Hydrophilic Astaxanthin: PEGylated Astaxanthin Fights Diabetes by Enhancing the Solubility and Oral Absorbability.

To develop hydrophilic astaxanthin with significantly enhanced solubility and stability, astaxanthin polyethylene glycol succinate (APGS) was synthesized by esterification of an astaxanthin succinate diester with polyethylene glycol 1000. The chemical structure of the hydrophilic derivative was confirmed by 1H nuclear magnetic resonance and mass spectra. APGS showed better solubility than free astaxanthin in water and enhanced bioavailability compared to that of free astaxanthin. Additionally, testing the effects on diabetes and inflammation in a high-fat- and high-sucrose-diet-induced insulin-resistant mouse model demonstrated its benefits, suggesting that APGS maintains the health-promoting properties of astaxanthin. These results suggest that APGS could be a better source of hydrophilic astaxanthin.