• Journal of Plant Biotechnology
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• v.36 no.3
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• pp.214-218
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• 2009

Sweetpotato [Ipomoea batatas (L.) Lam] leaves are excellent source of low molecular weight antioxidants such as polyphenols, anthocyanins and carotenoids compared to other leafy vegetables. Endogenous antioxidants in sweetpotato help our bodies to prevent ageing, heart diseases and cancer. In this study, to develop the proper cultivars for the functional feed materials, we investigated the contents of anthocyanin, $\beta$-carotene, and polyphenols as well as DPPH radical scavenging activity in leaves of 14 different cultivars at the time of the harvest. They showed a diverse antioxidation activity. In DPPH radical scavenging activity, cultivars of Nanjing 9, Yulmi and Shinzami showed higher activity, whereas cv. Huiza 6 showed the lowest. Cultivars of Shinzami and Shinhwangmi had the highest anthocyanin (3.5 mg/g fr wt) and polyphenol (15.8 mg/g fr wt) content, respectively. Interestingly, there was a high correlation between cultivars with colorful pigments in storage roots and antioxidants activity in leaves. These results suggest that sweetpotato leaves with high antioxidant activity at harvest would be suitable for functional feed materials.

• Korean Journal of Medicinal Crop Science
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• v.19 no.4
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• pp.238-245
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• 2011

In this study, we investigated antioxidative activity, antibacterial activity against pathogenic strains including methicillin resistant Staphylococcus aureus (MRSA), and tyrosinase inhibitory activity in 75% ethanol extract of Taraxacum coreanum and its fractions. The total polyphenol and flavonoid contents of the extract were 238.59mg/g and 33.18mg/g and the total polyphenol and flavonoid contents of the ethyl acetate fraction were 427.81mg/g and 148.90mg/g as the highest content of fractions. In DPPH radical scavenging ability, $SC_{50}$ values of the ethyl acetate and butanol fraction were 38.40${\mu}g/ml$ and 82.28 ${\mu}g/ml$, respectively. In antibacterial activity by the disc diffusion assay against S. aureus, S. epidermidis and MRSA, the ethyl acetate fraction showed stronger antibacterial activity than other fractions and the extract. Especially, the ethyl acetate fraction was exhibited effective antibacterial activity against MRSA. In the cytotoxicity measurement by MTT assay, the extract and fractions were exhibited Raw 264.7 cell viabilities of 96.32~143.21% as nontoxic result in concentration of 5~100 ${\mu}g/ml$. As a result, the ethyl acetate fraction of the 75% ethanol extract from T. coreanum could be applicable to functional materials for related fields.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4819-4825
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• 2010

In all of dental ceramics, these materials contained the radio-isotopes with natural abundance ratio. After dental treatment, remained dental ceramics in the oral cavity is caused for human internal dose. In this study, the gross beta activity levels were measured in dental materials including 22 dental ceramics, 1 resin, and 2 cements for estimation of human internal dose. In dental ceramic samples, the obtained results showed that the gross beta activity level varied between 1.317 ~ 2.935 Bq/g and the gross beta activity level was 2.379 Bq/g. And the same level for dentine, opacious dentine, translucent and enamel were 2.479 Bq/g, 2.491 Bq/g, 2.470 Bq/g and 2.069 Bq/g, respectively. The gross beta activity level of temporary resin and cements were negligible, compare to the same level of dental ceramics. The high gross beta activity level observed in opacious dentine code OD-A4 is 2.935 Bq/g thus mainly ascribable to 40K. The reduction of the radiation level of natural radio-isotopes and the improvement of the dental ceramic materials should be required for internal dose reduction.

• Journal of the Korean Chemical Society
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• v.67 no.2
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• pp.129-136
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• 2023

Osteoarthritis is to the abnormality of the inflammatory response of joint tissue caused by various causes such as aging, and muscle loss. In this study, the activity in joint inflammation was verified using SKBE, a plant extract, and the expression levels of arthritis-inducing proteins including MMP-1, MMP-3, MMP-13, and collagen type II in vitro were compared and analyzed. Furthermore, we synthesized α-spinasterol, an active ingredient of SKBE, by the previously reported synthesis method and these findings could provide a new starting point for the development of treatments for osteoarthritis.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.1
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• pp.29-33
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• 2004

Low molecular weight silk fibroin (LMSF), which was prepared by hydrolysis of silk fibroin using high-temperature and high-pressure method, was found to inhibit the oxidation of L-3,4,-dihydroxyphenylalanine (L-DOPA) catalyzed by mushroom tyrosinase (EC 1.14.18.1). LMSF contained mostly free amino acids such as L-glycine, L-alanine, and L-serine and oligopeptides, mainly glycine-alanine dimer. As a result of analyzing the inhibition kinetics from Lineweaver-Burk plots, L-glycine and glycine-alanine dimer showed noncompetitive behavior while uncompetitive behavior was observed in L-alanine, and L-serine. When weight percent concentration of ${ID_50}$ was compared, L-glycine was most effective on the inhibition and LMSF was also good enough for the inhibition effect of tyrosinase activity. LMSF showed a mixed-type inhibition and the inhibitory mechanism of LMSF might be caused by free amino acids and oligopeptides. As a result of spectroscopic observation with time, initial rate of increase of DOPAchrome decreased remarkably and the time to reach maximum absorbance increased as an increase of the concentration of L-glycine, meaning that L-glycine made itself mainly responsible for the formation of chelate with ${Cu^2+}$ in tyrosinase. However, in case of L-alanine, L-serine, and especially glycine-alanine dimmer, the production of DOPAchrome after an arrival at maximum absorbance decreased, indicating the production of adducts through the reaction with DOPAquinone.

