2 reference(s) found. Listing paper details in reverse chronological order. We are grateful to Keith Bradnam for improvment of this script
Title: Identification of human, rat and mouse hydrolyzing enzymes bioconverting amino acid ester prodrug of ketoprofen Huttunen KM Ref: Bioorg Chem, 81:494, 2018 : PubMed
Alkyl ester prodrugs are well known to be bioconverted by carboxylesterases, particularly in rodents' by first-pass metabolism in the systemic circulation and liver. However, the bioconversion of structurally more complex esters with polar functional groups is less well understood, especially in humans. Therefore, it is not clear if ester prodrugs can be utilized for targeted drug delivery. In the present study a brain-targeted ester prodrug (1) of ketoprofen, utilizing the l-type amino acid transporter 1 (LAT1) was prepared and the enzymes involved in its metabolism in human plasma and liver S9 subcellular fraction as well as rat brain S9 fraction were identified. Furthermore, species differences among mouse, rat and human plasma and liver S9 fraction were compared. The results showed that bioconversion of the ester prodrug was much faster in mouse plasma compared to human, while it's half-life in rat plasma was closer to the one of human. Moreover, both rodent species showed more efficient bioconversion in the liver S9 fractions compared to human and relatively efficient bioconversion in the brain S9 fractions. More specifically, butyrylcholinesterase (BChE) and paraoxygenase 1 (PON1) were the main hydrolyzing enzymes of the prodrug 1 in human plasma, while carboxylesterases 1 and 2 (CES1 and CES2) as well as PONs were the main bioconverting enzymes in human liver S9 fractions. In rat brain S9 fraction, acetylcholinesterase (AChE) was hydrolyzing the prodrug 1, although also other unidentified metal-and pH-dependent enzyme(s) were recognized to be participating to the total bioconversion of the compound 1 in the brain.
Title: Enantioseparation of (R,S)-ketoprofen using Candida antarctica lipase B in an enzymatic membrane reactor Ong AL, Kamaruddin AH, Bhatia S, Aboul-Enein HY Ref: J Sep Sci, 31:2476, 2008 : PubMed
An enzymatic membrane reactor (EMR) for enantioseparation of (R,S)-ketoprofen via Candida antarctica lipase B (CALB) as biocatalyst was investigated. A comparative study of free and immobilized CALB was further conducted. The catalytic behaviour of CALB in an EMR was affected by the process parameters of enzyme load, substrate concentration, substrate molar ratio, lipase solution pH, reaction temperature, and substrate flow rate. Immobilization of CALB in the EMR was able to reduce the amount of enzyme required for the enantioseparation of (R,S)-ketoprofen. Immobilized CALB in the EMR assured higher reaction capacity, better thermal stability, and reusability. It was also found to be more cost effective and practical than free CALB in a batch reactor.
