Improved syntheses of P2X(7) ligands based on substituted benzyl amide of pyroglutamic acid motif labelled with iodine-123 or iodine-125

• P2X(7) sites are emerging targets for molecular imaging research, notably in the context of neurodegeneration and inflammatory conditions. Therefore, we prepared a precursor for (radio)iodination of the P2X(7) ligand VPGIS191. We then developed a radioiodination method with I-123 for SPECT with a radiochemical yield of 71 +/- 13% and I-125 for autoradiography with a radiochemical yield of 85 +/- 6% Autoradiography of [I-125]VPGIS191 in mouse brain cryostat sections demonstrated approximately 36 nM binding affinity and B-max of approximately 400 pmol/gram tissue for P2X(7) binding sites. VPGIS191 (cis) had a two-fold lower affinity compared to its geometric trans-isomer TZ6019.

Subject headings

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Keyword

Radiopharmaceuticals

P2X(7) receptor

Autoradiography

Single photon

emission tomography

in-vitro characterization

p2x7 receptor

radioligand

binding

agent

Chemistry

Nuclear Science & Technology

Publication and Content Type

ref (subject category)

art (subject category)