Synthesis and in vitro evaluation of [18F]fluoroethyl triazole labelled [Tyr3]octreotate analogues using click chemistry
摘要:
A novel class of alkyne linked [Tyr(3)]octreotate analogues have been labelled by a copper catalysed azide-alkyne cycloaddition reaction (CuAAC) to form a 1,4-substituted triazole using the reagent [F-18]2-fluoroethyl azide. An unexpected variability in reactivity during the CuAAC reaction was observed for each alkyne analogue which has been investigated. Two lead alkyne linked [Tyr(3)]octreotate analogues, G-TOCA (3a) and beta AG-TOCA (5a) have been identified to be highly reactive in the click reaction showing complete conversion to the [F-18]2-fluoroethyl triazole linked [Tyr(3)]octreotate analogues FET-G-TOCA (3b) and FET-beta AG-TOCA (5b) under mild conditions and with short synthesis times (5 min at 20 degrees C). As well as ease of synthesis, in vitro binding to the pancreatic tumour AR42J cells showed that both FET-G-TOCA and FET-beta AG-TOCA have high affinity for the somatostatin receptor with IC50 of 4.0 +/- 1.4, and 1.6 +/- 0.2 nM, respectively. (C) 2011 Elsevier Ltd. All rights reserved.
Novel radiotracer(s) for Positron Emission Tomography (PET) imaging are described. Novel radiotracer(s) for Positron Emission Tomography (PET) imaging of neuorendocrine tumors are described. Specifically the present invention describes novel [18F]Fluoroethyltriazol-[Tyr3]Octreotate analogs; in particular those that target somatostatin receptors found on the cell surface of gastroenteropancreatic neuorendocrine tumors. The present invention also describes intermediate(s), precursor(s), pharmaceutical composition(s), methods of making, and methods of use of the novel radiotracer(s).
Synthesis and in vitro evaluation of [18F]fluoroethyl triazole labelled [Tyr3]octreotate analogues using click chemistry
作者:Lisa Iddon、Julius Leyton、Bård Indrevoll、Matthias Glaser、Edward G. Robins、Andrew J.T. George、Alan Cuthbertson、Sajinder Kaur Luthra、Eric O. Aboagye
DOI:10.1016/j.bmcl.2011.03.016
日期:2011.5
A novel class of alkyne linked [Tyr(3)]octreotate analogues have been labelled by a copper catalysed azide-alkyne cycloaddition reaction (CuAAC) to form a 1,4-substituted triazole using the reagent [F-18]2-fluoroethyl azide. An unexpected variability in reactivity during the CuAAC reaction was observed for each alkyne analogue which has been investigated. Two lead alkyne linked [Tyr(3)]octreotate analogues, G-TOCA (3a) and beta AG-TOCA (5a) have been identified to be highly reactive in the click reaction showing complete conversion to the [F-18]2-fluoroethyl triazole linked [Tyr(3)]octreotate analogues FET-G-TOCA (3b) and FET-beta AG-TOCA (5b) under mild conditions and with short synthesis times (5 min at 20 degrees C). As well as ease of synthesis, in vitro binding to the pancreatic tumour AR42J cells showed that both FET-G-TOCA and FET-beta AG-TOCA have high affinity for the somatostatin receptor with IC50 of 4.0 +/- 1.4, and 1.6 +/- 0.2 nM, respectively. (C) 2011 Elsevier Ltd. All rights reserved.