• Title/Summary/Keyword: synthesis of $MgB_2$

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Initial Risk Assessment of Acetanilide in OECD High Production Volume Chemical Program

  • Park, Hye-Youn;Park, Yoonho;Sanghwan Song;Kwon, Min-Jeoung;Koo, Hyun-Ju;Jeon, Seong-Hwan;Na, Jin-Gyun;Park, Kwangsik
    • Toxicological Research
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    • v.18 no.1
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    • pp.13-22
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    • 2002
  • In Korea, 2,320 tonnes of acetanilide were mostly wed as intermediates for synthesis in phar-maceuticals or additives in synthesizing hydrogen peroxide, varnishes, polymers and rubber. Only small amount of 120 kg were wed as a stabilizer for hydrogen peroxide solution for hair colouring agents in 1998. Readily available environmental or human exposure data do not exist in Korea at the present time. However, potential human exposures from drinking water, food, ambient water and in work places are expected to be negligible because this chemical is produced in the closed system in only one company in Korea and the processing factory is equipped with local ventilation and air filtering system. Acetanilide could be distributed mainly to water based on EQC model. This substance is readily biodegradable and its bioaccumulation is low. Acute toxicity of acetanilide is low since the L $D_{50}$ of oral exposure in rats is 1,959 mg/kg bw. The chemical is not irritating to skin, but slightly irritating to the eyes of rabbits. horn repeated dose toxicity, the adverse effects in rats were red pulp hyperplasia of spleen, bone marrow hyperplasia of femur and decreased hemoglobin, hematocrit and mean corpuscular hemoglobin concentration. The LOAEL for repeated dose toxicity in rats was 22 mg/kg/day for both sexes. Acetanilide is not considered to be genotoxic. In a reproductive/developmental toxicity study, no treatment-related changes in precoital time and rate of copulation, impregnation, pregnancy were shown in all treated groups. The NOAELs for reproduction and developmental toxicity (off-spring toxicity) are considered to be 200 mg/kg bw/day and 67 mg/kg bw/day, respectively. Ecotoxicity data has been generated in a limited number of aquatic species of algae (72 hr- $E_{b}$ $C_{50}$; 13.5 mg/l), daphnid (48hr-E $C_{50}$ > 100 mg/l) and fish (Oryzias latipes, 96hr-L $C_{50}$; 100 mg/l). Form the acute toxicity values, the predicted no effect concentration (PNEC) of 0.135 mg/1 was derived win an assessment factor of 100. On the basis of these data, acetanilide was suggested as currently of low priority for further post-SIDS work in OECD.in OECD.D.

Synthesis and Anticonvulsant Evaluations of N-Cbz-$\alpha$-amino-N- alkoxyglutarimides

  • Kim, Min-Jeong;Byun, Ae-Sun;Choi, Jong-Won;Moon, Kyung-Ho;Lee, Chung-Kyu;Park, Min-Soo
    • Archives of Pharmacal Research
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    • v.27 no.2
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    • pp.151-155
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    • 2004
  • In our previous studies for the development of new anticonvulsant of broad spectrum, we found that N-cbz-$\alpha$-aminoglutarimides showed significant anticonvulsant activities of broad spectrum enough to be recommended for the new anticonvulsants and their anticonvulsant activities were dependent on their imide substituent groups. Based on these results, various N-cbz--$\alpha$-amino-N-alkoxyglutarimides, where the imide N-H was substituted with the hydroxy and alkoxy group, were prepared and evaluated for their anticonvulsant activities using the Maximal electroshock seizure (MES) and Pentylenetetrazole induced seizure (PTZ) tests and also the rotorod test. A series of (R) or (S)-N-cbz--$\alpha$-amino-N-alkoxyglutarimides could be prepared from the corresponding (R) or (S)-N-cbz-glutamic acid following the usual synthetic procedure. Among them, (R)-N-cbz--$\alpha$-amino-N-hydroxyglutarimide ($ED_{50}$=86.25 mg/kg) was most active in the MES test. In the case of the PTZ test, (R)-N-cbz--$\alpha$-amino-N-benzyloxyglutarimide ($ED_{50}$= 62.5 mg/kg) was most active. Among the tested compounds, 2a-c, 3a, and 3b showed anticonvulsant activities in the MES and PTZ test. All of the tested compounds, except 2f and 3f, showed significant anticonvulsant activities in the MES or PTZ test. In addition, the neurotoxicities of these compounds were comparable to other anticonvulsant drugs.

