Objective Explore the preparation process, structural characteristics, and biological activity of Agaricus blazei polysaccharide-chromium(III) complex ABMP-Cr(III).

Methods Polysaccharides were extracted from Agaricus blazei by water extraction and alcohol precipitation. The optimum preparation conditions of ABMP-Cr(III) were studied by single factor and response surface method of reaction temperature, substrate concentration, reaction time and pH. Its structure was analyzed by scanning electron microscopy and infrared spectroscopy, and its hypoglycemic activity was analyzed by measuring the inhibition rate of α-amylase and α-glucosidase.

Results The optimum conditions for the preparation of ABMP-Cr (III) were as follows : reaction temperature 22.0°C, reaction time 40 min, pH 6.0, substrate concentration 24.00 mg·mL ⁻¹ . Under these conditions, the chelating rate of ABMP-Cr (III) was 90.13%. Agaricus blazei Murill polysaccharides ( ABMP) had a long block structure, and the surface of ABMP-Cr (III) was smooth and lamellar structure. The binding sites of Cr³⁺ to polysaccharides were O-H, C-H and C-O-H. The hypoglycemic activity of ABMP-Cr (III) increased with the increase of sample concentration, and its effect was better than that of ABMP. When ABMP-Cr (III) was 0.6 mg·mL ⁻¹, the inhibition rate of α-amylase could reach 55.11%. When the concentration of ABMP-Cr (III) was 5 mg·mL ⁻¹, the inhibition rate of α-glucosidase was 40.48%.

Conclusion ABMP-Cr (III) has high preparation efficiency under the optimal preparation conditions in this study, and its structure is significantly different from ABMP. ABMP-Cr (III) has good hypoglycemic activity and has good development prospects.