• Bulletin of the Korean Chemical Society
• /
• v.32 no.spc8
• /
• pp.3120-3122
• /
• 2011

• Journal of Microbiology and Biotechnology
• /
• v.9 no.5
• /
• pp.646-649
• /
• 1999

A thermophilic bacterium producing D-stereospecific dipeptidase was isolated from Korean soil samples. The enzyme hydrolyzed the peptide bond between D-alanyl-D-alanine (D-Ala-D-Ala). The isolated bacterial strain was rod shaped, gram-positive, motile, and formed an endospore. Morphological and physiological characteristics suggested this microorganism a thermophilic Bacillus species, and was named as Bacillus sp. BCS-l. The production of D-stereospecific dipeptidase was growth-associated and optimal at $55^{\circ}C$. The enzyme was applied for the synthesis of D-amino acid-containing peptide, N-benzyloxycarbonyl-L-aspartyl-D-alanine benzyl ester (Z-L-Asp-D-AlaOBzl), as a model reaction. A thermodynamically controlled synthesis of Z-L-Asp-D-AlaOBzl was achieved in an organic solvent.

• Bulletin of the Korean Chemical Society
• /
• v.23 no.12
• /
• pp.1823-1826
• /
• 2002

• Korean Journal of Pharmacognosy
• /
• v.17 no.1
• /
• pp.67-72
• /
• 1986

A stereospecific synthesis of 3-methyl-5-(1-hydroxy-4-oxo-2,6,6-trimethyl-2-cyclohexen-1-yl)-cis, trans-2,4-pentadienoic acid (abscisic acid) from ${\alpha}-ionone$ has been investigated. Ethyl 5-(2,6,6-trimetyl-2-cyclohexen-1-yl)-trans-4-penten-2-ynoate $({\alpha},{\beta}-acetylenic\;ester)$, which was synthesized from alpha-ionone in two steps, was stereospecifically converted in good yield into ethyl 3-methyl-5-(2,6,6-trimethyl-2-cyclohexen-1-yl)-cis, trans-2, 4-pentadienoate $({\alpha}-ionylideneacetate)$ by the conjugate addition of lithium dimethylcuprate at $-78^{\circ}C$. Basic hydrolysis of the ethyl ${\alpha}-ionylideneacetate$ gave an abscisic acid precursor, 3-methyl-5-(2,6,6-trimethyl-2-cyclohexen-1-yl)-cis, trans-2,4-pentadienoic acid, which can be oxidized to yield abscisic acid.

• Journal of Microbiology and Biotechnology
• /
• v.10 no.5
• /
• pp.573-579
• /
• 2000

Knowledge on the enzymes acting on p-amino-acid-containing peptides appears to be somewhat limited when compared with those acting on peptides composed on L-amino acids. Less than ten D-stereospecific enzymes are hitherto known. This review describes about several novel D-stereospecific peptidases and amidases of microbial origin, including D-aminopeptidase (E.C. 3.4.11.19), alkaline D-peptidase, and D-amino aicd amidase, which are applied to the synthesis of D-amino acid/or D-amino acid derivatives.

• Journal of the Korean Chemical Society
• /
• v.52 no.5
• /
• pp.588-592
• /
• 2008

• Journal of the Korean Chemical Society
• /
• v.26 no.4
• /
• pp.256-260
• /
• 1982

• Bulletin of the Korean Chemical Society
• /
• v.16 no.10
• /
• pp.985-988
• /
• 1995

2-Epideoxymannojirimycin 1 and (2R,3R,4R,5R)-3,4,5-trihydroxypipecolic acid 2 were prepared starting from D-glucosamic acid as a chiral educt. Key transformations were selective removal of the terminal isopropylidene group and intramolecular cyclization by SN2 reaction.

• YAKHAK HOEJI
• /
• v.30 no.6
• /
• pp.352-355
• /
• 1986

Methyl-6-deoxy-$\beta$-L-idopyranoside was prepared in good yield by treatment of methyl 2,3,4-tri-O-benzyl-6-deoxy-$\alpha$-D-xylo-hex-5-enopyranoside with H$_2$ on pd, followed by reaction of Na/NH$_3$ at $-50^{\circ}C$. The ratio of L-idopyranoside and D-glucopyranoside was 7 to 1 in 80.7%. It was confirmed that L-idopyranoside was 1C conformation as being expected.

• Bulletin of the Korean Chemical Society
• /
• v.15 no.7
• /
• pp.559-563
• /
• 1994

Glycosylation of benzoylated glycosyl halides of glucose, galactose and mannose with potassium p-nitrophenoxide and 18-crown-6 complex in chloroform resulted in the stereospecific formation of 1,2-trans p-nitrophenyl glycopyranosides in good yields. The same reaction with benzylated mannopyranosyl chloride gave the ${\alpha}-and\;{\beta}-p-nitrophenyl$ mannopyranosides in 3 : 1 ratio. However, acetylated 2-azido-altropyranosyl chloride gave ${\beta}-p-nitrophenyl$ altropyranoside only.