• Journal of the Korean Chemical Society
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• v.3 no.1
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• pp.31-35
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• 1954

Upon the basis of the results obtained hitherto in the studies of the stereochemical reaction mechanisms, the author has concluded that the stereospecificity of enzymes has essentially a relative character. And the author has pointed out the possibility of the occurrence of a new enzyme "inverskinase", which catalyses the reversible inversions such as D-compound ${\leftrighyarrow}$ L-compound in living organisms, and considered the stereospecificity of enzymes and the optical purity of components of living organism from this new standpoint.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.217.4-217
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• 2005

• The Microorganisms and Industry
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• v.20 no.1
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• pp.23-27
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• 1994

본고에서는 화학적수법으로 다양한 특이한 기질을 제조하여 여기에 입체특이적 성질(stereospecificity)과 입체선택적 성질(steroselectivity)이 높은 생물학적 방법들 중에서 주로 lipase를 이용한 부제가수분해반응(asymmetric hydrolysis)과 그 역반응인 에스테르화반응(esterification)등을 도입한 chiral building block의 제조와 이를 이용한 곤충 생리활성물질인 pheromone의 합성에 대한 최근의 많은 예들중 상품화를 시도하고 있는 매미나방의 pheromne인 (+)-disparlure에 대하여 간단히 소개하고자 한다.

• Bulletin of the Korean Chemical Society
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• v.6 no.4
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• pp.238-240
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• 1985

Carbonato and diammine platinum(Ⅱ) complexes of resolved 6,6'-dimehtyl-2,2'-diaminobiphenyl have been prepared. The absolute configuration of the square planar platinum(Ⅱ) complexes is determined on the basis of stereospecificity of the 6,6'-dimethyl-2,2'-diaminobiphenyl ligand, circular dichroism spectra of the complexes, and nonempirical circular dichroism method.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.3
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• pp.130-137
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• 2002

Microbial lactonohydrolases (intramolecular ester bond-hydrolyzing enzymes) with unique properties were found. The lactonohydrolase from Fusarium oxysporum catalyzes enantiose-lective hydrolysis of aldonate lactones and D-pantoyl lactone (D-PL). This enzyme is useful for the large-scale optical resolution of racemic PL. The Agrobacterium tumefaciens enzyme catalyzes asymmetric hydrolysis of PL, but the stereospecificity is opposite to that of the Fusarium enzyme. Dihydrocoumarin hydrolase (DHase) from Acinetobacter calcoaceticus is a bifunctional enzyme, which catalyzes not only hydrolysis of aromatic lactones but also bromination of monochlorodi-medon in the presence of H$_2$O$_2$and dihydrocoumarin. DHase also hydrolyzes several linear esters, and is useful for enantioselective hydrolysis of methyl DL-$\beta$-acetylthioisobutyrate and regioselective hydrolysis of methyl cetraxate.

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2644-2648
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• 2010

Catalytic conversion of structurally different epoxides to the corresponding 1,2-diacetoxy esters was carried out readily with phosphomolybdic acid alone or its supported on $SiO_2$. The reactions were carried out under solvolytic or solvent free conditions within 5-15 min at room temperature. The product 1,2-diacetates were obtained in high to excellent yields. Supporting of phosphomolybdic acid on $SiO_2$ showed the better catalytic activity than $Al_2O_3$. Conversion of optically pure R-(+)-styrene oxide to S-(+)-1,2-diacetoxy-1-phenylethane was carried with phosphomolybdic acid in high yield and stereospecificity.

• Bulletin of the Korean Chemical Society
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• v.29 no.7
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• pp.1315-1319
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• 2008

A trisaccharide, 6d-Altro-Hepp$\alpha$ (1$\rightarrow$3) GlcNAc$\beta$ (1$\rightarrow$3) Gal$\alpha$ (1$\rightarrow$$OCH_2CH_2N_3$, as an O-antigenic repeating unit of Campylobacter jejuni serotypes O:23 and O:36, was synthesized. Coupling of the 6d-altro-Hepp$\alpha$ (1$\rightarrow$3) GlcNAc$\beta$ (1$\rightarrow$SEt donor with Gal$\alpha$ (1${\rightarrow}OCH_2CH_2Cl$ acceptor in the presence of NIS-TfOH promoter afforded the trisaccharide having the $\beta$ (1$\rightarrow$3) Gal linkage. $\beta$ -Stereospecificity and the desired regioselectivity for the 3-OH Gal are obtained. Subsequent hydrogenation, acetylation, azide displacement, hydrazinolysis, Nacetylation, and finally deacetylation furnished the title trisaccharide hapten for further glycoconjugation.

• Bulletin of the Korean Chemical Society
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• v.17 no.1
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• pp.24-28
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• 1996

A procedure is described for the synthesis of the title compound via phosphotriester intermediates. The preparation of $R_p$ and $S_p$ diastereomeric dinucleotide of d[Cp(S)T] was performed by the condensation of the protected deoxycytidine, the protected thymidine, 2,5-dichlorophenylphosphorodichloridothioate and 1-hydroxybenzotriazole in THF. Their designation of configuration at phosphorus as $R_p$ and $S_p$ follows from anaylsis of ${31}^P$ NMR spectroscopy and reverse-phase HPLC and the stereospecificity in the hydrolysis catalyzed by Nuclease S1 and snake venom phosphodiesterase. Diastereomerically pure $R_p$ and $S_p$ d[Cp(S)T] were utilized to synthesize oligonucleotides containing the XhoI recognition sequence with a phosphorothioate group at the cleavage site.

• Bulletin of the Korean Chemical Society
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• v.7 no.1
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• pp.45-50
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• 1986

Separation of optical isomers of some derivatives of amino acids by reversed-phase HPLC has been accomplished by adding a chelate of an optically active amino acid to copper(Ⅱ) to the mobile phase. Cu(Ⅱ) complexes of L-proline and L-hydroxyproline in the mobile phase showed different degrees of separation. Optical isomers of DNS derivatives of amino acids are selectively separated, but those of several other derivatives are not at all. The kinds of buffer agents, the pH, and the concentrations of acetonitrile and the Cu(Ⅱ) ligand all affect the separations. The elution behavior between D and L DNS-amino acids appears to depend on the alkyl side chain of the amino acids. A chromatographic mechanism is proposed that is based on a stereospecificity of the formation of ternary complexes by the D, L-DNS-amino acids and the chiral additive associated with the stationary phase. The steric effects of the ligand exchange reactions are related with the feasibility of cis and/or trans attack of the amino acids to the binary chiral chelate retained on the stationary phase.

• Bulletin of the Korean Chemical Society
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• v.14 no.1
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• pp.52-55
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• 1993

A procedure is described for the synthesis of the title compound via phosphotriester intermediates. The preparation of $R_p\;and\;S_p$ diastereomeric dinucleotide of d[Ap(S)A] was performed by the condensation of protected deoxyadenosine, 2,5-dichlorophenylphosphorodichloridothioate and 1-hydroxybenzotriazole in THF. Their designation of configuration at phosphorus as $R_p\;and\;S_p$ follows from analysis of $^{31}P$-NMR spectroscopy and reversed-phase HPLC and the stereospecificity in the hydrolysis catalyzed by nuclease Pl.