• Biomolecules & Therapeutics
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• v.27 no.3
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• pp.241-253
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• 2019

Flavonoids are major plant constituents with numerous biological/pharmacological actions both in vitro and in vivo. Of these actions, their anti-inflammatory action is prominent. They can regulate transcription of many proinflammatory genes such as cyclooxygenase-2/inducible nitric oxide synthase and many cytokines/chemokines. Recent studies have demonstrated that certain flavonoid derivatives can affect pathways of inflammasome activation and autophagy. Certain flavonoids can also accelerate the resolution phase of inflammation, leading to avoiding chronic inflammatory stimuli. All these pharmacological actions with newly emerging activities render flavonoids to be potential therapeutics for chronic inflammatory disorders including arthritic inflammation, meta-inflammation, and inflammaging. Recent findings of flavonoids are summarized and future perspectives are presented in this review.

• Journal of the Korean Applied Science and Technology
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• v.29 no.4
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• pp.610-617
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• 2012

Trifoliate orange components consist of several kinds, such as monoterpenes, limonoids, flavonoids, and coumarins. Coumarin derivatives were shown to possess valuable pharmacological properties such as anti-inflammatory and dietary effect. Among them, 7-geranyloxycoumarin 6 is a promising chemopreventive agent againist skin, tongue, oesophaqus and colon carcinogenesis in rodents. Seven new coumarin derivatives structurally related to 7-geranyloxycoumarin were synthesised in good yields by $Cs_2CO_3$/acetonitrile condition. We investigated the effect of anti-inflammatory activity on interleukin-6 for synthesised geranyloxycoumarin derivatives. 6-Geranyoxycoumarin 9 (68.9% / $1{\mu}M$ ; 72.6% / $10{\mu}M$) of the anti-inflammatory activity is far higher than 7-Geranyloxycoumarin 5 (40.1% / $1{\mu}M$ ; 61.1% / $10{\mu}M$) and their other derivatives.

• Biomolecules & Therapeutics
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• v.23 no.5
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• pp.465-470
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• 2015

Chrysin is a 5,7-dihydroxyflavone and was recently shown to potently inhibit enterovirus 71 (EV71) by suppressing viral 3C protease ($3C^{pro}$ activity. In the current study, we investigated whether chrysin also shows antiviral activity against coxsackievirus B3 (CVB3), which belongs to the same genus (Enterovirus) as EV71, and assessed its ability to prevent the resulting acute pancreatitis and myocarditis. We found that chrysin showed antiviral activity against CVB3 at $10{\mu}M$, but exhibited mild cellular cytotoxicity at $50{\mu}M$, prompting us to synthesize derivatives of chrysin to increase the antiviral activity and reduce its cytotoxicity. Among four 4-substituted benzyl derivatives derived from C(5) benzyl-protected derivatives 7, 9-11 had significant antiviral activity and showed the most potent activity against CVB3 with low cytotoxicity in Vero cells. Intraperitoneal injection of CVB3 in BALB/c mice with $1{\times}10^6TCID_{50}$ (50% tissue culture infective dose) of CVB3 induced acute pancreatitis with ablation of acinar cells and increased serum CXCL1 levels, whereas the daily administration of 9 for 5 days significantly alleviated the pancreatic inflammation and reduced the elevation in serum CXCL1 levels. Collectively, we assessed the anti-CVB3 activities of chrysin and its derivatives, and found that among 4-substituted benzyl derivatives, 9 exhibited the highest activity against CVB3 in vivo, and protected mice from CVB3-induced pancreatic damage, simultaneously lowering serum CXCL1 levels.

• Journal of Applied Biological Chemistry
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• v.51 no.2
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• pp.57-60
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• 2008

Eight compounds, including 2 flavones, luteolin (1) and apigenin (2), 2 flavonols, kaempferol (3) and quercetin (4), and 4 flavonoid glucosides, luteolin-7-O-${\beta}$-D-glucoside (5), apigetrin (6), astragalin (7), and isoquercitrin (8), isolated from the whole herb of Sonchus oleraceus L. were analyzed on the basis of chemical and spectroscopic evidence. This was the first time to report compounds 3, 4, 6, 7 and 8 from the Sonchus oleraceus L. The antioxidant activities of the isolated flavonoids and their glucoside derivatives were evaluated by DPPH free radical-scavenging assay, showing that compounds 1, 3, 4 and 8 exhibited stronger antioxidant activities compared with ${\alpha}$, tocopherol and curcumin. Flavonoids containing more hydroxyl groups exhibited better antioxidant activities. The antioxidant activity of flavonols was superior to their corresponding flavones, and that of aglycone are more potent than their glucoside derivatives.

