Structure-biodistribution relation of neutral 99mTc(CO)3-complexes with tridentate N-substituted derivatives of aminoethylglycine and phenylenediamine

The 99mTc-tricarbonyl complexes [99mTc(CO)3(DBu)] (DBu = N,N′-dibutyl-ethylenediamine-N-acetic acid), [99mTc(CO)3(PDAA)] (PDAA = ortho-phenylenediamine-N-acetic acid) and [99mTc(CO)3(MPDAA)] (MPDAA = N-methyl-ortho-phenylenediamine-N-acetic acid) showed brain uptake in mice. With these compounds as examples, 99mTc-tricarbonyl complexes may also be considered as potential brain imaging agents.