• Natural Product Sciences
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• v.15 no.2
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• pp.90-95
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• 2009

Phytochemical investigation of the MeOH extract of the leaves of Nelumbo nucifera resulted in the isolation of five norsesquiterpenes, four flavonoids, two triterpenes and one alkaloid. Their chemical structures were characterized by spectroscopic methods to be (E)-3-hydroxymegastigm-7-en-9-one (1), (3S,5R,6S,7E)- megastigma-7-ene-3,5,6,9-tetrol (2), dendranthemoside B (3), icariside $B_2$ (4), sedumoside $F_1$ (5), luteolin (6), quercetin 3-0-${\beta}$-D-glucuronide (7), quercetin 3-0-${\beta}$-D-glucoside (8), isorhamnetin 3-0-rutinoside (9), alphitolic acid (10), maslinic acid (11), and N-methylasimilobine (12). Norsesquiterpenoids (1-5) and triterpenes (10-11) were isolated for the first time from this plant. Compounds 6 and 10-12 exhibited considerable cytotoxicity against four human cancer cell lines in vitro using a SRB bioassay.

• Natural Product Sciences
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• v.17 no.3
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• pp.221-224
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• 2011

A $CH_3Cl$ extract from the flower of Lonicera japonica (Lauraceae) significantly protected primary cultures of rat cortical cells injured by the excitotoxic amino acid, L-glutamate. Loganin (1), secoxyloganin (2), caffeic acid (3) rutin (4), hyperoside (5), quercetin-3-O-glucoside (6), lonicerin (7), kaempferol-3-O-rutinoside (8), luteolin-7-O-b-D-glucopyranoside (9), quercetin (10) and luteolin (11) were isolated by bioactivity-guided fractionation from the $CH_3Cl$ fraction and further separated using chromatographic techniques. Caffeic acid, lonicerin, kaempferol-3-O-rutinoside, quercetin and luteolin had significant neuroprotective activities against glutamate-induced neurotoxicity in primary cultures of rat cortical cells at concentrations ranging from $0.1{\mu}M$ to $10.0\;{\mu}M$.

• Horticulture, Environment, and Biotechnology : HEB
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• v.59 no.6
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• pp.919-927
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• 2018

To compare the antioxidant properties and flavonols in various parts; dry skin (DS) and edible portion (EP), of 8 red onions (Allium cepa L, ROs), total content of phenolics (TPC), flavonoids (TFC), and anthocyanins (TAC) and DPPH radical scavenging properties were estimated and the content of six flavonols were quantified by HPLC-PDA analysis. The major component of DS and EP of RO was quercetin and quercetin-4'-glucoside, respectively. Score plots of the PCA and PLS-DA were segregated by flavonols content and antioxidant properties according to the EP and DS of ROs. Loading plot of the PCA showed that the quercetin and sum of flavonol content were highly correlated with antioxidant activity of ROs. Therefore, flavonol content and antioxidant activity can be used as markers for distinct parts of ROs.

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.647-657
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• 2016

In this study, the antioxidative effects and active component analysis of 50% ethanol extract, ethyl acetate fraction and aglycone fraction obtained from Prunella vulgaris L. were investigated. The free radical scavenging activities ($FSC_{50}$) was investigated at 50% ethanol extract ($15.25{\mu}g/mL$), ethyl acetate fraction ($8.68{\mu}g/mL$), and aglycone fraction ($8.25{\mu}g/mL$) respectively. Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) in $Fe^{3+}-EDTA/H_2O_2$ system using the luminol-dependent chemiluminescence assay was investigated at 50% ethanol extract ($4.68{\mu}g/mL$), ethyl acetate fraction ($1.00{\mu}g/mL$), and aglycone fraction($1.02{\mu}g/mL$) respectively. In the cellular protective effect against $^1O_2$ induced cellular damage of human erythrocytes, extract/fractions of P. vulgaris L. were increased in a concentration dependent manner($1{\sim}25{\mu}g/mL$). Especially, ${\tau}_{50}$ of aglycone fraction at concentrations of $25{\mu}g/mL$ showed the most protective effects at 337.9 min. It's showed nine times higher (+)-${\alpha}$-tocopherol (${\tau}_{50}=38.7min$) as typical antioxidant in the $^1O_2$-induced photohemolysis of human erythrocytes. TLC and HPLC were used to analyse active components in the ethyl acetate fraction and aglycone fraction of P. vulgaris L. In ethyl acetate fraction, caffeic acid, rosmarinic acid, quercetin 3-${\beta}$-D-glucoside, rutin, kaempferol-3-O-rutinoside, astragalin (kaempferol-3-O-glucoside) were identified. In aglycone fraction, caffeic acid, rosmarinic acid, quercetin, kaempferol were identified. These results indicated that extract/fraction of P. vulgaris L. is may be used in cosmetics industry as natural antioxidants by quenching and/or scavenging $^1O_2$ and other ROS, and protecting cellular membranes.

