Yamada S, Nakayama K, Takayama H, Shinki T, Takasaki Y, Suda T
J Biol Chem. 1984 Jan 25;259(2):884-9.
23S,25R,26-Trihydroxyvitamin D3 and (23S,25R)-25-hydroxyvitamin D3 26,23-lactol were chemically synthesized, and the metabolism of the two compounds to (23S,25R)-25-hydroxyvitamin D3 26,23-lactone in chick kidney homogenates was studied. 23S,25R,26-trihydroxyvitamin D3 was efficiently metabolized to the lactone in kidney homogenates from vitamin D-supplemented chicks, but not from vitamin D-deficient chicks. In contrast, the (23S,25R)-25-hydroxyvitamin D3 26,23-lactol was converted to the lactone in kidney homogenates regardless of the vitamin D status of the animals used. A new metabolite was isolated in pure form from the incubation mixture of 23S,25R,26-trihydroxyvitamin D3 with kidney homogenates prepared from vitamin D-supplemented chicks. The metabolite was identified as (23S,25R)-25-hydroxyvitamin D3 26,23-lactol by its ultraviolet and mass spectra and by derivatization. The structure was confirmed by direct comparison with an authentic sample on high pressure liquid chromatography. The evidence suggests that the stereochemistries of the isolated lactol at the 23- and 25-positions are S and R, respectively.
化学合成了23S,25R,26 - 三羟基维生素D3和(23S,25R)-25 - 羟基维生素D3 26,23 - 内酯醇，并研究了这两种化合物在雏鸡肾脏匀浆中代谢为(23S,25R)-25 - 羟基维生素D3 26,23 - 内酯的情况。23S,25R,26 - 三羟基维生素D3在补充维生素D的雏鸡肾脏匀浆中能有效地代谢为内酯，但在维生素D缺乏的雏鸡肾脏匀浆中则不能。相反，无论所用动物的维生素D状态如何，(23S,25R)-25 - 羟基维生素D3 26,23 - 内酯醇在肾脏匀浆中都能转化为内酯。从23S,25R,26 - 三羟基维生素D3与补充维生素D的雏鸡制备的肾脏匀浆的孵育混合物中以纯形式分离出一种新的代谢产物。通过其紫外光谱和质谱以及衍生化作用，将该代谢产物鉴定为(23S,25R)-25 - 羟基维生素D3 26,23 - 内酯醇。通过在高压液相色谱上与标准样品直接比较，证实了其结构。证据表明，分离出的内酯醇在23位和25位的立体化学结构分别为S型和R型。
