Yang-Suk Lee’s research while affiliated with Daegu Haany University and other places

The fringe tree, Chionanthus retusus (Oleaceae) has been used as a natural remedy that helps a paralytic stroke, dementia, phlegm and malaria. This study was conducted to investigate the antioxidant and anti-aging activities of water extracts obtained from the flesh of C. retusus by reflux extraction at room temperature and 80°C, and pressure heating extraction at 110°C, for an increment of their practical use. The highest extraction yield from the flesh of C. retusus was 67.94% extract by pressure heating extraction at 110°C. The content of total polyphenol compounds was the highest by 72.71 mg/g in 80°C extract by reflux extraction. The highest content of total flavonoid compounds was 7.60 mg/g at 110°C extract. The results of soluble protein and reducing sugar contents showed the highest content of 4.93 mg/g and 46.77 mg/g in 110°C extract, respectively. In the analysis of DPPH radical scavenging activity, all extracts showed an excellent effect of 92% in 1.0 mg/mL concentration. The highest effect of ABTS radical scavenging activity was 88.67% at 110°C extraction in 1.0 mg/mL concentration. Nitrite scavenging ability was the highest as 66.16% at 110°C extract at pH 1.2 and 1.0 mg/mL concentration. The results of SOD-like activity and xanthine oxidase inhibition activities showed the highest effect of 14.95% and 59.45% at 110°C extract in 1.0 mg/mL, respectively. Tyrosinase inhibition activity for whitening effect was the highest of 35.31% at 85°C in 1.0 mg/mL. In the analysis of anti-aging effect, collagenase and elastase inhibition activity showed the highest effects of 37.78% at 110°C and 20.39% at 80°C, respectively. All results of antioxidant activities and anti-aging effects increased along with the concentration increases. These results indicated that the extracts extracted from the flesh of C. retusus at 80°C and 110°C have a large amount of useful ingredients, an excellent antioxidant activity, like as DPPH and ABTS radical scavenging activity, and anti-aging effects to develop functional products than those of 25°C.

This study was performed in order to investigate the antioxidant properties of hot water extract from the root and aerial part of the Syneilesis palmata in respect to its potential use as food, cosmetics material, or medicinal resource. The results showed that the S. palmata root hot water extract (RHW) possessed a higher content of total flavonoid compounds (4.58 mg/g) and total polyphenol compounds (59.11 mg/g). The SOD-like activities of the RHW and APHW were 23.74% and 21.61%, respectively, at a concentration . In the nitrite scavenging ability of a concentration, the RHW showed 63.06% (pH 1.2) and 47.16% (pH 3.0). The values of the nitrite scavenging abilities were (ascorbic acid), (RHW), and (APHW). The values of DPPH free radical scavenging abilities were (RHW) and (APHW). The inhibition values () of xanthine oxidase were (RHW) and (APHW). In all of the experiments, the S. palmata root hot water extracts have higher activities than the aerial hot water extract, except for the xanthine oxidase inhibitory activity. These results suggest that the S. palmata is a potentially useful antioxidant source for the development of functional nutraceuticals, cosmetics and medicine.

In the present study, the proximate composition, sugar, minerals, total phenolic and flavonoid compounds, and amino acids in Calystegia japonica (C. japonica) were measured to determine if it can be used as a nutritional and functional material for the development of valuable foods. The mean crude protein, fat, and ash contents of the leaves were 5.75, 2.46, and 7.77%, respectively. The soluble-protein contents of the leaves and roots were 146.78 and 33.67 mg%, respectively. The reducing-sugar and free-sugar contents of the leaves were 682.70 and 166.00 mg%, respectively, and those of the roots were 2,934.89 and 37.70 mg%. The mineral content of the leaves was 3,122.13 mg%, and that of the roots was 1,540.85 mg%. The three elements Ca, K, and Mg were very rich in all their parts, with minerals accounting for 96-99% of their total mineral contents. The total phenolic compound of the leaves was 3,028.89 mg%, and the total flavonoid compound was 382.67 mg%. The phenolic and flavonoid compounds in the leaves were more than 7.6 times those in the roots. The free-amino acid levels in the leaves and roots were 2,467.15 and 1,334.81 mg%, respectively. The results of the comparison of the leaves and roots of C. japonica showed that the leaves had a rich proximate composition consisting of minerals, total phenolic and flavonoid compounds, and amino acid. This suggests that C. japonica leaves are potentially useful sources of functional and favorite foods and nutraceuticals.

In this study, we evaluated the antioxidant activities and xanthine oxidase inhibition effects of water and ethanol extracts of Cynomorium songaricum. The ethanol extract of C. songaricum (EE) contained more phenolic and flavonoid compounds than the water extract (WE). The antioxidant activities of the extracts were increased as the concentration of the extract increased. The WE has better effectiveness than the EE for DPPH free radical scavenging activity and nitrite scavenging ability. The nitrite scavenging abilities of WE were 90.02% ( 653.15 /mL) at conditions of pH 1.2 and 2,000 /mL, and 84.34% ( 817.17 /mL) at pH 3.0. The EE has more effective SOD-like activity and XO inhibition than WE. The SOD-like activity of EE was 81.47% at a concentration of 2,000 /mL, was 951.70 /mL. The xanthine oxidase inhibition of the EE, with an of 112.47 /mL, is greater than that of ascorbic acid, which was 192.50 /mL (p

In this study, we assessed the free radical scavenging and xanthine oxidase inhibitory activities of extracts isolated from the dried roots and stems (including leaves) of Angelica dahurica. The irritation response from these extracts was also assessed to determine potential cosmetic use. Both sources of A. dahurica extracts exhibited radical scavenging properties to different extents. The free radical scavenging potency () of the stems (including leaves) of A. dahurica was 243.33 , which is significantly lower (p

