Resolution Pharmaceuticals Inc.

Ernest Wong

Alfred Pollak

Suman Rakhit

Theresa Fauconnier

Tam Nguyen

The labeling of biologically important molecules via a bifunctional chelator can result in the formation of isomers or multiple species, which can have significant impact on the biological properties of the radiopharmaceutical. For receptor-based radiopharmaceuticals, the target uptake is largely dependent on the receptor binding affinity of the targeting molecule and the blood clearance of the labeled molecule, which is determined by the physical properties of both the targeting molecule and the metal chelate. Hence, the presence of isomers for the metal chelate can have significant impact on the radiopharmaceutical. Therefore, in the development of a radiopharmaceutical or metallodrug, it is necessary to separate the isomers and evaluate the biological activities of each individual isomer. It would therefore be desirable to develop chelators that predominately form only a single stereoisomeric species upon coordination to a metal center. Disclosed herein are chelators that form a mixture enriched for a single stereoisomeric species upon coordination to a metal center.

Chelators that predominantely form a single stereoisomeric species upon coordination to a metal center

A peptide-chelator conjugate that is useful for imaging sites of inflammation in humans comprises a metal chelator coupled to a glycopeptide antibiotic. The metal chelator and the glycopeptide are coupled by a linking group. The linking group may be the divalent radical NH--(CH.sub.2).sub.3 --NH. Alternatively the linking group may be .beta.Ala.sub.3 LysGly-OH and the glycopeptide may be coupled to the N.sup..epsilon. of Lys. A method of imaging a site of inflammation is also provided. The method comprises the step of administering a diagnostically effective amount of a composition comprising a glycopeptide-chelator conjugate comprising a metal chelator coupled to a glycopeptide antibiotic. The glycopeptide-chelator conjugate is in a form complexed with a diagnostically useful metal or an oxide or nitride thereof.

Growing community of inventors

Langley, Canada

Ernest Wong