Phenylethanoid glycoside from Forsythia koreana (Oleaceae) flowers shows a neuroprotective effect

Abstract

A repeated column chromatography for Forsythia koreana Nakai. flowers afforded a phenylethane glycoside, which was identified as 8 0-(3,4-dihydroxyphenyl)ethyl-O-a-L-rhamnopyranosyl-(1 ? 4)-2-O-(E)-caffeoyl-a-L-arabinopyranoside based on spectroscopic analyses of 1D NMR (1 H-NMR, 13 C-NMR, DEPT), 2D NMR (gCOSY, gHSQC, gHMBC), FAB/ MS, specific rotation, and IR spectrometry. This compound was isolated from F. koreana flower for the first time in this study. The compound showed scavenge activities in ORAC and DPPH radicals with the values of 0.83 ± 0.01 and 84.66 ± 0.75% (at the concentration of 500 ppm), respectively. It also inhibited production of NO for RAW 264.7 stimulated by LPS and protected oxidative stress induced by glutamate in HT22-immortalized hippocampal. The IC 50 on inhibition of NO production and EC 50 value on protective efficacy of oxidative stress were 78.72 ± 1.43 lM and 176.25 ± 7.23 lM, respectively. These results demonstrate that the phenylethanoid glycoside might be useful as a neuroprotective agent because of their antioxidant, anti-inflammatory, and neuroprotective effects.

Flavonoids from Chionanthus retusus (Oleaceae) Flowers and Their Protective Effects against Glutamate-Induced Cell Toxicity in HT22 Cells

“…The equipment and chemicals used to isolate and identify flavonoids from C. retusus flowers and evaluate their neuroprotective activity were obtained from the literature [32,33,34,35].…”

“…Mouse hippocampal HT22 cells were donated by Wonkwang University, Iksan, Korea (Prof. Youn-Chul Kim). Cytoprotective activity assay was performed, as per the previously described method [35]. Cell viability was evaluated using the MTT assay reported in the literature [36].…”

“…Macrophage RAW 264.7 culture, viability assay, and NO measurement were carried out as per the previously described method [35].…”

Recovery effect of lignans and fermented extracts from Forsythia koreana flowers on pancreatic islets damaged by alloxan in zebrafish (Danio rerio)

“…The samples are same as those used in the previous studies [19,20]. BGP1 (GenBank accession number 603820) Escherichia coli cloning was obtained from KyungHee University, Ginseng Resource Bank, Yong-In, Korea.…”

“…EtOAc FR (FKE, 45 g), n-butanol FR (FKB, 110 g), H 2 O FR (FKW, 395 g) were obtained as reported in the previous study [19,20]. FKE was treated with silica gel (SiO 2 ) column chromatography (c.c.)…”