racemic

ra.ce.mic

adj.（形容词）
Of or relating to a chemical compound that contains equal quantities of dextrorotatory and levorotatory forms and therefore does not rotate the plane of incident polarized light.
外消旋的：属于或关于一种化合物的，该化合物由等量的左旋和右旋形式组成，因而对偏振光平面不旋光