ABSTRACT
Objective To determine the monosaccharide composition of polysaccharides in different Cordyceps powder preparations by capillary zone electrophoresis (CZE). Methods The orthogonal experiment was used to optimize the total degradation conditions of the extracted polysaccharides; The monosaccharide composition was determined by CZE method using 1-phenyl-3-methyl-5-pyrazolone (PMP) as a derivatizing reagent. The electrophoresis conditions were as follows: uncoated fused silica capillary column (70 cm × 50 μm i.d., effective length was 61 cm); 40 mmol/L borax solution (pH 10.1) was used as the running buffer; The detection wavelength was set at 245 nm; The operation voltage was 13 kV; Hydrodynamic pressure injection was employed (10 cm × 8 s). Results The optimum hydrolysis conditions were as follows: 1.0 mol/L sulfuric acid solution, hydrolysis temperature 100 ℃, and hydrolysis time 5 h. The common monosaccharides of polysaccharides in Xinganbao Capsule, Bailing Capsule, Zhiling Junsi Capsule, and Jinshuibao Capsule were xylose, glucose, mannose, and galactose, but the content was different. The monosaccharide components contained in the polysaccharides of the four preparations were basically the same as those of the Cordyceps sinensis, and monosaccharides included xylose, rhamnose and glucuronic acid which were not reported in Cordyceps sinensis were detected. Each monosaccharide had a good linear relationship with the concentration range of 0.01 to 0.20 mg/mL, the limits of detection (LOD, S/N = 3) and the limits of quantification (LOQ, S/N = 10) ranged from 0.205 to 0.397 μg/mL and 0.684 to 1.323 μg/mL, respectively. RSDs of the precision test were 0.8%-3.6%, RSDs of the repeatability test were 2.7%-4.7%, and 2.8%-4.7% in the stability test. The recovery rate of the method showed that the mean recoveries of glucose and galactose ranged from 96.1% to 99.8% and 95.1% to 99.6% respectively, and RSD values fell within 1.0%-2.0% and 1.5%-1.9%, respectively. Conclusion The method is fast and efficient, and provides a reference for the improvement of quality standard of Cordyceps powder preparations and the intensive study on the substitution of Cordyceps powder for Cordyceps sinensis.