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.
DOI
10.56808/3027-7922.2500
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.
DOI: https://doi.org/10.56808/3027-7922.2500
Available at:
https://digital.car.chula.ac.th/tjps/vol45/iss4/5