• Journal of Applied Biological Chemistry
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• 제51권1호
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• pp.17-19
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• 2008

Isoflavanone has been synthesized from the reduction of isoflavone in nearly quantitative yield. Isoflavone with seven equivalents of ammonium formate in the presence of Pd/C in ethanol under $N_2$ atmosphere exclusively produced the two-electron reduced product in two hours. It was characterized by various spectroscopic methods, including UV-VIS, EI-MS, $^1H$-NMR, $^{13}C$-NMR and $^1H$, $^1H$-COSY. The racemic mixture was separated by Sumi-Chiral column chromatography and the absolute configurations of the enantiomers were characterized by circular dichroism spectroscopy.

• Fisheries and Aquatic Sciences
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• 제15권1호
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• pp.15-19
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• 2012

A new cyclic peptide (six-membered amino acid), gamakamide-E (L-Leu-L-Met (SO)-L-Me-Phe-L-Leu-D-Lys-L-Phe), was isolated as a strongly bitter tasting compound from cultured oysters, Crassostrea gigas. The molecular formula of $C_{43}H_{61}N_7O_8S$ was deduced from high resolution fast atom bombardment mass spectrometry (HR FAB-MS) ($[M+H]^+$ m/z 836.4356 ${\Delta}$= -2.4 mmu). Its unique structure including a hydantoin structure was firstly elucidated by nuclear magnetic resonance (NMR) analysis. Stereochemistries of constituent amino acids were determined by chiral high performanced liquid chromatography analysis of natural and synthesized peptides.

• Bulletin of the Korean Chemical Society
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• 제30권2호
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• pp.415-418
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• 2009

Concerned with ambiguous stereochemistry assignment of natural (+)-glabridin, absolute configurations of (${\pm}$)-glabridin enantiomers were studied with synthetic glabridin. Synthetic glabridin enantiomers were separated by semi-preparative Sumi-chiral column chromatography, and characterized by UV-Vis and NMR spectroscopy. Three-dimensional molecular structure of glabridin was obtained as equatorial Ph-3 half chair chroman ring from semi-empirical PM3 calculation, and refined by coupling constants in $^1H$ NMR spectrum. Finally, absolute configurations of two enantiomers were determined by circular dichroism spectroscopy based on the empirical helicity rules. Absolute configuration of natural (+)-glabridin was confirmed as (R)-glabridin, as known.

• Biomolecules & Therapeutics
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• 제31권5호
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• pp.566-572
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• 2023

A chiral derivatization strategy with phenylglycine methyl ester (PGME) was employed to develop a straightforward method to determine the absolute configurations of N,N-dimethyl amino acids. The PGME derivatives were analyzed using liquid chromatography-mass spectrometry to identify the absolute configurations of various N,N-dimethyl amino acids based on their elution time and order. The established method was applied to assign the absolute configuration of the N,N-dimethyl phenylalanine in sanjoinine A (4), a cyclopeptide alkaloid isolated from Zizyphi Spinosi Semen widely used as herbal medicine for insomnia. Sanjoinine A displayed production of nitric oxide (NO) in LPS-activated RAW 264.7 cells.

• 대한화학회지
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• 제58권3호
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• pp.277-282
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• 2014

2013년 국내에서 시판된 7개의 이부프로펜과 11개의 덱시부프로펜의 광학순도를 키랄 HPLC로 조사하였다. Chiralcel OD-H 칼럼과 LUX-Cellulose-1 칼럼을 키랄 정지상으로 사용하였고, hexane:isopropanol:acetic acid가 100:1:0.1로 혼합된 용액을 전개용매로 사용하여 흐름속도 1.0 mL/min에서 분석하였다. 각 시료를 최소 3회 이상 분석하여 얻은 평균값을 각각 계산하여 데이터로 이용하였고, 이들의 상대표준편차 평균값도 0.19%로 아주 작게 나타나 실험의 정밀도가 높음을 확인하였다. 실험에 사용된 11개 덱시부프로펜의 광학순도 평균값은 처음 판매가 허가된 2004년의 평균값인 99.2%에 비해 낮아졌지만 2010년의 평균값인 95.6% 보다는 높은 97.5%를 보였다. 그리고 실험에 이용된 모든 이부프로펜 두 거울상 이성질체의 조성비는 2010년 조사값(44:56)과는 달리 거의 50:50으로 얻어졌다.

