• Food Science and Preservation
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• v.24 no.6
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• pp.879-884
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• 2017

In a continuing screening of selected medicinal plants native to Mongolia, the antioxidant and ${\alpha}$-glucosidase inhibitory activities of methanol extract of Iris bungei were investigated. After extraction with 80% of methanol, the methanol fraction was further extracted with n-hexane, EtOAc and n-BuOH in order to obtain four different solvent-soluble fractions, namely n-hexane-soluble, EtOAc-soluble, n-BuOH-soluble and $H_2O$ residue. The antioxidant properties were evaluated by radical scavenging assay using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) ($ABTS^+$) radicals. The anti-diabetic efficacy of I. bungei extract was investigated by ${\alpha}$-glucosidase assay. All tested samples showed dose-dependent radical scavenging and ${\alpha}$-glucosidase inhibitory activities. Among the tested extracts, the EtOAc-soluble fractions showed the greatest radical scavenging activity and ${\alpha}$-glucosidase inhibitory properties among other solvent-soluble fractions. This result suggested that there was a significant relationship between the total phenolic content and biological efficacy. Thus, I. bungei extract might be considered as a new potential source of natural antioxidant and as a ${\alpha}$-glucosidase inhibitory source. A more systematic investigation of this biomass sill be performed for further investigation of activity against antioxidative and anti-diabetic effects.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.1 s.49
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• pp.103-109
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• 2005

UV irradiation leads to distinct changes in skin connective tissue, which is degradation of collagen. Many of these alterations in the extracellular matrix are mediated by matrix metalloproteinases. In this study, to develop a new anti-aging agent, we screened the antioxidant activity of solvent fractions from ethanolic extract of Melothria Heterophylla. Among the four solvent fractions tested, the EtOAc fraction exhibited the highest antioxidant activity. It was investigated the inhibitory effect of the EtOAc fraction on the expression and activity of MMP-1 in UVA-irradiated human dermal fibroblasts. The EtOAc fraction inhibited the activity of MMP-1 in a dose dependent manner with the $IC_{50}$ values of $9{\mu}g/mL$. Also, UVA-induced MMP-1 expression was reduced about $90\%$ by $100{\mu}g/mL$ of the EtOAc fraction but MMP-1 mRNA expression was not inhibited. Therefore, we conclude that the EtOAc fraction significantly inhibits MMP-1 expression at the protein level. From these results, we suggest that the EtOAc fraction from M. heterophylla could be used as a new anti-aging agent for the photo-damaged skin.

• Journal of Life Science
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• v.29 no.1
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• pp.69-75
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• 2019

Rosemary (Rosmarinus officinalis L.) is widely used as a food material. Although various physiological activities of rosemary have been reported, there have been no studies on the physiological activity of solvent extracts with different polarities. Rosemary extracts were obtained by extraction of dried powder using 0%, 25%, 50%, 70%, and 95% ethanol (EtOH) in distilled water, methanol, ethyl acetate, and hexane. As these ratios of EtOH are generally chosen by default and scarcely optimized, we investigated the impact of the composition of EtOH in distilled water on extract-related characteristics, such as DPPH free radical scavenging and ${\alpha}$-glucosidase inhibition, on the differentiation of 3T3-L1 adipocytes and inhibition of tyrosinase. Adipogenesis inhibition was highest at 70% EtOH. DPPH scavenging activity and inhibition of tyrosinase activity were reduced with 50% EtOH in water. However, inhibition of ${\alpha}$-glucosidase activity was higher in 50% EtOH in water. The best solvents in terms of DPPH scavenging activity, inhibition of tyrosinase and ${\alpha}$-glucosidase, and differentiation of adipocytes obtained with different concentrations of EtOH, although a lower similar activities were found with 50% ethanol. Considering the extraction solvents, a ratio of EtOH in water gives different content and constituents of compounds. These differences will give activities inhibition of adipogenesis, tyrosinase, ${\alpha}$-glucosidase activity, and DPPH scavenging activity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.10-15
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• 2020

Ultraviolet rays, which have wavelengths smaller than 400 nm, are very harmful to the eyes. Recently, high-energy visible light was also revealed to be harmful to retinal cells. Therefore, polymer eyeglass lenses that can block UV and high-energy visible light are needed for eye health. In this study, high-refractive-index polymer eyeglass lens, n=1.67, were manufactured using the injection-mold method with the m-xylene diisocyanate monomer, 2,3-bis((2-mercaptoethyl)thio)-1-propanethiol monomer, benzotriazole UV absorber, release of alkyl phosphoric ester, dye mixture of CI solvent violet 13, and catalyst of dibutyltin dichloride mixture. A multi-layer anti-reflection coating was applied to manufactured polymer eyeglass lenses for both sides using an E-beam evaporation system. The optical properties of the manufactured lenses with the UV and high-energy visible light-blocking function were analyzed by UV-visible spectrophotometry. As a result, the polymer eyeglass lens with a UV absorber of 0.5 wt. % blocked 99% of UV and high-energy visible light shorter than 411 nm. The average transmittance of the polymer eyeglass lens with a UV absorber of 0.5wt.% was 97.9% in the range of 460 ~ 660 nm for photopic eye sensitivity higher than 10%. Therefore, clear image acquisition in photopic vision is possible.

