Premium
A new method for the high performance liquid chromatographic determination of TA‐870, a dopamine prodrug (catechol ester compound)
Author(s) -
Yoshikawa Masayoshi,
Endo Hiroshi,
Hoshino Kumiko,
Sugawara Yoichi,
Takaiti Osasi,
Kanda Susumu,
Imai Kazuhiro
Publication year - 1990
Publication title -
biomedical chromatography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 65
eISSN - 1099-0801
pISSN - 0269-3879
DOI - 10.1002/bmc.1130040503
Subject(s) - chemistry , chromatography , carboxylesterase , high performance liquid chromatography , elution , enzyme , organic chemistry
A new method for the high performance liquid chromatographic (HPLC) determination of N ( N ‐acetyl‐ L ‐methionyl)‐ O , O ‐bis(ethoxycarbonyl)dopamine (TA‐870), a dopamine prodrug, in biological fluid has been developed. In order to measure with an electrochemical detector (ECD), TA‐870 was passed first through an immobilized carboxylesterase column to be converted to the electrochemically active deethoxycarbonylated TA‐870 (DEC‐TA‐870). The properties of this carboxylesterase immobilized on Sepharose 4B were examined by this flow injection system. Hydrolysis of TA‐870 with this immobilized carboxylesterase was a maximum at pH 7 – 8 and 50 °C, and the activity decreased in the presence of organic solvent such as acetonitrile. For the determination of TA‐870 in biological fluids, an HPLC‐immobilized enzyme‐ECD system using a column‐switching technique was developed. The blood was deproteinized with ethanol, and TA‐870 in the ethanol extracts was adsorbed in Bond Elut C 18 . The dichloromethane eluate from Bond Elut C 18 was injected into the HPLC system. The HPLC apparatus was composed of three pumps, two separation columns (LiChrosorb Si 60 and μ Bondasphere), a trap column (Bond Elut), an enzyme column, ECD and the column‐switching system. The calibration curve for TA‐870 in blood was linear in the range from 2 to 200 ng/mL. This new assay method might be useful also for the determination of other catechol ester compounds.