• Journal of Photoscience
• /
• v.6 no.3
• /
• pp.91-96
• /
• 1999

Zeolites and microporouos materials continue to attract attention as novel hosts for photochemical reactions. Zeolities are attractive because of their ability to selectivity exchange and incorporate species within the void spaces and interconnecting channels, providing a spatial arrangement of molecules. Our research has primarily focused on intrazeolitic electron transfer from excited Ru(bpy)32+ in supercages of zeolite Y to a series of bipyridinium ions. In the Ru(bpy)32+ viologen-zeolite Y samples, the slowing of the back electron transfer from the bipyridinium radical cation to Ru(bpy)32+ allows for charge propagation via self exchange between diquat molecules. This provides an opportunity for permanent charge separation. When the migrating charge on the diquat radical within the zeolite reaches the surface, it can be transferred to a neutral viologen (PVS) in solution, resulting in permanent charge separation. The advantage of long-lived charge separation can be exploited for useful chemistry if suitable catablysts can be assembled on the zeolities. We have studied Ru(bpy)2 as water oxdiation catalysts. We have demonstrated that synthesis of RuO2 fibers on a zeolite via thermal decomposition of Ru3(CO)12 leads to the most active water decomposition catalyst reported to date. Because of the extensive interest of photochemical water reduction to H2, much is known about catalytic systems usin gone electron catalyst, and even more importantly, that no reaction of viologen occurred with H2 over this catalyst. The present challenge is to incorporate all these elements of the system into an architecture and we are examining zeolite membranes for this purpose.

• Food Science and Biotechnology
• /
• v.17 no.6
• /
• pp.1387-1390
• /
• 2008

This study evaluated the effects of heat treatment on antioxidant activity of Rehmannia radix Libosch (RRL). RRL was heated at various temperatures ($110-150^{\circ}C$) for various times (1-5 hr), and the total polyphenol, flavonoid content, and antioxidant activity were investigated. With increased heating temperature and exposure time, total content of polyphenol, flavonoid, as well as antioxidant activity increased. The highest total polyphenol and flavonoid contents were 21.65 and 3.56 mg/g, respectively, these values were occurred after heating for 3 hr at $150^{\circ}C$ (RRL was 5.09 and 0.83 mg/g, respectively). The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was highest value of 83.46% after heating for 3hr at $150^{\circ}C$. The 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) cation radical scavenging activity was highest value of 20.43mg ascorbic acid (AA) eq/g after heating for 2 hr at $150^{\circ}C$. There were highly significant differences in the total polyphenol, flavonoid content, and antioxidant activity among heating temperatures and times (p<0.001), with heating temperature having the greater effect.

• Korean journal of food and cookery science
• /
• v.32 no.5
• /
• pp.600-608
• /
• 2016

Purpose: To investigate the antioxidant, physicochemical sensory, and microbial safety qualities of sunsik containing fermented Curcuma longa L. powder. Methods: Quality characteristics of samples were measured using pH, moisture content, crude ash content, color and sensory evaluation. Antioxidant activities of samples were compared using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) cation radical scavenging activities. Microbial safety of samples were tested for Aerobic plate counts, Salmonella spp., Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, and Escherichia coli O157:H7. Results: The pH of samples was between pH 5.51 and pH 5.64, which was significantly lower than the optimum microbial living range. The DPPH and ABTS radical activities of sunsik containing 0.8% fermented Curcuma longa L. were significantly increased compared to that of the control (p<0.05). In sensory intensities, sunsik containing 0.8% fermented Curcuma longa L. showed significantly (p<0.05) similar savoy aroma and flavor, spicy aroma, spicy hot flavor, sweet flavor, and throat swallowing values to those of the control samples. Samples of sunsik added 0.8% and 1.2% fermented Curcuma longa L. showed significantly similar overall acceptance values to those of the control. All samples tested were found to free of microbes and microbiologically safe according to the food code standards. Conclusion: The sunsik added with 0.8% or 1.2% fermented Curcuma longa L. powder were successfully developed. we conclude that the developed sunsik with the fermented turmeric powder can be potentially high value products in the highly competitive sunsik food industry.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.3
• /
• pp.833-838
• /
• 2014

The energy- and time-dependent branching to the competing dissociation paths are studied by theory for coupled unimolecular dissociations of the o-, m-, and p-chlorotoluene radical cations to $C_7{H_7}^+$ (benzylium and tropylium). There are four different paths to $C_7{H_7}^+$, three to the benzylium ion and one to the tropylium ion, and all of them are coupled together. The branching to the multiple paths leads to the multiexponential decay of reactant with the branching ratio depending on both internal energy and time. To gain insights into the multipath branching, we study the detailed kinetics as a function of time and internal energy on the basis of ab inito/RRKM calculations. The number of reaction steps to $C_7{H_7}^+$ is counted for each path. Of the three isomers, the meta mostly goes through the coupling, whereas the para proceeds with little or no coupling. In the beginning, some reactants with high internal energy decay fast to the benzylium ion without any coupling and others rearrange to the other isomers. Later on all three isomers dissociate to the products via long-lived intermediates. Thus, the reactant shows a multiexponential decay and the branching ratio varies with time as the average internal energy decreases with time. The reciprocal of the effective lifetime is taken as the rate constant. The resulting rate-energy curves are in line with experiments. The present results suggest that the coupling between the stable isomers is thermodynamically controlled, whereas the branching to the product is kinetically controlled.

