• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2251-2255
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• 2013

Second-order rate constants ($k_{HOO^-}$) for the nucleophilic substitution reactions of Y-substituted-phenyl diphenylphosphinates (4a-4i) with $HOO^-$ in $H_2O$ have been measured spectrophotometrically. The ${\alpha}$-nucleophile $HOO^-$ is 10-70 times more reactive than the reference nucleophile $OH^-$ although the former is ca. $4pK_a$ units less basic than the latter, indicating the ${\alpha}$-effect is operative. The Bronsted-type plot for the reactions of 4a-4i with $HOO^-$ is linear with ${\beta}_{lg}=-0.51$, a typical ${\beta}_{lg}$ value for reactions which were reported to proceed through a concerted mechanism. The Yukawa-Tsuno plot is also linear with ${\rho}=1.40$ and r = 0.47, indicating that a negative charge develops partially on the O atom of the leaving group, which can be delocalized to the substituent Y through resonance interactions. Thus, the reactions have been proposed to proceed through a concerted mechanism. The magnitude of the ${\alpha}$-effect (i.e., the $k_{HOO^-}/k_{HO^-}$ ratio) decreases linearly as the leaving-group basicity increases. It has been concluded that solvation effect is not solely responsible for the ${\alpha}$-effect found in this study but the transition-state stabilization through an intramolecular H-bonding interaction is also responsible for the ${\alpha}$-effect.

• Journal of Microbiology and Biotechnology
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• 제18권12호
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• pp.1975-1983
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• 2008

The neuropeptide ${\alpha}$-melanocyte-stimulating hormone (${\alpha}$-MSH) has anti-inflammatory property by down regulating the expressions of proinflammatory cytokines. Because ${\alpha}$-MSH elicits the anti-inflammatory effect in various inflammatory disease models, we examined the therapeutic effect of oral administration of recombinant Lactobacillus casei, which secretes ${\alpha}$-MSH (L. casei-${\alpha}$-MSH), on dextran sulfate sodium (DSS)-induced colitis in Balb/c mice. Thus, we constructed the ${\alpha}$-MSH-secreting Lactobacillus casei by the basic plasmid, pLUAT-ss, which was composed of a PldhUTLS promoter and ${\alpha}$-amylase signal sequence from Streptococcus bovis strain. Acute colitis was induced by oral administration of 5% DSS in drinking water for 7 days. To investigate the effect of L. casei-${\alpha}$-MSH on the colitis, L. casei or L. casei-${\alpha}$-MSH was orally administered for 7 days and their effects on body weight, mortality rate, cytokine production, and tissue myeloperoxidase (MPO) activity were observed. Administration of L. casei-${\alpha}$-MSH reduced the symptom of acute colitis as assessed by body weight loss (DSS alone: $14.45{\pm}0.2\;g$; L. casei-${\alpha}$-MSH: $18.2{\pm}0.12\;g$), colitis score (DSS alone: $3.6{\pm}0.4$; L. casei-${\alpha}$-MSH: $1.4{\pm}0.6$), MPO activity (DSS alone: $42.7{\pm}4.5\;U/g$; L. casei-${\alpha}$-MSH: $10.25{\pm}0.5\;U/g$), survival rate, and histological damage compared with the DSS alone mice. L. casei-${\alpha}$-MSH-administered entire colon showed reduced in vitro production of proinflammatory cytokines and $NF-{\kappa}B$ activation. The ${\alpha}$-MSH-secreting recombinant L. casei showed significant anti-inflammatory effects in the murine model of acute colitis and suggests a potential therapeutic role for this agent in clinical inflammatory bowel diseases.

