Wang Chunlei, Armstrong Daniel W, Chang Chau-Dung
Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX 76019, USA.
J Chromatogr A. 2008 Jun 20;1194(2):172-7. doi: 10.1016/j.chroma.2008.04.063. Epub 2008 May 1.
Astaxanthin (3,3'-dihydroxy-beta,beta-carotene-4,4'-dione) is widely used as important colorant in the aquaculture feed industry, and as nutraceuticals in human health products. Synthetic all-trans-astaxanthin consists of a mixture of a pair of enantiomers (3R,3'R and 3S,3'S) and a mesoform (3R,3'S). A high-performance liquid chromatography (HPLC) method for direct, rapid, and baseline separation of three stereoisomers of all-trans-astaxanthin is described for the first time on an immobilized cellulosic column (Chiralpak IC). Enantiomers of two important precursors in the biosynthetic pathway of astaxanthin, adonirubin and adonixanthin, were also directly separated. In addition, the major cis form of astaxanthin (13-cis-astaxanthin) resulted from isomerization was isolated with preparative C18 separation, and the separation of all four stereoisomers of 13-cis-astaxanthin is achieved. Finally, a stereoisomeric purity test of commercial astaxanthin supplements confirmed that they were from a natural source, although their levels were quite low.
虾青素(3,3'-二羟基-β,β-胡萝卜素-4,4'-二酮)在水产养殖饲料工业中被广泛用作重要的着色剂,在人类健康产品中用作营养保健品。合成的全反式虾青素由一对对映体(3R,3'R和3S,3'S)和一种内消旋体(3R,3'S)的混合物组成。首次描述了一种在固定化纤维素柱(Chiralpak IC)上直接、快速且基线分离全反式虾青素三种立体异构体的高效液相色谱(HPLC)方法。虾青素生物合成途径中两种重要前体的对映体,即3'-羟基-β-阿朴-8'-胡萝卜醛和3'-羟基-β-阿朴-8'-胡萝卜素,也被直接分离。此外,通过制备型C18分离法分离出了由异构化产生的虾青素主要顺式异构体(13-顺式虾青素),并实现了13-顺式虾青素所有四种立体异构体的分离。最后,对市售虾青素补充剂的立体异构体纯度测试证实它们来自天然来源,尽管其含量相当低。