• Fibers and Polymers
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• v.2 no.2
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• pp.86-91
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• 2001

Liquid crystalline (LC) poly(ethylene terephthalate-co-2(3)-chloro-1,4-phenylene terephthalate) [copoly(ET/CPT)] was prepared using poly(ethylene terephthalate) (PET) as a flexible spacer, terephthalic acid (TPA), and chlorohydroquinone diacetate (CHQDA). All reactions involved in the copolymerization were investigated using some model compounds: TAP was used for acidolysis, diphenylethyl terephthalate (DPET) for interchange reaction between PET chains, and 야-o-chlorophenyl terephthalate (DOCT) and di-m-chlorophenyl terephthalate (DMCT) for interchange reaction between PET and rigid rodlike segments. Activation energies obtained for the acidolysis of PET with TPA and for interchange reaction of PET with DPET, DOCT, and DMCT were 19.8 kcal/mol, 26.5 kcal/mole, and 45.9 kcal/mole, respectively. This result supports that the copolymerization proceeds through the acidolysis of PET with TPA first and subsequent polycondensation between carboxyl end group and CHQDA or acetyl end group, which is formed from the reaction of CHQDA and TPA. Also, it was found that ester-interchange reaction can be influenced by the steric hindrance. Copoly(ET/CPT)s obtained has ethylene acetate end groups formed from acetic acid hydroxy ethylene end groups and showed almost the random sequence distribution for all compositions.

• Nutrition Research and Practice
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• v.7 no.4
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• pp.287-293
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• 2013

This study determined the effects of fucoxanthin on gene expressions related to lipid metabolism in rats with a high-fat diet. Rats were fed with normal fat diet (NF, 7% fat) group, high fat diet group (HF, 20% fat), and high fat with 0.2% fucoxanthin diet group (HF+Fxn) for 4 weeks. Body weight changes and lipid profiles in plasma, liver, and feces were determined. The mRNA expressions of transcriptional factors such as sterol regulatory element binding protein (SREBP)-1c, Carnitine palmitoyltransferase-1 (CPT1), Cholesterol $7{\alpha}$-hydroxylase1 (CYP7A1) as well as mRNA expression of several lipogenic enzymes were determined. Fucoxanthin supplements significantly increased plasma high density lipoprotein (HDL) concentration (P < 0.05). The hepatic total lipids, total cholesterols, and triglycerides were significantly decreased while the fecal excretions of total lipids, cholesterol, and triglycerides were significantly increased in HF+Fxn group (P < 0.05). The mRNA expression of hepatic Acetyl-CoA carboxylase (ACC), Fatty acid synthase (FAS), and Glucose-6-phosphate dehydrogenase (G6PDH) as well as SREBP-1C were significantly lower in HF+Fxn group compared to the HF group (P < 0.05). The hepatic mRNA expression of Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) and Acyl-CoA cholesterol acyltransferase (ACAT) were significantly low while lecithin-cholesterol acyltransferase (LCAT) was significantly high in the HF+Fxn group (P < 0.05). There was significant increase in mRNA expression of CPT1 and CYP7A1 in the HF+Fxn group, compared to the HF group (P < 0.05). In conclusion, consumption of fucoxanthin is thought to be effective in improving lipid and cholesterol metabolism in rats with a high fat diet.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.660-667
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• 2017

