Synthesis of no-carrier-added C-11 labeled D- and L-enantiomers of phenylalanine and tyrosine for comparative PET Studies

详细信息    查看全文

• 作者：Studenov ; Andrei R. ; Szalda ; Dava E. ; Ding ; Yu-Shin
• 关键词：Tyrosine ; Phenylalanine ; Bucherer-Strecker synthesis ; Chiral separation ; C-11 ; Positron Emission Tomography
• 刊名：Nuclear Medicine and Biology
• 出版年：2003
• 出版时间：January, 2003
• 年：2003
• 卷：30
• 期：1
• 页码：39-44
• 全文大小：79.3 K

文摘

The natural amino acids tyrosine (Tyr) and phenylalanine (Phe) were labeled with carbon-11 via a modified Bucherer-Strecker synthesis. A rapid reaction of the sodium bisulfite adduct of the aldehyde precursor with ammonia provided the precursor for radiosynthesis. [¹¹C]Cyanide displacement followed by base hydrolysis afforded the corresponding ¹¹C-labeled amino acids. The purification and chiral separation were simply achieved by using a combination of solid-phase extraction and chiral HPLC to afford individual enantiomers of each amino acid. The decay corrected radiochemical yields for each of the enantiomers were 12–16 % with respect to the [¹¹C]cyanide after 40–45 min of radiosynthesis. Radiochemical purity of the products was >97 % (typically >99 % ), enantiomeric excess was >98 % with the specific radioactivity 2–3 Ci/μmol at the end of bombardment. Because of its simplicity and wide applicability, the described procedure could be the method of choice to produce [¹¹C]amino acids for PET studies.