类胡萝卜素是一类存在于水果和蔬菜中的天然色素，除了植物，许多光合细菌和真菌也可以合成类胡萝卜素，它们是萜类衍生物，并且在其结构中存在很多共轭双键。天然生成的类胡萝卜素主要有两大类：（1）α-胡萝卜素和 β-胡萝卜素，属于类胡萝卜素类；（2）玉米黄质、 新黄质、 紫黄质，属于类胡萝卜素的氧化衍生物。玉米黄质是黄玉米的主要色素，它的分子式为 C40H56O2，分子量为 568.88 道尔顿，其 CAS 登记号为 144-68-3。玉米黄质广泛的分布于黄色玉米、 蛋黄、 橙色和黄色的一些蔬菜和水果当中。玉米黄质本身不具有维生素 A 的活性，但是它与其同分异构体叶黄质在预防老年性黄斑变性（AMD）中发挥了重要的作用。玉米黄质被广泛的用于食品添加剂，并且在食品工业中，常用在给肉类食品的着色上。
用途
存在于玉米，菠菜，鸡蛋，鱼类，藻类等到各种植物和动物中。利用现代的生物技术萃取得到的天然色素。
靶点
Human Endogenous Metabolite
体外研究
Much of the Lutein and Zeaxanthin in the leaves of plants is protein-bound.In fruits and flower petals, the xanthophylls are esterified and are concentrated into chromoplasts where they are found to be solubilized in the membranes. In humans and higher animals, Lutein and Zeaxanthin are accumulated in lipophilic tissues such as adipose tissue and are carried in the blood by the lipoproteins, probably in a nonspecific manner similar to cholesterol. Lutein and Zeaxanthin are distributed equally between LDL and HDL fractions in human blood, in contrast to the hydrocarbon carotenoids that are preferentially found in LDL fractions, up to 75%.
编辑结构
