Mechanochemical-assisted extraction of platycodin D from the roots of Platycodon grandiflorum with solid alkalis

Abstract

Mechanochemistry is an interdisciplinary science, which refers to chemical and physicochemical reactions generated by the input of high mechanical energy. The mechanochemical pretreatment with solid alkalis was for the first time successfully used prior to water extraction of platycodin D from roots of Platycodon grandiflorum. The factors affecting the efficiency of mechanochemical-assisted extraction were the solid alkaline reagent type, reagent/material ratio, grinding time, extraction time, material/water ratio and acidification pH value. The highest yield of platycodin D via mechanochemical-assisted extraction (7.16 ± 0.14 mg/g) was obtained by grinding samples with NaOH according to 5 % reagent/material ratio for 5 min in a planetary ball mill, extracting with water at room temperature for 20 min, 1: 30 g/mL material/water ratio and acidification pH 3.5. Compared with superfine grinding extraction (3.26 ± 0.12 mg/g) and Soxhlet extraction (4.18 ± 0.11 mg/g), mechanochemical-assisted extraction reduced both extraction time and temperature, and achieved a higher yield of platycodin D. Furthermore, it used water as solvent, which is more environmental friendly and cheaper. The results indicated that mechanochemical-assisted extraction could be an effective method for extraction of natural compounds.