Study on Fundamental Process of Codonopsis pilosula Desulfurization and In Vitro Antibacterial Activity of its Polysaccharide Extract on Escherichia coli

Abstract

The present study was aimed to optimize the conditions of Codonopsis pilosula desulfurization using orthogonal experiment analysis with four independent variables including desulfurization temperature, time, ultrasonic power, and ratio of ethanol to raw material. Aspects of the antibacterial activity of polysaccharides extracted from sulfur-fumigated C. pilosula and after desulfurization by the agar-well diffusion method against Escherichia coli have also been studied. The results showed that the optimum extraction conditions were as follows: desulfurization temperature, 45°C; desulfurization time, 50 min; ultrasonic power, 700 W; and ethanol to raw material ratio, 10 : 1. Under these conditions, the desulfurization rate was 55.4%. The antibacterial activity of polysaccharides extracted from desulfurized C. pilosula was higher than that of polysaccharides extracted from sulfur-fumigated herbs, with the MIC values of 35 and 70 mg/mL, respectively.