• Archives of Pharmacal Research
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• v.26 no.10
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• pp.809-815
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• 2003

Since reactive oxygen species (ROS) and hydroxyl radicals ($^-OH$) play an important role in the pathogenesis of many human degenerative diseases, much attention has focused on the development of safe and effective antioxidants. Preliminary experiments have revealed that the methanol (MeOH) extract of the stem of Prunus davidiana exerts inhibitory/scavenging activities on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals, total ROS and peroxynitrites ($ONOO^-$). In the present study, the antioxidant activities of this MeOH extract and the organic solvent-soluble fractions, dichloromethane (CH$_2$Cl$_2$), ethyl acetate (EtOAc), and n-butanol (n-BuOH), and the water layer of P. davidiana stem were evaluated for the potential to inhibit $^-OH$ and total ROS generation in kidney homogenates using 2',7'-dichlorodihydrofluorescein diacetate (DCHF-DA), and for the potential to scavenge authentic $ONOO^-$. We also evaluated the inhibitory activity of seven flavonoids isolated from P. davidiana stem, kaempferol, kaempferol 7-Ο-$\beta$-D-glucoside, (+)-catechin, dihydrokaempferol, hesperetin 5-Ο-$\beta$-D-glucoside, naringenin and its 7-Ο-$\beta$-D-glucoside, on the total ROS, $^-OH$ and $ONOO^-$ systems. For the further elucidation of the structure-inhibitory activity relationship of flavonoids on total ROS and 'OH generation, we measured the antioxidant activity of sixteen flavonoids available, including three active flavonoids isolated from P. davidiana, on the total ROS and 'OH systems. We found that the inhibitory activity on total ROS generation increases in strength with more numerous hydroxyl groups on their structures. Also, the presence of an ortho-hydroxyl group, whether on the Aring or S-ring, and a 3-hydroxyl group on the C-ring increased the inhibitory activity on both total ROS and $^-OH$ generation.

• Archives of Pharmacal Research
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• v.23 no.4
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• pp.338-343
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• 2000

The effects of methanol extract of Rubus crategifolius roots and its solvent fractions were investigated on the proliferation of MCF-7 human breast carcinoma cells. The methanol extract inhibited the proliferation of MCF-7 cells in a concentration dependent manner. Moreover, their methanol soluble (W-M) fraction had the greatest inhibitory effect on the growth of MCF-7 cells. To evaluate whether the W-M fraction affects on the cell cycle of MCF-7 cells, cells treated with this fraction were analyzed with flow cytometry. The W-M fraction increased $G_0$/$G_1$phase after 24 h-treatment and induced apoptosis after 48 h-treatment. The hallmark of apoptosis, DNA fragmentation, also appeared by W-M fraction after 48 h-treatment. Furthermore, the methanol extract and its W-M fraction inhibited the activity of the topoisomerase 1 enzyme in the relaxation assay, From these results, their W-M fraction as well as methanol extract of R. crategifolius roots are necessary for further studies as a potent inhibitor of the growth of cancer cells.

• Korean Journal of Plant Taxonomy
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• v.35 no.4
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• pp.313-335
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• 2005

Many plants take up soluble silica from the soil, and they deposit in plant tissues. Silica bodies are most commonly found in the leaf epidermis. Silica body is important factor in growth and development of plant. It help to maintain rigidity in stem and linear leaves, and its content may be correlated with resistance to fungal disease. In this study, several morphologically distinctive forms of silica bodies on Cyperaceae in Korea are recognized, which are eventually classified into two groups. Silica body type of first group (Rhynchospora, Fuirena, Scleria, Carex, Eriophorum) is A-type, which is conical in shape. Silica body type of second group (Cyperus, Scirpus, Eleocharis, Fimbristylis, Kyllinga, Bulbostylis, Lipocarpha) is B-type, which is conical in shape with numerous satellite body. These types are consistent enough to use as characters in taxonomic studies within genus. Silica body type may be associated with habitat: the species in dry region have A-type, whereas the species in wet region have B-type. These results suggested that shapes and presence or absence of silica body might be valuable to systematic analysis.

