• Natural Product Sciences
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• v.27 no.3
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• pp.176-182
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• 2021

The phytochemical investigation of Broussonetia kazinoki roots led to the isolation of ten compounds, including six flavonoids (1-6), two lignans (7 and 8), and two coumarins (9 and 10) by comparing their ¹H and ¹³C NMR spectra with reference values. To the best of our knowledge, compounds 9 and 10 were isolated from this plant for the first time. Among the ten isolates, compounds 2, 4, and 6 exhibited inhibitory effects against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in macrophage RAW264.7 cells with IC₅₀ values of 11.98, 10.16, and 24.06 μM, respectively. Furthermore, compounds 2, 4, and 6 reduced LPS-induced inducible nitric oxide synthase (iNOS) expression in a dose-dependent manner. Pre-incubation of cells with these compounds also significantly suppressed LPS-induced COX-2 protein expression. Compounds 2, 4, and 6 also showed cytotoxic activity against HL-60 cells with IC₅₀ values ranging between 46.43 and 94.06 μM.

• Korean Journal of Pharmacognosy
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• v.51 no.2
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• pp.139-145
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• 2020

The leaves of Diospyros kaki Thunb. were used to treat heart disease and hypotension in traditionally East Asia. The purpose of this study is to simultaneously quantitiative analyze the content of flavonoids in leaves of D. kaki. The isolated flavonoids from the leaves of D. kaki, and the structure of the isolated flavonoids were analyzed based on ¹H and ¹³C NMR spectrum compared to literature data. Simultaneous quantitative analysis of the isolated flavonoids was validated using high performance liquid chromatography (HPLC). Results showed that the calibration curves of the flavonoid compounds were confirmed that they have a large linearity with a correlation coefficient (R²) of 0.99. In the intra-day and inter-day analysis, accuracy and precision of five compounds were measured that accuracy was 94.39 to 114.47% and precision was less than 3.00%. Content analysis showed hyperoside (1.30 ± 0.09%), astragalin (0.81 ± 0.06%), trifoline (1.58 ± 0.07%), quercetin (0.13 ± 0.02%) and kaempferol (1.33 ± 0.25%).

• Food Science and Biotechnology
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• v.14 no.1
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• pp.171-174
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• 2005

Three flavonoid compounds - quercetin, luteolin, and kaempferol - were analyzed from two commercially available concentrated pomegranate extracts produced in Turkey and Italy, respectively. The samples were freeze-dried and hydrolyzed by 0.4 M hydrochloric acid in 50% ethanol at $80^{\circ}C$. HPLC (high-performance liquid chromatography) with DAD (diode array detection) at a wavelength of 260 nm was used for the detection of the three flavonoids. The detection limits of the three compounds were in hundreds of picograms and the signal-to-noise ratio ranged from 4 to 5: quercetin: >308 pg, s/n=4.0; luteolin: >262 pg, s/n=4.5; kaempferol: >688 pg, s/n=5.0. Quercetin, but not luteolin and kaempferol, was detected in the both pomegranate extracts. The concentrations of quercetin were $49.7\;{\mu}g/g$ and $27.7\;{\mu}g/g$ in the two pomegranate extracts made in Turkey and Italy, respectively.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.143-146
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• 2005

Although many studies have been performed to elucidate the molecular consequences of ultraviolet irradiation, little is known about the effect of natural products. Ultraviolet irradiation is widely considered to be an environmental stress. Here we investigated the effect of 2',4',7-trihydroxyisoflavone on the regulation of MMP-1 and type 1 procollagen in Ultraviolet irradiation of cultured human dermal fibroblasts. Phytochemical investigation of the whole plants of Viola hondoensis led to the isolation of five flavonoids. The structures of these compounds were identified 2',4',5,7-tetrahydroxyisoflavone (1), 2',4',7-trihydroxyisoflavone (2), 4',7-dihydroxyflavone (3), isoorientin (4), and isovitexin (5) using spectroscopic analysis. Among these, 2',4',7-trihydroxyisoflavone reduced the expression of MMP-1 at the protein levels in a dose-dependent manner by ultraviolet irradiation. Taken together, our results suggest that 2',4',7-trihydroxyisoflavone an important role in the reduction of MMP-1 induction by ultraviolet irradiation.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.2
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• pp.250-256
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• 2013

