• Bulletin of the Korean Chemical Society
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• 제21권12호
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• pp.1251-1253
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• 2000

• YAKHAK HOEJI
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• 제55권6호
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• pp.478-484
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• 2011

Non-alcoholic fatty liver disease is known to be frequently associated with obesity and type 2 diabetes. We examined the effects of EtOH extracts from Triticum aestivum on lipid accumulation during the differentiation of 3T3-L1 preadipocytes to screening the candidate materials in preventing non-alcoholic fatty liver disease. The lipid level in adipocytes was determined by Oil Red O staining. The treatment of 50% ethanol, but not water and 100% ethanol extracts, from Triticum aestivum at concentration of 0.5 $mg/ml$ inhibited lipid accumulation in 3T3-L1 cells, revealing no cell toxicity. Thus, the fractions of $CH_2Cl_2$, EtOAc and BuOH were separated from 50% EtOH extract to characterize anti-adipogenic effect. The $CH_2Cl_2$ fraction at concentration of $50{\mu}g/ml$ effectively inhibited the lipid accumulation in the adipocytes compared to those of EtOAc and BuOH at concentration of $50{\mu}g/ml$. The intracellular triglyceride accumulation also was significantly reduced by treatment of $CH_2Cl_2$ fraction in concentration-dependent manner. Western blot analysis showed that the $CH_2Cl_2$ fraction attenuated the intracelluar level of fatty acid synthase(FAS) accompanied by attenuated expression of Peroxidase proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$) adipogenic transcription factor. These results suggest that $CH_2Cl_2$ fraction from 50% EtOH extract of Triticum aestivum may has the potent anti-adipogenic effects by inhibiting the transactivation of $PPAR{\gamma}$.

• Journal of the Korean Chemical Society
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• 제38권10호
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• pp.719-725
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• 1994

Kinetic studies were carried out for substitution reaction of $cis-[Co(NH_3)_4Cl(OH_2)]^{2+}(\mu$ = 0.75) with GlyOR (R = $C_2H_5$, $CH_3$, H) in pH 5 buffer solution at $20^{\circ}C$ by UV/Vis-spectrophotometry. We obtained cis-[Co$(NH_3)_4$Cl(glyOR)]$^{2+}$ as product. The reaction turns out to be first order for Co(III) and GlyOR, respectively. The rate constants are obtained as 9.21, 11.66 and 15.33 l${\cdot}\;mol^{-1}{\cdot}sec^{-1}$ for GlyOEt, GlyOMt and GlyOH, respectively. The activation parameters $E_a,\;{\Delta}H^{\neq}\;and\;{\Delta}S^{\neq}$ for GlyOEt were obtained as 65.77, 63.35 kJ/mol and -53.51(e.u.), respectively and were obtained as 70.91, 68.50 kJ/mol and -38.42(e.u.) for GlyOMt. In case of GlyOH, respectable values of 79.72, 77.30 kJ/mol and -26.59(e.u.) were obtained. On the basis of kinetic data and the observed activation parameters, we propose that the proper mechanism involves $S_N$2 step.

• Journal of the Korean Chemical Society
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• 제43권4호
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• pp.393-400
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• 1999

Dendritic carbosilanes based on hyperbranched polycarbosilanes as core molecule have been prepared The core molecules were obtained by the use of hydrosilation of $HSiMe_{3-n}$$(CH_2CH=CH_2)_n$(n=2; $AB_2$,3;$AB_3$type). The hyperbranched core $AB_2\;and\; AB_3$ type polymers were generated to higher molecular dendritic carbosilanes Gn+1 by the use of hydrosilation and alkenylation sequence. The Gn+2P generations were not obtained as unified molecules by the use of hydrosilation with $HSiMeCl_2$. Gn and Gn+1 type polymers were produced to polysilol by the reaction of 9-BBN and alkali medium oxidation of hydroborated compounds. The degree for reaction has been controlled by the NMR spectroscopy.

• Journal of the Korean Chemical Society
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• 제34권3호
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• pp.260-266
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• 1990

The electrochemical behavior of N-methyl-2-amino-l-cyclopentene-l-dithiocarboxylic acid $(N-CH_3 acdc) and 2-amino-l-cyclopentene-l-dithiomethyl ester (S-CH_3 acdc) in DMF have been investigated by the use of polarography, cyclic voltammetry and coulometry. The dimer of N-CH_3 acdc is further oxidized at +0.98 V via 2-electron process to produce free sulfur atom and cyclization product. The ring formation between two dithio group occurs along with the elimination of one sulfur atom. The elimination of sulfur atom occurs via two electron oxidation process at + 0.98 V vs. Ag/AgCl electrode. However, the cyclization does not occur in the S-CH_3$ acdc.