• Journal of Integrative Natural Science
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• v.3 no.1
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• pp.1-6
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• 2010

Bis(silyl)alkylbenzenes such as bis(1-sila-sec-butyl)benzene (1) and 2-phenyl-1,3-disilapropane (2) were synthesized in high yields by the reduction of the corresponding chlorosilanes with $LiAlH_4$ in diethyl ether. The dehydrocoupling of 1 and 2 was performed using group IV metallocene complexes generated in situ from $Cp_2MCl_2$/Red-Al and $Cp_2MCl_2$/n-BuLi (M = Ti, Hf), producing two phases of polymers. The TGA residue yields of the insoluble polymers were in the range of 64-74%. The molecular weights of the soluble polymers produced ranged from 700 to 5000 ($M_w$ vs polystyrene using GPC) and from 500 to 900 ($M_w$ vs polystyrene using GPC). The dehydropolymerization of 1 and 2 seemed to initially produce a low-molecular-weight polymer, which then underwent an extensive cross-linking reaction of backbone Si-H bonds, leading to an insoluble network polymer.

• Safety and Health at Work
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• v.1 no.2
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• pp.175-182
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• 2010

Objectives: This study examined how ethanolamines (EAs) with the same functional alcohol group ($HOCH_2CH_2$), such as mono-EA (MEA), di-EA (DEA), and tri-EA (TEA), in water-based metalworking fluids (wbMWFs) are vaporized, condensed, and transformed by heat generated during metalworking. Methods: Two types of experimental apparatus were manufactured to achieve these objectives. Results: Vaporization tests using a water bath showed that the vaporization rate increased markedly from $0.19\;mg/m^2{\cdot}min$ at $23.5^{\circ}C$ to $8.04\;mg/m^2{\cdot}min$ at $60^{\circ}C$. Chamber tests with a heat bulb revealed that "spiked" MEA was fully recovered, while only 13.32% of DEA and no TEA were recovered. Interestingly, non-spiked types of EAs were detected, indicating that heat could convert EAs with more alcohol groups (TEA or DEA) into other EAs with fewer group(s) (DEA or MEA). The EA composition in fresh fluid was 4% DEA, 66% TEA, and 30% MEA, and in used fluids (n = 5) was 12.4% DEA, 68% TEA, and 23% MEA. Conversion from TEA into DEA may therefore contribute to the DEA increment. Airborne TEA was not detected in 13 samples taken from the central coolant system and near a conveyor belt where no machining work was performed. The DEA concentration was $0.45\;mg/m^3$ in the only two samples from those locations. In contrast, airborne MEA was found in all samples (n = 53) regardless of the operation type. Conclusion: MEAs easily evaporated even when MWFs were applied, cleaned, refilled, and when they were in fluid storage tanks without any metalworking being performed. The conversion of TEA to DEA and MEA was found in the machining operations.

• Archives of Pharmacal Research
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• v.24 no.3
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• pp.229-233
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• 2001

This Paper deals with the development of a technology for making a hydrophilic gel of Polyethylene oxide reception in which radiating ability is employed to cause cross-linking of Polymers in a water solution. The gel of polyethylene oxide was shown to be nontoxic contain 5-50% of polymer and be useful in composite medicinal forms along with biologically active substances including Bac. subtilis proteases. Proteases immobilized in the gel possess high thermal stability and proteolytic activity and are readily applied in medicine. The effect of immobilized proteolytic and glucolytic enzymes of Bac. subtillis (Immozimase) on the warm ischemia-reperfusion (I/R) which can cause hepatic and jejunum injury was also studied. These enzymes were immobilized on water-soluble polymer polyethylene glycol by means of an electron beam. The number of degraanulated mast cells as well as serum ALT after I/R in the group with Immozimase was decreased to almost half as compared with the control group. Pretreatment with Immozimase resulted in significant reduction of hepatic and gut neutrophil accumulation as compared with control animals. It was concluded that Immozimase has a protective effect for hepatic and gut ischemia/reperfusion, and this effect seems to be associated with prevention of leukocyte accumulation .