Synthesis and Rietveld Structure Refinement of Mn-Tourmalines (Tsilaisite) (Mn-전기석(Tsilaisite)의 합성 및 리트벨트 구조분석)

  • Grover John;Choi Jin-Beom
    • Journal of the Mineralogical Society of Korea
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    • v.19 no.1 s.47
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    • pp.15-29
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    • 2006
  • Synthetic Mn-tourmalines (tsilaisite) were obtained by hydrothermal synthesis under the condition of 2 Kbar, $375{\sim}700^{\circ}C$, and 50 day-run-time with complete substitution of Mg in dravite by Mn (Mn%=0, 25, 50, 75, and 100%). They are all 6 samples containing Mn-tourmaline with some amounts of albite, spessartine, rhodocrosite, phlogopite etc, showing different synthetic condition of temperature and Mn composition. Synthetic Mn-tourmalines are of site deficiency in X-site ($0.53{\sim}0.68$) more than that of natural ones (approx. $0.2{\sim}0.3$) and show Mn cations occupying Y-site less than expected with initial experiments, leading to failure in synthesis of end-member tsilaisite. Rietveld structural refinements reveal that $R_{wp}$ ($R_{p}/R_{exp}$) is in the range of 13.35 and 18.62%, $R_{B}$ and S (CofF) are $4.85{\sim}6.25%$ (S-18: 8.57%), $1.31{\sim}1.59$ (S-18: 1.81), respectively. Unit cell parameters (space group R3m, z=3) are ${\alpha}=15.8994\;{\AA}$ and $c=7.1846\;{\AA}$ in average (S-18: ${\alpha}=15.9491\;{\AA},\;c=7.1773\;{\AA}$). Average bond lengths of and are $2.67{\sim}2.69\;{\AA}$ (S-18: $2.65\;{\AA}$) and $2.00{\sim}2.02\;{\AA}$ (S-18: $1.96\;{\AA}$), respectively. Ditrigonality (${\delta}$) are in the range of 0.022 and 0.031 (S-18: 0.061), indicating degrading symmetry with increase of Mn content.

Inhibitory Effect on Melanogenesis of Radix Glycyrrhizae Water Extract (감초 물추출물의 멜라닌 형성 억제효과)

  • Mun Yeun Ja;Kim Jin;Lim Nan Young;Lee Seung Yon;Seop Gwak;Hwang Chung Yeon;Woo Won Hong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.16 no.6
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    • pp.1230-1235
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    • 2002
  • This study was conducted to evaluate the effects of Glycyrrhizae Radix water extract, known as depigmenting agent, on melanin biosynthesis in cellular level. The inhibitory effect of Glycyrrhizae Radix water extract on melanogenesis was identified by mushroom tyrosinase assay, To determine whether Glycyrrhizae Radix water extract suppress melanin synthesis in cellular level, B16 mouse melanoma cells were cultured in the presence of different concentrations of Glycyrrhizae Radix water extract. The maximum concentration of Glycyrrhizae Radix water extract that was not inhibitory to growth of the cells was 2 mg/ml. At that concentration, melanin synthesis was significantly inhibited without cytotoxicity after 5 days, compared with untreated cells. The treatment with Glycyrrhizae Radix water extract reduced tyrosinase and DOPAchrome tautomerase activity in a dose-dependent manner. These results suggest that the inhibitory effect of Glycyrrhizae Radix water extract on melanogenesis is due to the suppression of tyrosinase and DOPAchrome tautomerase activity.

Antioxidant and Skin Whitening Effects of Rhamnus yoshinoi Extracts (짝자래나무 추출물의 항산화 및 미백 효과)

  • Seo, Eun-Jong;Hong, Eun-Suk;Choi, Min-Hee;Kim, Ki-Sun;Lee, Sung-Jun
    • Korean Journal of Food Science and Technology
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    • v.42 no.6
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    • pp.750-754
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    • 2010
  • The purpose of this study was to investigate the antioxidant and skin whitening effects of Rhamnus yoshinoi extracts. Rhamnus yoshinoi was extracted with 100% ethanol and water. The antioxidative and skin whitening effects of extracts were determined by in vitro assays using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and inhibitory effects against tyrosinase activity and melanogenesis in B16F1 melanoma cells. The radical scavenging activities of the Rhamnus yoshinoi extracts were tested by DPPH assay and showed high DPPH radical scavenging activities (SC50; 21.6 ppm in EtOH, 40.5 ppm in water). As for tyrosinase inhibitory activity, the Rhamnus yoshinoi ethanol extract had the highest inhibition activity ($IC_{50}$; 256.3 ppm). In B16F1 mouse melanoma cells, the Rhamnus yoshinoi ethanol extract significantly inhibited melanin synthesis by 53.36% at the concentration of 50 ppm. These results suggest that Rhamnus yoshinoi ethanol extract has significant antioxidant activity and whitening activity.

