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Partition and substrate concentration effect in the enzymatic synthesis of cephalexin in aqueous two-phase systems

Paper ID Volume ID Publish Year Pages File Format Full-Text
35192 45080 2010 5 PDF Available
Title
Partition and substrate concentration effect in the enzymatic synthesis of cephalexin in aqueous two-phase systems
Abstract

The kinetically controlled synthesis of cephalexin in aqueous two-phase systems was studied, using immobilized penicillin acylase, 7-amino 3-desacetoxycephalosporanic acid as nucleophile and phenylglycine methyl ester as acyl donor. The organic phases used were 80% (v/v) polyethyleneglycol 400 and 600 and the aqueous phase was 2.5 M (NH4)2SO4. 7-amino 3-desacetoxycephalosporanic acid and cephalexin partition coefficients were determined at pH 7.4 and 7.8, at 14 °C and 20 °C. Highest partition coefficient for cephalexin was obtained for polyethyleneglycol 400–(NH4)2SO4 at pH 7.4 and 20 °C, while the lowest partition coefficient for 7-amino desacetoxycephalosporanic acid was obtained in the same system at pH 7.8 and 14 °C. No significant effect of pH was observed on conversion yield and productivity of cephalexin synthesis; however, higher values were obtained with polyethyleneglycol 400 as organic phase. Higher conversion yields with both biphasic systems were obtained at the lowest temperature, where product hydrolysis was lower; volumetric productivity was higher for the fully aqueous medium (control), being higher at 20 °C. All parameters of synthesis were improved at higher substrates concentrations, obtaining conversion yields of 78.2% and 65.4%, with 60 mM 7-amino desacetoxycephalosporanic acid for the polyethyleneglycol 400–(NH4)2SO4 system and the control, respectively.

Keywords
Penicillin acylase; Cephalexin; β-Lactam antibiotics; Enzymatic synthesis; Partition coefficient; Aqueous two-phase systems
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Partition and substrate concentration effect in the enzymatic synthesis of cephalexin in aqueous two-phase systems
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Publisher
Database: Elsevier - ScienceDirect
Journal: Process Biochemistry - Volume 45, Issue 7, July 2010, Pages 1163–1167
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us