Small interfering RNAs (siRNAs), a class of macromolecules constituted by the association of two single-stranded ribonucleic acids of short sequences, have been labelled with the positron-emitter fluorine-18 (T1/2: 109.8 min). The strategy involves (1) prosthetic conjugation of a single-stranded oligonucleotide with [18F]FPyBrA (N-[3-(2-[18F]fluoropyridin-3-yloxy)-propyl]-2-bromoacetamide) followed by (2) formation of the target duplex by annealing with the complementary sequence, therefore, permitting parallel and combinatorial preparation of [18F]siRNAs. Pure fluorine-18-labelled siRNAs (0.55–1.11 GBq, specific activity: 74–148 GBq/µmol at EOB) could be obtained within 165 min starting from 37.0 GBq of starting [18F]fluoride (1.5–3.0%, non-decay-corrected isolated yields). Copyright © 2007 John Wiley & Sons, Ltd.
                                    小干扰 RNA(siRNA)是由两个短序列的单链
核糖核酸结合而成的一类大分子,已被正电子发射体
氟-18 标记(T1/2:109.8 分钟)。该策略包括:(1) 用[18F]FPyBrA(N-[3-(2-[18F]
氟吡啶-3-氧基)-丙基]-2-
溴乙酰胺)对单链寡核苷酸进行修复性连接,然后(2) 通过与互补序列退火形成目标双链,因此可以平行和组合地制备[18F]siRNA。从 37.0 GBq 的起始[18F]
氟化物(1.5-3.0%,非衰变校正分离产率)开始,可在 165 分钟内获得纯的
氟-18 标记 siRNA(0.55-1.11 GBq,比活度:74-148 GBq/µmol at 
EOB)。Copyright © 2007 John Wiley & Sons, Ltd. All Rights Reserved.