• Archives of Pharmacal Research
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• v.28 no.2
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• pp.172-176
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• 2005

Phytochemical investigation of the whole plant of Amberboa ramosa led to the isolation of six sesquiterpene lactones which could be identified as $8{\alpha}$-hydroxy-$11{\beta}$-methyl-$1{\alpha}H,\;5{\alpha}H,\;6{\beta}H,\;7{\alpha}H,\;11{\alpha}H-guai-10(14)$, 4(15)-dien-6, 12-olide(2), $3{\beta},\;8{\alpha}-dihydroxy-11{\alpha}-methyl-1{\alpha}H,\;5{\alpha}H,\;6{\beta}H,\;7{\alpha}H,\;11{\beta}H-guai-10(14)$, 4(15)-dien-6, 12-olide (2), $3{\beta},\;4{\alpha},\;8{\alpha}-trihydroxy-4{\beta}(hydroxymethyl)-1{\alpha}H,\;5{\alpha}H,\;6{\beta}H,\;7{\alpha}H-guai-10(14)$, 11(13)-dien-6, 12-olide (3), $3{\beta},\;4{\alpha},\;8{\alpha}-trihydroxy-4{\beta}-(chloromethyl)-1{\alpha}H,\;5{\alpha}H,\;6{\beta}H,\;7{\alpha}H-guai-10(14)$, 11(13)-dien-6, 12-olide(4), $3{\beta},\;4{\alpha},\;dihydroxy-4{\beta}-(hydroxymethyl)-1{\alpha}H,\;5{\alpha}H,\;6{\beta}H,\;7{\alpha}H-guai-10(14)$, 11(13)-dien-6, 12-olide(5), $3{\beta},\;4{\alpha}-dihydroxy-4{\beta}-(chloromethyl)-8{\alpha}-(4-hydroxymethacrylate)-1{\alpha}H,\;5{\alpha}H,\;6{\beta}H,\;7{\alpha}H-guai-10(14)$, 11(13)-dien-6, 12-olide (6) by spectroscopic methods. All of them showed inhibitory potential against butyrylcholinesterase.

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.647-654
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• 1992

In order to study the physiological properties of the intestinal bacteria, we isolated the intestinal bacteria of Koreans and tested the enzymatic patterns. Isolated Bifidobacterium sp. Int-57 had the higher activity of $\alpha$-glucosidase, $\beta$-glucosidase, $\alpha$-galactosidase, $\beta$-galactosidase. $\beta$-xylosidase and $\alpha$-arabinofuranosidase than other intestinal microorganisms. The effect of the carbon sources on the production of each enzymes of Bijidobacterium sp. Int-57 was investigated. The most suitable carbon source for the production of $\beta$-glucosidase was maltose, for a-glucosidase cellobiose, for $\alpha$-galactosidase raffinose, for $\beta$-galactosidase lactose, and for $\beta$-xylosidase and $\alpha$-arabinofuranosidase xylose, respectively. In addition, we investigated the optimal conditions and pH stability of each crude enzymes. The optimal condition of a-glucosidase was pH 6.0 and $40^{\circ}C$. that of Jj-glucosidase pH 7.0 and 50oe, that of $\beta$-galactosidase pH 7.0 and $50^{\circ}C$, that of $\beta$-xylosidase pH 6.0 and $40^{\circ}C$ , and that of $\alpha$-arabinofuranosidase pH 5.0 and $50^{\circ}C$. respectively. a-Glucosidase was stable at pH 4.0-9.0. Jj-glucosidase at pH 4.0-7.0. $\beta$-galactosidase at pH 4.0-9.0, $\beta$-xylosidase at pH 4.0-6.0, and /3-arabinofuranosidase at pH 7.0-9.0, respectively.

