Shiba K, Mori H, Hisada K
Radioisotopes. 1986 Jul;35(7):361-6. doi: 10.3769/radioisotopes.35.7_361.
In order to study the tumor specificity of synthetic nonmetabolizing amino acids, 10 different 14C labeled alicyclic amino acids (3a-3j) were synthesized in high yield and with high specific radioactivity. Carbon-14 labeled alicyclic hydantoins (2a-2j) were synthesized from a small amount of radioactive potassium [14C] cyanide and corresponding ketones (1a-1j). Th 14C hydantoins (2a-2j) thus obtained were hydrolyzed without isolation to give 14C labeled alicyclic amino acids (3a-3j). The overall radiochemical yields of the amino acids (3a-3j) from potassium [14C] cyanide were 55.6-93.2% with radiochemical purity more than 99%. Specific activities of these 14C labeled compounds (3a-3j) were 209- 250 MBq/mmol (5.66-6.75 mCi/mmol). When non-radioactive potassium cyanide was not added as a carrier, 1-aminocyclopentane[14C]-carboxylic acid (3b) and 1-aminocyclooctane[14C]carboxylic acid (3e) were synthesized in the yield of 64.9 and 19.0% respectively with the specific activity exceed more than 1.85 GBq/mmol (50mCi/mmol).
为了研究合成的非代谢氨基酸的肿瘤特异性，以高产率和高比放射性合成了10种不同的14C标记脂环族氨基酸（3a - 3j）。由少量放射性[14C]氰化钾和相应的酮（1a - 1j）合成了14C标记的脂环族乙内酰脲（2a - 2j）。如此得到的14C乙内酰脲（2a - 2j）无需分离直接水解，得到14C标记的脂环族氨基酸（3a - 3j）。从[14C]氰化钾得到的氨基酸（3a - 3j）的总放射化学产率为55.6 - 93.2%，放射化学纯度大于99%。这些14C标记化合物（3a - 3j）的比活度为209 - 250 MBq/mmol（5.66 - 6.75 mCi/mmol）。当不添加非放射性氰化钾作为载体时，分别以64.9%和19.0%的产率合成了1 - 氨基环戊烷[14C] - 羧酸（3b）和1 - 氨基环辛烷[14C]羧酸（3e），比活度超过1.85 GBq/mmol（50mCi/mmol）。