Three bark extracts of Albizia julibrissin were prepared using water (AW), 70% (v/v) ethanol (AE), and hot water (AHW). Organic solvent fractions were analyzed for total flavonoids and polyphenols, antioxidant activities, and inhibitory activities against xanthine oxidase. Total flavonoid and polyphenol contents of the AHW extract were 8.57 mg/g and 108.67 mg/g, respectively. The SOD-like activities of all extracts, assayed at 1.0 mg/mL, were 10.46-16.73%. The nitrite-scavenging ability of the AHW extract, assayed at pH 1.2, was 60.82%, and the value was /mL. The electron-donating ability of the AHW extract, at 0.3 mg/mL, was 92.30%; the values of the AW and AHW extracts were /mL and /mL, respectively; thus higher than that of ascorbic acid (/mL). Xanthine oxidase inhibition by the AHW extract, at 1.0 mg/mL, was 94.05%. These results indicate that the AHW of A. julibrissin has potential as a natural antioxidant, for addition to foods and nutraceuticals.

Ripe fruits of Poncirus trifoliata were examined with a view to development of functional foods and physiological activities were assessed. The flavonoid compound of the sarcocarp extract (SC), at 20.39 mg/g, was the highest of all extracts studied, whereas that in fruit juice extract (FJ) was 18.72 mg/g. The total polyphenol content of pericarp ethanol (PE) and water (PW) extracts were 60.54 mg/g and 45.91 mg/g, respectively. The nitrite scavenging ability of PW (2.0 mg/mL) was 52.27% at pH 1.2. The tyrosinase inhibitory activity of PE (2.0 mg/mL) was 23.23%, but SW showed no such activity at any tested concentration. The electron donating abilities of PW, SC, and FJ were greater than 50% when tested at 0.5 mg/mL. Notably, the of PW was 147.73 /mL. Inhibition of xanthine oxidase by PW and SE (0.5 mg/mL) were more than 90%, whereas the of SC was 18.28 /mL. These results indicate that P. trifoliate ripe fruits may potentially serve as components of valuable new functional foods.

This research analyzed useful nutritional component data in stems and leaves of the Albizzia julibrissin for proximate composition, contents of soluble protein, reducing sugar, free sugar, total polyphenol compound, mineral, free amino acid, and amino acid derivative. The carbohydrate contents of A. julibrissin stems and leaves were 71.08% and 64.85%, and crude protein contents were 8.05% and 11.38%, respectively. In addition, the crude fat contents were 2.95% and 3.03%, and the crude ash contents were 8.98% and 9.07%, respectively. Reducing sugar and free sugar in stems were 711.80 mg% and 15.66 mg%, and 1,422.83 mg% and 40.3 mg% in leaves, respectively. The contents of soluble protein were 229.57 mg% in stems and 1,073.59 mg% in leaves. The polyphenol and flavonoid compounds were 446.67 mg% and 16.36 mg% in stems, and 2,583.33 mg% and 2,234.75 mg% in leaves. In the results of mineral analysis, the content of Ca was the highest in stems as 933.07 mg% followed by K (605.07 mg%). The content of K was also the highest (1,489.53 mg%) in leaves, and Ca was 287.73 mg%. The free amino acid content of A. julibrissin stems was 2,977.28 mg%, and 8,840.66 mg% in leaves. Total contents of amino acid derivative were 263.53 mg% in stems and 696.47 mg% in leaves.

This study was conducted to examine the antioxidant activities of the extracts from aerial parts and roots of Syneilesis palmata. The ethanol extract of aerial parts showed the highest content of flavonoid compounds (31.72 mg/g), and the ethanol extract of roots has the highest content of total polyphenol compounds (68.11 mg/g). The water extract of S. palmata roots showed the highest xanthine oxidase inhibition of 99.29% and the ethanol extract of aerial parts showed 98.48% at 1.0 mg/mL. The ethanol extract of roots showed the highest value of nitrite scavenging ability of 70.89% at pH 1.2, SOD-like activity of 13.06% and electron donating ability of 98.58% at 1.0 mg/mL concentration. The effect of tyrosinase inhibition was found at only the ethanol extracts of roots (9.33%). We found that root extracts contain abundance polyphenol compounds and their antioxidant activities were greater than those of the extracts of aerial part.

This study was investigated to analyze the contents of flavonoid and polyphenol compounds, and inhibitory activities of tyrosinase and antioxidation to measure physiological effect of reflux water extraction (WE), reflux ethanol extraction (EE) and hot water extract under high pressure (HWE) of Torreya nucifera seed. HWE yields the highest contents of flavonoid compounds (176.34 mg/g) and polyphenol compounds (112.95 mg/g). The tyrosinase inhibitory rates were 5.62~28.71% at 2.0 mg/mL and HWE showed the highest inhibition rate. The nitrite scavenging abilities of all extracts were over 90% at pH 1.2 and 3.0 at the concentration of 2.0 mg/mL. The superoxide dismutase (SOD)-like activities of HWE was the highest value of 33.58%. The electron donating abilities (EDA) were 66.46~89.72% and HWE was the highest when the extracts were tested at 0.1 mg/mL. The EDA of all extracts were decreased with an increment of the extracts concentrations. The xanthine oxidase inhibitory rate of HWE was the highest value of 89.29% at the concentration of 2.0 mg/mL and the WE and HWE were over 75% rate of xanthine oxidase inhibition at 0.5 mg/mL.