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Browsing by Author "Sampaio, P. N."

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  • A new approach for rapid detection of bioactive compounds using MIR spectroscopy and machine learning algorithms
    Publication . Sampaio, P. N.; Duarte, Fernando B.; Calado, Cecília
    Nowadays, microbial infections and resistance to antibiotic drugs are the biggest challenges, which threaten the health of societies. Due to several pharmacological activities associated with Cynara cardunculus, such as hepatoprotective, antioxidative, anticarcinogenic, hypocholesterolemic, antibacterial, anti-HIV, among others, extracts from seeds, leaves, and flowers were tested in Escherichia coli cells. The sensibility of the Mid-infrared (MIR) spectroscopy allowed to perform a detailed analysis of the antimicrobial action of extracts in terms of their biomolecular changes. A comparative model based on several commercial antibiotics such as metronidazole, kanamycin, clarithromycin, chloramphenicol, and ampicillin, was developed. The clustering analysis was performed using unsupervised algorithms such as Principal Component Analysis (PCA), and Kohonen Self-Organizing Maps (SOM). The extracts characterized with antioxidant activity were clustered with antibiotics and presented a promissory antimicrobial activity. According to this preliminary result, it is possible to use the MIR spectroscopy and machine learning algorithm to discover promissory bio compounds characterized by antimicrobial properties, allowing to develop a platform to discover new bioactive molecules, reducing time and costs.
    2023-06Conference object Restricted access Show more
  • Use of chemometrics in the selection of a Saccharomyces cerevisiae expression system for recombinant cyprosin B production
    Publication . Sampaio, P. N.; SOUSA, LISETE; Calado, Cecília; Pais, M. S.; Fonseca\, L. P.
    Two multivariate statistical methods, factor analysis (FA) and hierarchical cluster analysis (HCA), were applied to experimental data set to evaluate their usefulness in selecting the adequate expression system and optimal growth parameters for recombinant cyprosin B production. Using FA, the large data set was reduced to two factors representing 73.4% of variability. Factor 1, with 53.5% of variability, corresponds to recombinant cyprosin B expression and efficient secretion, while factor 2, accounting for 19.9% of variability, represents cell growth and physiological characteristics. FA and HCA allowed the establishment of correlations among different variables and the clusters obtained providing clear identification of the experimental parameters related to cyprosin B production, which results on more accurate scientific output and time saving when selection of an adequate expression system is concerned.
    2011-11Journal article Restricted access Show more