Valorization of Amphidinium carterae for Integrated Preparation of Peridinin and Diadinoxanthin Cycle Carotenoids

An integrated microalgae biorefinery producing high-purity xanthophylls using a sustainable and efficient strategy still faces critical challenges. In this study, the microalga <i>Amphidinium carterae</i> can accumulate peridinin and diadinoxanthin cycle carotenoids. Notably, valorization of wet <i>A. carterae</i> using integrated preparation of peridinin and diadinoxanthin cycle carotenoids was developed, containing four main steps including microalgae cultivation, solvent extraction, octadecylsilyl open-column chromatography, and ethanol precipitation for the first time. Under the optimum integrated preparation conditions, the purities of obtained peridinin, diadinoxanthin, and diatoxanthin were all more than 95%, with total recovery rates of approximately 70%, 51%, and 74%, respectively. Based on nuclear magnetic resonance techniques, the purified peridinin, diadinoxanthin, and diatoxanthin were identified as all-<i>trans</i>-peridinin, all-<i>trans</i>-diadinoxanthin, and all-<i>trans</i>-diatoxanthin, respectively. In all, the developed method may hold significant implications for future purification of peridinin and diadinoxanthin cycle carotenoids, as well as for the integrated biorefinery of wet <i>A. carterae</i>.