• Microbiology and Biotechnology Letters
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• v.33 no.4
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• pp.288-294
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• 2005

Flavonoid compounds show several biological activities and generally exist in the forms of glycones linking sugar moiety to main structure. Flavonoid glycones such as naringin and hesperidin in korean citrus peel are slower absorbed and consequently less active than their aglycone, naringenin and hesperetin, respectively. Therefare to increase the content of flavonoid aglycone in korean citrus peel, we used commercial carbohydrate-hydrolysing enzymes, AMG 300 L, Pectinex 100 L, and Viscozyme for transforming flavonoid glycones to aglycones. Optimal conditions of enzyme reaction were pH 5.0-7.0, $5\%$ enzyme, and 24-48 hrs. The content of naringenin and hesperetin as flavonoid aglycones in untreated citrus peel is $100\~200\;ng/g$ of dried citrus peel. In case of enzyme-treated citrus peel the content of naringenin and hesperetin increased to $1,539\∼6,674\;ng/g\;and\;1,974\∼8,906\;ng/g$ of dried citrus peel, respectively. Finally the content of flavonoid aglycones could be extracted to 10-80 times. Now enzyme-treated citrus peel may be applied to use for functional food because of its higher flavonoid aglycones as more active compounds.

• Applied Biological Chemistry
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• v.43 no.4
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• pp.314-316
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• 2000

• Journal of the Korean Wood Science and Technology
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• v.25 no.2
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• pp.45-51
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• 1997

주목 잎을 채취하여 건조하고 아세톤-물 (7 : 3, v/v) 의 혼합액으로 추출한 후 에틸아세테이트 및 수용성 부분으로 분리하고 Sephadex-LH 20으로 충진한 칼럼을 이용하여 2개의 flavan 단량체와 2개의 후라보노이드 배당체를 단리하였다. 에틸아세테이트용성 추출물은 대부분 (+)-catechin 과 (-)-epicatechin으로 구성되어 있었으며 수용성 부분에서는 quercetin-3-0-arabinopyranosyl-($1"'{\rightarrow}6"$)-${\beta}$-D-glucoside와 quercetin-3-O-rutinoside 인 두 개의 탄수화물로 구성된 배당체를 분리하였으며 주목에서는 이들 화합물은 아직 보고된 바가 없다. 이들의 구조결정을 위하여 박층크로마토그래피를 실시하고 $^1H$-NMR과 $^{13}C$-NMR 스펙트럼을 기존의 스펙트럼과 비교, 분석하여 정확한 구조를 규명하였다.

• Applied Biological Chemistry
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• v.41 no.2
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• pp.197-200
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• 1998

The MeOH extracts obtained from the flower petals of Carthamus tinctorius were solvent-fractionated with EtOAc, n-BuOH, and $H_2O$, successively. From the n-BuOH extract 2 flavonoid compounds were isolated through the repeated silica gel column chromatographies. From not only the results of physico-chemical data including HMBC but also the adaptation of acid hydrolysis, the chemical structures of the compounds were determined as $3-O-[{\beta}-D-glucopyranosyl(1{\rightarrow}2)\;{\beta}-D-glucopyranosyl]\;kaempferol$ and $3-O-[{\alpha}-L-rhamnopyranosyl(1{\rightarrow}6)\;{\beta}-D-glucopyranosyl]\;kaempferol$. The compounds exhibited $IC_{50}$ values in Grab2-Shc activity to be 43 and $47{\mu}g/ml$, respectively.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2002.04a
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• pp.79.1-79
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• 2002

• Food Science and Preservation
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• v.23 no.7
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• pp.1004-1011
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• 2016

