Vitamin-targeted imaging agents

A composition for diagnostic imaging comprising a compound of the formula

• wherein V is a vitamin or V is a receptor-binding analog or derivative of the vitamin, wherein V is a substrate for receptor-mediated transmembrane transport in vivo;
• L is a divalent linker;
• R is a side chain of an amino acid;
• M is a cation of a radionuclide;
• n is 1 or 0;
• and
• a pharmaceutically acceptable carrier therefor.

A method of imaging a population of cells in an animal wherein said cells are characterized by a vitamin receptor on the surface of said cells, the method comprising the steps of

• administering to the animal an effective amount of a composition comprising a compound of the formula
• wherein V is the vitamin or V is a vitamin receptor binding derivative or analog of the vitamin, specific for said cell surface vitamin receptor;
• L is a divalent linker;
• R is a side chain of an amino acid;
• M is a cation of a radionuclide;
• n is 1 or 0;
• and
• a pharmaceutically acceptable carrier therefor;
• and
• monitoring the biodistribution of said compound in the animal.

A compound of the formula

• wherein V is a vitamin or V is a receptor-binding analog or derivative of the vitamin, wherein V is a substrate for receptor-mediated transmembrane transport in vivo;
• L is a divalent linker;
• R is a side chain of an amino acid;
• M is a cation of a radionuclide;
• n is 1 or 0;
• and
• k is 1 or 0.

A composition for diagnostic imaging comprising a compound of the formula

• wherein V is a vitamin or V is a receptor-binding analog or derivative of the vitamin, wherein V is a substrate for receptor-mediated transmembrane transport in vivo;
• L is a divalent linker;
• R is a side chain of an amino acid;
• M is a cation of a radionuclide;
• n is 1 or 0;
• and
• a pharmaceutically acceptable carrier therefor.

A method of imaging a population of cells in an animal wherein said cells are characterized by a vitamin receptor on the surface of said cells, the method comprising the steps of

• administering to the animal an effective amount of a composition comprising a compound of the formula
• wherein V is the vitamin or V is a receptor-binding analog or derivative of the vitamin, specific for said cell surface vitamin receptor;
• L is a divalent linker;
• R is a side chain of an amino acid;
• M is a cation of a radionuclide;
• n is 1 or 0;
• and
• a pharmaceutically acceptable carrier therefor;
• and
• monitoring the biodistribution of said compound in the animal.