title: Trifluoroacetyl-HYNIC peptides: synthesis and 99mTc radiolabeling.
abstract: Fmoc-lys(HYNIC-Boc)-OH, a precursor for solid-phase synthesis of 99mTc-labeled peptides, was synthesized efficiently without HPLC purification. HPLC-ESMS showed that deprotection and decoupling of peptide from the resin with trifluoroacetic acid gave initially HYNIC-peptide, which was trifluoroacetylated upon prolonged incubation. The trifluoroacetyl-HYNIC group was hydrolyzed during 99mTc labeling, rendering deprotection unnecessary. Trifluoroacetyl-HYNIC peptide was 99mTc-labeled as efficiently, producing the same product, as HYNIC-peptide. These modifications enhance the versatility of HYNIC for 99mTc peptide labeling.
authors.affiliation: Cancer Research Group, Department of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, United Kingdom.
authors.forename: M Bashir-Uddin
authors.initials: MB
authors.lastname: Surfraz
authors.forename: Robert
authors.initials: R
authors.lastname: King
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Mather
authors.forename: Stefano C G
authors.initials: SC
authors.lastname: Biagini
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Blower
mesh_terms: D005463:Fluoroacetates; D005755:Gastrins / Q000138:chemical synthesis* / Q000737:chemistry; D006834:Hydrazines / Q000138:chemical synthesis* / Q000737:chemistry; D006868:Hydrolysis; D007553:Isotope Labeling; D009539:Nicotinic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry; D010446:Peptide Fragments / Q000138:chemical synthesis* / Q000737:chemistry; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000737:chemistry; D013667:Technetium; D014269:Trifluoroacetic Acid / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: C120392:6-hydrazinopyridine-3-carboxylic acid; D005463:Fluoroacetates; D005755:Gastrins; D006834:Hydrazines; D009539:Nicotinic Acids; D009842:Oligopeptides; D010446:Peptide Fragments; D019275:Radiopharmaceuticals; C519112:nanogastrin; D013667:Technetium; D014269:Trifluoroacetic Acid