliveira, Ana Rafaela; Almeida, Agostinho; Gomes, Lígia RebeloGums and carrageenans are food additives widely used in food preparations to improve texture and as viscosifiers. Although they are typically added in small amounts, nowadays people tend to use more and more pre-prepared food. In this work, the content of a wide panel of trace elements in commercial products were analyzed. Carrageenans and gums (n = 13) were purchased in the Portuguese market and were from European suppliers. Samples were solubilized by closed-vessel microwave-assisted acid digestion and analyzed by ICP-MS. Globally, the content of essential trace elements decreased in the following order: Fe (on average, on the order of several tens of µg/g) > Mn > Zn > Cr > Cu > Co > Se > Mo (typically < 0.1 µg/g), while the content of non-essential/toxic trace elements decreased in the following order: Al > Sr > Rb > As > Li > Cd > Pb > Hg. The consumption of these food additives can significantly contribute to the daily requirements of some essential trace elements, namely Cr and Mo. The toxic trace elements Cd, As, Pb, and Hg were below the EU regulatory limits in all analyzed samples. Additional research is needed to define the potential risk of introducing toxic trace elements into food products through the use of these additives.
- Structural study of N-(1,3-Benzothiazol-2-yl)-4-Halobenzenesulfonylhydrazides: hirshfeld surface analysis and PIXEL calculationsPublication . Gomes, Lígia Rebelo; Low, John N.; Pinheiro, Alessandra C.; Wardell, James L.Hydrazonylsulfones such as Bt-NHNHSO2R and their iminotautomers have been studied as optical materials and for their biological potential. In this work, a structural study has been carried out on N-(1,3-benzothiazol-2-yl)-4-(halogenobenzenesulfonyl)-hydrazides (1: X = F, Cl, Br). For (1: X = F), single-crystal X-ray diffraction, Hirshfeld surface analysis, and PIXEL calculations were conducted, while in (1: X = Cl) and (1: X = Br), only single-crystal X-ray diffraction studies were successfully conducted due to the disordering of the solvent. Each compound crystallises with two independent but similar amino tautomers in the asymmetric units: compound (1: X = F) crystallises in the monoclinic P21/c, and the isostructural pair (X: 1 = Cl and Br) crystallises in the tetragonal P-421c space group. In the most stable motif of the supramolecular arrangement, the molecules of the asymmetric unit are connected by classical N–H(hydrazinyl)•••N(thiazoyl) hydrogen bonds and several face-to-face, offset π•••π interactions. This motif has a very powerful influence on the crystal structure due to its direct links with the other weaker motifs. Other significant intermolecular interactions found in the structure include N–H(hydrazonyl)•••O(sulfonate) bonds. Analogous intermolecular interactions were found in similar compounds, leading to the conclusion that those interactions are the most important instabilizing the solid state of hydrazonylsulfones.
- Assessment of Rhodopirellula rubra as a supplementary and nutritional food source to the microcrustacean Daphnia magnaPublication . Marinho, Maria da Conceição; Lage, Olga Maria; Sousa, Carla D.; Catita, José; Antunes, Sara C.The daily use of the planctomycete Rhodopirellula rubra as an alternative or supplementary food source for Daphnia magna and its feasibility in the nutrition of transgenerational populations were studied. The life history parameters, fatty acids (saturated, mono- and polyunsaturated; SFAs, MUFAs and PUFAs), glycogen and protein contents of organisms during feeding assays and of the first generation were analysed. An increase in the yields of D. magna with the increase of the cell concentration of R. rubra was evident, but overall, bacteria supplied as the only food source was nutritionally insufficient as observed for all the parameters analysed. However, when R. rubra was added as supplement to the microalgae Raphidocelis subcapitata a significant improvement in the life history parameters was observed namely in the reproductive output and the somatic growth rate. The identified SFAs, MUFAs and PUFAs were the fatty acids more abundant in daphniids, and the feed regimens influenced daphniids fatty acid profiles. Additionally, the mixed diet resulted in a larger number and size of offspring in the different F1 broods as also observed with the results of F0 generation. The pink colouration present in D. magna body and eggs confirmed that bacteria were absorbed, the pigment(s) retained and passed on to the next generation. Our results showed that R. rubra can play an essential role in D. magna diet as a nutritional supplement showing potential biotechnological applications.
- Potential of FTIR spectroscopy applied to exosomes for Alzheimer’s disease discrimination: a pilot studyPublication . Soares Martins, Tânia; Magalhães, Sandra; Rosa, Ilka Martins; Vogelgsang, Jonathan; Wiltfang, Jens; Delgadillo, Ivonne; Catita, José; da Cruz e Silva, Odete A.B.; Nunes, Alexandra; Henriques, Ana GabrielaAlzheimer's disease (AD) diagnosis is based on psychological and imaging tests but can also include monitoring cerebrospinal fluid (CSF) biomarkers. However, CSF based-neurochemical approaches are expensive and invasive, limiting their use to well-equipped settings. In contrast, blood-based biomarkers are minimally invasive, cost-effective, and a widely accessible alternative. Blood-derived exosomes have recently emerged as a reliable AD biomarker source, carrying disease-specific cargo. Fourier-transformed infrared (FTIR) spectroscopy meets the criteria for an ideal diagnostic methodology since it is rapid, easy to implement, and has high reproducibility. This metabolome-based technique is useful for diagnosing a broad range of diseases, although to our knowledge, no reports for FTIR spectroscopy applied to exosomes in AD exist. In this ground-breaking pilot study, FTIR spectra of serum and serum-derived exosomes from two independent cohorts were acquired and analyzed using multivariate analysis. The regional UA-cohort includes 9 individuals, clinically diagnosed with AD, mean age of 78.7 years old; and the UMG-cohort comprises 12 individuals, clinically diagnosed with AD (based on molecular and/or imaging data), mean age of 73.2 years old. Unsupervised principal component analysis of FTIR spectra of serum-derived exosomes revealed higher discriminatory value for AD cases when compared to serum as a whole. Consistently, the partial least-squares analysis revealed that serum-derived exosomes present higher correlations than serum. In addition, the second derivative peak area calculation also revealed significant differences among Controls and AD cases. The results obtained suggest that this methodology can discriminate cases from Controls and thus be potential useful to assist in AD clinical diagnosis.
