Rosen M A, Jones R M, Yano Y, Budinger T F
J Nucl Med. 1985 Dec;26(12):1424-8.
We report an improved method for the synthesis and purification of [11C]methylcholine from the precursors [11C]methyliodide and 2-dimethylaminoethanol (deanol). Preparation time, including purification, is 35 min postbombardment. Forty millicuries of purified injectable [11C]choline were produced with a measured specific activity of greater than 300 Ci/mmol and a radiochemical purity greater than 98%. The decay corrected radiochemical yield for the synthesis and purification was approximately 50%. Residual precursor deanol, which inhibits brain uptake of choline, is removed by a rapid preparative high performance liquid chromatography (HPLC) method using a reverse phase cyano column with a biologically compatible 100% water eluent. Evaporation alone did not completely remove the deanol precursor. Brain uptake of the [11C]choline product was six times greater after HPLC removal of deanol because doses of less than 1 microgram/kg significantly inhibit [14C]choline brain uptake.
我们报告了一种从前体[¹¹C]甲基碘和2-二甲基氨基乙醇（二甲氨基乙醇）合成及纯化[¹¹C]甲基胆碱的改进方法。包括纯化在内的制备时间为轰击后35分钟。制备出了40毫居里的可注射纯化[¹¹C]胆碱，其测量的比活度大于300居里/毫摩尔，放射化学纯度大于98%。合成及纯化的衰变校正放射化学产率约为50%。抑制胆碱脑摄取的残留前体二甲氨基乙醇，通过使用反相氰基柱和生物相容性100%水洗脱液的快速制备高效液相色谱（HPLC）方法去除。仅靠蒸发不能完全去除二甲氨基乙醇前体。在通过HPLC去除二甲氨基乙醇后，[¹¹C]胆碱产物的脑摄取增加了六倍，因为低于1微克/千克的剂量会显著抑制[¹⁴C]胆碱的脑摄取。
