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Trabajos Finales de Graduación

URI permanente para esta colecciónhttp://10.0.96.45:4000/handle/11056/14824

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Examinando Trabajos Finales de Graduación por Autor "Álvarez Valverde, Víctor"

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    Determinación del contenido de ácido quínico y ácido clorogénico presentes en helechos de la familia Polypodiaceae
    (Universidad Nacional (Costa Rica), 2021) Salazar Chacón, Yaclyn Lucía; Álvarez Valverde, Víctor
    Studies have revealed that the secondary metabolites contained in ferns have various pharmacological effects and that the extracts of fern species belonging to the Polypodiaceae family are of importance for the treatment of dermatological diseases such as psoriasis, atopic dermatitis and vitiligo. The species with the most studies is Polypodium leucotomos and it has been shown that the extract has a high content of phenolic compounds such as chlorogenic acid (AC) and quinic acid (AQ), the latter being an active principle, as well as a precursor of some medicines and substances essential for the body. As a general objective of the research, twenty-one promising species of ferns of the Polypodiaceae family were evaluated in terms of the content of AQ and AC for their possible dermatological use. In the present investigation, the optimization of the extraction process was carried out in rhizomes and leaves of twenty-one species of ferns of the Polypodiaceae family native to Costa Rica, and the subsequent determination of the AC and AQ analytes by means of HPLC-DAD. In addition, the susceptibility of the bacteria S. epidermidis, S. aureus, P. aeruginosa and E. coli to the crude extracts of the samples was evaluated, determining the relative percentage of the diameter of the zone of inhibition (% PRDZI) by means of the Kirby-Bauer diffusion method. According to the results, the suitable solvent for the extraction is methanol 75%, when carrying out three extractions from the same sample. The separation and analysis of the analytes were obtained by means of the chromatographic gradient run with methanol, acetonitrile and 0.1% trifluoroacetic acid in water. The limits of detection and instrumental quantification for AC were 5.27 mg / L and 34.4 mg / L, respectively; and for AQ they were 28.6 mg / L and 68.1 mg / L, correspondingly. The promising sample in terms of AQ content was that of the leaves of the species P. macrocarpa with (30.09 ± 0.38) mg / g and of AC, the sample of the leaves of the species P. ursipes with (8 , 48 ± 0.35) mg / g. The antibiotic activity test showed efficacy of some samples in inhibiting the growth of the two Gram-positive bacteria used, but not with the Gram-negative bacteria. The main% PRDZI with the S. aureus bacteria was that of the rhizomes of N. crassifolium with 79% and that of the rhizomes of S. loriceum with 77%; in a similar way these two species with the bacterium S. epidermidis, which with these samples obtained 69% and 70%, respectively.