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- A sustainable synthesis of asymmetric phenazines and phenoxazinones mediated by CotA-LaccasePublication . Sousa, Ana Catarina; Oliveira, Maria Conceição; Martins, Lígia O.; Robalo, Maria PaulaAn efficient and sustainable one-step procedure for the synthesis of new asymmetric phenazines and phenoxazinones from commercially available ortho-substituted diamines and ortho-substituted hydroxyamines is reported. In this study we have expanded the substrate scope of CotA-laccase-catalyzed aerobic oxidations through the use of aromatic amines presenting variable functional groups, including N-substitution, contributing to the rational synthesis of different heterocyclic scaffolds. The transformations proceed smoothly through a cascade of oxidative reactions to the benzoquinonediimine intermediates followed by nucleophilic addition, intramolecular cyclization and aromatization, all performed in mild conditions.
- Action of euptox A from Ageratina adenophora juice on human cell lines: a top-down study using FTIR spectroscopy and protein profilingPublication . André, Rebeca; Catarro, Joana; Freitas, Dalia; Pacheco, Rita; Oliveira, Maria Conceição; Serralheiro, Maria Luisa; Fale, PedroEuptox A, from Ageratina adenophora juice, is a toxin associated with the plant's resistance to infections, invasiveness and traditional use in cancer treatment. We used FTIR spectroscopy and protein profiling of cell lines to study the impact of euptox A on human cells, to clarify its mechanism of action in a top-down approach. Euptox A was extracted from the juice of A. adenophora. Its stability in the gastrointestinal tract was evaluated, as the compound/juice is generally taken orally. Cytotoxicity was determined in HeLa, Caco-2 and MCF7 cells, and the mechanism of action analyzed by protein and metabolite profiles using electrophoresis and FTIR spectroscopy. Euptox A resisted gastrointestinal digestion and was the most cytotoxic component of the extract for all cell lines tests. Euptox A-treated HeLa cells showed changes in protein profile, especially on 40S ribosomal protein S8 (RP), generally associated with cancer cells. FTIR profiles of treated cells diverged in the same metabolites as cells treated with cisplatin, both in metabolite directed analysis and in multivariate analysis (principal component analysis). In conclusion, euptox A in this top-down study showed a cellular impact that suggests a strong potential against cancer, acting on cancer targeted cellular characteristics.
- Composition and in vitro antioxidants activity of Chamaerops humilis L.Publication . Coelho, Jose; Veiga, Jerson G.; Elvas Leitao, Ruben; Brigas, Amadeu F.; Dias, Ana M.; Oliveira, Maria ConceiçãoThe aim of this work is to evaluate the polyphenols composition and the antioxidant activity of methanol extracts of Chamaerops humilis L. Methanol extracts from dried leaves of Chamaerops humilis were prepared using Soxhlet extraction and examined as potential sources of phenolic compounds. Different methods were used to evaluate antioxidant activity of the extracts, including colored (ABTS*+), DPPH radical scavenging assay and reducing power. Total phenolic and flavonoid contents of the extracts were evaluated by Folin-Ciocalteu and aluminum chloride (AlCl3) methods, respectively. Phenolic compositions of the methanol extracts were elucidated by high performance liquid chromatography coupled on-line with tandem mass spectrometry (HPLC-MS/MS). The extract was mainly composed of C- and O-flavones and its O-methylated derivatives. The results suggest that methanol extracts have good potential as sources of bioactive compounds and presents an important antioxidants capacity, which can ensures its potential recommendation for application in the pharmaceutical and nutraceutical sectors.
- Predicting critically ill patients outcome in the ICU using UHPLC-HRMS dataPublication . Henrique Fonseca, Tiago Alexandre; Von Rekowski, Cristiana; Araújo, Rúben Alexandre Dinis; Oliveira, Maria Conceição; Bento, Luís; Justino, Gonçalo; Calado, Cecília; Domingues, Nuno A. S.; Gomes, Vítor; Topcuoglu, BulentThe available scores to predict patients’ outcomes in specific settings generally present low sensitivities and specificities when applied to intensive care units’ (ICUs) populations. Advancements in analytical techniques, notably Ultra-High Performance Liquid Chromatography- Mass Spectrometry (UHPLCHRMS) transformed biomarker identification, enabling a comprehensive profiling of biofluids, including serum. In the current work, untargeted metabolomics, utilizing UHPLC-HRMS serum analysis, was performed on 16 ICU patients, categorized as either discharged (n=8), or deceased (n=8) in average seven days post sample collection. Linear discriminant analysis (LDA) or principal component analysis (PCA)-LDA models involving different metabolite sets were developed, enabling to predict patients’ outcomes in the ICU with 92% accuracy and 83% sensitivity on validation datasets. These results highlight the advantages of UHPLC-HRMS as a platform capable of providing a set of clinically significant biomarkers to predict patients’ outcome. The available scores to predict patients’ outcomes in specific settings generally present low sensitivities and specificities when applied to intensive care units’ (ICUs) populations. Advancements in analytical techniques, notably Ultra-High Performance Liquid Chromatography- Mass Spectrometry (UHPLCHRMS) transformed biomarker identification, enabling a comprehensive profiling of biofluids, including serum. In the current work, untargeted metabolomics, utilizing UHPLC-HRMS serum analysis, was performed on 16 ICU patients, categorized as either discharged (n=8), or deceased (n=8) in average seven days post sample collection. Linear discriminant analysis (LDA) or principal component analysis (PCA)-LDA models involving different metabolite sets were developed, enabling to predict patients’ outcomes in the ICU with 92% accuracy and 83% sensitivity on validation datasets. These results highlight the advantages of UHPLC-HRMS as a platform capable of providing a set of clinically significant biomarkers to predict patients’ outcome.