• Natural Product Sciences
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• v.23 no.4
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• pp.253-257
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• 2017

The phytochemical study for the extract of Nelumbo nucifera (Nymphaceae) seeds has led to the isolation of ten compounds including five simple phenolic compounds, two indole derivatives, a flavonoid glycoside, two abscisic acid derivatives. The interpretation of 1D and 2D NMR and ESI-Q-TOF-MS spectroscopic data revealed the chemical structures of isolates to be p-hydroxybenzoic acid (1), protocatechuic acid (2), (E)-p-coumaric acid (3), (E)-ferulic acid (4), (E)-sinapate-4-O-${\beta}$-$\text\tiny{D}$-glucopyranoside (5), tryptophan (6), 3-indoleacetic acid (7), isoschaftoside (8), dihydrophaseic acid (9), dihydrophaseic acid 3'-O-${\beta}$-$\text\tiny{D}$-glucopyranoside (10). To the best of our knowledge, 1 - 5 and 7 were identified for the first time from N. nucifera seeds, and the presence of dihydrophaseic acid (9) and its glucoside (10) were demonstrated secondly in this plant.

• Biomolecules & Therapeutics
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• v.14 no.1
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• pp.36-39
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• 2006

Some flavones/flavonols were previously found to inhibit collagenase. To establish a therapeutic potential for skin inflammation, twenty-three synthetic flavone derivatives were examined for their inhibitory potential against collagenase from Clostridium histolyticum. From the results, it was found that most of them having various hydroxyl, methoxyl, methylsulfuryl and/or chloro substitution(s) on A- and B-rings were not efficient collagenase inhibitors. Among the synthetic flavones tested, only two synthetic derivatives, 3',4'-dihydroxyflavone and 5-hydroxy-4'-methoxyflavone, weakly inhibited bacterial collagenase (13-29% inhibition at 50-100 ${\mu}M$).

• YAKHAK HOEJI
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• v.47 no.6
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• pp.376-381
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• 2003

2-Arylchromones, also known as flavones, are among the most ubiquitous classes of natural products occurring in the plant kingdom. On the other hand, 2-styrylchromones are relatively scarce in nature and only a few compounds has been isolated from the blue-green algae species. Therefore, new 2-arylethenylchromone derivatives ( 4a∼n, 5a∼f) were synthesized by the aldol condensation of 2-methylchromone ( 3) with several aromatic aldehydes in order to evaluate their cytotoxicities using a MTT assay on three tumor cells. 2-Arylethenylchromone derivative 4a showed the significant cytotoxic activities on KB, HL-60 and P-388 cell lines with $IC_{50}$/ values of 25.2, 63.59 and 49.51 $\mu$M, respectively, indicating that 2-arylethenylchromone skeleton has a potential anti-tumor application.

• Archives of Pharmacal Research
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• v.29 no.7
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• pp.582-586
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• 2006

Due to consumer reluctance to take synthetic drugs for nematode infections and the appearance of resistance to anthelminthic drugs, new drugs from natural products must be developed. Caenorhabditis elegans is one of the freely living nematodes and serves as a good model system for screening anthelminthic drugs. In this study, thirteen flavonoid derivatives were tested for anthelminthic activity and the relationships between their activities and structures were investigated. The structural information combined with the data for the larval growth inhibition of C. elegans provided meaningful structural insights in the search for new anthelminthic drugs.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.136-137
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• 2002

Lonicera japonica Thunb. is a twining shrub that has been used as an antidote and to treat urinary disorders, fever and headache. It has been known as an anti-inflammatory agent in Korea from ancient times and is used widely for treating upper-respiratory tract infections, diabetes mellitus and rheumatoid arthritis. In the previous research, we isolated several flavonoid derivatives from the EtOAc soluble fraction. (omitted)

• Natural Product Sciences
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• v.10 no.1
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• pp.1-10
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• 2004

Plant flavonoids possess anti-inflammatory activity in vitro and in vivo. Although the action mechanisms are not fully understood, recent studies have clearly shown that certain flavonoids, especially flavone derivatives, express their anti-inflammatory activity at least in part by modulation of proinflammatory gene expression such as cyclooxygenase-2, inducible nitric oxide synthase and various cytokines. This review summarizes the recent findings of flavonoids modulating expression of proinflammatory molecules.