We investigated noodles supplemented with turmeric, purple sweet potato, or seaweed (Hizikia fusiforme) for their functional properties, including total phenol, flavonoid contents, electron donating abilities, and nitrite scavenging abilities. The percentage of total phenolic compounds in turmeric, purple sweet potato, and seaweed noodles were 2.40, 2.47, and 1.27%, respectively, whereas the percentage of total flavonoid contents were 0.55, 0.92, 0.74%, respectively. Results showed that purple sweet potato noodles had the highest amount of phenolic compounds and flavonoids compared to the other types of noodles. The electron donating abilities of the turmeric, purple sweet potato, and seaweed noodles were 4.72, 4.11, and 3.11 at 1,000 ppm respectively. The nitrite scavenging abilities of the turmeric, purple sweet potato, and seaweed noodles were 75.93, 79.81, and 73.51% at pH 1.2, respectively. Purple sweet potato noodles had the highest nitrite scavenging abilities, with an effect better than BHT and ascorbic acid. The ferrous ion chelating effect of turmeric, purple sweet potato, and seaweed noodles were 12.17, 13.63, and 42.12%. All of the experimental results showed good anti-oxidative activity; thus rice noodles supplemented with turmeric, purple sweet potato, or seaweed, have good functional effects for human beings.

• Korean Journal of Pharmacognosy
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• v.44 no.3
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• pp.253-256
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• 2013

Six flavonoid compounds were isolated from the underground parts of Curcuma longa (Zingiberaceae) through repeated column chromatography. Their chemical structures were elucidated as kaempferol-3-O-${\alpha}$-L-rhamnopyranosyl(1${\rightarrow}$2)-O-${\alpha}$-L-rhamnopyranoside (1), quercetin-3-O-${\alpha}$-L-rhamnopyranosyl(1${\rightarrow}$2)-O-${\alpha}$-L-rhamnopyranoside (2), quercetin-3-O-${\beta}$-Dglucopyranoside-7-O-${\alpha}$-L-rhamnopyranoside (3), kaempferol-3-O-${\alpha}$-L-rhamnopyranoside (4), quercetin-3-O-${\alpha}$-L-rhamnopyranoside (5), and quercetin (6), respectively, by spectroscopic analysis. These compounds were isolated for the first time from this plant.

• International Journal of Industrial Entomology and Biomaterials
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• v.42 no.2
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• pp.25-32
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• 2021

Mulberry fruit (Morus alba L.) contains phytochemicals, including 1-deoxynojirimycin, quercetin-glucoside, kaempferol-glucoside, and anthocyanins, which have antioxidant effects. In this study, mulberry fruit extract was prepared at various temperatures (25-100℃) and water/ethanol solvent concentrations (0%-100% ethanol). Fourier-transform infrared spectroscopy (FT-IR) and circular dichroism (CD) data indicated that the content of bioactive compounds such as polyphenols and flavonoids was lower in 100% ethanolic extracts than in 30%-50% ethanolic extracts. Radical scavenging activity determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-di-3-ethylbenzthiazoline sulfonic acid (ABTS) assays was highly correlated with polyphenol and flavonoid content. In conclusion, 30%-50% ethanolic extracts contained the highest contents of bioactive compounds and exhibited high levels of radical scavenging activity. These findings may inform the use of mulberry fruit extract as a functional food.

• Food Science and Preservation
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• v.12 no.6
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• pp.650-655
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• 2005

To produce a flavonoid-enriched vinegar from onion, vinegar fermentations of onion juice, extraction of flavonoids from onion-dry scale, and change of the flavonoids in vinegar were investigated. Alcohol and vinegar fermentations from the onion juice were effectively improved by using the onion juice heated at $80^{\circ}C$ for 10 min. When various types of onion juices were used for onion vinegar production, the vinegar fermentation of heat-treated onion juice containing $4\%$ ethyl alcohol showed maximal acid production. Flavonoid compounds in onion vinegar made from fresh onion juice was larger than the other onion vinegar. To produce a flavonoid-enriched vinegar, when it was examined the $05\%$ onion-dry scale was added to $6\%$ acetic acid, optimum extraction time was 90 min. And by adding $0.5\%$ onion-dry scale to onion vinegar, quercerin monoglucoside and quercetin contents increased.

• 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 Applied Science and Technology
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• v.33 no.3
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• pp.474-482
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• 2016

The black raspberry (Rubus coreanus Miquel) contains anthocyanin, tannins, gallotannin, gallic acid, ferulic acid and phenolics. It brightens the eyes and protects the liver and kidneys. It was effective for anti-aging. Thus, the purpose of this study was to inform the excellence of black raspberry and to screen antioxidant activity to ensure the possibility as a functional material. In this study, bioactive compounds in black raspberry were determined. Additionally, black raspberry was extracted by CM (chloroform:methanol, 2:1, v/v), 70% methanol and 70% ethanol, and were investigated and compared in vitro methods. Total phenol and flavonoid contents were measured to compare each different solvents. In addition, DPPH radical scavenging activity and ABTS radical scavenging activity, ferric reducing antioxidant power, reducing power were determined to measure the antioxidant activity. The results were the highest in 70% ethanol extracts, and the higher the concentration showed a significantly higher antioxidant capacity. When observed the relationship between the study, antioxidant activity of black raspberry was supposed to affect by the anthocyanin, phenol and flavonoid contents.