Synthesis of 1-11C-labeled fatty acid from [11C]HCN

A new chemical approach to the preparation of [1-11C]fatty acids from [11C]HCN has been developed. Four straight chain [l-11C]fatty acids (C15-C18) and one branched chain [l-11C]fatty acid (3-methylheptadecanoic acid) were produced by the reaction of alkyl bromides with 11Cn- and subsequent hydrolysis. The synthesis time was 47-67 min after the end of bombardment, with radiochemical yields of 16-20 mCi (70-83%) for a series of straight chain [l-11C]fatty acids and 4-8 mCi (33-42%) for 3-methyl [l-11C]heptadecanoic acid (from 120 mCi of trapped [11C]HCN). This method has some advantages, such as no requirement of absolutely anhydrous solvent, easy 11C-labeling using an extremely small amount of substrate, and good reproducibility. (author)