Flavonoids, non-nutrient secondary metabolites of plants, are widely distributed in commonly consumed agro-food resources. Flavonoids include aglycones, and their glycosides are reported to have potential health-promoting compounds. The aim of this study was to investigate flavonoid glycosides in the fruit and leaves of Zizyphus jujuba var. inermis (Bunge) Rehder (jujube). A total of six flavonoids (five flavonols and one chalcone) were identified in jujube fruit and leaves by using ultra-performance liquid chromatography-diode array detector-quadrupole time of flight mass spectrometry along with chemical library and an internal standard. In positive ion mode, six flavonoids were linked to the C- and O-glycosides which were conjugated with sugar moieties based on kaempferol, quercetin, and phloretin aglycones. Total flavonoid contents of leaves (8,356.5 mg/100 g dry weight (DW)) was approximately 900-fold higher than that of fruit (fresh fruit, 13.6 mg/100 g dry DW; sun-dried fruits, 9.2 mg/100 g dry DW). Quercetin 3-O-rutinoside (rutin) and quercetin 3-O-robinobioside were the predominant flavonols in fruit and leaves of jujube. In particular, rutin had the highest content (6,735.2 mg/100 g DW) in leaves, and rutin is a widely reported bioactive compound. Phloretin 3',5'-di-C-glucoside (chalcone type) was detected only in leaves. The leaves of jujube contain a high content of flavonoids and the results of this study indicate that jujube leaves may be a source of bioactive flavonoids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.1
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• pp.76-79
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• 1996

생강나무 (Libdera obtusiloba BL.)의 페놀성 화합물들을 분리하기 위하여 잎고 줄기의 MeOH 엑스로부터 계통 분획한 EtOAc 분획물은 silica gel column chro-matography로 분리하여 2종의 화합물을 얻었다. IR, UV,$^1H-NMR$, $^13C-NMR$ 등의 분석을 행하여 화학구조를 밝힌 결과 이들 화합물의 화학구조는 잎에서 $quer-cetin-3-O-\alpha-L-rhamnopyranoside(quercitrin),$ 줄기에서는 quercetin $3-O-\beta-D-galactoyranoside(hyperoside)로$ 각각 결정하였다. 이 화합물들은 생강나무에서 처음으로 분리하였다.

• Journal of Life Science
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• v.21 no.3
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• pp.464-467
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• 2011

Quercetin is a major flavonoid present in onions, which acts as an antioxidant. Quercetin exists both as a free compound and conjugated with carbohydrates, primarily as glucosides in onion. Aged black onion was made through a 30 day aging process in which the onions were kept in an environment of $60^{\circ}C$ and high humidity (90% RH). Quercetin and quercetin glucosides were assayed in onion bulbs before and after the aging process, using high performance liquid chromatography-electrospray ion trap mass spectrometry (HPLC-ESI/MS/MS). Quercetin mono- and diglucosides were identified in fresh onion bulbs, whereas quercetin aglycone was the only form present in aged black onion bulbs. These findings indicate that the quercetin mono- and di-glucosides present in fresh onions undergo complete deglycosylation during the aging process. Such profiling will provide a rapid method that can be used to assess changes in the two major quercetin glycosides during the aging process of onion bulbs.

• Applied Biological Chemistry
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• v.42 no.2
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• pp.166-169
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• 1999

The repeated silica gel colum chromatographies of n-BuOH fraction obtained from MeOH extracts of Eucommia ulmoides leaves led to isolation of a flavonoid-glycoside inhibiting monoamine oxidase B activity. Its chemical structure was determined to be $3-O-[{\beta}-D-glucopyranosyl\;(1{\rightarrow}2)\;{\beta}-D-xylopyranosyl]$ quercetin through interpretation of spectral data and adaptation of acid hydrolysis. The $IC_{50}$ value of this compound in rat brain mitochondrial MAO-B inhibitory activity was evaluated to be $8.05\;{\mu}mol/l$.

• YAKHAK HOEJI
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• v.33 no.2
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• pp.124-128
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• 1989

The drug consists of the dried entire plant of Viola diamantica (family Violaceae). It is used for the treatment of acute pyogenic diseases such as boil and carbuncles; also as tumor, high fever, tuberculosis and astringent hemostatic. Two flavonol glycosides have been isolated from the aerial parts of Viola diamantica and could be identifed as kaempferol 7-rhamnoside and kaempferol 3,7-dirhamnoside (bright yellow needle crystal, mp $225^{\circ}$, $C_{27}\;H_{30}\;O_4\;4H_2O$). Kaempferol 7-rhamnoside and kaempferol 3,7-dirhamnoside were first isolated from Viola diamantica.