A previous report has demonstrated the existence of a C4-hydroxylated vitamin D2 metabolite in serum of rats treated with pharmacological doses of vitamin D2. However, the biological significance and metabolic fate of this metabolite have not been described. To explore its potential biological activities, we therefore synthesized 1α,4α,25-trihydroxyvitamin D3 and its diastereoisomer, 1α,4β,25-trihydroxyvitamin D3, using Trost Pd-mediated coupling reaction, and studied their vitamin D receptor (VDR) binding affinity, osteocalcin promoter transactivation activity, and their further metabolism by human CYP24A1 as well as by human liver microsomal fraction based on CYP- and UDP-glucuronosyltransferases (UGTs)-reactions.
之前的一份报告显示,在接受药理剂量
维生素 D2 治疗的大鼠血清中存在一种 C
4-羟化
维生素 D2 代谢物。然而,这种代谢物的
生物学意义和代谢命运尚未得到描述。为了探索其潜在的
生物活性,我们利用 Trost Pd 介导的偶联反应合成了 1α,4α,25-三羟
维生素 D3 及其非对映异构体 1α,4β,25-三羟
维生素 D3、并研究了它们与
维生素 D 受体(VDR)的结合亲和力、骨
钙素启动子的转录活性,以及它们在人类 CYP24A1 和人类肝脏微粒体组分中的进一步代谢(基于 CYP 和
UDP-
葡萄糖醛酸转移酶(UGTs)反应)。