A green and efficient protocol for industrial-scale preparation of dioscin from Dioscorea nipponica Makino by two-step macroporous resin column chromatography

A green and efficient method for the large-scale preparation of dioscin from Dioscorea nipponica Makino, a well known traditional Chinese medicinal herb, was developed. The preparation procedure consisted of two separation steps. In the first step, several types of macroporous resins including NKA-II, DA201, DM-301, AB-8, D1400, D4020, X-5, HPD-100 and D101 were investigated in order to choose the best resin. D101 resin was selected according to its adsorption and desorption properties. Other parameters during static and dynamic procedures were also investigated. In order to obtain a pure target, a second step was established, which involved the screening of various types of macroporous resins (D900, D318, D315, D280 and D301). The results demonstrated that D900 resin was the most suitable resin for use in this study. Under these conditions, the large-scale preparation of dioscin was carried out. The purity of dioscin after the first step was increased 9.16-fold from 9.35% to 85.64% with a recovery of 81.47%. The purity of dioscin then increased to 96.55% with a recovery of 89.64% after the second purification. A total of 1.486 kg of pure dioscin was produced from 100.0 kg raw material by the developed two-step macroporous resin column chromatography method using only aqueous ethanol as the solvent. Our study provides a green and efficient protocol for industrial-scale preparation of dioscin for pharmaceutical use.