• Journal of ILASS-Korea
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• 제6권3호
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• pp.1-7
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• 2001

In this study, quantitative measurement of nitric oxide concentration distributions visualization were investigated in the laminar $CH_4/O_2N_2$ nixed flame by Planar laser-induced fluorescence(PLIF). The NO A-X (0,0) vibrational band around 226nm was excited using a XeCl excimer-pumped dye laser. Selecting an appropriate NO transition minimizes interference from Rayleigh scattering and $O_2$ fluorescence. The measurements were taken in $CH_4/O_2N_2$ premixed flame with equivalence ratios varying from $1.0{\sim}1.6$, and a fixed flow rate of 3slpm. NO was found to produce primarily between an inner premixed and an outer nonpremixed flame front, and total NO concentration is raised when equivalence ratios increase. These results suggest that prompt NO is likely to contribute to MO formation in $CH_4/O_2N_2$ premixed flame. Furthermore, this trend was well matched with previous works.

• Nutrition Research and Practice
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• 제8권5호
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• pp.509-515
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• 2014

BACKGROUND/OBJECTIVES: The root of Vitis amurensis Ruprecht, a sort of wild-growing grape, has been used in oriental medicine for treatment of skin ailments; however, its dermatological activity is not sufficiently understood. The aim of this study was to investigate tyrosinase inhibitory and anti-melanogenic activities of V. amurensis Ruprecht root methanol extract (VARM) in B16F10 mouse melanoma cells and to attempt to isolate and identify the active compound issued from VARM. MATERIALS/METHODS: Anti-melanogenic activity of VARM was analyzed in ${\alpha}$-melanocyte stimulating hormone (MSH)-stimulated B16F10 cells through evaluation of antioxidative activity as well as inhibited tyrosinase activity and melanin contents compared with those of kojic acid and arbutin. After anti-melanogenic analysis of VARM, serial fractionation, nuclear magnetic resonance (NMR), and thin layer chromatorgraphy (TLC) were applied for identification of active compounds contained in VARM. RESULTS: VARM significantly inhibited oxidative stress and tyrosinase activity and attenuated ${\alpha}$-MSH-induced melanin production in B16F10 cells. For isolation of active compounds, VARM was fractionated using a series of organic solvents, including dichloromethane ($CH_2Cl_2$), ethyl acetate (EtOAc), and n-butanol (n-BuOH). Among fractions showing anti-melanogenic activity, the CH2Cl2 fraction induced the most potent attenuation of melanogenesis without cytotoxicity and the major compound in the $CH_2Cl_2$ fraction was identified as betulinic acid. Betulinic acid isolated from the $CH_2Cl_2$ fraction of VARM significantly attenuated ${\alpha}$-MSH-induced melanogenesis in a dose dependent manner, which was stronger than that of arbutin used as a positive control. CONCLUSIONS: These results indicate that VARM inhibits oxidative stress, tyrosinase activity, and ${\alpha}$-MSH-induced melanogenesis in B16F10 cells, due primarily to the active compound, betulinic acid, in the $CH_2Cl_2$ fraction.

• Journal of Environmental Science International
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• 제18권7호
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• pp.735-746
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• 2009

Hydrochloric acid salt of a new $N_2O_3$ pentadentate ligand, N,N'-Bis(2-Hydroxybenzyl)-1,3-diamino-2-propanol(H-BHDP 2HCl) was synthesized. Br-BHDP 2HCl, CI-BHDP 2HCl, $CH_3-BHDP$ 2HCl and $CH_3O$-BHDP 2HCl having Br, Cl, $CH_3$ and $CH_3O$ substituents at 5-position of the phenol group of H-BHDP 2HCl were also synthesized. The potentiometry study in aqueous solution revealed that the proton dissociations of the synthesized ligands occurred in four steps and their order of the calculated overall proton dissociation constants($log{\beta}_p$) was Br-BHDP < Cl-BHDP < H-BHDP < $CH_3O-BHDP$ < $CH_3-BHDP$. The order showed a similar trend to that of Hammett substituent constants(${\delta}_p$). The order of the stability constants($logK_{ML}$) was Co(II) < Ni(II) < Cu(II) < Zn(II) < Cd(II) < Pb(II). The order in their stability constants ($logK_{ML}$) of each transition metal complex agreed with that of the overall proton dissociation constants ($log{\beta}_p$).

• Journal of the Korean Chemical Society
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• 제25권5호
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• pp.311-317
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• 1981

A new nickel(II) compound, $Ni(CH_2SiMe_3)_2((C_6H_5)_2PCH_2CH_2P(C_6H_5)_2)$, 1, has been prepared by the reaction of $NiCl_2((C_6H_5)_2PCH_2CH_2P(C_6H_5)_2)$ with $Me_3SiCH_2Li$. The compound, 1, is stable under nitrogen at room temperature both in solution and in the solid state. Thermal decomposition of 1 in solution or in the solid produces the reductive coupling product, $Me_3SiCH_2CH_2SiMe_3$ which is also afforded by the reactions of 1 with CO and $O_2$ at room temperature, and with $(C_6H_5)_2PCH_2CH_2P(C_6H_5)_2$ at 80${\circ}$C.

• Food Science and Preservation
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• 제22권3호
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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.