• Food Science and Preservation
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• v.22 no.3
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• pp.437-442
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• 2015

In a continuing screening of selected medicinal plants native to South Korea, the antioxidant and pancreatic lipase inhibitory activities of an aqueous methanolic extract from the heartwood of Aquilaria agallocha were investigated. Eighty percent of the methanolic extract of A. agallocha was further divided into $CH_2Cl_2$, EtOAc and n-BuOH in order to yield four solvent-soluble portions, namely $CH_2Cl_2$-soluble, EtOAc-soluble, n-BuOH-soluble and $H_2O$ residue. The antioxidant properties were evaluated by employing radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) ($ABTS^+$) radicals, while the anti-obesity efficacy of A. agallocha extracts and solvent-soluble portions were tested by porcine pancreatic lipase assay. All tested samples showed dose-dependent radical scavenging and pancreatic lipase inhibitory activities. Among the tested extracts and solvent-soluble portions, the $CH_2Cl_2$-soluble portion showed much higher radical scavenging activity and pancreatic lipase inhibitory properties when compared with other solvent-soluble portions. This result suggested that there was a significant relationship between the total phenolic content and biological efficacies, and A. agallocha extract might be considered as a new potential source of natural antioxidants and as a pancreatic lipase inhibitory source. A more systematic investigation of this biomass will be performed for further investigation of activity against antioxidative and anti-obesity effects.

• Journal of Life Science
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• v.32 no.8
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• pp.633-640
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• 2022

Recently, kenaf (Hibiscus cannabinus L.) has been highlighted due to its rapid growth in dry, infertile land and its versatile applications in textiles, paper, feed, food, medicine, and phyto-remediation. In Korea, a new cultivar, 'Jangdae', which has the merit of feasible seed-gathering, was established in 2013. However, most of the kenaf seeds used are still imported, and a comparison study of useful bio-activities between Jangdae and imported seeds has not been conducted. In this study, anti-thrombosis, antioxidant and anti-diabetic activities of the ethanol extracts of the Jangdae seed (E-JS) and 8 imported cultivar seeds (E-ICS) were investigated. The E-JS has 14.4 mg/g of total polyphenol and 5.3 mg/g of total flavonoids, whereas the E-ICS has 5.9~8.7 mg/g and 0.7~1.5 mg/g, respectively. Among the 9 kenaf seed extracts, IT 181215 and IT 207877 seed extracts showed 1.92 and 1.88-folds extended thrombin time (TT), and IT 207886 seed extracts showed 3.04-folds extended activated partial thromboplastin time (aPTT). All extracts, except Hong-ma seed, showed 1.36~1.56-folds extended prothrombin time (PT). The E-JS showed strong anti-thrombosis activities with 1.46-folds (TT), 1.38-folds (PT) and 2.37-folds (aPTT) compared to those of solvent controls. The E-JS has the strongest antioxidant activities among the seed extracts, with 0.48 mg/ml of RC₅₀ for ABTS cation and 0.27 mg/ml of RC₅₀ for nitrite scavenging. Meanwhile, the E-JS and IT 181215 extracts showed strong inhibition against α-glucosidase with 10.3~10.6% inhibition at 0.5 mg/ml. Our results suggest the E-JS has potential as an anti-thrombosis, antioxidant and anti-diabetic agent.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5350-5355
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• 2012

Human tyrosinase (hTyr) catalyzes the first and rate limiting step in the biosynthesis of a skin color determinant, melanin. Although a number of cosmetic companies have tried to develop hTyr inhibitors for several decades, absence of 3D structure of hTyr make it impossible to design or screen inhibitors by structure-based approach. Therefore, we built a 3D structure by comparative modeling technique based on the crystal structure of tyrosinase from Bacillus megaterium to provide structural information and to search new hit compounds from database. Our model revealed that two copper atoms of active site located deep inside and were coordinated with six strictly conserved histidine residues coming from four-helix-bundle. Substrate binding site had narrow funnel like shape and its entrance was wide and exposed to solvent. In addition, hTyr-tyrosine and hTyr-kojic acid, a well-known inhibitor, complexes were modeled with the guide of solvent accessible surface generated by in-house software. Our model demonstrated that only phenol group or its analogs could fill the binding site near the nuclear copper center, because inside of binding site had narrow shape relatively. In conclusion, the results of this study may provide helpful information for designing and screening new anti-melanogenic agents.

