The Thai Journal of Pharmaceutical Sciences
Abstract
Radiosynthesis of a novel bifunctional chelator for gallium-68 (Ga-68) chelation has been fabricated through peptide synthesis. Using of solid phase peptide synthesizer, linear structure of three repeating unit of glutamic acid was primarily generated. Protecting group of tert-butyl in intermediate was then cleaved and eventually yield as tri-γ-glutamic acid polypeptide (tri- γ-GAP). Mass spectrometry revealed m/z was 406.1378 that well corresponded with proposed structure of three repeating unit of glutamic acids. To label Ga-68 with synthesized tri-γ-GAP, the elution of 68GaCl3 was chelated to tri-γ-GAP with high temperature condition. It was subsequently purified through Sep-Pak C18 cartridge. Radio thin-layer chromatography demonstrated that the labeling efficiency of 68Ga-tri-γ-GAP was 3.5–3.8 mCi with radiochemical purity more than 98%. The pH was 4.5–5.0. Conclusively, synthesized tri-γ-GAP comprising three N-dentate and four OH-dentate. One more free OH-dentate of tri-γ-GAP provided more applicability over universal chelator of (N,N’,N’’-1,4,7,-triazacyclononane-1,4,7-triyl)triacetic acid (NOTA) on Ga-68 labeling. It is able to link with pharmacological substances without any further modification whereas NOTA needs to be synthesized a specific linker for an attaching with bioactive pharmacological molecule. Novel small peptide chelator of tri-γ-GAP is a promising molecule for Ga-68 labeling with versatile application in radiopharmaceutical diagnosis.
Publisher
Faculty of Pharmaceutical Sciences, Chulalongkorn University
First Page
259
Last Page
263
Recommended Citation
Chongcharoen, Wanchai and Shiratori, Shuichi
(2021)
"Development and radiosynthesis of a
novel bifunctional tri-γ-glutamic acid
polypeptide for gallium-68 labeling,"
The Thai Journal of Pharmaceutical Sciences: Vol. 45:
Iss.
4, Article 5.
Available at:
https://digital.car.chula.ac.th/tjps/vol45/iss4/5