Synthesis, characterization and biocompatibility of quaternized derivatives of gum arabic

Abstract

Gums are a group of naturally occurring polysaccharides that have the ability to form viscous gels and solutions. Gum arabic is a branched polysaccharide, chemically complex and widely used as emulsifier and stabilizer by the pharmaceutical and the food industry. Quaternization is a chemical modification reaction capable of altering the physicochemical properties of polysaccharides while keeping their fundamental properties intact, giving rise to derivatives with characteristics distinct from native polysaccharides. Therefore, gum arabic at a concentration of 10 g was quaternized using 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (CHPTAC) at different reaction times (3, 7 and 14 hours) and temperatures (50, 70 and 90ºC). Quaternization of all samples was confirmed by FTIR. The highest degree of substitution was observed for the GAQ-1 derivative, obtained to 50°C e 3 hours of reaction. All derivatives demonstrated thermal stability. Quaternized samples showed cytotoxicity when in contact with colorectal cancer cells HCT-116 at a concentration of 2 mg/mL. The quaternized derivatives proved to be safe when in contact with normal cells and the initial studies point to a possible use in biological applications as a potential coadjunct in the treatment of some types of cancer. However, further studies are needed to confirm its applicability. • The quaternization of arabic gum was performed for the first time. • Quaternized derivatives showed antitumor activity against colorectal cancer cells. • All derivatives have been shown to be safe in normal cells.