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Interconverting flavanone glucosides and other phenolic compounds in Lippia salviaefolia Cham. ethanol extracts
journal contributionposted on 2023-05-18, 00:20 authored by Funari, CS, Passalacqua, TG, Rinaldo, D, Napolitano, A, Festa, M, Capasso, A, Piacente, S, Pizza, C, Young, MCM, Durigan, G, Silva, DHS
Four interconverting flavanone glycosides [(2R)- and (2S)-3′,4′,5,6-tetrahydroxyflavanone 7-O-β-d-glucopyranoside, and (2R)- and (2S)-3′,4′,5,8-tetrahydroxyflavanone 7-O-β-d-glucopyranoside], in addition to eight known flavonoids [naringenin, asebogenin, sakuranetin, 6-hydroxyluteolin 7-O-β-d-glucoside, (2R)- and (2S)-eriodictyol 7-O-β-d-glucopyranoside, aromadendrin and phloretin], three phenylpropanoid glycosides [forsythoside B, alyssonoside and verbascoside] and the epoxylignan lariciresinol 4′-O-β-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, β-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 μM. Additionally, phloretin exhibited a significant growth inhibitory effect at 20–40 μM in both HEK-293 and M14 cells and induced a concentration dependent apoptosis at 20 μM in M14 cells, suggesting a selective action towards malignant cells. Due to their equilibria, the four interconverting flavanone glycosides were studied using 1D and 2D NMR, HPLC–CD–PDA and HRMS analyses.
Department/SchoolSchool of Natural Sciences
PublisherPergamon-Elsevier Science Ltd
Place of publicationThe Boulevard, Langford Lane, Kidlington, Oxford, England, Ox5 1Gb
Rights statementCopyright 2011 Elsevier Ltd.