• 한국식품영양과학회지
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• 제35권7호
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• pp.874-880
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• 2006

건생강 제품의 진위판별을 위한 기초자료를 제공하기 위하여 건조된 생강으로부터 휘발성 향기성분을 추출하여 향기특성을 분석하고, MDGC/MS에 의해 키랄성 휘발성분의 enantiomeric composition을 분석하였다. 건생강에서 총 57종을 동정하였으며 주요 휘발성 향기성분은 zingiberene, ${\beta}-sesquiphellandrene$, ${\beta}-bisabolene$, (E,E)-${\alpha}-farnesene$ 및 ${\alpha}-curcumene$이었다. 건생강에 함유된 키랄성 향기성분 중에서 enaniomeric composition을 측정하기 위해 선택된 키랄화합물 중 ${\alpha}-pinene$ 및 nerolidol은 높은 enantiomeric purity(>96%)로 검출되었으며, ${\beta}-pinene$은 (R)-enantiomer만이 검출되어 특이적이었다. ${\alpha}-Terpineol$은 (R)-enantiomer가 72%로 높게 나타났으며 linalool과 4-terpineol은 두 이성질체가 혼합된 것으로 나타났다. Limonene의 enantiomeric excess(ee, %)는 17.2%로 (S)-enantiomer가 주요 이성질체이었다. 따라서 이러한 키랄성 향기성분의 enantiomeric composition은 건생강의 진위평가를 위한 변수로 사용될 수 있을 것으로 생각된다.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 춘계학술대회
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• pp.188-188
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• 2003

Examination was made of the urinary metabolite(s) of CKD-712, which is a chiral compound, named S-YS49 derived from higenamine (one component of Aconite spp.) derivatives. First of all, to analyze the metabolite(s) of CKD-712, a simple and sensitive detection method for CKD-712 was developed by using gas chromatography-mass spectrometry GC/MS). Urine was collected from adult male Sprague-Dawley rats 250${\pm}$10g) in metabolic cage for 24hr after oral administration of 100 mg/kg of CKD-712. The recovery of CKD-712 after extraction and concentration with AD-2 resin column was above 90 % from rat urine. The detection limits of CKD-712 in urine was approximately 0.1 ng/mL. It has well been suggested that isoquinoline possessing catechol moiety such as CKD-712 should be subjected to the catechol-O-methyl kransferase activity in vivo. We detected three major peaks of presumed CKD-712 metabolites in the total ion chromatogram obtained from the rat urine sample after oral administration of CKD-712. From these results, it is assumed that the urinary metabolites are mono-methylation in the naphthyl moiety (metabolite I ), methylation at the C-6 or 7 hydroxy group in the isoquinoline moiety and hydroxylation at in the naphthyl moiety (metaboliteII), and methylation at the C-6 or 7 hydroxy group in the isoquinoline moiety (metaboliteIII).

• 대한화학회지
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• 제30권2호
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• pp.216-223
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• 1986

Dansyl 유도화된 아미노산의 광학이성질체를 분리하기 위해 광학활성인 L-arginine과 몇가지 금속(구리, 아연, 카드뮴, 니켈)의 킬레이트를 이동상에 첨가하여 역상 칼럼내에서 분리를 시도했다. 구리 킬레이트 이외의 것은 광학이성질체의 분리가 안되었다. 아미노산의 광학이성질체의 분리 거동은 이동상의 pH 및 유기용매조성, 완충용액의 종류와 농도, 금속의 종류와 킬레이트 농도에 의해 영향을 받음을 알 수 있었다. Valine, metionine, leucine, phenylalanine은 D형이 먼저 용리되고 serine과 alanine은 L형이 먼저 용리되었으며 threonine은 D형과 L형의 분리현상이 나타나지 않았다. 이러한 분리거동은 리간드 교환반응에 의한 (D, L-DNS-AA) (M) (L-Arg) 3종류 착물이 형성될때의 입체 특이성효과로써 설명할 수 있다.

• Journal of Microbiology and Biotechnology
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• 제16권11호
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• pp.1832-1836
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• 2006

Mesorhizobium sp. LUK, which utilizes 3-amino-3-phenylpropionic acid as the sole source of nitrogen with high enantioselectivity (E(S)>100), was isolated using enrichment culture. The enzyme involved in the utilization of (S)-3-amino-3-phenylpropionic acid was confirmed to be a transaminase and was purified by 235-folds with a specific activity of 0.72 U/mg. The molecular weight of the purified protein was ca. 47 kDa and the active enzyme was determined as a dimer on gel filtration chromatography. The N-terminal sequence was obtained from the purified protein. Spontaneous decarboxylation of produced ${\beta}-keto$ acids was observed during the chiral resolution of 3-amino-3-phenylpropionic acid.

• 대한화학회지
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• 제34권4호
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• pp.345-351
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• 1990

역상 고성능 액체 크로마토그래피에 Cu (Ⅱ)-L-Proline 킬레이트를 이동상에 첨가하여 답실아미노산(DABS-AA)을 광학분리했다. DABS-아미노산에 관한 머무름거동을 이동상으로 아세토니트릴, 착물 및 완충용액의 농도와 pH에 따라 연구 검토했다. DABS-아미노산의 광학분리선택성은 이동상의 pH와 킬레이트의 농도가 증가하면 증가하나 유기용매의 농도에 따라 감소한다. 완충액의 농도에는 무관하다. DABS-아미노산과 구리 착물간의 리간드 교환반응의 입체효과에 따른 시스-트란스 생성으로 분리메카니즘을 설명할 수 있다.