- Comparison of radioiodine- or radiobromine-labeled rgd peptides between direct and indirect labeling methods
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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.
- Ogawa, Kazuma,Takeda, Takuya,Yokokawa, Masaru,Yu, Jing,Makino, Akira,Kiyono, Yasushi,Shiba, Kazuhiro,Kinuya, Seigo,Odani, Akira
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p. 651 - 659
(2018/06/11)
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- Synthesis and evaluation of radioiodinated acyloxymethyl ketones as activity-based probes for cathepsin B
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Dipeptidyl (acyloxy)methyl ketones (AOMKs) were functionalized with different iodine-containing prosthetic groups to generate a library of candidate cathepsin B probes. Compound 23a, (S)-20-[(S)-2-{[(benzyloxy)carbonyl]amino}-3-phenylpropanamido]-1-(4-iod
- Edem, Patricia E.,Czorny, Shannon,Valliant, John F.
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supporting information
p. 9564 - 9577
(2015/02/02)
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- Preparation of asymmetric urea derivatives that target prostate-specific membrane antigen for SPECT imaging
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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.
- Harada, Naoya,Kimura, Hiroyuki,Ono, Masahiro,Saji, Hideo
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p. 7890 - 7901
(2013/11/06)
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- Synthesis and evaluation of aryl-naloxamide opiate analgesics targeting truncated exon 11-associated μ opioid receptor (MOR-1) splice variants
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3-Iodobenzoylnaltrexamide 1 (IBNtxA) is a potent analgesic acting through a novel receptor target that lack many side-effects of traditional opiates composed, in part, of exon 11-associated truncated six transmembrane domain MOR-1 (6TM/E11) splice variant
- Majumdar, Susruta,Subrath, Joan,Le Rouzic, Valerie,Polikar, Lisa,Burgman, Maxim,Nagakura, Kuni,Ocampo, Julie,Haselton, Nathan,Pasternak, Anna R.,Grinnell, Steven,Pan, Ying-Xian,Pasternak, Gavril W.
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experimental part
p. 6352 - 6362
(2012/09/22)
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- Generation of novel radiolabeled opiates through site-selective iodination
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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
- Majumdar, Susruta,Burgman, Maxim,Haselton, Nathan,Grinnell, Steven,Ocampo, Julia,Pasternak, Anna Rose,Pasternak, Gavril W.
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supporting information; experimental part
p. 4001 - 4004
(2011/08/06)
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- RADIOIODINATION METHOD
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The present invention provides a method for the synthesis of radioiodinated compounds which is advantageous over prior art methods. Using a hydrazine or an aminoxy in place of a primary amine for indirect radioiodination facilitates a much quicker reaction thus reducing reaction time and increasing the yield. In addition, where there are primary amines in the molecule to be radioiodinated, such as the N-terminus of a peptide or lysine residues, reaction at the hydrazine or aminoxy is greatly favoured.
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Page/Page column 23
(2010/08/09)
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- FORMATION OF 18F AND 19F FLUOROARENES BEARING REACTIVE FUNCTIONALITIES
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An iodonium compound of formula (I): where RAR1 is a C5-6 aryl group, bearing at least one substituent selected from formyl, thionoacyl, acylamidocarboxy, thionoester, azo, C2-20 alkenyl, C2-20 alkynyl, and (CH
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Page/Page column 9
(2009/12/05)
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- A simple and efficient method to label l-fucose
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This letter reports a new labeling method of fucoidan and more precisely of its monomer, l-fucose. We studied the coupling processes of new aryliodide precursors to l-fucose in order to prepare the next step, that is, the fucoidan radiolabeling. The use o
- Jestin, Emmanuelle,Bultel-Rivière, Karine,Faivre-Chauvet, Alain,Barbet, Jacques,Loussouarn, Anthony,Gestin, Jean-Fran?ois
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p. 6869 - 6873
(2007/10/03)
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- Nonsymmetrical bipiperidyls as inhibitors of vesicular acetylcholine storage
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Introduction of a nitrogen atom into the cyclohexane ring of 2-(4- phenylpiperidinyl)cyclohexanol (vesamicol, AH5183) yielded two positional isomers, 5-azavesamicol (5, prezamicol) and 4-azavesamicol (6, trozamicol). As inhibitors of vesicular acetylcholi
- Efange,Khare,Parsons,Bau,Metzenthin
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p. 985 - 989
(2007/10/02)
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