title: Chemical form of tumor-tropic 99mTc-DL-homocysteine.
abstract: Analyses of the chemical forms of 99mTc-complexes provide important information for the development of a new tumor-tropic 99mTc-labeled radiopharmaceutical. We attempted to determine the chemical form of 99mTc-DL-homocysteine (99mTc-Hcy) which was previously reported to be tumor-tropic. By analyzing the functional residues of Hcy in the 99mTc-Hcy molecule, it was estimated that the sulfhydryl and amino residues participated in the chelate formation. Gel filtration analysis of 99mTc-Hcy indicated that its molecular size was bigger than that of 99mTc-penicillamine monomer. The analysis also indicated that 99mTc-Hcy complex seemed to be a relatively small oligomer. Although an uncertainty remains on the valency of Tc in 99mTc-Hcy molecule and the accurate molecular size of this complex, its putative chemical form is described.
authors.affiliation: Department of Radiobiochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Takeda
authors.forename: S
authors.initials: S
authors.lastname: Okada
mesh_terms: D000327:Adsorption; D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D006710:Homocysteine / Q000493:pharmacokinetics; D006863:Hydrogen-Ion Concentration; D007553:Isotope Labeling; D008297:Male; D051379:Mice; D008970:Molecular Weight; D009374:Neoplasms, Experimental / Q000378:metabolism*; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics
chemical_list: D015609:Organotechnetium Compounds; C061202:technetium Tc 99m homocysteine; D006710:Homocysteine