- Comparison of neutral lipid fatty acids composition in organisms from different trophic levelsPublication . Lage, Olga M.; Antunes, Sara C.; Marinho, Conceição; Catita, JoséThe profiles of total fatty acids (TFAs) and the neutral lipid fatty acids (NLFAs) were compared for the bacterium Rhodopirellula rubra and the alga Raphidocelis subcapitata (conventional food source for Daphnia magna). D. magna NLFAs were assessed when this crustacean was fed with bacterium and alga, individually or in combination. After NLFA extraction, the profiles of the various organisms were characterized by gas chromatography. Results evidenced the relevance of the different composition of the fatty acid (FAs) fractions in the different organisms, R. rubra and R. subcapitata. In these species, the NFLA analyses revealed high amounts of long chain FAs (C19). The FA profile of D. magna was influenced by the different diets provided although the preferred diet was the alga. D. magna showed the capacity to adapt to the available food resources as it defines its FA profile according to its needs, namely for the long chain FAs (C19).
- Sleep duration, body composition, dietary profile and eating behaviours among children and adolescents: a comparison between portuguese acrobatic gymnastsPublication . Silva, Maria Raquel; Silva, Hugo-Henrique; Paiva, TeresaSleep, body composition and dietary intake are crucial for athletes' health and performance but have never been investigated in acrobatic gymnasts. Thus, this study aimed to evaluate sleep, body composition, dietary intake and eating behaviours of acrobatic gymnasts. Using a cross-sectional study, 82 Portuguese acrobatic gymnasts (12.8 ± 3.1 years, 61 females and 21 males) were evaluated during the competitive period to collect training data, sleep duration, body composition, dietary intake and eating behaviours before, during and after practices. Most of the gymnasts (91.5%) slept less than 8 h/night. Female adolescents slept significantly less on weekdays than female children (P = 0.024). Female adolescents' mean body mass was below the normal and 60.0% showed menstrual irregularities; 4.9% of females bases were overweight and 2.4% obese. Male adolescents slept significantly less on weekdays than male children (P = 0.001); significant differences were shown for fat-free mass (P = 0.014); however, 3.7% were overweight. All daily energy and macronutrient intakes were significantly different according to age and gender, with exception for fibre and energy intake in females (P = 0.057 and P = 0.052, respectively), and for protein in males (P = 0.068). Female and male adolescents demonstrated significant lower energy availability (32.8 ± 9.4 kcal/kg FFM/day and 45.1 ± 14.7 kcal/kg FFM/day) than children (45.8 ± 8.7 kcal/kg FFM/day and 53.8 ± 9.1 kcal/kg FFM/day), respectively. Significant low intakes of important vitamins and minerals were reported. Most of the participants did not eat or drink during or immediately after training sessions. Conclusion: Acrobatic gymnasts revealed low BF, short sleep duration and macro- and micronutrients inadequate intakes. The Female Athlete Triad was demonstrated by female adolescent gymnasts.
- Demystifying thickener classes food additives though molecular gastronomyPublication . Gomes, Lígia Rebelo; Simões, Catarina D.; Silva, CláudiaIn order to meet the nutritional needs of the increasing world population, a higher demand for food production seems to be imperative. This challenge is peremptory because it is necessary to find sustainable forms of production that have, in one hand, to meet the requirements of safety and quality and, simultaneously, the increase in demand. One way to achieve such a goal is to reduce waste along the food supply chain, which implies ensuring that most of the food produced reaches the population in conditions to be consumed. Food additives allow manufacturers to overcome the problem of limited supply of natural ingredients, increase the shelf life of food and simplify the complex procedures involved in cooking: they contribute to the reduction of waste and, thus, to the sustainability of nutrition of the global population. Nevertheless, food additives raise a number of ethical issues, such as consumer sovereignty, that is, “the consumer's ability to act in accordance with their informed judgments". In this revision, some of the physical chemical properties of widely used additives belonging to E400 to E490 types, namely alginates, agar-agar, methyl-celluloses, and pectin are revised in a simple manner using models derived from molecular gastronomy. Recipes models are presented to explain how the physical chemical properties allow food processing in order to attain of a particular characteristic of the food formulation. Preparations coming from the discipline of molecular gastronomy have been chosen to illustrate the concepts since they are based in laboratory related procedures and they use only a few ingredients. This work aims to add a valuable contribution for demystifying the use of the referred additives in food processing, thus contributing to rise consumer sovereignty.