91487-18-2Relevant articles and documents
Comparison of radioiodine- or radiobromine-labeled rgd peptides between direct and indirect labeling methods
Ogawa, Kazuma,Takeda, Takuya,Yokokawa, Masaru,Yu, Jing,Makino, Akira,Kiyono, Yasushi,Shiba, Kazuhiro,Kinuya, Seigo,Odani, Akira
, p. 651 - 659 (2018/06/11)
Radiolabeled cyclic peptides containing the (Arg-Gly-Asp) RGD sequence for use in positron emission tomography (PET) imaging, single-photon emission computed tomography (SPECT) imaging, and targeted radionuclide therapy of cancer have been reported. In this study, RGD was used as a model carrier peptide for diagnosis and therapy of cancer. To evaluate the characteristics of radiohalogen-labeled peptides, several kinds of labeled RGD peptides [125I-c(RGDyK), 77Br-c(RGDyK), [125I]SIB-c(RGDfK), [77Br]SBrB-c(RGDfK), [125I]SIB-EG2-c(RGDfK), and [77Br]SBrB-EG2-c(RGDfK)] were designed, prepared, and evaluated. In these initial studies, 77Br (t1/2=57.0h) and 125I (t1/2=59.4d) were used because of their longer half-lives. Precursor peptides were synthesized using a standard 9-fluorenylmethyloxycarbonyl (Fmoc)-based solid-phase methodology. Radiolabeled peptides were prepared by chloramine-T method or conjugation of RGD peptides with [125I]N-succinimidyl 3-iodobenzoate ([125I]SIB) or [77Br]N-succinimidyl 3-bromobenzoate ([77Br]SBrB). Measurement of the partition coefficients, integrin binding assay, and biodistribution experiments in tumor-bearing mice were performed. 125I and 77Br labeling were successfully performed using similar methods, and in vitro characteristics and biodistributions were similar between the 125I-labeled and corresponding 77Br-labeled peptides. [125I]SIB- and [77Br]SBrB-conjugated RGD peptides showed higher partition coefficients, lower tumor uptakes, and higher intestinal uptake than 125I-c(RGDyK) and 77Br-c(RGDyK). [125I]SIB-EG2-c(RGDfK) and [77Br]SBrB-EG2-c(RGDfK), which possess an ethylene glycol linker, decreased lipophilicity and uptake in intestine compared with [125I]SIB-c(RGDfK) and [77Br]SBrB-c(RGDfK), which possess no linker. However, the improvement in biodistribution of [125I]SIB-EG2-c(RGDfK) and [77Br]SBrB-EG2-c(RGDfK)] was insufficient. In conclusion, directly radiohalogenated c(RGDyK) peptides are potentially more useful for tumor imaging and therapy than indirectly radiohalogenated ones.
Preparation of asymmetric urea derivatives that target prostate-specific membrane antigen for SPECT imaging
Harada, Naoya,Kimura, Hiroyuki,Ono, Masahiro,Saji, Hideo
, p. 7890 - 7901 (2013/11/06)
Prostate-specific membrane antigen (PSMA) has been identified as a diagnostic and therapeutic target for prostate cancer. (S)-2-[3-[(R)-1-Carboxy- 2-mercaptoethyl]ureido-pentanedioic acid (Cys-CO-Glu) were used to design novel PSMA targeting probes by nucleophilic conjugate addition between cysteine and maleimide based reagents. 3 ([123I]IGLCE) was synthesized by this strategy and showed high affinity for PSMA. Results of binding inhibition assays of these derivatives suggested the importance of an aromatic group and succinimide moiety for high affinity. [123I]3 was evaluated in vivo with PSMA positive LNCaP and PSMA negative PC-3 human prostate cancer xenograft bearing mice. [125I]3 accumulated in LNCaP tumors but not in PC-3 tumors, and the accumulation was inhibited by 2-(phosphonomethyl)pentanedioic acid (2-PMPA). Use of [123I]3 provided positive images of LNCaP tumors in single photon emission tomography scans. These results warrant further evaluation of [123I]3 and its derivatives as radiolabeled probes for the diagnosis of prostate cancer.
Generation of novel radiolabeled opiates through site-selective iodination
Majumdar, Susruta,Burgman, Maxim,Haselton, Nathan,Grinnell, Steven,Ocampo, Julia,Pasternak, Anna Rose,Pasternak, Gavril W.
supporting information; experimental part, p. 4001 - 4004 (2011/08/06)
Tritiated opioid radioligands have proven valuable in exploring opioid binding sites. However, tritium has many limitations. Its low specific activity and limited counting efficiency makes it difficult to examine low abundant, high affinity sites and its