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.613-618
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• 2005

We investigated the effect of chicory (Chicorium intybus) extract on triglyceride concentration and microsomal triglyceride transfer protein (MTP) activity in rats. The effect of water-soluble extract of chicory fed at the $2.0\%\;and\;4.0\%(w/w)$ levels for 2 weeks on the concentration of serum triglyceride and the activity of hepatic microsomal riglyceride transfer protein (MTP) was investigated in male Sprague-Dawley rats. The triglyceride concentrations in serum of the chicory extract fed groups were significantly lower than in the control group. MTP activity, known to be essential for the assembly/secretion of apolipoprotein B-containing lipoproteins, was also significantly lower in the chicory extract groups than in the control group. The concentrations of other lipids in serum and liver and the activity of phosphatidate phosphohydrolase, the rate-limiting enzyme in triglyceride synthesis, showed no significant differences among in the chicory fed groups. These results indicate that dietary chicory extract decrease hepatic MTP activity and serum triglyceride concentration, and therefore reduces hepatic lipoprotein assembly and secretion.

• Animal Bioscience
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• v.34 no.1
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• pp.85-92
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• 2021

Objective: The objectives of this study were to determine the in situ degradation parameters and appropriate feeding level of pineapple cannery by-products (PCB) based on the growth performance and blood parameters of growing Hanwoo (Bos taurus coreanae) steers fed various levels of PCB. Methods: Two ruminally cannulated Holstein cows were used for in situ disappearance rate measurements. Nylon bags (5×10 cm, 45 ㎛ pore size) filled with 5 g of PCB in triplicate were inserted into the ventral sac of the two cannulated Holsteins cows and incubated for 0, 2, 4, 8, 16, 24, and 48 h. A total of 16 castrated growing Hanwoo steers (12.5±0.5 months old, 302.9±25.7 kg of initial body weight [BW]) were used for the experiment. Animals were stratified by initial BW and then randomly assigned to one of four experimental diets (0%, 1.5%, 3.0%, or 6.0% of PCB, on the dry matter [DM] basis) fed for 91-d, including 30-d of adaptation. Results: Soluble fraction a of DM and crude protein (CP) was 61.9% and 86.0%, fraction b of DM and CP was 32.7% and 11.2%, and indigestible fraction c of DM and CP was 5.4% and 2.8%. The 6.0% PCB feeding group showed lower productivity compared to animals in the other treatments. Increasing the dietary level of PCB did not alter DM intake, but it was numerically lowest in the 6.0% feeding group. The gain to feed ratio was linearly decreased by increasing of PCB. The quadratic broken-line test estimated that 2.5% (DM basis) was the maximum feeding level of PCB in growing Hanwoo steers (y = 0.103 - 0.001×[1.245-x]2, R2 = 0.18). Conclusion: Diets containing up to 2.5% PCB can be fed to growing Hanwoo steers without adverse effects on growth performance.

• Korean Journal of Environmental Agriculture
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• v.42 no.2
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• pp.104-111
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• 2023

As apple trees mature, it is important to maintain good light distribution within the canopy to produce marketable fruits. Tree thinning is the selective removal of a proportion of trees growing in the orchard to provide more growing space and a good light environment for the remaining trees. This study was conducted over 3 years (14-16 years after planting) to investigate the influence of tree thinning on vegetative growth, yield, fruit quality, and blooming in the 14 years old slender spindle 'Fuji'/M.9 apple trees planted with the tree space of 3.2×1.2 m. The trees were placed in a control group (no thinning; 260 trees per 10 a) or a tree thinning group (thinned 50% of the control; 130 trees per 10 a). The tree thinning successfully improved light penetration, yield per tree, fruit red color, and yield efficiency for 3 years, and the tree thinning controlled the occurrence of biennial bearing. However, tree thinning significantly decreased accumulated yield per 10 a compared with the control. The vegetative growth, yield per tree, soluble solid contents, and blooming were not clear by the occurrence of biennial bearing in the control. These results indicated that tree thinning was a good method for improving light penetration and preventing biennial bearing in the old 'Fuji'/M.9 high-density apple orchards.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.810-817
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• 2023

Oysters are a highly consumed seafood throughout Korea, but they have a short shelf life because they support rapid microbial growth due to their of high moisture content and fragile muscle tissue. We examined natural food additives including lactic acid bacteria fermentation powder, rosemary extract, and lemon juice for their ability to preserve raw oyster Crassostrea gigas quality. Samples were stored at 4℃, and microbiological and physicochemical analyses were conducted. Among the natural additives tested, lemon juice was the most effective. Lemon juice was thus applied at different concentrations (50-300 ppm) to quantitatively assess its effect on total viable cell count, pH, glycogen, soluble protein, and turbidity. 200 ppm was confirmed to be optimal, and is projected to extend shelf life by 2 days compared to the control group.