PineXol, extracted from Korean red pine bark, has beneficial effects, such as antioxidant, antiinflammatory, and antilipogenic activities in vitro. We tested the hypothesis that PineXol supplementation could have anti-obesity effects on mice fed a high-fat diet (HFD). Four-week-old male C57BL/6 mice were fed normal chow (18% kcal from fat) or a HFD (60% kcal from fat). HFD-fed animals were also subjected to PineXol treatment at a dose of 10 or 50 mg/kg body weight (BW) (PX10 or PX50, respectively) body weight. The body weight and body fat mass in the PX50 group were statistically lower than those in the HFD group (p < 0.05 and p < 0.001, respectively). The concentration of hepatic triglycerides, total cholesterol, and low-density lipoprotein cholesterol were reduced in the PX50 group compared with the HFD group (p < 0.01). Acetyl CoA carboxylase (p < 0.01), elongase of very long chain fatty acids 6 (p < 0.01), stearoyl CoA desaturase 1 (p < 0.05), microsomal triglyceride transfer protein (p < 0.01), and sterol regulatory element-binding protein 1 (p < 0.05) were significantly decreased in the PX50 group compared with that in the HFD group. In white adipose tissue, CCAAT-enhancer-binding protein alpha (p < 0.05), peroxisome proliferator-activated receptor gamma (p < 0.001), and perilipin (p < 0.01) were decreased in the PX50 group compared with those in the HFD group. Therefore, the current study implies the potential of PineXol for the prevention and/or amelioration of obesity, in part by inhibition of both hepatic lipid synthesis and adipogenesis in white adipose tissue.

• Nutrition Research and Practice
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• v.12 no.4
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• pp.298-306
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• 2018

BACKGROUND/OBJECTIVES: Obesity is a global health problem of significant importance which increases mortality. In place of anti-obesity drugs, natural products are being developed as alternative therapeutic materials. In this study, we investigated the effect of Brassica juncea L. leaf extract (BLE) on fat deposition and lipid profiles in high-fat, high-cholesterol diet (HFC)-induced obese rats. MATERIALS/METHODS: Male Sprague-Dawley rats were divided into four groups (n = 8 per group) according to diet: normal diet group (ND), high-fat/high-cholesterol diet group (HFC), HFC with 3% BLE diet group (HFC-A1), and HFC with 5% BLE diet group (HFC-A2). Each group was fed for 6 weeks. Rat body and adipose tissue weights, serum biochemical parameters, and tissue lipid contents were determined. The expression levels of mRNA and proteins involved in lipid and cholesterol metabolism were determined by reverse transcription polymerase chain reaction and western blot analysis, respectively. RESULTS: The HFC-A2 group showed significantly lower body weight gain and food efficiency ratio than the HFC group. BLE supplementation caused mesenteric, epididymal, and total adipose tissue weights to decrease. The serum levels of triglyceride, total cholesterol, and low-density lipoprotein cholesterol were significantly reduced, and high-density lipoprotein cholesterol was significantly increased in rats fed BLE. These results were related to lower glucose-6-phosphate dehydrogenase, acetyl-coA carboxylase, and fatty acid synthase mRNA expression, and to higher expression of the cholesterol $7{\alpha}$-hydroxylase and low density lipoprotein-receptor, as well as increased protein levels of peroxisome proliferator-activated receptor ${\alpha}$. Histological analysis of the liver revealed decreased lipid droplets in HFC rats treated with BLE. CONCLUSIONS: Supplementation of HFC with 3% or 5% BLE inhibited body fat accumulation, improved lipid profiles, and modulated lipogenesis- and cholesterol metabolism-related gene and protein expression.

• Nutrition Research and Practice
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• v.9 no.1
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• pp.30-36
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• 2015

