• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.693-696
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• 2001

Ketoprofen racemate is very useful pharmaceutical intermediate, but the hardness of separation to each enantiomer is most a barrier to apply pharmaceutical industry. To overcome this difficulty, we would like to separate S-ketoprofen from ketoprofen racemate. To design suitable mobile phase, hexane and t-BME(tri-buthyl-methyle-ether) were used to elute peaks of ketoprofen racemate separately. When the ratio of hexane/t-BME/acetic acid was 60/40/0.1(%v/v), each component was separated successfully. In order to separate large amount of S-ketoprofen, sample concentration was increased from 100ppm to 2000ppm. In this case, resolution was decreased due to the overlapping of peaks(1.65${\rightarrow}$0.94).

• YAKHAK HOEJI
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• v.39 no.4
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• pp.433-437
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• 1995

Optically pure(-)-and (+)-$\alpha$-hydroxy-$\alpha$-(p-chlorobiphenyl)acetic acids were prepared. The racemate was synthesized through three steps. By condensation of p-cnorobiphenyl with diethyl ketomalonate in the presence of SnCl$_{4}$, diethyl $\alpha$-hydroxy-$\alpha$-(p-chlorobiphenyl)malonate (1) was formed and subsequently ($\pm$)-$\alpha$-hydroxy-$\alpha$-(p-chlorobiphenyl)acetic acid (3) was obtained through hydrolysis and decarboxylation. For the separation of the racemate the classical resolution method, derivatization of a racemate by reaction with an optically pure compound was employed. In this case the optically pure compound were [R]-(+)-$\alpha$-methylbenzylamine and [S]-(-)-$\alpha$-methylbenzylamine. Diastereomeric salts between acids and bases could be easily separated by crystallization in absolute ethanol.

• 대한임상약리학회:학술대회논문집
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• 2006.11a
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• pp.69-69
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• 2006

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.559-559
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• 2005

• KSBB Journal
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• v.20 no.4
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• pp.260-265
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• 2005

In this work, molecular imprinted polymers (MIPs) using the template of the N-CBZ (carbobenzyloxy)-L-phenylalanine, MAA and 4-VPY as a monomer, EGDMA as a crosslinker and AIBN as an initiator were considered. The prepared polymer particles $(Ca.\;25-35\;{\mu}m)$ were packed into a chromatographic column $(3.9\;\times\;150\;mm)$. The chromatographic characteristics of the retention on the MIP were experimented with acetonitrile as a mobile phase at the flow rate of mobile phase, 0.5 ml/min. The retention factors and resolutions of chiral racemate of the N-CBZ-D, L-phenylalanine were measured. The results showed that the retention factor and resolution by the two co-monomer imprinting polymer were higher than the single monomer imprinting polymers, which indicated an increase in the affinity of the MIP with the sample as a result of the cooperation effect of the binding sites.

• Korean Chemical Engineering Research
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• v.49 no.5
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• pp.623-627
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• 2011

Simulated moving bed(SMB) chromatography was simulated for separating loxoprofen racemates. Aspen chromatography simulator was utilized with Henry's constants of loxoprofen racemates which were obtained by batch chromatography experiments. Raffinate stream concentrations as well as purities were calculated with various $m_2$ and $m_3$ values in the triangle diagram obtained from two Henry's constants 7.9 and 10.1. Purity values are high under the conditions that the $m_2-m^3$ coordinates are near the left central region in the diagram and feed flow rates are lower. Concentration profiles of raffinate and extract streams along SMB columns explain the purity change in the case of increasing the column numbers installed at SMB.

• YAKHAK HOEJI
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• v.55 no.5
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• pp.426-431
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• 2011

This study was performed to investigate the current regulatory guidances of safety and efficacy evaluation for the development and approval of stereoisomeric drugs in US, EU, Canada and Japan. The important categories for the development of stereoisomeric drugs are classified as 1) development of a single enantiomer as a new active substance 2) development of a racemate as a new active substance 3) development of a new single enantiomer from an approved racemate. The regulatory documents adopted in major countries for the safety and efficacy evaluation of stereoisomeric drugs were investigated with the focus on three major categories mentioned above. For the regulatory approval of stereoisomeric drugs in Korea, it is expected that the investigated results obtained in this study will be useful for the basic materials to ensure the safety and efficacy of stereoisomeric drugs as well as the stereochemical issues in chiral drug development in domestic pharmaceutical company.

• KSBB Journal
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• v.21 no.3
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• pp.224-229
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• 2006

FEMLAB is a powerful interactive environment for modeling, solving all kinds of scientific and engineering problems based on partial differential equations(PDEs). Separation process of chiral compound in HPLC columns was simulated by FEMLAB. To study change of elution profile with isotherm models, non-competitive and competitive Langmuir adsorption isotherm were adopted. Separated material was (R, S)-ibuprofen [(R, S)-2-(4-isobutyl phenyl) propionic acid], an anti-inflammatory agent, which retain the pharmacological activity in the (S)-(+)-enantiomer. Sample concentrations were changed from 0.5 mg/ml to 2.0 mg/ml at a flow rate of 1 ml/min and flow rate varied from 1 ml/min to 3 ml/min at an ibuprofen concentration of 2.0 mg/ml and $20{\mu}l$ of injection volume. Simulated results were well fitted with experimental data.

• Bulletin of the Korean Chemical Society
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• v.29 no.2
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• pp.519-520
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• 2008

• Bulletin of the Korean Chemical Society
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• v.16 no.11
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• pp.1122-1125
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• 1995

Three inherently chiral calix[4]arenes 3-5 were synthesized as racemate starting from the ethylation at 1.3-distal hydroxy groups of calix[4]arene 2 which has two phenyl groups at upper rim in AABB fashion, and then two remaining hydroxy groups were acetylated by treatment with acetyl chloride in the presence of NaH to produce calix[4]arene 4. Treatment of 4 with AlCl3 under Fries rearrangement conditions, only one acetyl group was rearranged to the para-position to afford calix[4]arene 5 with AABC substitution pattern at the upper rim of calix. The structure of chiral calix[4]arenes were confirmed based on NMR and massspectra.