• Food Science and Biotechnology
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• v.16 no.2
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• pp.265-269
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• 2007

There is significant interest in finding new sources of acetylcholinesterase (AChE) inhibitors for use in treating Alzheimer's disease, since only a few AChE inhibitors are available for clinical use, such as galanthamine, physostigmine, and tacrine. The ethanol extract of Chrysanthemum indicum Linne flowers was analyzed and found to markedly decrease AChE activity. Acaciin and $acacetin-7-O-{\beta}-D-galactopyranoside$ were identified as the active compounds responsible for the AChE inhibition by using an activity-guided fractionation strategy. The relationship between structure and activity for five flavonoids (acaciin, $acacetin-7-O-{\beta}-D-galactopyranoside$, luteolin, and two other commercially available flavonoids, i.e., apigenin and acacetin) was also investigated, revealing that the presence of methoxy groups at C-4' in the B ring and a sugar at O-7 in ring A appear to be essential for the inhibition of AChE.

• Archives of Pharmacal Research
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• v.17 no.2
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• pp.71-75
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• 1994

The antimutagenic effects of 27 kinds of plant flavonoids on the mutagenicity of aflatoxin $B_1(AFB_1)$ and N-methyl-N'-nitro-N-nitrosoguanidine(MANG) in Salmonella typhimurium TA 100 were investigated. In the mixed applications of $AFB_1\;(1\;\mu{g/plate)}$ with the flavonoids $(300\;\mu{g/plate)}$ in the presence of a mammalian metabolic activation system (S9 mix), chrysin, apigenin, luteolin and its glucoside, kaempferol, fisetin, morin, naringenin, hesperetin, persicogenin, (+)-catechin and (-)epicatechin showed the antimutagenic effect against $AFB_1$ with more than 70% inhibition rate. A little or no antimutagenicities except flavone against MNNG $(0.5\;\mu{g/plate)}$ were observed. For the antimutagencity of the flavonoids on $AFB_1$, the flavonoid structure that contains the free 5, 7-hydroxyl gorup seemed to be essential. However, saturation of the 2, 3-double bond of elimination of the 4-keto group did not affect the activity.

• Archives of Pharmacal Research
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• v.28 no.5
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• pp.573-581
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• 2005

Flavonoids, a group of low molecular weight phenylbenzopyrones, have various pharmacological properties including antioxidant activity, anticancer, and immunomodulatory effects. In the present study, lipopolysaccharide (LPS) and phorbol 12-myristate 13-acetate/phytohemagglutinin (PMA/PHA) were used as stimulants for RAW 264.7 macrophages and human peripheral blood mononuclear cell (hPBMC), and tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-2 productions were measured. In addition, flavonoids were examined for their effects on LPS-induced NO production in RAW 264.7 macrophages. The results showed that all compounds were not strongly cytotoxic at the tested concentrations on hPBMC and RAW 264.7 macrophages. On immunomodulatory properties, catechin, epigallocatechin (EGC), naringenin, and fisetin repressed NO production and TNF-${\alpha}$ secretion. Furthermore, catechin, epigallocatechin gallate (EGCG), epicatechin (EC), luteolin, chrysin, quercetin, and galangin increased IL-2 secretion while EGC, apigenin, and fisetin inhibited the secretion. These results indicated that flavonoids have the capacity to modulate the immune response and have a potential anti-inflammatory activity. There was no obvious structure-activity relationship regard to the chemical composition of the flavonoids and their cell biological effects.

