23,25-二羟基维生素D3：25-羟基维生素D3-26,23-内酯生物合成中的天然前体。
23,25-Dihydroxyvitamin D3: a natural precursor in the biosynthesis of 25-hydroxyvitamin D3-26,23-lactone.
作者信息
Tanaka Y, DeLuca H F, Schnoes H K, Ikekawa N, Eguchi T
出版信息
Proc Natl Acad Sci U S A. 1981 Aug;78(8):4805-8. doi: 10.1073/pnas.78.8.4805.
To elucidate the biosynthesis of 25-hydroxyvitamin D3-26,23-lactone, two known metabolites of 25-hydroxyvitamin D3--23,25-dihydroxyvitamin D3 and 25,26-dihydroxyvitamin D3--were incubated individually with kidney homogenate prepared from vitamin D-supplemented chickens, a preparation known to produce the lactone from 25-hydroxyvitamin D3. The 25-hydroxyvitamin D3-26,23-lactone produced in vitro was then separated, purified, identified, and quantitated by consecutive straight-phase and reverse-phase high-performance liquid chromatography. 23,25-Dihydroxyvitamin D3 is a far better substrate for production of 25-hydroxyvitamin D3-26,23-lactone than is 25,26-dihydroxyvitamin D3. Production of lactone is highly selective for the natural 23(S)-hydroxy-23,25-dihydroxyvitamin D3 while both epimers of 25,26-dihydroxyvitamin D3 resulted in small amounts of product comigrating with natural lactone. It appears that 23(S),25-dihydroxyvitamin D3, but not 25,26-dihydroxyvitamin D3, is a natural precursor in the synthesis of 25-hydroxyvitamin D3-26,23-lactone; this result also implies that the configuration of the lactone at C-23 is S.
为阐明25-羟基维生素D3-26,23-内酯的生物合成过程，将25-羟基维生素D3的两种已知代谢产物——23,25-二羟基维生素D3和25,26-二羟基维生素D3——分别与从补充了维生素D的鸡制备的肾匀浆一起孵育，该制剂已知可从25-羟基维生素D3产生内酯。然后通过连续的正相和反相高效液相色谱法分离、纯化、鉴定并定量体外产生的25-羟基维生素D3-26,23-内酯。与25,26-二羟基维生素D3相比，23,25-二羟基维生素D3是生成25-羟基维生素D3-26,23-内酯的更好底物。内酯的生成对天然的23(S)-羟基-23,25-二羟基维生素D3具有高度选择性，而25,26-二羟基维生素D3的两种差向异构体都产生了少量与天然内酯共迁移的产物。看来23(S),25-二羟基维生素D3而非25,26-二羟基维生素D3是合成25-羟基维生素D3-26,23-内酯的天然前体；这一结果也意味着内酯在C-23处的构型为S。
Zotero 插件