• Analytical Science and Technology
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• v.14 no.4
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• pp.331-339
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• 2001

Methoxylated flavonoids (sinenstin, nobiletin, tangeretin) were isolated and identified by preparative HPLC, mass and NMR. Chung-pi(I) and Chung-pi(II) contained methoxylated flavonoids most richly. Methoxylated flavonoids in Chung-pi obtained from Korean Milgam increased with fruit maturity, while contents of the methoxylated flavonoids gradually decreased after mid of October.

• Archives of Pharmacal Research
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• v.22 no.1
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• pp.18-24
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• 1999

Various flavonoid derivatives were previously reported to possess the inhibitory activity on cyclooxygenase/lipoxygenase. And these properties of flavonoids might contribute to their anti-inflammatory activity in vivo. In this study, several polyhydroxylated/methoxylated flavonoid derivatives such as oroxylin A. wogonin, skullcapflavone II, tectorigenin and iristectorigenin A were isolated from the medicinal plants. these compounds were evaluated fro their inhibitory effects on cyclooxygenase/lipoxygenase from the homogenate of human platelets in vitro. It was found that isoflavones including daidzein and tectorigenin possessed the inhibitory activity on cycloooxygenase, although the potency of inhibition was far less than that of indomethacin. In addition, oroxylin A, baicalein and wogonin inhibited 12-lipoxygenase activity without affecting cyclooxygenase, which suggested that 5,6,7- or 5,7,8-trisubstitutions of A-ring of flavone gave favorable results. The IC50 values of oroxylin A and NDGA against 12-lipoxygenase were found to be 100 and 1.5 uM, respectively.

• Preventive Nutrition and Food Science
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• v.7 no.1
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• pp.1-4
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• 2002

Eleven flavonoids, including rutin, naringin, hesperidin, neohesperidin, quercetin, naringenin, kaempferol, hesperetin, nobiletin, 3,5,6,7,8,3',4'-methoxylated flavone and tangeretin in the peel of late maturing citrus fruit species of Mucott (smith tangerine), Singamha (C. natsudidai), Sambogam (C. sulcata), Hongpalsak (C. hassaku), Seminol (Dancy tangerine) and Jawdung (C. aurantium) harvested during from August to December were analyzed with HPLC. The mobile phase consisted of water and acetonitrile with 0.5% acetic acid. Wavelength in UV detector was determined at 254 nm. Naringin and neohesperidin content in the peel of Jawdung harvested at the early stage of maturation were 34.02 mg/g and 13.68 mg/g, respectively, and it was highest among the tested citrus fruits. Hesperidin content in the peel of Mucott harvested at the earthy stage of maturation was 12.48 mg/g. Rutin content of Sambogam harvested at the early stage of maturation was 5.13 mg/g. Quercetin, naringein, kaempferol, nobiletin, 3,5,6,7,8,3',4'-methoxylated flavone flavonoids were in trace. Flavonoid contents of Singamha, Sambogam and Jawdung were high in the peel of fruits at the early stage of maturation, after which time they decreased rapidly.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.815-822
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• 1999

Twenty one flavonoids were isolated from ethyl acetate layer of aqueaus EtOH extracts of Artemisia vulgaris and identified as tricin, jaceosidine, eupafolin, diosmetin, chrysoeriol, homoeriodictyol, isorhamnetin, apigenin, eriodictyol, luteolin, luteolin 7-glucoside, kaempferol 3-glucoside, kaempferol 7-glucoside, kaempferol 3-rhamnoside, kaempferol 3-rutinside, quercetin, quercetin 3-glucoside, quercetin 3-galactoside, quercetrin, quercetin 7-glucoside, rutin, and vietexin. The inhibitory activity for all purified flavonoids were examined against lipid peroxidation in rat liver microsome. All examined flavonoids showed considerable antioxidant activity. Among them, $IC_{50}$ value of apigenin, luteolin, isorhamnetin, quercetin, and eriodictyol were showed higher than that of vitamin E used as positive control. And methoxylated flavonoids, tricin, eupafolin, jaceosidine, diosmetin, and isorhamnetin showed considerable antioxidant activity. Each $IC_{50}$ values were shown at 0.9, 1.0, 1.4, 1.0, and $0.7\;{\mu}g/mL$, respectively.

• Journal of Applied Biological Chemistry
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• v.44 no.3
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• pp.143-146
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• 2001

Eight flavonoids, including rutin, naringin, hesperidin, quercetin, hesperetin, nobiletin, 3,5,6,7,8,3',4'-methoxylated flavone, and tangeretin, in the peels of satsuma mandarin (Citrus unshiu) species of Halla, Gungcheon, Hungjin, Namgam-20, Illnam-1, and Chungdo harvested between August and December were analyzed through HPLC. Hesperidin content of Halla harvested during early maturation was 28.70 mg/g, and was the highest among the tested citrus fruits. Rutin content of Hungjin harvested during early maturation was 2.66 mg/g. Naringin in all citrus species and hesperetin in Halla, Gungchun, Namgam-20, and Chungdo were only detected in the peel of fruits harvested during early maturation. Hesperidin and rutin were detected mainly in all citrus species, and other flavonoids in trace. Flavonoid content in the peel of fruits was high during early maturation. Flavonoid contents in the peels of all fruit samples were generally high in the early stage of maturation, which then decreased rapidly.

• Applied Biological Chemistry
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• v.50 no.3
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• pp.154-159
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• 2007

In order to prepare liqueur of Citrus platymamma, 500 g dried peel was soaked in 10 l (5%, w/v) of $30{\sim}95%$ ethanol concentration for 70 days. Changes in pH was $5.19{\sim}4.80$ with 30% ethanol concentration, and the pH was decreased as ethanol concentration decreases for 10 days after soaking. Color a-value was decreased and color b-value was increased according to higher ethanol concentration. Extract was $2.00{\sim}2.19%$ (w/v) with $30{\sim}70%$ ethanol concentration. Acid content was $0.18{\sim}0.21%$ (v/v) with $30{\sim}70%$ ethanol concentration, while $0.13{\sim}0.15%$ (v/v) with 95% ethanol concentration. The contents of fructose and glucose was increased with lower ethanol concentration, and sucrose content was decreased with longer soaking time. Main flavonoids were narirutin, hesperidin, nobiletin, 3,5,6,7,8,3'4'-methoxylated flavone, and tangeretin. Most flavonoids were extracted more than 80% of ethanol for $3{\sim}5$ days soaking. Total polyphenol was $628.8{\sim}711.2$ ${\mu}g/ml$ with $30{\sim}70%$ ethanol concentration for 20 days soaking. Therefore, to prepare Citrus platymamma peel liqueur, it is necessary to soak the material in $50{\sim}70%$ ethanol concentration for 20 days.

• Journal of the Korean Chemical Society
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• v.46 no.3
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• pp.205-212
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• 2002

Bioactive compounds of Chung-pi methoxy flavonoids were isolated by column chromatography and preparative chromatography, and investigated on the smoothing effect for the tracheal smooth muscle of rats. The tracheal smooth muscles of rats were treated with acetylcholine ($ED_{50}:3${\times}$10^{-6}M$) and with chromatographic fractions. We found that six-methoxylated flavonoid (nobiletin) was the most active compound fro the smoothing effect of which the contracted tracheal smooth muscle was screened with further separated ethyl acetate fraction. This result shows how nobiletin and its analogues could be using as a promising drug of bronchial asthma.