• Bulletin of the Korean Chemical Society
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• v.29 no.3
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• pp.590-594
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• 2008

The inclusion complexes of cyclodextrins (CDs) with flavones in aqueous solution were investigated by phase solubility measurements. The effect of b -cyclodextrin (b -CD), heptakis (2,6-di-O-methyl) b -cyclodextrin (DM-b -CD) and 2-hydroxypropyl-b -cyclodextrin (HP-b -CD) on the aqueous solubility of three flavones, namely, chrysin, apigenin and luteolin was investigated, respectively. Solubility enhancements of all flavones obtained with three CDs followed the rank order: HP-b -CD > DM-b -CD > b -CD, and besides, CDs show higher stability constant on luteolin than that on others flavones. 1H-nuclear magnetic resonance (NMR) spectroscopy and molecular modeling was used to help establish the model of interaction of the CDs with luteolin. NMR spectroscopic analysis suggested that A-C ring, and part of the B ring of luteolin display favorable interaction with the CDs, which was also confirmed by docking studies based on the molecular simulation. The observed augmentation of solubility of luteolin by three CDs was explained by the difference of electrostatic interaction of each complex, especially hydrogen bonding.

• Food Science and Preservation
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• v.4 no.2
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• pp.181-187
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• 1997

New HPLC method was developed for determination of some flavonoids such as naringin, hesperidin, neohesperidin, rutin, quercitrin, naringenin, hesperetin and apigenin and their contents in citrus juice and citrus peel from citrus varieties Brown in Cheju. Detection was at 280nm and reverse phase ${\mu}$-Bondapak C-18 column was used. Water/methanol/acetic acid as the mobile phase was better than water/acetonitrile/acetic acid. Flavonoids were more stable in 20% n,n-dimethylformamide in methanol(20% DMF) than methanol and pH 12 adjusted by 1N-sodium hydroxide solution. Standard flavonoid solutions were injected three times consecutively and the reproduciability was 0.236 to 3.550%, Correlation coefficient of the calibration curve was 0.9946 to 0.9999. The exiraction efficiency of hesperidin from citrus peel was evaluated with different extraction method such as reflux, ultra-sonicating method, using three solvents (aqueous solutions with pH12 adjusted by 1N-sodium hydroxide, methanol and 20% DMF), respectively. The reflux for 4 hour in 20% DMF was the most efficient of the tested methods and solvents, and recovery percentage were 78.0∼130.0%. Flavonoids were determined in citrus juice. Naringin was 68.2mg/100$m\ell$ in Natsudaidai, Hesperidin were 85.6mg/100$m\ell$ in Sankyool and Neohesperidin was 25.3mg/100$m\ell$ in Dangyooja. Flavonoids were determined in citrus peel. Naringin was 110mg/g in Dangyooja, Hesperidin was 242mg/g in Hungjin and Neohesperidin was 87.9mg/g in Dangyooja.

• Journal of Forest and Environmental Science
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• v.21 no.1
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• pp.16-23
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• 2005

The leaves of Paulownia Coreana Uyeki were collected, extracted with acetone-$H_2O$(7:3, v/v), fractionated with n-hexane, methylene chloride and ethylacetate, and freeze dried to give some dark brown powder. The ethylacetate soluble mixture was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. Spectrometric analysis such as NMR and MS including TLC were performed to characterize the structures of the isolated compounds. From the ethylacetate fraction, five flavonoides and three phenolic acids were isolated and determined.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.211-220
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• 2013

The characteristic fluorescence properties of quercetin (QCT) and apigenin (API) were studied in various $CH_3OH-H_2O$ and $CH_3CN-H_2O$ mixed solvents. The structure of QCT is completely planar. API is not planar at the ground state but becomes nearly planar at the excited state. If the molecules are excited to the $S_1$ state in organic solvents, QCT exhibits no fluorescence due to excited state intramolecular proton transfer (ESIPT) between the -OH and the carbonyl oxygen, but API shows significant fluorescence because ESIPT occurs slowly. If the molecules are excited to the $S_2$ state, both QCT and API exhibit strong $S_2{\rightarrow}S_o$ emission without any dual fluorescence. As the $H_2O$ composition of both solvents increases, the fluorescence intensity decreases rapidly due to the intermolecular hydrogen bonding interaction. The theoretical calculation further supports these results. The change in fluorescence properties as a function of the solvatochromic parameters was also studied.

