FLUORINATED PROTEINS AS POTENTIAL F-19 MAGNETIC-RESONANCE-IMAGING ANDSPECTROSCOPY AGENTS

Fluorinated proteins have been synthesized and characterized as potent ial in vivo F-19 magnetic resonance imaging (MRI) and spectroscopy (MR S) agents. Proteins labeled with fluorine include bovine serum albumin , gamma-globulin, and purified immunoglobulin (IgG). The amino groups in proteins were selectively trifluoroacetylated using S-ethyl trifluo rothioacetate to synthesize fluorinated proteins (TFA-protein; 1-3). I n another approach, trifluoroacetamidosuccinic anhydride has been used to prepare corresponding fluorinated derivatives of proteins (TFASA-p rotein; 4-6). The fluorinated proteins have been purified by exhaustiv e dialysis and isolated in good yields (55-76%). The fluorinated prote ins exhibit useful NMR characteristics and the biocompatibility for in vivo studies. The initial investigations demonstrate the potential of these new fluorinated proteins as in vivo MRI/MRS probes.