Preparation of (6R)-tetrahydrofolic acid and (6R)-5-formyltetrahydrofolic acid of high stereochemical purity.
Preparation of (6R)-tetrahydrofolic acid and (6R)-5-formyltetrahydrofolic acid of high stereochemical purity.
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高立体化学纯度的(6R)-四氢叶酸和(6R)-5-甲酰基四氢叶酸的制备。
DOI：
10.1016/0003-2697(86)90024-2
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发表时间：
1986
影响因子：
2.9
通讯作者：
Moran,RG
中科院分区：
文献类型：
--
作者：
Sato,JK;Newman,EM;Moran,RG
可商购的5-甲酰基四氢叶酸（5-CHO-H4 PteGlu）在反应中化学制备，该反应在6碳引入不对称中心，因此是在该位置手性不同的非对映异构体的混合物。（6 R）-5-CHO-H4 PteGlu，通常在体内不存在的非对映体，由叶酸制备。叶酸被化学还原，并且（6 R）-四氢叶酸（H4 PteGlu）通过用干酪乳杆菌胸苷酸合酶酶促消耗（6 R，S）-5，10-CH 2-H4 PteGlu的天然非对映异构体（在甲醛存在下由（6 R，S）-H4 PteGlu可逆形成）而从所得的（6 R，S）-H4 PteGlu获得。纯化的（6 R）-H4 PteGlu的5位在马来酰亚胺催化的反应中直接甲酰化。使用氟脱氧尿苷酸与胸苷酸合酶的结合来估计这些制剂被相应的6S非对映异构体污染的水平，所述胸苷酸合酶由叶酸辅因子（对于H4 PteGlu）和需要叶酸的细菌的生长（对于5-CHO-H4 PteGlu）促进。纯化的（6 R）-H4 PteGlu制剂促进氟脱氧尿苷酸与L.酪蛋白胸苷酸合酶（在甲醛存在下）仅在比（6S）-H4 PteGlu的等活性水平高>1000倍的浓度下。同样，通过该方法制备的（6 R）-5-CHO-H4 PteGlu作为酿酒片球菌的生长因子的活性比真实的（6S）-5-CHO-H4 PteGlu低600倍。因此，这些制备物的最小立体化学纯度对于（6 R）-H4 PteGlu为99.9%，对于（6 R）-5-CHO-H4 PteGlu为99.8%。
Commercially available 5-formyltetrahydrofolate (5-CHO-H4PteGlu) is chemically prepared in a reaction that introduces an asymmetric center at the 6 carbon, and hence is the mixture of diastereomers differing in chirality about this position. (6R)-5-CHO-H4PteGlu, the diastereomer that is not normally found in vivo, was prepared from folic acid. Folic acid was chemically reduced and (6R)-tetrahydrofolate (H4PteGlu) was obtained from the resultant (6R,S)-H4PteGlu by enzymatic consumption of the natural diastereomer of (6R,S)-5,10-CH2-H4PteGlu (reversibly formed from (6R,S)-H4PteGlu in the presence of formaldehyde) with Lactobacillus casei thymidylate synthase. The 5 position of purified (6R)-H4PteGlu was directly formylated in a carbodiimide-catalyzed reaction. The level of contamination of these preparations with the corresponding 6S diastereomers was estimated using the binding of fluorodeoxyuridylate to thymidylate synthase promoted by folate cofactor (for H4PteGlu) and by the growth of folate requiring bacteria (for 5-CHO-H4PteGlu). Purified preparations of (6R)-H4PteGlu promoted the binding of fluorodeoxyuridylate to L. casei thymidylate synthase (in the presence of formaldehyde) only at concentrations >1000-fold higher than equiactive levels of (6S)-H4PteGlu. Likewise, the (6R)-5-CHO-H4PteGlu made by this method was 600 times less active as a growth factor for Pediococcus cerevisiae than was authentic (6S)-5-CHO-H4PteGlu. Hence, the minimum stereochemical purity of these preparations was 99.9% for (6R)-H4PteGlu and 99.8% for (6R)-5-CHO-H4PteGlu.
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DOI：
10.1073/pnas.78.11.6689
发表时间：
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