Radiolabeled guanine derivatives for the in vivo mapping of O(6)-alkylguanine-DNA alkyltransferase: 6-(4-[(18)F]Fluoro-benzyloxy)-9H-purin-2-ylamine and 6-(3-[(131)I]Iodo-benzyloxy)-9H-purin-2-ylamine.

Journal Article

Two radiolabeled analogues of 6-benzyloxy-9H-purin-2-ylamine (O(6)-benzylguanine; BG) potentially useful in the in vivo mapping of O(6)-alkylguanine-DNA alkyltransferase (AGT) were synthesized. Fluorine-18 labeling of the known 6-(4-fluoro-benzyloxy)-9H-purin-2-ylamine (FBG; 6) was accomplished by the condensation of 4-[(18)F]fluorobenzyl alcohol with 2-aminopurin-6-yltrimethylammonium chloride (4) or 2-amino-6-chloropurine in average decay-corrected radiochemical yields of 40 and 25%, respectively. Unlabeled 6-(3-iodo-benzyloxy)-9H-purin-2-ylamine (IBG; 7) was prepared from 4 and 3-iodobenzyl alcohol. Radioiodination of 9, prepared from 7 in two steps, and subsequent deprotection gave [(131)I]7 in about 70% overall radiochemical yield. The IC(50) values for the inactivation of AGT from CHO cells transfected with pCMV-AGT were 15 nM for IBG and 50 nM for FBG. The binding of [(18)F]6 and [(131)I]7 to purified AGT was specific and saturable with both exhibiting similar IC(50) values (5-6 microM).

Full Text

Duke Authors

Cited Authors

  • Vaidyanathan, G; Affleck, DJ; Cavazos, CM; Johnson, SP; Shankar, S; Friedman, HS; Colvin, MO; Zalutsky, MR

Published Date

  • November 2000

Published In

Volume / Issue

  • 11 / 6

Start / End Page

  • 868 - 875

PubMed ID

  • 11087336

International Standard Serial Number (ISSN)

  • 1043-1802

Language

  • eng

Conference Location

  • United States