The present invention provides a trans-astaxanthin derivative or a salt thereof having excellent antioxidant activity and having excellent water solubility and the like, and a composition containing the derivative of high purity or a salt thereof. The present invention provides an optically active trans astaxanthin derivative represented by the formula (I) or a salt thereof. (wherein m 1 , m 2 , n 1 and n 2 are the same or different, respectively, meaning an integer of 1 to 6)本發明提供一種具有優異之抗氧化活性且具有優異之水溶性等之光學活性之反式蝦紅素衍生物或其鹽、及含有高純度之該衍生物或其鹽之組合物。本發明提供一種式(I)所表示之光學活性之反式蝦紅素衍生物或其鹽。(式中，m1、m2、n1及n2分別相同或不同，意指1～6之整數)