• Bulletin of the Korean Chemical Society
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• 제34권1호
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• pp.49-53
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• 2013

Second-order rate constants have been measured spectrophotometrically for the reactions of phenyl Y-substituted-phenyl carbonates 7a-g with butane-2,3-dione monoximate ($Ox^-$) in 80 mol % $H_2O$/20 mol % DMSO at $25.0{\pm}0.1^{\circ}C$. The ${\alpha}$-nucleophile $Ox^-$ is 53-95 times more reactive than the corresponding normal-nucleophile 4-$ClPhO^-$ toward 7a-g, indicating that the ${\alpha}$-effect is operative. The magnitude of the ${\alpha}$-effect (e.g., the $k_{Ox^-}/k_{4-ClPhO^-}$ ratio) is independent of the electronic nature of the substituent Y. The cause of the ${\alpha}$-effect for the reactions of 7a-g has been suggested to be ground-state (GS) effect rather than transition-state (TS) stabilization through a six-membered cyclic TS, in which $Ox^-$ behaves a general acid/base catalyst. This idea is further supported by the result that $OH^-$ exhibits negative deviation from the linear Br${\o}$nsted-type plot composed of a series of aryloxides, while $Ox^-$ deviates positively from the linearity. Differential solvation of the GS of $Ox^-$ and 4-$ClPhO^-$ has been suggested to be responsible for the ${\alpha}$-effect exerted by $Ox^-$.

• Journal of Nutrition and Health
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• 제23권2호
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• pp.108-114
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• 1990

The concentrations of $\alpha$-tocopherol in the brain, liver, and serum were studied with and without saponification process between control and vitamin E supplemented rats. Young rats, 80-120g body weight, were fed control and vitamin E supplemented diets, ad libitum, for four weeks. $\alpha$-Tocopherol concentrations were determined by high pressure liquid chromatography. The $\alpha$-tocopherol concentration per wet weight base in the brain tissue was significantly lower than that in the liver. Vitamin E supplementation had no effect on brain $\alpha$-tocopherol levels in contrast to the significant increase in lover $\alpha$-tocopherol concentration with and without saponification is significantly greater in the brain than in the liver or serum. Further study is needed to clarify the nature of interaction or /and binding between $\alpha$-tocopherol and the complex membrane system in brain tissue. It can be speculated from this and other studies that the metabolism and the nature of interaction of $\alpha$-tocopherol with the complex membrane system in brain tissue rich in polyunsaturated fatty acids seems different from that in liver tissue or serum.

• Journal of Ginseng Research
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• 제8권2호
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• pp.75-81
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• 1984

The effect of the saponin fraction extracted from Panax ginseng C.A. Meyer on the absorption of ${\alpha}$-tocopherol in rat has been investigated and realized that the saponin fraction stimulated not only the absorption of ${\alpha}$-tocopherol (1.5-2 times that of control) but also its transport and excretion. ${\alpha}$-tocopherol is known to be transported mainly in the form of ${\beta}$-lipoprotein but the present study showed that the ${\alpha}$-tocopherol was transported in the form of albumin bound or micellar structure as well.

• The Korean Journal of Physiology and Pharmacology
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• 제20권4호
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• pp.347-355
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• 2016

Cryptotanshinone (CPT) is a natural compound isolated from traditional Chinese medicine Salvia miltiorrhiza Bunge. In the present study, the regulatory effect and potential mechanisms of CPT on tumor necrosis factor alpha ($TNF-{\alpha}$) induced lectin-like receptor for oxidized low density lipoprotein (LOX-1) were investigated. Human umbilical vein endothelial cells (HUVECs) were cultured and the effect of $TNF-{\alpha}$ on LOX-1 expression at mRNA and protein levels was determined by Real-time PCR and Western blotting respectively. The formation of intracellular ROS was determined with fluorescence probe $CM-DCFH_2-DA$. The endothelial ox-LDL uptake was evaluated with DiI-ox-LDL. The effect of CPT on LOX-1 expression was also evaluated with SD rats. $TNF-{\alpha}$ induced LOX-1 expression in a dose- and time- dependent manner in endothelial cells. $TNF-{\alpha}$ induced ROS formation, phosphorylation of $NF-{\kappa}B$ p65 and ERK, and LOX-1 expression, which were suppressed by rotenone, DPI, NAC, and CPT. $NF-{\kappa}B$ inhibitor BAY11-7082 and ERK inhibitor PD98059 inhibited $TNF-{\alpha}-induced$ LOX-1 expression. CPT and NAC suppressed $TNF-{\alpha}-induced$ LOX-1 expression and phosphorylation of $NF-{\kappa}B$ p65 and ERK in rat aorta. These data suggested that $TNF-{\alpha}$ induced LOX-1 expression via ROS activated $NF-{\kappa}B/ERK$ pathway, which could be inhibited by CPT. This study provides new insights for the anti-atherosclerotic effect of CPT.

