Abstract:Bound polyphenols were obtained from Dendrocalamus hamiltonii shoot shells via ultrasoundassisted alkali extraction to enhance the comprehensive utilization value and advance the D.hamiltonii industry.On a foundation of single-factor experiments，a Box-Behnken response surface design was adopted to optimize the extraction process.Subsequently，the antioxidant capacity and blood glucose-lowering activity of the extracted bound polyphenols were evaluated.The optimal extraction parameters were determined as follows：an alkali concentration of 8 mol/L，a liquid-to-solid ratio of 17∶1 （mL/g），ultrasonic duration of 54 min，and ultrasonic power of 200 W.Under these conditions，the yield of bound polyphenols was the highest （18.69 mg GAE/g），showing excellent agreement with the value （18.70 mg GAE/g） predicted by the regression model.The bound polyphenols demonstrated potent scavenging activities against DPPH· and ABTS+· radicals，with median inhibitory concentration （IC50） values of 0.22 mg/mL and 0.020 3 mg/mL，respectively，outperforming free polyphenols （IC50 values of 0.32 mg/mL and 0.023 1 mg/mL，respectively）.Furthermore，the bound polyphenols exhibited strong inhibitory effects on α-amylase and α-glucosidase，with IC50 values of 0.05 mg/mL and 0.16 mg/mL，respectively，whereas free polyphenols showed marginally lower corresponding inhibitory effects，with IC50 values of 0.06 mg/mL and 0.19 mg/mL.In summary，the bound polyphenols derived from D.hamiltonii shoot shells possessed significant antioxidant activity and considerable blood glucose-lowering potential.