BACKGROUD/OBEJECTIVES: The mechanism of how black garlic effects lipid metabolism remains unsolved. Therefore, the objectives of this study were to determine the effects of black garlic on lipid profiles and the expression of related genes in rats fed a high fat diet. MATERIALS/METHODS: Thirty-two male Sqrague-Dawley rats aged 4 weeks were randomly divided into four groups (n=8) and fed the following diets for 5 weeks: normal food diet, (NF); a high-fat diet (HF); and a high-fat diet + 0.5% or 1.5% black garlic extract (HFBG0.5 or HFBG1.5). Body weights and blood biochemical parameters, including lipid profiles, and expressions of genes related to lipid metabolism were determined. RESULTS: Significant differences were observed in the final weights between the HFBG1.5 and HF groups. All blood biochemical parameters measured in the HFBG1.5 group showed significantly lower values than those in the HF group. Significant improvements of the plasama lipid profiles as well as fecal excretions of total lipids and triglyceride (TG) were also observed in the HFBG1.5 group, when compared to the HF diet group. There were significant differences in the levels of mRNA of sterol regulatory element binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and glucose-6-phosphate dehydrogenase (G6PDH) in the HFBG1.5 group compared to the HF group. In addition, the hepatic expression of (HMG-CoA) reductase and Acyl-CoA cholesterol acyltransferase (ACAT) mRNA was also significantly lower than the HF group. CONCLUSIONS: Consumption of black garlic extract lowers SREBP-1C mRNA expression, which causes downregulation of lipid and cholestrol metahbolism. As a result, the blood levels of total lipids, TG, and cholesterol were decreased.

• Biomolecules & Therapeutics
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• v.6 no.2
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• pp.130-138
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• 1998

In this study, the effect of verapamil (VER) on cyclosporin A (CsA)-induced nephrotoxicity was investigated in uninephrectomized rats. Male Wistar rats were administered CsA (50 mg/kg/day, p.o.) or VER (0.5 mg/kg/day, i.p.) with CsA (50 mg/kg/day, p.o.) for 20 days. The urinary N-acetyl-$\beta$-D-glucosaminidase (NAG) activity along with BUN, serum creatinine, creatinine clearance (CLcr), body weight, and 24 hr-urine output were measured and histopathologic changes of kidney were evaluated by light and electron microscopy. The results obtained from this study can be summarized as follows: While NAG activity, BUN and serum creatinine was progressively increased and CLcr significantly decreased in CsA group, VER almost signifi-cantly (p<0.05) suppressed and normalized CsA-induced changes in VER+CSA group. While urine output increased until 12th days and thereafter progressively decreased in CsA group, it gradually increased in control and VER+CSA group. While body weight progressively made a gain in control and VER+CSA groups, it significantly (p<0.05) lost in CsA group. On light microscopy, the glomerular hyperemia and proximal convoluted tubular (PCT) dilatation, focal tubular cell vacuolation and necrosis were clearly evident in CsA group, but, were not seen in other groups. Ultrastructural studies revealed thickened glomerular endothelium and basal lamina of capillary, irregular shaped pedicels of podocytes, indistinct slit pores and narrowed bowman's space. The large oval vacuoles with dense debris and phagosome were distributed in apical zone and deformed microvilli and mitochondria were seen in the PCT cell of CsA group. But, glomeruli and PCT cell were relatively preserved in normal apperance in other groups. In conclusion, it is suggested that verapamil has a protective effect on cyclosporine-induced nephrotoxicity in uninephrectomized rats.

• Biomolecules & Therapeutics
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• v.10 no.3
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• pp.193-199
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• 2002

The arylamine N-acetyltransferases (NATs) are a family of enzymes that N-acetylate mylhydrazines and arylamines through transfer of an acetyl group from acetyl coenzyme A. This activity was found to vary among individuals as a Mendalian trait and the basis of the genetic differences in human NAT activity is one of the best of the genetic studied examples of pharmacogenetic variation. The classical N-acetylation polymorphism is regulated at the NAT2 locus, which segregates individuals into rapid, intermediate, and slow acetylator phenotypes. In this study, the relationship between NAT2 activity phenotype using HPLC:UV assay for the determination of dapsone and monoacetyldapsone in plasma and NAT2 genotype by PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) was investigated in the F2 hybrid (Fischer 344 vs Wistar-Kyoto) rats. Three Common mutant alleles at the NAT2 gene locus have been identified in the F2 generation progeny of Fischer 344 rats as raid acetylator and Wistar-Kyoto rats as slow acetylator segregated into three modes (low, intermediates, and high) with simple Mendelian inheritance. The metabolic activity of NAT2 of the intermediate and rapid acetylators is significant1y greater than slow acetylator, but the metabolic activity of rapid acetylator is not significantly different from Intermediate type. Therefore, we could observe that complete trimodal NAT2 genotypic alleles and incomplete trimodal NAT2 metabolic phenotypic distribution in tile F2 hybrid rats. These observations suggest that the relationships between NAT2 genotype and metabolic phenotype exists and F2 hybrid (Fischer 344: Wistar-Kyoto) animal models about NAT2 polymorphism might be applied in the toxicity and pharmacogenetic studies of arylamine drugs and carcinogens.