• 대한의생명과학회지
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• 제18권4호
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• pp.329-337
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• 2012

${\alpha}$-synuclein (${\alpha}$-syn) is known to be implicated in the pathogenesis of Parkinson's disease and transiently bind to biological vesicles. In this study, we examined the effect of molecular crowding on the interaction of ${\alpha}$-syn with biological vesicles by using inert polymers since the environment of proteins in cells are crowded with other macromolecules. The addition of different polymers including polyethylene glycol, dextran, and ficoll enhanced the binding of ${\alpha}$-syn to vesicles in a concentration-dependent manner and the association of ${\alpha}$-syn with vesicle was proportionally augmented by increased expression of ${\alpha}$-syn. However, molecular crowding had a neglectable effect on the vesicle binding of ${\alpha}$-syn mutants (A30P, TG6), which has been reported to show impaired vesicle binding capacity. These results suggest that transient interaction of ${\alpha}$-syn with vesicles occurs more commonly in cells than expected implying interaction with vesicles may be one of the physiological processes in which ${\alpha}$-syn is involved.

• 대한가정학회지
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• 제19권2호
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• pp.183-188
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• 1981

This study was conducted to investigate the effects of synthetic antioxidants con the degradation of angiotensin II which is made up of 8 amino acids: Asp-Arg-Val-Try-Ile-Gly-Pro-Phe, by the $\alpha$-chymotrypsin and trypsin. the results obtained were as follow; 1. Dibutyl hydroxytoluene, butyl hydroxyanisole and sodium L-ascorbate showed no inhibitory effect on the activity of $\alpha$-chymotrypsin on the angiotensin II, but ethyl protocathechuate inhibited. its activity at the concentration of 100ppm. However, the angiotension II was gradually degradated by $\alpha$-chymotrypsin after one hour incubation with ethylprotecathechuate. 2. Butyl hydroxyanisole inhibited trypsin activities above 100ppm, but no inhibitory activities was observed by the other antioxidants used in this experiment.

• 한국가축번식학회지
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• 제7권1호
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• pp.3-14
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• 1983

Estrus was induced and the therapeutic effect was examined with 25mg of PGF2$\alpha$ intramuscular injection and 3mg of PGF2$\alpha$ intraovarian injection to Holstein and Simmental cows which were raised in the large size stockfarms and the dairy farms, and were diagnosed to anestrus. The results obtained were summarized as follows: 1. The estrus inducing effect observed in the cows treated by PGF2$\alpha$ was 83.3% with 25/30 heads in the intramuscular injection group, and 86.7% with 26/30 heads in the intraovarian injection group. 2. Average duration from PGF2$\alpha$ administration to the onest of estrus was 2.7 day in the intramuscular injection group, and 2.6 days in the intraovarian injection group. 3. In status of estrus in the cows treated by PGF2$\alpha$, vigorous estrus was 12.0%, normal estrus 60.0% and silent estrus was 28.0% in the intramuscular injection group, and vigorous estrus was 15.4%, normal estrus 61.5%, and silent estrus 23.1% in the intraovarian injection group. 4. Conception rate in the cows induced to estrus was 64.0% in the intramuscular injection group and 65.4% in the intraovarian injection group.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.213.1-213.1
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• 2003

Alpha-viniferin was isolated from Carex humilis (Cyperaceae), and showed anti-inflammatory effects on carrageenin or histamine-induced paw edema in mice. To understand mode of the anti-inflammatory action. effects of alpha-viniferin on cyclooxygenase (COX)-2, iNOS, oxygen radicals and proinflammatory cytokines have been analyzed. Alpha-viniferin showed selective inhibitory effect with an IC50 value of 5 $\mu\textrm{m}$ on COX-2 activity but showed weak inhibitory effect on the synthesis of COX-2 transcript which was identified by RT-PCR. (omitted)