Synthesis of carbon-11 labelled glycine and the dipeptides L-phenylalanylglycine and L-leucylglycine.
Carbon-11 labelled glycine has been prepared in 30 min by carboxylation of alpha-lithiomethylisocyanide with a radiochemical yield of 10-15%. After coupling with L-phenylalanine-N-carboxyanhydride and L-leucine-N-carboxyanhydride followed by HPLC purification, the corresponding dipeptides were obtained in 20 min with a radiochemical yield of 30-40%. Consequently, starting with 11CO2, non carrier added L-phenylalanyl[1-(11)C]glycine and L-leucyl-[1-(11)C]glycine in 0.1 N NaH2PO4 were obtained in 50 min with a radiochemical yield of 3-6%. The radiochemical yield figures are not corrected for decay.
D002247:Carbon Isotopes; D004151:Dipeptides / Q000138:chemical synthesis*; D005998:Glycine / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D007553:Isotope Labeling / Q000379:methods*
D002247:Carbon Isotopes; D004151:Dipeptides; D007202:Indicators and Reagents; C040500:phenylalanylglycine; C015905:glycylleucine; D005998:Glycine