Structural modification and biological activities of carboxymethyl Pachymaran

Polysaccharides are good chelating agents for metal ions, which are often used to synthesize polysaccharide metal ion complexes. With carboxymethyl pachymaran (CMP) as the substrate, carboxymethyl pachymaran iron (CMPF), carboxymethyl pachymaran selenium (CMPS), and carboxymethyl pachymaran zinc (CMPZ) were synthesized by response surface methodology, and their biological characteristics were studied. The results showed that the CMP was a β-polysaccharide, and the degree of carboxymethylation was 0.6352. The polysaccharide metal ion complexes were characterized by physicochemical methods, scanning electron microscopy, Fourier transform infrared spectroscopy, circular dichroism spectroscopy, and nuclear magnetic resonance spectroscopy. All the polysaccharides and complexes possessed antioxidant activity in vitro with scavenging activities to ABTS, superoxide anions, and ferrous ions. CMPF, CMPS, and CMPZ caused significant inhibition of A2780 cell proliferation, promoted the production of reactive oxygen species, and induced apoptosis in a human ovarian cancer cell line (A2780 cells). These results suggest that the CMP complex may be an effective candidate drug for cancer treatment in the field of functional food and pharmacology.