• Natural Product Sciences
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• v.15 no.4
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• pp.234-240
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• 2009

Phytochemical investigation of the MeOH extract of the aerial parts of Bistorta manshuriensis resulted in the isolation of two cerebrosides, two lactams, six phenolic compounds and seven flavonoids. Their chemical structures were characterized by spectroscopic methods to be pinelloside (1), soyacerebroside I (2), pterolactam (3), 5-hydroxypyrrolidine-2-one (4), vanillic acid (5), caffeic acid methyl ester (6), protocatechuic acid (7), caffeic acid (8), 3,5-di-O-caffeoyl quinic acid methyl ester (9), chlorogenic acid methyl ester (10), avicularin (11), afzelin (12), quercetin (13), isoorientin (14), quercetin 3-O-${\beta}$-D-glucoside (15), quercitrin (16), and luteolin (17). The isolated compounds (1 - 4, 7, 12, 14) were isolated for the first time from this plant source and the compounds 1 - 4, 9 and 10 were first reported from the genus Bistorta. Compound 17 exhibited moderate cytotoxicity and compound 6 exhibited weak cytotoxicity against four human cancer cell lines in vitro using an SRB bioassay.

• Archives of Pharmacal Research
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• v.27 no.3
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• pp.300-304
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• 2004

Five caffeic acid derivatives; methyl ester of caffeoylglycolic acid (1), dimethyl ester of caffeoyltartaric acid (2), dimethyl ester of caffeoyltartronic acid (3), monomethyl ester of caffeoyltartronic acid (4), methyl ester of caffeic acid (5), and some other secondary metabolites including; quercetin, quercetin 3-O-$\beta$-D-glucuronide methyl ester, kaempferol, 3,5,7,4'-O-tetramethylkaempferol, $\beta$-sitosterol glucoside, 2$\alpha$-hydroxyursolic acid and 2,24-dihydroxyursolic acid, have been isolated and characterized. All the isolated compounds were characterized with the help of NMR spectroscopy and mass spectrometry. Structure of compound 3 was also confirmed by a single X-ray crystallographic technique. Isolates were evaluated for anti-oxidant activities and most of the tested compounds were found to be potent in DPPH free radical scavenging ($IC_{50}{\;}={\;}4.56-14.17{\;}{\mu\textrm{g}}/mL$) and superoxide anion scavenging ($IC_{50}{\;}={\;}0.58-7.39{\;}{\mu\textrm{g}}/mL$) assays.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.908-913
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• 2000

To enhance the utilization of apple pomace for the functional food resources, we analyzed the useful components and examined the antioxidant activity of apple pomace. The contents of total dietary fiber, total flavonoid, total phenolic acid and vitamine C were 55.56%, 458 mg%, 1048 mg% and 19.8 mg%, respectively. Protocatechuic acid, cinamic acid, caffeic acid, ferulic acid, syringic acid, vanillic acid and phydroxybenzoic acid were identified in the apple pomace extract by GC-MS. Phloridzin and quercetin-3-glucoside were identified in the apple pomace extract by HPLC. Ethyl acetate fraction showed the highest antioxidative ability by ferric thiocyanate method. Malondialdehyde(MDA) formation in normal rat liver tissue also showed the lowest in ethyl acetate fraction.

