[32] Synthesis of radioactive (−)-carnitine from γ-aminobutyrate

摘要: Publisher Summary This chapter discusses the Synthesis of Radioactive (—)-carnitine from γ-aminobutyrat. γ-Aminobutyrate is methylated to γ-butyrobetaine using radioactive methyl iodide under conditions giving high yields with respect both these precursors. γ-Butyrobetaine then quantitatively converted a 50–60% ammonium sulfate fraction rat liver supernatant as source hydroxylase. The product purified by column chromatography on cation exchanger and desalted passing through ion-retardation resin. A employed obtained follows: thirty percent (w/v) homogenate adult prepared in 210 m M mannitol, 70 sucrose, 0.1 mM EDTA, 10 Tris–HCl (pH 7.4), dithiothreitol Potter–Elvehjem homogenizer centrifuged at 17,000 g for min. All operations are carried out 0–4°. assay procedure involves methylation γ-aminobutyrate γ-butyrobetaine, conversion (—)-carnitine, characterization (—)-carnitine. ability hydroxylase hydroxylate stereospecifically ensures stereochemical purity synthesized method presented chapter; conversely procedures that employ β -hydroxy intermediate group acceptor, limited acceptor employed. Methyl-labeled can also be which demethylation commercial obtain (—)dimethylamino- -hydroxybutyrate back iodide.