Paquin J, Baugh C M, MacKenzie R E
Anal Biochem. 1985 Apr;146(1):52-8. doi: 10.1016/0003-2697(85)90394-x.
Tritium-labeled [6S]-tetrahydropteroylpolyglutamates of high radiospecific activity were prepared from the corresponding pteroylpolyglutamates. Malic enzyme and D,L-[2-3H]malate were used as a generating system to produce [4A-3H]NADPH which was coupled to the dihydrofolate reductase-catalyzed reduction of chemically prepared dihydropteroylpolyglutamate derivatives. Passage of the reaction mixtures through a column of immobilized boronate effectively removed NADPH, and the tetrahydropteroylpolyglutamates were subsequently purified by chromatography on DEAE-cellulose. Overall yields of the [6S]-tetrahydro derivatives were 18-48% and the radiospecific activities were 3-4.5 mCi X mumol-1.
高放射性比活度的氚标记[6S]-四氢蝶酰多聚谷氨酸盐由相应的蝶酰多聚谷氨酸盐制备而成。苹果酸酶和D,L-[2-³H]苹果酸用作生成系统，以产生[4A-³H]NADPH，其与化学制备的二氢蝶酰多聚谷氨酸衍生物的二氢叶酸还原酶催化还原反应相偶联。反应混合物通过固定化硼酸盐柱可有效去除NADPH，随后通过DEAE-纤维素柱色谱法纯化四氢蝶酰多聚谷氨酸盐。[6S]-四氢衍生物的总产率为18%-48%，放射性比活度为3-4.5 mCi·μmol⁻¹。