• Journal of the Korean Chemical Society
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• v.17 no.4
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• pp.269-274
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• 1973

The rate constants of the hydrolysis of ${\alpha}$-Cyano-${\beta}$-piperonylacrylic acid were determined by Ultraviolet spectrophotometry at various pH and a rate equation which can be applied over wide pH range was obtained. The reaction mechanism of hydrolysis of ${\alpha}$-Cyano-${\beta}$-piperonylic acid and especially the catalytic contribution of hydroxide ion which not studied carefully before in acidic media, can be fully explained by the rate equation obtained. The rate equation reveals that; below pH 4.0, the reaction is initiated by the addition of water molecule to ${\alpha}$-Cyano-${\beta}$-piperonyl acrylic acid. At pH $5.0{\sim}7.5$, ${\alpha}$-Cyano-${\beta}$-piperonylacrylic acid compete with ${\alpha}$-Cyano-${\beta}$-piperonyl acrylate ion in adding of water. At pH 8.0, water is the only nucleophile for ${\alpha}$-Cyano-${\beta}$-piperonylacrylate ion, however, above pH 12.0, hydroxide ion is an addendum and the accepter is ${\alpha}$-Cyano-${\beta}$-piperonylacrylate ion.

• The Korean Journal of Pharmacology
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• v.27 no.2
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• pp.119-123
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• 1991

${\beta}-Adrenoceptor$ binding study of ${\beta}-agonist$ ((-)NE), ${\beta}-antagonists$ $(({\pm})\;propranolol,\;labetalol)$ and PDE inhibitors (imazodan, KR-30045, KR-30075 etc.) was performed using $(-)-[^3H]-DHA$, as a $non-{\beta}_1/{\beta}_2$ selective radioligand. In saturation studies, $K_d$ and $B_{max}$ of $(-)-[^3H]-DHA$ to ${\beta}-adrenoceptors$ in rat left ventricle in which both ${\beta}_1$ and ${\beta}_2$ receptors coexist were determined to be $1.5{\pm}0.43\;nM$ and $22.0{\pm}0.9\;fmol/mg$ protein, respectively. $({\pm})Propranolol$, labetalol and (-)NE competed for $(-)-[^3H]-DHA$ binding sites in an essentialy monophasic manner with $Ki=17.0{\pm}0.40\;nM,\;57.3{\pm}1.30\;nM,\;and\;1.57{\pm}0.95\;{\mu}M$, respectively. All of PDE inhibitors inhibited the $(-)-[^3H]-DHA$ binding by only below 10% even at the high concentration of $10^{-3}M$. The present results suggest that propranolol, labetalol and NE are $non-{\beta}_1/{\beta}_2$ selective antagonists and agonist, respectively. Additionally, this study shows that imazodan and new synthesized PDE inhibitors may hardly have the affinities to ${\beta}-adrenoceptors$ in cardiac muscle.

• Journal of Biomedical Engineering Research
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• v.16 no.3
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• pp.257-264
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• 1995

The $\beta$-chitin derivatives were synthesized by reacting $\beta$-chitin with chloropropane, propyleneoxide and chloropropane diol to form propyl chitin (PPC), hydroxypropyl chitin (HPC) and dihydroxypropyl chitin (DHPC), respectively. Cast films from $\beta$-chitin and $\beta$-chitin derivatives solutions degraded by Iyrozyme in pseudo-extrra cellular fluid (PECF) solutions, at pH1.2, pH6.7 and pH8.2. Chitin derivatives rapidly degraded compared with virgin $\beta$-chitin within the first week. DHPC showed the best biodegradation among these derivatives.

• Journal of Astronomy and Space Sciences
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• v.11 no.2
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• pp.208-231
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• 1994

We have undertaken CCD observations of fie이 standard stars with H$\beta$ photometric system to investigate the reliability of H$\beta$ CCD photometry. Flat fielding with dome flat and sky flat for H$\beta$w and H$\beta$n filter was compared with that of B filter in UBV system and, from these, we have not found any difference. It was confirmed that there is a good linear relationship between our H$\beta$ values observed with 2.3m reflector and standard values. However, H$\beta$ values observed with 60cm reflector at Sobaeksan Astronomy Observatory showed very poor relationship. To investigate the accuracy of H$\beta$ CCD photometry for fainter objects, open cluster NGC2437 was observed and reduced with DoPHOT, and the results were compared with those for photoelectric photometry of Stetson(1981).

