• Bulletin of the Korean Chemical Society
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• v.29 no.10
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• pp.2039-2042
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• 2008

• Korean Journal of Pharmacognosy
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• v.23 no.4
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• pp.201-210
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• 1992

Scutellariae plants contain a large number of flavonoids and in addition, many of them are with unusual A- and/or B-ring substitutions. The total number of flavonoids reported up to the middle of 1991 are 137 including 89 of flavones, flavonols and their glycosides including 3 C-glycosides$(1{\sim}89)$, 39 of flavanones, dihydroflavonols and their glycosides $(90{\sim}128)$, 8 of chalcones $(129{\sim}136)$ and one biflavonoid, 8, 8'-bibaicalein(137). More than half of the flavonoids are with either unusual 5-metboxy(2'-methoxy in case of chalcones) in A-ring and/or 2'-oxygenation(2-oxygenation in case of chalcones) in B-ring substitutions. Four flavones, four flavanones and two chalcones are with methylation at 5-OH(2'-OH in case of chalcones) and six of them also have 2'-oxygenations(2- in case of chalcones). Sixtyeight out of total 137 flavonoids have oxygenated substitution at 2'-(2- in case of chalcones) position of B-ring and in addition, 27 of them have another oxygen function at 6'-(6- in case of chalcones) and 18 of them have additional oxygen substitutions either at 3'-, 5'-,3',6'-or 3', 4', 5'-(3, 4, 5- in case of chalcones) positions. The distribution and isolation of flavonoid components of Scutellariae plants are tabulated with references.

• YAKHAK HOEJI
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• v.45 no.6
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• pp.588-590
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• 2001

Two flavanones, (2S) -2'-methoxykurarinones (1) and kurarinones (2) , were isolated from the ethyl acetate extract of the roots of Sophora flavescense Ait. Their structrures were elucidated using NMR, UV and IR spectral analysis. These compounds exhibited a moderate antimicrobial activities against Staphylococcus aureus, Staphylococcus epidermidis Pseudomonas Putida and a weak anti-fungal activity against Candida albicans.

• Archives of Pharmacal Research
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• v.28 no.10
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• pp.1152-1155
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• 2005

We examined the inhibitory activities of various flavonoids, including the flavanones, flavones/isoflavones and flavonols, on collagenase from Clostridium histolyticum to establish their therapeutic potential against skin inflammation and photoaging. In general, the flavonols were stronger inhibitors than the flavones/isoflavones, and this indicated the importance of the C-3 hydroxyl substitution. Quercetin was the most active flavonoid among those tested, and it showed an $IC_{50}$ of 286 ${\mu}M$. These novel results suggest that certain flavonoids, particularly the flavonols, may prevent collagen breakdown by inhibiting collagenase in inflamed skin as well as photoaged skin.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.373-378
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• 2008

Contents of phytochemicals in citron (Citrus junos Sieb. ex Tanaka) seeds and their effects on antioxidant activities were investigated. Methanol extract of defatted citron seeds contained the highest amounts of total polyphenols followed by 70% ethanol and water extracts. Neohesperidin was the most predominant citrus flavanones in these extracts. The highest amounts of limonoids were found in methanol extract, and this extract was the most efficient in scavenging both DPPH and ABTS radicals. All 3 extracts also exhibited good antioxidant activities against attack of linoleate free radicals on $\beta$-carotene. When methanol extract was sequentially fractionated into ether, ethyl acetate, n-butanol, and water fractions, butanol fraction contained the highest amounts of polyphenols otherwise most of limonoids were concentrated in ethyl acetate fraction. A positive relationship between radical scavenging activities and total polyphenol contents in fractions was observed while antioxidant activity on $\beta$-carotene seemed more related with contents of limonoids and other hydrophobic polyphenols.

• Food Science and Preservation
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• v.6 no.1
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• pp.121-135
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• 1999

Effective synthetic antioxidants such as butylated hydroxyanisole(BHA) and butylated hydroxytoluene(BHT) have been widely used in the food industry, but they are suspected to be toxic and carcinogenic effects. Therefore, the development of safely available natural antioxidants such as ascorbic acid, ${\alpha}$-tocopherol, ${\beta}$-carotene, flavonoids and selenium is essential. In particular, flavonoids, 2-phenyl-benzo-${\alpha}$-pyrones, are polyphenolic compounds that occur ubiquitously in food of plant origin. flavonoids occur in foods generally as O-glycosides with sugars bound usually at the C\ulcorner position. And variations in their heterocyclic ring gibes rise to flavones, flavonols, flavanones, flavanols, catechins, anthocyanidins, chalcone and isoflavones. Vegetables, fruits, and beverages are the main dietary sources of the flavonols, primarily as quercetin, kaempferol, and myricetin and the corresponding flavones, apigenin and luteolin. These flavonoids have biological activity such as antioxidant, anti-inflammatory, antithrombotic, antimutagenic, anticarcimogenic antiallergic and antimicrobial activity effects in vitro and in vivo. Flavonoids posses strong antioxidant activities acting as oxygen radicals scavenger, metal chelators and enzyme inhibitor. The antioxidant activity of flavonoids is determined by their molecular structure and more specially, by the position and degree of hydroxylation of the ring structure. All flavonoids with the 3`, 4`-dihydroxy(ortho-dihydroxy) posses marked antioxidant activity. And antioxidant activity increases with the number of hydroxyl groups substituted on the A-and B-rings. There is as yet no certainty about the effect of the presence of a double bond between C\ulcorner and C\ulcorner on the antioxidant activity of flavonoids.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.420-424
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• 2002