Production and Application of Galacto-oligosaccharides from Lactose by a Recombinant $\beta$-Galactosidase of Bifidobacterium infantis Overproduced by Pichia pastoris

  • Jung, Sung-Je;Lee, Byong-Hoon
    • Food Science and Biotechnology
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    • v.17 no.3
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    • pp.514-518
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    • 2008
  • After overproduction of a recombinant $\beta$-galactosidase of Bifidobacterium infantis in Pichia pastoris, a synthesis of galacto-oligosaccharides (GOS) from 36% lactose using the enzyme (170.74 U/mg) was investigated. The transgalactosylation ratio reached up to 25.2% with 83.1% conversion of initial lactose and the maximum yield of GOS was 40.6%. The GOS syrup was composed of a 13.43% galacto-oligosaccharides, 5.06% lactose, and 8.76% monosaccharides. The prebiotic effect of GOS on the growth of bifidobacteria and lactobacilli strains was investigated in vitro. The maximum growth rate of Bifidobacterium breve and Lactobacillus acidophillus in GOS syrup (5%, v/v) media were 0.49 and 0.96/hr that are higher than those in 1%(w/v) galactose and 1%(w/v) lactose containing media. However, there was no significant difference between the specific growth rates of L. acidophillus in 1%(w/v) glucose and 5%(v/v) GOS syrup. Our data showed that GOS definitely promoted the growth of B. breve ATCC $15700^T$ and L. acidophilus ATCC 33323.

Dietary Niacin Supplementation Suppressed Hepatic Lipid Accumulation in Rabbits

  • Liu, Lei;Li, Chunyan;Fu, Chunyan;Li, Fuchang
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.12
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    • pp.1748-1755
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    • 2016
  • An experiment was conducted to investigate the effect of niacin supplementation on hepatic lipid metabolism in rabbits. Rex Rabbits (90 d, n = 32) were allocated to two equal treatment groups: Fed basal diet (control) or fed basal diet with additional 200 mg/kg niacin supplementation (niacin). The results show that niacin significantly increased the levels of plasma adiponectin, hepatic apoprotein B and hepatic leptin receptors mRNA (p<0.05), but significantly decreased the hepatic fatty acid synthase activity and adiponectin receptor 2, insulin receptor and acetyl-CoA carboxylase mRNA levels (p<0.05). Plasma insulin had a decreasing tendency in the niacin treatment group compared with control (p = 0.067). Plasma very low density lipoproteins, leptin levels and the hepatic adiponectin receptor 1 and carnitine palmitoyl transferase 1 genes expression were not significantly altered with niacin addition to the diet (p>0.05). However, niacin treatment significantly inhibited the hepatocytes lipid accumulation compared with the control group (p<0.05). In conclusion, niacin treatment can decrease hepatic fatty acids synthesis, but does not alter fatty acids oxidation and triacylglycerol export. And this whole process attenuates lipid accumulation in liver. Besides, the hormones of insulin, leptin and adiponectin are associated with the regulation of niacin in hepatic lipid metabolism in rabbits.

Synthesis and characterization of α-mangostin imprinted polymers and its application for solid phase extraction

  • Zakia, Neena;Zulfikar, Muhammad A.;Amran, Muhammad B.
    • Advances in materials Research
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    • v.9 no.4
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    • pp.251-263
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    • 2020
  • α-mangostin imprinted polymers have been synthesized by a non-covalent imprinting approach with α-mangostin as a template molecule. The α-mangostin molecularly imprinted polymers (MIPs) prepared by radical polymerization using methacrylic acid, ethlylene glycol dimethacrylate, benzoyl peroxide, and acetonitrile, as a monomer, crosslinker, initiator, and porogen, respectively. The template was removed by using methanol:acetic acid 90:10 (v/v). The physical characteristics of the polymers were investigated by Fourier Transform Infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The rebinding studies were carried out by batch methods. The results exhibited that the MIPs was able to adsorb the α-mangostin at pH 2 and the contact time of 180 min. The kinetic adsorption data of α-mangostin performed the pseudo-second order model and followed the Langmuir isotherm model with the adsorption capacity of 16.19 mg·g-1. MIPs applied as a sorbent material in solid-phase extraction, namely molecularly imprinted solid-phase extraction (MISPE) and it shows the ability for enrichment and clean-up of α-mangostin from the complex matrix in medicinal herbal product and crude extract of mangosteen (Garcinia mangostana L.) pericarp. Both samples, respectively, which were spiked with α-mangostin gives recovery more than 90% after through by MISPE in all concentration ranges.

