A Polar Substituent-Containing Acylation Agent for the Radioiodination of Internalizing Monoclonal Antibodies: N-Succinimidyl 4-Guanidinomethyl-3-[131I]iodobenzoate ([131I]SGMIB) was written by Vaidyanathan, Ganesan;Affleck, Donna J.;Li, Jean;Welsh, Phil;Zalutsky, Michael R.. And the article was included in Bioconjugate Chemistry in 2001.Application In Synthesis of 5-Iodonicotinic acid This article mentions the following:
The objective of this study was to develop an acylation agent for the radioiodination of monoclonal antibodies that would maximize retention of the label in tumor cells following receptor- or antigen-mediated internalization. The strategy taken was to add a polar substituent to the labeled aromatic ring to impede transport of labeled catabolites across lysosomal and cell membranes after antibody degradation Preparation of unlabeled N-succinimidyl 4-guanidinomethyl-3-iodobenzoate (SGMIB) was achieved in six steps from 3-iodo-4-methylbenzoic acid. Preparation of 4-guanidinomethyl-3-[131I]iodobenzoic acid from the silicon precursor, 4-(N1,N2-bis-tert-butyloxycarbonyl)guanidinomethyl-3-trimethylsilylbenzoic acid proceeded in less than 5% radiochem. yield. A more successful approach was to prepare [131I]SGMIB directly from the tin precursor, N-succinimidyl 4-(N1,N2-bis-tert-butyloxycarbonyl)guanidinomethyl-3-trimethylstannylbenzoate, which was achieved in 60-65% radiochem. yield. A rapidly internalizing anti-epidermal growth factor receptor variant III antibody L8A4 was labeled using [131I]SGMIB in 65% conjugation efficiency and with preservation of immunoreactivity. Paired-label in vitro internalization assays demonstrated that the amount of radioactivity retained in cells after internalization for L8A4 labeled with [131I]SGMIB was 3-4-fold higher than that for L8A4 labeled with 125I using either Iodogen or [125I]SIPC. Catabolite assays documented that the increased retention of radioiodine in tumor cells for antibody labeled using [131I]SGMIB was due to pos. charged, low mol. weight species. These results suggest that [131I]SGMIB warrants further evaluation as a reagent for labeling internalizing antibodies. In the experiment, the researchers used many compounds, for example, 5-Iodonicotinic acid (cas: 15366-65-1Application In Synthesis of 5-Iodonicotinic acid).
5-Iodonicotinic acid (cas: 15366-65-1) belongs to iodide derivatives. Iodide-containing intermediates are common in organic synthesis, because of the easy formation and cleavage of the C–I bond. Polyiodoorganic compounds are sometimes employed as X-ray contrast agents, in fluoroscopy, a type of medical imaging. This application exploits the X-ray absorbing ability of the heavy iodine nucleus.Application In Synthesis of 5-Iodonicotinic acid
Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com