• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.3
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• pp.211-214
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• 2006

Immobilized Candida antarctica lipase was used to catalyze the separation of ketoprofen into its components by means of esterification followed by the enzymatic hydrolysis of the ester product. In this study, ketoprofen underwent esterification to ethanol in the presence of isooctane. When the reaction was complete, 58.3% of the ketoprofen had been transformed into an ester. The ketoprofen remaining in solution after the reaction was complete consisted primarily of its S-enantiomer (83.0%), while the 59.4% of the ketoprofen component of the ester consisted of its R-enantiomer. We then subjected the ester product to enzymatic hydrolysis in the presence of the same enzyme and produced a ketoprofen product rich in the R-enantiomer; 77% of this product consisted of the R-enantiomer when 50% of the ester had been hydrolyzed, and 90% of it consisted of the R-enantiomer when 30% of the ester had been hydrolyzed. By contrast, the R-enantiomer levels only reached approximately 42 and 65%, respectively, when 50 and 30% of the racemic ester was hydrolyzed under the same conditions.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.4
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• pp.285-291
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• 2004

A simulated moving bed (SMB) chromatography system is a powerful tool for preparative scale separation, which can be applied to the separation of chiral compound. We have de-signed our own lab-scale SMB chromatography using 5 HPLC pumps, 6 stainless steel columns and 4 multi-position valves, to separate a racemic mixture of ketoprofen in to its enantiomers. Our design has the characteristics of the low cost for assembly for the SMB chromatography and easy repair of the unit, which differs from the designs suggested by other investigators. It is possible for the flow path through each column to be independently changed by computer control, using 4 multi-position rotary valves and 5 HPLC solvent delivery pumps. In order to prove the operability of our SMB system, attempts were made to separate the (S)-ketoprofen enantiomer from a ketoprofen racemic mixture. The operating parameters of the SMB chromatography were calculated for ketoprofen separation from a batch chromatography experiment as well as by the triangle theory. With a feed concentration of 1 mg/mL, (S)-ketoprofen was obtained with a purity of 96% under the calculated operating conditions.

• 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).

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.4
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• pp.341-345
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• 2005

Since it is troublesome to estimate adequate flow rates in four sections of SMB chromatography, a systematic determination of the flow rates has been suggested by using ketoprofen as a model chiral enantiomer. S-ketoprofen. less retained species, was separated from raffinate stream and the variation in its purity was dependent on the changes of the flow rate of section 4 ($Q_4$), the raffinate flow rate ($Q_{raf}$), and the feed flow rate ($Q_{feed}$) under a fixed switch­ing time t$^{\ast}$. When one parameter was changed at the given experimental condition, purities of product were changed and these phenomena has be well explained by the triangle theory.

• KSBB Journal
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• v.14 no.2
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• pp.225-229
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• 1999

Enzymatic resolution reactions were investigated using Candida rugosa lipase for the production of potically pure S-(+)-Ketoprofen. When the enzymatic hydroysis (and esterification) of recemic ketoprofen esters (and recemic ketoprofen with alcohol) was investigated comparatively, aqueous media was more specific for S-enantiomer than organic media. In the enzymatic hydrolysis of racemic ketoprofen ethyl ester in aqueous media, optimal temperature and pH for enantioselectivity were $37^{\circ}C$ and 4, respectively. The stereoselectivity of the enzyme was enhanced by adding dialcohols such as ethylene glycol and propylene glycol. The enantiomeric ratio obtained in the 40 %(v/v) ethylene glycol was 2-fold higher than that without the additive. By adding $CH_2Cl_2$, $CHCl_3$ and $CCl_4$ (5%,v/v), the enantioselectivity was reversed. A dramatic increase in the stereoselectivity was achieved using lipase purified by anion exchange chromatography. The type A lipase(the first eluted lipase fraction) showed an enantiomeric ratio of >100, whereas the type B lipase(the second eluted lipase fraction) exhibited enantimomer ratio of 9.0 in the hydrolysis of racemic ketoprofen ethyl ester.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.625-628
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• 2001

To isolate novel strains that hydrolyzed the rac-ketoprofen ethyl ester to ketoprofen in the stereospecific manner, we screened broad ecological niches and soil samples in which the activity was expected to be found. From thousands of strains, we isolated a Pseudomonas sp. S34 producing a (S)-stereospecific esterase, and a thermostable esterase with (R)-form selectivity was also 。 btained from Bacillus stearothermophilus JYl44. To further analyse the gene structure and to induce a high level expression, two genes from each strain were cloned and sequenced. BLAST search results with the esterase gene from 534 revealed that both of gene (80-84 %) and amino acid sequences (89- 95 %) were highly conserved in the related esterases from Pseudomonas strains (fluorescens and aeruginosa). The thermostable esterase from JY144, however, revealed a relative low homology (45-52 %) to other esterase and/or lipase from related strains. Obviously, a complete conversion with pure enantiomer (R - or S) were readily achieved by recombinant clones expressing either (R)- or (S)- stereospecific esterase.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.489-492
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• 2002

We have performed batch chromatography experiments to calculate parameters which are used to design SMB chromatography system. Isotherms of S- and R-ketoprofen enantiomers were gained from small amount loading experiments in a column, and flow rate of four zones of SMB chromatography were calculated using mass balance equations. As a results, diameter and length of columns were 10mm and 600mm, and flow rate of each zone were as follows; $Q_{Feed}$=1.00ml/min ,$Q_{Elu}$=2.81ml/min ,$Q_{Raf}$=1.81ml/min ,$Q_{Ext}$=2.00ml/min , and $Q_{Rec}^{TMB}$=10.75ml/min , From the Darcy's equation, the pressure drop in whole columns of SMB chromatography was 128bar.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.215.1-215.1
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• 2003

A various ${\alpha}$-arylmethylpropionic acids(profen) have been widely used as non-steroidal anti-inflammatory drugs for the relief of acute and chronic rheumatoid arthritis and osteoarthritis, as well as for other connective tissue disorders and pains. Example is fenoprofen, ibuprofen, ketoprofen, and naproxen. All are chiral and, except for naproxen and ibuprofen, are marketed in racemic form. Enantioseparations of profens have been of considerable interest becaus their anti-inflammatory and analgesic effects have been attirbuted almost exclusively to their (S)-enantiomer. (omitted)

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.506-510
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• 2003

SMB(simulated moving bed) chromatography system has been developed to realize continuous separation and save solvent consumption for binary mixture in especial. The parameters of SMB chromatography system can be calculated from mass balance equations of true moving bed chromatography, and they are used in design of 6-column SMB chromatography. We can separate S-ketoprofen enantiomer as a raffinate product in 85% of purity and 0.3mg/ml using assembled SMB chromatography system.