Otro
Interconverting flavanone glucosides and other phenolic compounds in Lippia salviaefolia Cham. ethanol extracts
Registro en:
Phytochemistry. Oxford: Pergamon-Elsevier B.V. Ltd, v. 72, n. 16, p. 2052-2061, 2011.
0031-9422
10.1016/j.phytochem.2011.07.004
WOS:000295950100015
Autor
Funari, Cristiano Soleo
Passalacqua, Thais Gaban
Rinaldo, Daniel
Napolitano, Assunta
Festa, Michela
Capasso, Anna
Piacente, Sonia
Pizza, Cosimo
Marx Young, Maria Claudia
Durigan, Giselda
Siqueira Silva, Dulce Helena
Resumen
Four interconverting flavanone glycosides [(2R)- and (2S)-3',4',5,6-tetrahydroxyflavanone 7-O-beta-D-glucopyranoside, and (2R)- and (2S)-3',4',5,8-tetrahydroxyflavanone 7-O-beta-D-glucopyranoside], in addition to eight known flavonoids [naringenin, asebogenin, sakuranetin, 6-hydroxyluteolin 7-O-beta-D-glucoside, (2R)- and (25)-eriodictyol 7-O-beta-D-glucopyranoside, aromadendrin and phloretin], three phenylpropanoid glycosides [forsythoside B. alyssonoside and verbascoside] and the epoxylignan lariciresinol 4'-O-beta-D-glucopyranoside were isolated and identified in the EtOH extract of the aerial parts of Lippia salviaefolia Cham. The phytochemical study herein was guided by preliminary antioxidant tests, namely, beta-carotene protection and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity. The crude extracts, their active fractions and the isolated compounds were assayed against intracellular reactive oxygen species (ROS) and human embryonic kidney HEK-293 and human melanoma M14 cancer cell growth. Aromadendrin and phloretin were able to counteract elevation of ROS induced by the oxidant t-butylhydroperoxide (t-BOOH) in HEK-293 cells, whereas phloretin strongly protected HEK-293 cells from ROS damage at 1 mu M. Additionally, phloretin exhibited a significant growth inhibitory effect at 20-40 mu M in both HEK-293 and M14 cells and induced a concentration dependent apoptosis at 20 mu M in M14 cells, suggesting a selective action towards malignant cells. Due to their equilibria, the four interconverting flavanone glycosides were studied using 10 and 2D NMR, HPLC-CD-PDA and HRMS analyses. (C) 2011 Elsevier Ltd. All rights reserved. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)