title: Characterization and preliminary evaluation of ester-modified technetium-99m SNS/S mixed ligand complexes as potential brain perfusion agents.
abstract: Two novel [99mTc](SNS/S) mixed ligand complexes carrying a pendant ester function on the monothiolate coligand were synthesized. The corresponding oxorhenium and [99gTc]oxotechnetium complexes prepared at the macroscopic level and chemically characterized were used for structure assignment of [99mTc](SNS/S) complexes prepared at the nanomolar level. Enzymatic hydrolysis of the pendant ester group of [99mTc](SNS/S) mixed ligand complexes by esterase was investigated in vitro and compared with that of the ethyl cysteinate dimer, [99mTc]ECD. Preliminary biodistribution data in mice shows that the complexes are lipophilic and exhibit significant initial uptake in rodent brain.
authors.affiliation: Institute of Radioisotopes, Radiodiagnostic Products, NCSR Demokritos, Athens, Greece.
authors.forename: C
authors.initials: C
authors.lastname: Tsoukalas
authors.forename: M S
authors.initials: MS
authors.lastname: Papadopoulos
authors.forename: T
authors.initials: T
authors.lastname: Maina
authors.forename: I C
authors.initials: IC
authors.lastname: Pirmettis
authors.forename: B A
authors.initials: BA
authors.lastname: Nock
authors.forename: C
authors.initials: C
authors.lastname: Raptopoulou
authors.forename: A
authors.initials: A
authors.lastname: Terzis
authors.forename: E
authors.initials: E
authors.lastname: Chiotellis
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D018360:Crystallography, X-Ray; D003545:Cysteine / Q000031:analogs & derivatives / Q000737:chemistry / Q000493:pharmacokinetics; D004952:Esters / Q000737:chemistry; D008024:Ligands; D008297:Male; D051379:Mice; D015609:Organotechnetium Compounds / Q000737:chemistry / Q000493:pharmacokinetics; D010477:Perfusion; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000493:pharmacokinetics*; D012211:Rhenium / Q000737:chemistry; D013667:Technetium / Q000737:chemistry; D013671:Technetium Tc 99m Sulfur Colloid / Q000138:chemical synthesis / Q000737:chemistry / Q000493:pharmacokinetics*; D017971:Tin Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000493:pharmacokinetics*; D014018:Tissue Distribution
chemical_list: D004952:Esters; D008024:Ligands; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D017971:Tin Compounds; C037609:technetium Tc 99m tin-sulfur colloid; D013671:Technetium Tc 99m Sulfur Colloid; D012211:Rhenium; D013667:Technetium; C059659:technetium Tc 99m bicisate; D003545:Cysteine