• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.8
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• pp.1172-1179
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• 2015

This study investigated optimal extraction conditions for application of Ulmus pumila L. as a natural antioxidant. U. pumila L. was extracted using ethanol (EtOH) at various concentrations (0, 40, and 80%) and extraction times (1, 2, and 3 h) at $70^{\circ}C$ and then evaluated for extraction yield, total phenolic contents, total flavonoid contents, as well as antioxidant activities [2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, reducing power, and oxygen radical absorbing capacity (ORAC)]. Antioxidant activities were correlated with total phenolic and flavonoid contents. Of the solvent conditions, 80% EtOH extracts for 3 h at $70^{\circ}C$ showed the highest total phenolic and flavonoid contents with strong antioxidant activities, although there were no significant time effects on DPPH and ABTS radical scavenging activities and reducing power. However, ORAC values of all EtOH extracts remarkably increased in a time-dependent manner. In addition, 80% EtOH extract for 3 h exhibited strong antioxidant effects on HDF and 3T3-L1 cells. Therefore, the antioxidant capacity of U. pumila L., may due to phenolic and flavonoid contents, and extraction conditions were 80% EtOH for 3 h at $70^{\circ}C$. This extract could be a good source for natural antioxidants.

• Food Science and Preservation
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• v.7 no.2
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• pp.211-217
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• 2000

The effects of Citrus flavonoids, hesperetin, hesderidin, naringenin, and naringin, on nonenzymatic lipid peroxidation were studied in three different in vitro experimental models. Hesperetin showed the most antioxidant effect in this experimental condition by measuring the malondialdehyde production using the thiobarbiturate and thiocyanate methods, the lipid peroxidation of microsomal membranes, and DPPH (${\alpha},{\alpha}'-diphenyl-{\beta}-picrylhydrazyl$) method. The antioxidative activity of the flavonoid aglycone forms, hesperetin, Citrus aglycone flavonoid, suggest the most antioxidant effect in this experimental condition, and this effect indicate more potent in the aglycones than their corresponding glycosides.

• Preventive Nutrition and Food Science
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• v.14 no.3
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• pp.195-200
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• 2009

This study was carried out to investigate the biological activities of star anise extracts obtained from four different solvents (water, methanol, ethanol and chloroform) by measuring total polyphenol and flavonoid contents, DPPH radical scavenging, hydroxyl radical scavenging, nitrite scavenging activity and antimicrobial activity. The methanol extract showed the highest extraction yield, followed by ethanol, water and chloroform. The properties of the extracting solvents significantly affected the total polyphenol content. Methanol extracts contained more total polyphenols than any other extracts. The highest DPPH radical scavenging activity was found in methanol extract. The hydroxyl radical and nitrite scavenging activity were highest in methanol and ethanol extracts. In antimicrobial activity, water extract showed stronger activities than methanol and ethanol extract against Micrococcus luteus and Bacillus subtilis, and no inhibitory effects on Gram negative bacteria were found in all extracts at the concentration used.

• Korean Journal of Pharmacognosy
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• v.40 no.1
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• pp.51-58
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• 2009

The anti-hyperlipidemic effects of an ethyl acetate fraction from Orostachy japonicus in a high lipid diet-induced hyperlipidemic rat model were assessed. The fraction, which contained kaempferol, astragalin, and isoquercitrin, was associated with significant weight loss and reduction of lipid contents in serum and liver tissues. The fraction, which contains mainly flavonoids, diminished the levels of malondialdehyde and hydroxyl radical, and increased the anti-oxidative enzyme activities of superoxide dismutase, catalase, and glutathione peroxidase. Reduced bleeding and plasma clotting times resulting from the administration of the ethyl acetate fraction may reduce cardiovascular disease associated with hyperlipidemia.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.818-821
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• 2009

Total phenol, total flavonoid, reducing powder, electron donating activity, ascorbic acid equivalent antioxidant capacity, antimicrobial and antiproliferative activities of olive leaf extracts were investigated. The contents of total phenol and flavonoid were 257.48 and 92.33 mg in 100 g of olive leaf extract, respectively. The reducing power of the olive leaf extract increased with concentration increasing. Electron donating activity was high in 100 ${\mu}g/mL$ treated olive leaf extract as 95.20%. The ascorbic acid equivalent antioxidant capacity of the olive leaf extract was 68.93 mg/g olive leaf extract. The olive leaf extracts showed relatively high antimicrobial activity against Escherichia coli, Salmonella typhimurium, Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, and Pseudomonas aeruginosa. All of the cancer cell lines including MKN45, HCT116, NCI-H460, and MCF7 have 70-81% as effective growth inhibition.

• Applied Chemistry for Engineering
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• v.27 no.3
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• pp.276-279
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• 2016

In this study, we extracted active components from thistle, persimmon leaf, and new green which are known to have a high content of antioxidants and also analyzed the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavening activity and flavonoid content. Both ultrapure water and alcohol were used as extraction solvents and the ratio of both solvents, sample, amunts extraction time, and extraction temperature were varied. The optimal extraction condition of each natural compounds were 2.5~3.5 h of the extraction time and 50 g/L of the sample amount. The optimal ratio of ultrapure water and alcohol and extraction temperature were as follows; persimmon leaf (55~65 vol%, $50{\sim}60^{\circ}C$), thistle (40~50 vol%, $55{\sim}65^{\circ}C$) and new green (55~65 vol%, $50{\sim}60^{\circ}C$). In addition, the antioxidant capacity and flavonoid content of the extract increased in the order of persimmon leaf, thistle, and new green.

