Preparation and characterization of feruloylated oat β-glucan with antioxidant activity and colon-targeted delivery

Ferulic acid (FA) is an effective chemopreventive and therapeutic agent for colorectal cancer. However, FA cannot stably reach the colon through human digestive system, and it can be grafted into oligosaccharides to improve its digestion stability. Therefore, in this study, different degrees of substitution of feruloylated oat β-glucan (FA-OβG) were prepared by grafting FA onto water soluble oat β-glucan. FA grafting changed the crystallinity and surface morphology of OβG, and the thermal stability of the FA-OβG improved. As the DS increased, the antioxidant activity of FA-OβG increased, and FA-OβG III with DS of 0.184 showed the same antioxidant activities compared to the equal amount of free FA. The FA-OβG showed higher stability under gastrointestinal and colonic conditions than free FA. Furthermore, the FA-OβG conjugates exhibited good in vitro anticancer activity against human colorectal cancer cells, while FA-OβG III showed better anticancer activity than an equal amount of free FA.