• YAKHAK HOEJI
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• v.54 no.1
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• pp.22-26
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• 2010

We studied the antimicrobial activities of five compounds isolated from the stems of Vitis coignetiae Pulliat and the seeds of Perilla frutescens (L.) Britton. Based on spectroscopic evidence, compounds 1 to 5 were characterized as resveratrol, $\varepsilon$-viniferin, ampelopsin E, apigenin, and luteolin, respectively. The antimicrobial activities against Gram-positive (Staphylococcus aureus) and -negative (Pseudomonas aeruginosa) bacteria and a fungus (Candida albicans) were investigated using the disc diffusion and broth dilution methods. C. albicans was not inhibited by the five compounds. Compounds 2 and 5 had significant anti-microbial activity against S. aureus, and the 50% inhibitory concentration ($IC_{50}$) of compound 2 against S. aureus was 7.2 ${\mu}M$. Compounds 4 and 5 significantly inhibited P. aeruginosa and the minimum inhibitory concentration (MIC) of compounds 2 and 5 was 0.07 and 2.0 ${\mu}M$, respectively. Compounds 2, 4, and 5 had strong anti-microbial activity against S. aureus and P. aeruginosa.

• Molecules and Cells
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• v.22 no.3
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• pp.291-299
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• 2006

Vitexin, a natural flavonoid compound identified as apigenin-8-C-${\beta}$-D-glucopyranoside, has been reported to exhibit antioxidative and anti-inflammatory properties. In this study, we investigated its effect on hypoxiainducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) in rat pheochromacytoma (PC12), human osteosarcoma (HOS) and human hepatoma (HepG2) cells. Vitexin inhibited HIF-$1{\alpha}$ in PC12 cells, but not in HOS or HepG2 cells. In addition, it diminished the mRNA levels of hypoxia-inducible genes such as vascular endothelial growth factor (VEGF), smad3, aldolase A, enolase 1, and collagen type III in the PC12 cells. We found that vitexin inhibited the migration of PC12 cells as well as their invasion rates, and it also inhibited tube formation by human umbilical vein endothelium cells (HUVECs). Interestingly, vitexin inhibited the hypoxia-induced activation of c-jun N-terminal kinase (JNK), but not of extracellular-signal regulated protein kinase (ERK), implying that it acts in part via the JNK pathway. Overall, these results suggest the potential use of vitexin as a treatment for diseases such as cancer.

• International Journal of Advanced Culture Technology
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• v.7 no.3
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• pp.120-125
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• 2019

In this paper, we have isolated six phenolic compounds, such as (+)-catechin (1), taxifolin (2), taxifolin-3-O-${\beta}$-D-(+)-xylose (3), quercetin (4), quercetin-3-O-${\alpha}$-L(+)-rhamnose (quercitrin) (5), apigenin-8-C-rhamnosyl-(1'''${\rightarrow}$2'')-glucoside (2''-O-rhamnosylvitexin) (6) from the EtOAc(Ethyl Acetate) and $H_2O$ soluble fractions of Japanese anise(Illicium anisatum L) leaves and twigs. Also, we have evaluated antioxidative and antiviral activity for each isolated compound. The antioxidative test was DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity. According to the experimental results, all of the isolated compounds indicated the increased radical scavenging activities as the concentration increases and most of the isolated compounds indicated generally good antioxidative values compare to the controls, ascorbic acid and ${\alpha}$-tocopherol. In the antiviral activities, all of the isolated compounds had no potentials in rhinovirus 1B (HRV 1B). But in enterovirus 71 (EV 71) and Influenza virus A/PR/8 (Influenza PR8), only quercetin (4) indicated the good antiviral activity compare to the control. Based on the above results, we found that the phenolic compounds of Japanese anise may be applied for one of the natural biomass sources that can be used as an antioxidant and an antiviral substance.