The purpose of this study is to investigate anticariotic activity of the ethyl acetate soluble extract of Sophora flavescens Ait. for the prevention of dental caries and glucosyltransferase activity caused by Streptococcus mutans. The fraction 5-4-3 showed strong growth inhibition activity against Streptococcus mutans (MIC, 3.13 $\mu\textrm{g}$/ml). The glucosyltransferase activity of the active fraction 5-4-3 inhibited the formation of glucan and showed 77% of the antiproliferative effect at 100 $\mu\textrm{g}$/ml (P<0.05). Two flavanones, (2S)-2'-methoxy kurarinone (1) and (+)-kurarinone (2), were isolated from the active fraction 5-4-3 of the ethyl acetate soluble extract of S. flavescens Ait. Their structures were elucidated using spectroscopic methods.

• BMB Reports
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• v.41 no.1
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• pp.68-71
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• 2008

Flavones are synthesized from flavanones through the action of flavone synthases (FNSs). There are two FNSs, FNS I and II. FNS I is a soluble dioxygenase present in members of the Apiaceae family and FNS II is a membrane bound cytochrome P450 enzyme that has been identified in numerous plant species. In this study, we cloned OsFNS I-1 from rice by RTPCR, expressed it in E. coli, and purified the recombinant protein. By NMR analysis, we found that OsFNS I-1 converted the flavanone (2S)-naringenin into the flavone, apigenin. Moreover, we found that the cofactors oxoglutarate, $FeSO_4$, ascorbate and catalase are required for this reaction. OsFNS I-1 encodes a flavone synthase I. This is the first type I FNS I found outside of the Apiaceae family.

• Archives of Pharmacal Research
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• v.27 no.5
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• pp.507-511
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• 2004

From the flowers of Chromolaena odorata (Eupatorium odoratum) four flavanones, isosakuranetin (5,7-dihydroxy-4'-methoxyflavanone) (1), persicogenin (5,3'-dihydroxy-7,4'-dimethoxyflavanone) (2), 5,6,7,4'-tetramethoxyflavanone (3) and 4'-hydroxy-5,6,7-trimethoxyfla-vanone (4), two chalcones, 2'-hydroxy-4,4',5',6'-tetramethoxychalcone (5) and 4,2'-dihydroxy-4',5',6'-trimethoxychalcone (6), and two flavones, acacetin (5,7-dihydroxy-4'-methoxyflavone) (7) and luteolin (5,7,3',4'-tetrahydroxyflavone) (8) were isolated and identified. Compound 1 exhibited moderate antimycobacterial activity against Mycobacterium tuberculosis with the MIC value of 174.8 $\mu$M, whereas compounds 4,7, and 8 exhibited weak activity with the MIC values of 606.0, 704.2 and 699.3 $\mu$M respectively. Compound 7 showed moderate cytotoxicity against human small cell lung cancer (NCI-H187) cells with the MIC value of 24.6 $\mu$M, whereas compound 8 exhibited moderate toxicity against NCI-H187 cells and week toxicity against human breast cancer (BC) cells with the MIC values of 19.2 and 38.4 $\mu$M respectively.

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.422-429
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• 2008

In this work, we analyzed the activity of control enzymes of flower color biosynthesis, chalcone synthase (CHS) and flavanone 3-hydroxylase (FHT) using biochemical and enzymological methods in Lilium longiflorum and 11 Lilium cultivars. The results obtained are as follows ; Naringenin (NAR) was synthesized in all Lilium cultivars tested by the catalytic activity of CHS which used malonyl-CoA and 4-coumaryol-CoA as substrates. Substrate-specific activity of CHS was observed because eridictiol (ERI), which uses caffeoyl-CoA as a substrate, was not detected in tested cultivars. In next step, dihydroflavone product was synthesized by FHT using flavanones as a substrate. FHT synthesized dihydrokaempferol (DHK) by using NAR as substrates. A remarkable activity of FHT was observed in other 11 cultivars.