Hydrolysable Tannins and Biological Activities of Meriania hernandoi and Meriania nobilis (Melastomataceae)

Authors :: Francisco A. Macías
Carlos Rial
José M. G. Molinillo
Ana Julia Colmenares Dulcey
José Hipólito Isaza Martínez
Rosa M. Varela
Claudia Lorena Valverde Malaver
Química Orgánica
Source :: Molecules, Volume 24, Issue 4, Molecules, Vol 24, Iss 4, p 746 (2019), Molecules 2019, 24, 746, RODIN. Repositorio de Objetos de Docencia e Investigación de la Universidad de Cádiz, instname
Publication Year :: 2019
Publisher :: MDPI, 2019.
Abstract: A bio-guided study of leaf extracts allowed the isolation of two new macrobicyclic hydrolysable tannins, namely merianin A (1) and merianin B (2), and oct-1-en-3-yl &beta xylopyranosyl-(1&rdquo 6&rsquo )-&beta glucopyranoside (3) from Meriania hernandoi, in addition to 11 known compounds reported for the first time in the Meriania genus. The structures were elucidated by spectroscopic analyses including one- and two-dimensional NMR techniques and mass spectrometry. The bioactivities of the compounds were determined by measuring the DPPH radical scavenging activity and by carrying out antioxidant power assays (FRAP), etiolated wheat coleoptile assays and phytotoxicity assays on the standard target species Lycopersicum esculentum W. (tomato). Compounds 1 and 2 exhibited the best free radical scavenging activities, with FRS50 values of 2.0 and 1.9 &micro M, respectively.

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