Amino acid-PEGylated resveratrol and its influence on solubility and the controlled release behavior.

A set of polyethylene glycol (PEG)-resveratrol (RES) conjugates with amino acid as spacers was designed and synthesized to improve certain defects of resveratrol, such as poor solubility, its short half-life and the difficulty of obtaining controlled release. Amino acids, which are released along with RES, are necessary for human health and likely have a facilitating effect on the absorption of the drug. The prepared PEG conjugates were characterized by FT-IR, (1)H-NMR, X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Evaluation of free RES, loading capability, solubility and in vitro release of conjugates was also conducted. The results show that solubility in water of all the conjugates is over 900 mg·mL(-1) and controlled release of RES was achieved. Therefore, the developed PEG conjugate is a favorable system for modifying the solubility and bioavailability of RES.