• Journal of Life Science
• /
• v.23 no.6
• /
• pp.751-756
• /
• 2013

This research old age chestnut tree that loss function chestnut leaf renewal efficiency enlargement and development of cosmeceutical product by purpose. Chestnut leaf (CL) exhibits numerous pharmacological effect including anti-allergy and anti-microbial properties. However, the anti-wrinkle effect of CL is not completely understood. In this study, to find a possible explanation for the anti-wrinkle effects of CL, we evaluated the effects of CL on radical scavenging activity, elastase inhibition activity and collagenase inhibition activity. CL was extracted with various solvents including water (CLW), 70% ethanol (CLE) and 70% acetone (CLA). The results showed that CLW, CLE, and CLA have the radical scavenging activity. In addition, we showed that CLW, CLE, and CLA have the elastase inhibition activity and collagenase inhibition activity. Consequently, the CL has a potent anti-wrinkle effect and it could be a useful cosmeceutical product for anti-aging purposes.

• Journal of Life Science
• /
• v.20 no.8
• /
• pp.1235-1240
• /
• 2010

Natural compounds have been studied to substitute synthetic antioxidants. In this study, the anti-oxidant activity of 70% acetone extracts from the Vaccinium oldhami fruit was investigated for utilization as ingredients for the cosmetic and bio-industries. Anti-oxidant activity was determined by determining total polyphenolic content, electron donating ability, nitric oxide (NO) radical scavenging activity, $ABTS{\cdot}^+$ cation radical scavenging activity and hydrogen peroxide scavenging activity. The polyphenolic content of 70% acetone extracts of the Vaccinium oldhami fruit was 55.972 mg TAE/g. In electron donating activity, 70% acetone extracts of the Vaccinium oldhami fruit showed an effect of 93.9%, which was similar to BHA effect at a concentration of 500 ${\mu}g/ml$. In the NO radical scavenging ability, 70% acetone extracts of the Vaccinium oldhami fruit showed 60% at 500 ${\mu}g/ml$. $ABTS{\cdot}^+$ cation radical scavenging activity of the Vaccinium oldhami fruit at a concentration of 1000 ${\mu}g/ml$ was 75.7%. Also, hydrogen peroxide scavenging activity of 70% acetone extracts showed 80.8% at 100 ${\mu}g/ml$, whichwas higher than BHA. In the natural compound market, the most important factors are the ability to obtain high effects of a material in low concentrations and a long-lasting supply. The Vaccinium oldhami fruit can be harvested every year - this fulfills one of the requirements. From these results, we can confirm that the Vaccinium oldhami fruit has anti-oxidant abilities and has potential as a natural anti-oxidant agent to be utilized in the cosmeceutical and bio-industries.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.380.1-380.1
• /
• 2016

In this study, we report a novel antioxidant ZnO nanoparticle that is newly designed and prepared by simple surface modification process. Antioxidative functionality is provided by the immobilization of antioxidant of 3,4,5-trihydroxybenzoic acid (galic acid, GA) onto the surface of ZnO nanoparticles. Microstructure and physical properties of the ZnO@GA nanoparticles were investigated by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), infrared spectroscopy (IR) and steady state spectroscopic methods. The antioxidative activity of ZnO@GA was also evaluated using ABTS (3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization assay. Notably, ZnO@GA showed strong antioxidative activity in spite of the conjugation process of GA on the ZnO surface. These results provide that GA-coating onto ZnO nanoparticles may offer an intriguing potential for biomedical devices as well as nanomaterials.

• The Korea Journal of Herbology
• /
• v.26 no.2
• /
• pp.67-73
• /
• 2011

Objectives : The purpose of this research was total polyphenol contents, anti-oxidant activities, anti-inflammatory activities and anti-wrinkle activities of Ulleung islands plants for application as a cosmeceutical ingredients Methods : We were experimented total polyphenol contents, anti-oxidant activities, anti-inflammatory activity and anti-wrinkle activities. Results : In the physiological activities, most Ulleung islands plants is showed the highest anti-oxidant, anti-inflammatory activity in ABTS+ radical cation scavenging activity, hydrogen peroxide($H_2O_2$) scavenging activity, nitric oxide scavenging activity. All experiment of the water and ethanol extract from the Ulleung islands plants ingredients were gradually increased as well. Conclusions : These results suggest that extracts from Ulleung islands plants can be used in natural ingredient in food or cosmetic industry.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.8 no.1
• /
• pp.53-70
• /
• 1990

It is well known that viologens such as 1.1 - disubstituted 4, 4` - bipyridinium salts and those used as redox indicator, herbicide and electrocheromic display device because those possess the lowest redox potential in any organic system. Viologen salts produced reversible high blue color under the influence of radical cation by photoreduction This study is related to the synthesis of viologen derivatives and the photoreduction property in water solution stats and the polar aprotic polyvinylpyrrolidone(PVP) matrix.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.3
• /
• pp.851-857
• /
• 2014

Carotenoids, natural antenna pigments in photosynthesis share a symmetric backbone of conjugated polyenes. Contrary to the symmetric and almost planar geometries of carotenoids, excited state structure and dynamics of carotenoids are exceedingly complex. In this paper, recent infrared and visible transient absorption measurements and excitation dependent dynamics of 8'-apo-${\beta}$-caroten-8'-al and 7',7'-dicyano-7'-apo-${\beta}$-carotene will be reviewed. The recent visible transient absorption measurements of 8'-apo-${\beta}$-caroten-8'-al in polar and nonpolar solvents will also be introduced to emphasize the complex excited-state dynamics and unsolved problems in the $S_2$ and $S_1$ excited states.