• International Journal of Highway Engineering
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• v.18 no.6
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• pp.97-104
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• 2016

OBJECTIVES : The objective of this research is to develop additives for the modification of Solvent DeAsphalting Residue (SDAR) to be used as pavement materials, and evaluate the performance of asphalt mixture manufactured using the SDAR modified by developed additives. METHODS : The SDAR generally consists of more asphaltenes and less oil components compared to the conventional asphalt binder, and hence, the chemical/physical properties of SDAR are different from that of conventional asphalt binder. In this research, the additives are developed using the low molecular oil-based plasticizer to improve the properties of SDAR. First, the chemical property of two SDARs is analyzed using SARA (saturate, aromatic, resin, and asphaltene) method. The physical/rheological properties of SDARs and SDARs containing additives are also evaluated based on PG-grade method and dynamic shear-modulus master curve. Second, various laboratory tests are conducted for the asphalt mixture manufactured using the SDAR modified with additives. The laboratory tests conducted in this study include the mix design, compactibility analysis, indirect tensile test for moisture susceptibility, dynamic modulus test for rheological property, wheel-tracking test for rutting performance, and direct tension fatigue test for cracking performance. RESULTS : The PG-grade of SDARs is higher than PG 76 in high temperature grades and immeasurable in low temperature grades. The dynamic shear modulus of SDARs is much higher than that of conventional asphalt, but the modified SDARs with additives show similar modulus compared to that of conventional asphalt. The moisture susceptibility of asphalt mixture with modified SDARs is good if, the anti-stripping agent is included. The performance (dynamic modulus, rutting resistance, and fatigue resistance) of asphalt mixture with modified SDARs is comparable to that of conventional asphalt mixture when appropriate amount of additives is added. CONCLUSIONS : The saturate component of SDARs is much less than that of conventional asphalt, and hence, it is too hard and brittle to be used as pavement materials. However, the modified SDARs with developed additives show comparable or better rheological/physical properties compared to that of conventional asphalt depending on the type of SDAR and the amount of additives used.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.84-89
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• 2005

Mongolian dandelion (Taraxacum mongolicum H.) extracted with solvents having different polarities were prepared to investigate protection activity of gastric mucosa. Ethanol extracts were successively reextracted with methylene chloride, and n-butanol. Concentrations of total flavonoids and luteolin in n-butanol extracts were 27.75 and 1.14%, respectively, much higher than those of other solvent extracts. Results of anti-microbial acitivity test against Helicobacter pylori and urease inhibition test revealed n-butanol extract exerted higher inhibition (13.16%) than other solvent extracts. Based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, n-butanol extract showed the highest efficiency of free radical-scavenger activity among the extracts ($SC_{50}\;47{\mu}g/mL$). Erythrocytic photohemolysis tests, for the protection of cell membrane showed that half-life of human erythrocytes was increased by the addition of n-butanol extract $({\tau}_{50}=172min;C=5.0{\mu}g/mL)$. These results indicate n-butanol extract of Mongolian dandelion may be useful as a adjuvant for gastric diseases.

• Analytical Science and Technology
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• v.17 no.1
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• pp.1-7
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• 2004

The synergistic solvent extraction of Mn(II) by N-nitroso-N-phenylhydroxylamineammonium salt (cupferron) and tetrabutylammonium ion ($TBA^+$) has been studied. In the presence of $TBA^+$, over 95% Mn(II) was extracted from an aqueous solution into chloroform by the cupferron in the pH range of 4 to 10. But a part of Mn(II) was extracted with only cupferron. The ternary complex of Mn(II) was more efficiently extracted into $CH_2Cl_2$ and $CHCl_3$ than other nonpolar solvents. The extracted Mn(II) was determined in the back-extracted $HNO_3$ solution by GF-AAS. This fixed procedure was applied to the determination of trace Mn(II) in tap water samples of pH 5.0. The detection limit equivalent to 3 times standard deviation of the background absorption was 0.37 ng/mL and Mn(II) was determined with the range of 0.4 to 1.01 ng/mL in our laboratory's tap water. And the recovery was 94 to 107% in samples in which 2.0 ng/mL Mn(II) was spiked. The interferences of common concomitant elements such as Cu(II), Ca(II), Fe(III) and so on were not shown up to $10{\sim}20{\mu}g/mL$. From these results, this procedure could be concluded to be applied for the determination of trace Mn(II) in other environmental water samples.