title: Synthesis of N-succinimidyl 4-guanidinomethyl-3-[*I]iodobenzoate: a radio-iodination agent for labeling internalizing proteins and peptides.
abstract: This protocol describes a detailed procedure for the synthesis of N-succinimidyl 4-guanidinomethyl-3-[*I]iodobenzoate ([*I]SGMIB), an agent useful in the radio-iodination of proteins, including monoclonal Abs, and peptides that undergo internalization after receptor or antigen binding. In this procedure, the tin precursor N-succinimidyl 4-[N1,N2-bis(tert-butyloxycarbonyl)guanidinomethyl]-3-(trimethylstannyl)benzoate (Boc-SGMTB, 3) was first radio-iodinated to [*I]Boc-SGMIB, a derivative of [*I]SGMIB with the guanidine function protected with Boc groups. Treatment of [*I]Boc-SGMIB with trifluoroacetic acid delivered the final product. The total time for the synthesis and purification of [*I]Boc-SGMIB and its subsequent de-protection is approximately 140 min.
authors.affiliation: Department of Radiology, Duke University Medical Center, Durham, North Carolina, USA. ganesan.v@duke.edu
authors.forename: Ganesan
authors.initials: G
authors.lastname: Vaidyanathan
authors.forename: Michael R
authors.initials: MR
authors.lastname: Zalutsky
mesh_terms: D001565:Benzoates / Q000138:chemical synthesis* / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D019791:Guanidine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000302:isolation & purification; D015394:Molecular Structure; D011506:Proteins / Q000032:analysis*; D013194:Staining and Labeling / Q000379:methods*
chemical_list: D001565:Benzoates; C438937:N-succinimidyl 4-guanidinomethyl-3-iodobenzoate; D011506:Proteins; D019791:Guanidine