• Journal of the Korean Wood Science and Technology
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• v.29 no.4
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• pp.60-66
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• 2001

For examine anti-degradation factors of acetylated wood, acetylated wood was incubated on Trametes versicolor. The laccase activity was examined in broth culture and solid fermentation that contain acetylated chips. The change of acetyl groups and chemical composition in the acetylated wood having massloss analysed by $^{13}C$-CP/MAS NMR. The laccase activity was detected in broth culture. When the T. versicolor contact to acetylated wood directly, the laccase activity was very low and couldn't maintain during test periods. Through the analysing of $^{13}C$-CP/MAS NMR, the acetylation took place carbohydrates as well as lignin and hydroxyl group of amorphous region was more easily substituted that of crystalline region The spectral analyses of $^{13}C$-CP/MAS NMR were shown that introduced acetyl bond was stable against fungal attack.

• Bulletin of the Korean Chemical Society
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• v.25 no.10
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• pp.1477-1483
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• 2004

We present the tandem mass spectrometry applications carried out to elucidate the coordination structure of Zn(II) bound lysine ternary complexes, $(Zn+Lys+Lys-H)^+$, which is a good model system to represent a simple (metallo)enzyme-substrate complex (ES). In particular, experimental efforts were focused on revealing the involvement of a lysine side chain ${\varepsilon}$-amino group in the coordination of $Zn^{2+}$ divalent ions. MS/MS fragmentation pattern showed that all the oxygen species within a complex fell off in the form of $H_2O$ in contrast to those of other ternary complexes containing amino acids with simple side chains (4-coordinate geometries, Figure 1a), suggesting that the lysine complexes have different coordination structures from the others. The participation of a lysine basic side chain in the coordination of Zn(II) was experimentally evidenced in MS/MS for $N{\varepsilon}$-Acetyl-L-Lys Zn(II) complexes with acetyl protection groups as well as in MS/MS for the ternary complexes with one $NH_3$ loss, $(Zn+Lys+Lys-NH_3-H)^+$. Detailed structures were predicted using ab initio calculations on $(Zn+Lys+Lys-H)^+$ isomers with 4-, 5-, and 6-coordinate structures. A zwitterionic 4-coordinate complex (Figure 7d) and a 5-coordinate structure with distorted bipyramidal geometry (Figure 7b) are found to be most plausible in terms of energy stability and compatibility with the experimental observations, respectively.

• Food Engineering Progress
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• v.13 no.3
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• pp.216-220
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• 2009

The several functional properties of freeze-dried powder of Aloe vera gel was examined as influenced by pre-concentration degrees of the gel solution. As a pre-treatment prior to freeze drying, the gel solution was vacuum-concentrated by three levels (unit: g-water/g-solids) - high (H), 76; medium (M), 119; low (L), 159. In FT-IR spectra, the sample H showed the highest absorbance in the range of 1600-1550 $cm^{-1}$ and 1450-1400 $cm^{-1}$, which corresponded to level of the acetyl group in glucomannan. The sample H of freeze-dried powder was the highest in polysaccharide content, jack bean urease inhibition rate, and FAC (fat adsorption capacity). It could be inferred that the sample H had an effect on Helicobacter pylori inhibition and fat adsorption suppression according to urease inhibition rate and FAC, respectively.