• KSBB Journal
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• v.13 no.5
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• pp.540-546
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• 1998

For the purpose of screening the functionality in aloe, the mucilage from Aloe vera Linne was prepared by extraction of mucilaginous parenchyma with ethanol followed homogenation, filtration and centrifigation. Flocculability of this mucilage from Aloe vera L. was investigated and the identification fro flocculating active materials were carried out. The mucilage exhibited an excellent flocculability for 1% bentonite and 5,000 ppm kaolin suspensions. The good correlations between mucilage volume(concentration) and flocculability for 1% bentonite suspension were obtained. The flocculated volume or flocculation rate was affected depending upon the degrees of processing such as a heat treatment and purification. A major component showing the flocculaing activity was considered as a highly polymerized polysaccharide having flocculating activity was about 1,000,000 daltons.

• Journal of the Korean School Mathematics Society
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• v.11 no.1
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• pp.69-96
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• 2008

The purpose of this paper is to perceive the problems of current geometry education in the middle school mathematics, to develop some learning materials fitted for the mathematising activities based on Freudenthal's learning theories and to analyze the mathematising process followed by teaching-learning activities. For this purpose, we design activity-oriented learning materials for geometry based on Freudenthal's learning theories, and appropriate teaching-learning models are established for the middle school geometry at the 8-NA stage level according to the theory of van Hiele's geometry learning steps. After applied to the practical lessons, the effects of mathematical activities are analyzed.

• Preventive Nutrition and Food Science
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• v.19 no.2
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• pp.59-68
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• 2014

The extracts and pure saponins from the roots of Platycodon grandiflorum (PG) are reported to have a wide range of health benefits. Platycosides (saponins) from the roots of PG are characterized by a structure containing a triterpenoid aglycone and two sugar chains. Saponins are of commercial significance, and their applications are increasing with increasing evidence of their health benefits. The biological effects of saponins include cytotoxic effects against cancer cells, neuroprotective activity, antiviral activity, and cholesterol lowering effects. Saponins with commercial value range from crude plant extracts, which can be used for their foaming properties, to high purity saponins such as platycodin D, which can be used for its health applications (e.g., as a vaccine adjuvant). This review reveals that platycosides have many health benefits and have the potential to be used as a remedy against many of the major health hazards (e.g., cancer, obesity, alzheimer's) faced by populations around the world. Methods of platycoside purification and analysis are also covered in this review.

• Korean Journal of Medicinal Crop Science
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• v.26 no.2
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• pp.119-126
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• 2018

Background: The flowering plant Hippophae rhamnoides L. has been used for many studies on fruit or leaf extracts. This study was conducted to investigate the development of a new cosmetic material from H. rhamnoides fruits and leaves that have by antioxidant, anti-inflammatory and wrinkle improvement activities. Methods and Results: The antioxidant abilities of H. rhamnoides extracts, including of a water-soluble fruit powder (FW), a fatsoluble fruit powder (FF), a supercritical extract of fruit by-product (BS), and a mixture of leaf and fruit (MIX), were investigated in vitro. A DPPH radical assay for antioxidant activity was performed for these fractions alongside assay to evaluate the total phenolic and flavonoid content (TPC and TFC). As expected, the MIX had the highest DPPH radical scavenging activity ($RC_{50}=10.27{\mu}g/m{\ell}$), and the TPC and TFC also were highest in MIX ($225.7mg{\cdot}GAE/g$, and $25.18mg{\cdot}QE/g$, respectively). Nitric oxide (NO) production in LPS-induced RAW264.7 cells was estimated and the results indicated an over 75% decrease of NO production in FF and MIX. In other assays, the highest elastase inhibitory activity was found in FW. Conclusions: These results revealed that H. rhamnoides extracts have a high potential for antioxidant, anti-inflammatory and antiwrinkle activities. H. rhamnoides products are suggested to be applied as the functional materials of cosmetic ingredients.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.880-888
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• 2006

Pleurocidin, an $\alpha$-helical cationic antimicrobial peptide, was isolated from skin mucosa of winter flounder (Pleuronectes americamus). It had strong antimicrobial activities against Gram-positive and Gram-negative bacteria, but had very weak hemolytic activity. The Gly$^{13,17}\rightarrow$Ala analog (pleurocidin-AA) showed similar antibacterial activities, but had dramatically increased hemolytic activity. The bacterial cell selectivity of pleurocidin was confirmed through the membrane-disrupting and membrane-binding affinities using dye leakage, tryptophan fluorescence blue shift, and tryptophan quenching experiments. However, the non-cell-selective antimicrobial peptide, pleurocidin-AA, interacts strongly with both negatively charged and zwitterionic phospholipid membranes, the latter of which are the major constituents of the outer leaflet of erythrocytes. Circular dihroism spectra showed that pleurocidin-AA has much higher contents of $\alpha$-helical conformation than pleurocidin. The tertiary structure determined by NMR spectroscopy showed that pleurocidin has a flexible. structure between the long helix from $Gly^3$ to $Gly^{17}$ and the short helix from $Gly^{17}$ to $Leu^{25}$. Cell-selective antimicrobial peptide pleurocidin interacts strongly with negatively charged phospholipid membranes, which mimic bacterial membranes. Structural flexibility between the two helices may play a key role in bacterial cell selectivity of pleurocidin.