Skin Regeneration, Anti-wrinkle, Whitening and Moisturizing Effects of Cheongsangbangpung-tang Aqueous Extracts with Cytotoxicity (청상방풍탕 열수 추출물의 피부재생, 주름개선, 미백, 보습 효과 및 세포독성 평가)

  • Woo, Chang-Yoon;Kim, Dong-Chul
    • The Journal of Korean Obstetrics and Gynecology
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    • v.30 no.2
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    • pp.49-70
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    • 2017
  • Objectives: The present study is to observe the skin-regeneration, anti-wrinkle, whitening and skin moisturizing effects of Cheongsangbangpung-tang (CSBPT) with cytotoxicity. Methods: In the present study, cytotoxicity of CSBPT lyophilized aqueous extracts (yield=18.71%) was experimented against human normal fibroblast cells and B16F10 murine melanoma cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide (MTT) assay, and skin regeneration and anti-wrinkle effects were also showed through the assay of collagen type I synthesis by an enzyme immunoassay (EIA) kit as comparing with transforming growth factor (TGF)-${\beta}1$, hyaluronidase, collagenase and matrix metalloproteinase (MMP)-1 inhibitory assays as comparing with oleanolic acid (OA), and elastase inhibitory effects as comparing with phosphoramidon disodium salt (PP). In addition, whitening effects of CSBPT were observed by tyrosinase inhibitory assay and melanin formation test in B16/F10 melanoma cells as comparing with arbutin, and skin moisturizing effects were measured through mouse skin water contents test, respectively. Results: No CSBPT treatment related cytotoxic effects were demonstrated against human normal fibroblast cells and B16/F10 murine melanoma cells. CSBPT concentration-dependent increased collagen type I synthesis at human normal fibroblast cells. It also effectively suspreessed hyaluronidase, collagenase, elastase and MMP-1 activities, which were enzymes that related to declining of ECM and formation of wrinkle. CSBPT supressed B16/F10 melanoma cells's melanin productions with tyrosinase activity, which was an enzyme connected with melanin formation, and dose-dependent and significant increases of skin water contents were detected in CSBPT treated mouse skin as compared with vehicle control skins. Conclusions: CSBPT showed favorable and enough skin regeneration, anti-wrinkle, whitening and skin moisturizing effects at least in a condition of this experiment. However, more detail mechanism and in vivo skin protective efficacy studies should be conducted in future with the screening of the biological active compounds in individual herbs of Cheongsangbangpung-tang.

Inhibitory Effect of Bee Venom on Lipopolysaccharide-induced Memorial Impairment and Acetylcholine Esterase, Secretase Activity

  • Kwon, Dae-Hyun;Song, Ho-Sueb
    • Journal of Acupuncture Research
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    • v.23 no.2
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    • pp.33-46
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    • 2006
  • Alzheimer's disease (AD) is the most prevalent form of neurodegenerative disease associated with aging in the human population. This disease is characterized by the extracellular deposition of beta-amyloid peptide $(A{\beta})$ in cerebral plaques. $A{\beta}$ is derived from the ${\beta}-amyloid$ precursor protein (APP) by the enzymes, ${\beta}-$ and ${\eta}o-secretase$. Compounds that ${\beta}-$ or ${\eta}o-secretase$ inhibit activity, can reduce the production of $A{\beta}$ peptides, and thus have therapeutic potential in the treatment of AD. Increasing body of evidence has been demonstrated that Bee Venom(BV) Acupuncture could compete with complex protein involving in multiple step of $NF-{\kappa}B$ activation and exert the anti-inflammatory potential of combined inhibition of the prostanoid and nitric oxide synthesis systems by inhibition of IKK and $NF-{\kappa}B$. In this study, I investigated possible effects of BV on memory dysfunction caused by lipopolysaccharide (LPS) and $A{\beta}$ through inhibition of secretases activities and $A{\beta}$ aggregation. I examined the improving effect of BV on the LPS (2.5 mg/Kg, i.p.)-induced memory dysfunction using passive avoidance response and water maze tests in the mice. BV (0.84, $1.67\;{\mu}g/ml$) reversed the LPS-induced memorial dysfunction in dose dependent manner. BV also dose-dependently attenuated LPS-induced ${\beta}$ and ${\eta}o-secretase$ activities in cerebral cortex and hippocampus of the mice brain. This study therefore suggests that BV acupuncture method may be useful for prevention of development or progression of AD.

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