• Preventive Nutrition and Food Science
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• v.17 no.4
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• pp.280-285
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• 2012

Six polyphenolic compounds, such as chlorogenic acid (CA), rutin (RT), isoquercitrin (IQT), quercetin-3-O-(6-O-malonyl)-${\beta}$-D-glucoside (QMG), astragalin (AG), kaempferol-3-O-(6-O-malonyl)-${\beta}$-D-glucoside (KMG), were isolated from mulberry leaves by a series of isolation procedures, such as Diaion HP-20, silica-gel, Sephadex LH-20, and ODS-A column chromatographies. The chemical structures of the phenolic compounds were identified by UV and NMR spectral analyses. Levels of polyphenols in mulberry leaves from six different mulberry cultivars ranged from 1,042.16 to 1,871.97 mg% per dry weight; Guksang cultivar showed the highest levels of polyphenols, whereas Gaeryangdaehwa contained the least polyphenol contents. Generally, levels of polyphenols in mulberry leaves decreased with increasing harvest time, except for Yoolmok, but increased with heat processing time, except QMG and KMG. These results suggest that the heat processed mulberry leaves of Guksang cultivar harvested in early May can be potentially useful sources for production of high quality mulberry leaf teas.

• Korean Journal of Pharmacognosy
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• v.54 no.2
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• pp.53-60
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• 2023

Athyrium acutipinnulum, called as Ulleungdo ladyfern (Seom-go-sa-ri), is a native plant of South Korea. A. acutipinnulum has been consumed as foods and also traditionally used for the treatment of epilepsy, gonorrhea and nerve disorder. The methanolic extract and EtOAc soluble fraction of A. acutipinnulum showed the antioxidant activity. Fractionation using various chromatographic techniques resulted in the isolation of 13 compounds. The structures were elucidated on the basis of spectroscopic methods as seven phenolic compounds, methyl 2-hydroxy-3-phenylpropanoate (1), protocatechualdehyde (2), caffeic acid (3), trans-p-coumaric acid (4), (-)-4-E-caffeoyl-L-threonic acid (5), 5-O-caffeoyl shikimic acid (6) and 5-O-caffeoyl quinic acid (7), three flavonoids, quercetin 3-O-β-glucoside (8), naringenin-7-O-β-glucoside (9) and sutchenoside A (10), two steroids, ponasterone A (11) and ecdysone (12) and a coumarin, esculetin (13). Among them, compounds 5 and 10 were first reported from Athyrium spp and compounds 2, 5, 6 and 7 showed the antioxidant activity.

• Microbiology and Biotechnology Letters
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• v.51 no.1
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• pp.83-92
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• 2023

In this study, bioconversion of rutin to quercetin was confirmed by the fermentation of Korean indigenous probiotics and tartary buckwheat. Based on whole genome sequencing of 17 probiotics species, α-rhamnosidase, related to bioconversion of isoquercetin (quercetin 3-β-D glucoside) from rutin, is identified in the genome of CBT BG7, LC5, LR5, LP3, LA1, and LGA1. β-Glucosidase, related to bioconversion of isoquercetin to quercetin, is identified in the genome of all 17 species. Among the 17 probiotics species, 6 probiotics including CBT BG7, LR5, LP3, LA1, LGA1 and ST3 performed the bioconversion of rutin to quercetin up to 21.5 ± 0.3% at 7 days after fermentation. The fermentation of each probiotics together with enzyme complex Cellulase KN^® was conducted to reduce the time of bioconversion. As a result, CBT LA1 which showed the highest yield of bioconversion of 21.5 ± 0.3% when the enzyme complex was not added showed high bioconversion yield of 84.6 ± 0.5% with adding the enzyme complex at 1 day after fermentation. In particular, CBT ST3 (96.2 ± 0.4%), SL6 (90.1 ± 1.4%) and LP3 (90.0 ± 0.4%) showed high yield of bioconversion more than 90%. In addition, such probiotics including high levels in quercetin indicated the inhibitory effects of NO production in LPS-induced RAW264.7 cells. In this study, we confirmed that the fermentation of Korean indigenous probiotics and enzyme complex together with roasted tartary buckwheat increased the content of quercetin and reduced the time of bioconversion of rutin to quercetin which is a bioactive compound related to anti-inflammatory, antioxidants, anti-obesity, and anti-diabetes.