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.507-513
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• 1996

Three sesquiterpene lactone compounds, two novel(1.betha.,3.betha.-dihydroxy-6.betha.,11.betha.,4.alpha.,5.alpha.,7.alpha.H -eudesm-12, 6-olide-1-O-.betha.-D-glucopyranoside, 1.betha.,3.betha.-dihydroxy-6.betha.,11.betha.,4.alpha.,5.alpha.,7.alpha.H-eudes m-12,6-olide-1-O-.betha.-D-glucopyranoside) and 1.betha.,3.betha.-dihydroxy-6.betha.,11.betha.,4.alpha.,5.alpha., 7.alpha.H-eudesm-12,6-olide were isolated from the aqueous fraction of MeOH extract of the roots from Taraxacum hallaisanensis (Compositae) employing Amberlite XAD-2, ODS-gel, silica gel and Sephadex LH-20 column chromatographics. Another known compound, (-)-epicatechin, was isolated from the aqueous fraction of the MeOH extract. The total MeOH extract also contained phytosterol and a mixture of .betha.-amyrin acetate, .alpha.-amyrin acetate and lupeol acetate. Structures of isolated compounds were elucidated by spectroscopic parameters of IR, Mass, /sup 13/C-NMR, /sup 1/H-NMR, /sup 1/H-/sup 1/H COSY, /sup 13/C-/sup 1/H COSY and HMBC.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3829-3834
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• 2013

$H{\beta}$ (core)/SAPO-11 (shell) composite molecular sieve was synthesized by the hydrothermal method in order to combine the advantages of $H{\beta}$ and SAPO-11 for the methylation of naphthalene with methanol. For comparison, the mechanical mixture was prepared through the blending of $H{\beta}$ and SAPO-11. The physicochemical properties of $H{\beta}$, SAPO-11, the composite and the mechanical mixture were characterized by various characterization methods. The characterization results indicated that $H{\beta}$/SAPO-11 composite molecular sieve exhibited a core-shell structure, with the $H{\beta}$ phase as the core and the SAPO-11 phase as the shell. The pore diameter of the composite was between that of $H{\beta}$ and SAPO-11. The composite had fewer acid sites than $H{\beta}$ and mechanical mixture while more acid sites than SAPO-11. The experimental results indicated that the composite exhibited high catalytic performances for the methylation of naphthalene with methanol.

• Journal of the Korean Chemical Society
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• v.17 no.5
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• pp.363-370
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• 1973

The rate constants of the nucleophilic addition of n-propyl-mercaptan to $\alpha$-cyano-$\beta$-piperonylacrylic acid were determined at various pH and a rate equation which can be applied over wide pH range is obtained. The rate equation reveals that below pH 4.5 the reaction is initiated by the attack of n-propylmercaptan to $\alpha$-cyano-$\beta$-piperonylacrylic acid. At pH 4.5~6.5, however, n-propylmercaptan is added to $\alpha$-cyano-$\beta$-piperonylacrylate ion; at pH 7.04~9.5 the competitive reaction between n-propylmercaptan and n-propylmercaptide ion is anticipated to occur. Above pH 10 the addendum is n-propylmercaptide ion and the acceptor is $\alpha$-cyano-$\beta$-piperonylacrylate ion.

• Journal of Life Science
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• v.18 no.4
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• pp.461-466
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• 2008

Transforming growth $factor-{\beta}$ ($TGF-{\beta}$)-dependent apoptosis is important in the elimination of damaged or abnormal cells from normal tissues in vivo. Gadd45b has been known to participate in $TGF-{\beta}-induced$ apoptosis by the activation of p38 kinase. In this report, we show that Gadd45b is an immediate-early response gene for $TGF-{\beta}$ during apoptosis in EpH4 cells. To elucidate the molecular mechanism of $TGF-{\beta}-induced$ Gadd45b gene expression, we cloned the 5'-flanking region of the mouse Gadd45b gene. When transfected into EpH4 cells, this 5'-flanking region conferred promoter activity and inducibility by $TGF-{\beta}$. Deletion analyses demonstrated that the minimal promoter activity was detected in the proximal region 220 bp upstream of the transcription initiation site. We also found that the proximal Gadd45b promoter is activated by $TGF-{\beta}$ through the action of Smad2, Smad3, and Smad4. Finally, we show that the expression of Gadd45b gene by $TGF-{\beta}$ is suppressed in EpRas cells in which $TGF-{\beta}$ could not induce apoptosis, suggesting that Gadd45b may be a crucial target for $TGF-{\beta}-induced$ apoptosis in EpH4 cells.