Synthesis, radiolabeling, and biological evaluation of (R)- and (S)-2-amino-3-[(18)F]fluoro-2-methylpropanoic acid (FAMP) and (R)- and (S)-3-[(18)F]fluoro-2-methyl-2-N-(methylamino)propanoic acid (NMeFAMP) as potential PET radioligands for imaging brain tumors.