• Korean Journal of Environmental Agriculture
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• v.36 no.4
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• pp.263-268
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• 2017

BACKGROUND: Lespedeza cuneata G. Don is a well-known medicinal plant. In this study, the biological activities of L. cuneata extracts were investigated. METHODS AND RESULTS: L. cuneata shoot was extracted with 30% ethanol and further fractionated with organic solvents. Total phenolic and flavonoid content, antioxidant activity, and matrix metalloproteinase inhibition effect of the extract and fractions were measured. Among the tested extract and fractions, the highest contents of total phenolic and flavonoids were found in ethyl acetate fraction (117.8 mg GAE/g and 35.9 mg QE/g, respectively). Ethyl acetate fraction showed the highest DPPH and ABTS radical scavenging activity, and the antioxidant activity of the other fractions followed the order n-hexane fraction>ethanol extract>methyl chloroform>n-butanol fraction. Inhibitory effect on the expression of matrix metalloproteinases (MMP1 and MMP3) was highest in the fraction of ethyl acetate, and n-butanol fraction also significantly inhibited the expression of MMP3. Antioxidant activities of L. cuneata extracts were significantly positively related to their phenolic and flavonoid content. CONCLUSION: Ethyl acetate fraction of L. cuneata ethanol extract showed potent antioxidant and matrix metalloproteinases inhibitory activities. Those activities might be related to the high total phenolic and flavonoid content of the extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.969-972
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• 2000

Quality characteristics and functional properties of four kinds of propolis collected from 4 different regions were compared. Ethanol extract of propolis (EEP) showed high absorbance of UV at 208 ~ 212 nm and at 292~294 nm. Total flavonoid contents of 4 propolis were at a range of 16.30~21.87 mg/g However, no significant difference in the flavonoid content was observed among four kinds of sample. All EEP showed the high antimicrobial activities, especially against Salmonella typhimurium. Hydrogen donating activities of the EEP were high appear 65.94 to 78.67% in all samples. The EEP from Sunchon showed the highest activity of hydrogen donation among samples. All extracts had the higher nitrite-scavenging activity than 0.1% BHT. Compared to control, a significant decrease in lipid oxidation was found in all 4 extracts.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.238-243
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• 2018

This study aimed to compare total phenolic, total flavonoid, and vitamin C contents, antioxidant capacities, and sensory characteristics of jangachi made from green kiwifruit (Actinidia deliciosa cv. Hayward) and golden kiwifruit (A. chinensis cv. Hort16A), which were cured with doenjang and kochujang. Golden kiwifruit had higher total phenolic, total flavonoid, and vitamin C contents, and antioxidant capacities than green kiwifruit. Jangachi of both cultivars of kiwifruit had generally higher total phenolic and flavonoid contents, and antioxidant capacities than fresh kiwifruit. Doenjang jangachi of kiwifruit had higher total phenolic contents and antioxidant capacities than kochujang jangachi. Jangachi made from golden kiwifruit cured with kochujang, following pretreatment with sugar solution, had the highest overall quality on sensory evaluation among jangachies tested herein. Together, our findings suggest that kiwifruit jangachi may serve as a good dietary source of phenolics and antioxidants.

• The Korean Journal of Food And Nutrition
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• v.29 no.5
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• pp.785-794
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• 2016

This research was conducted to evaluate quality changes in traditional Doenjang and manufactured Doenjang during a storage period of 8 weeks. Low-salt Doenjang and commercial Doenjang were purchased from different manufacturers and proximate analysis as well as changes in isoflavone, polyphenol, flavonoid contents of the samples were investigated using a mass spectrophotometer. The salinity of traditional Doenjang, low salt Doenjang, and commercial Doenjang were $13.2{\pm}1.15$, $7.17{\pm}2.74$, $10.67{\pm}0.35%$, respectively and the salt concentrations of the soybean pastes did not change during storage. After 8 weeks at $35^{\circ}C$, chromatic values of all the paste samples decreased somewhat, with traditional Doenjang exhibiting fewer changes as compared to manufactured Doenjang. Amino acid nitrogen, acidity, microbial population all tended to increase with time, although some samples showed fluctuations during the test period. Moreover, the total isoflavone contents of traditional Doenjang increased with storage time while that of manufactured Doenjang tended to decrease. The isoflavone aglycone was shown to be the highest in traditional Doenjang, while isoflavone glycoside was abundant in manufactured Doenjang. Total flavonoid contents showed similar trends regardless of samples; initial contents of total flavonoid was 0.6 mg/g which increased to more than twice to 1.4 mg/g at the end of storage period. Composition profile of Doenjang extracts was analyzed using UPLC-Q-ToF.