Preparation of poly (styrene‐co‐allyl sulfonic acid) as a novel catalyst for the alcoholysis of dioscin

Abstract

This work describes the preparation of a novel solid acid, poly (styrene‐co‐allyl sulfonic acid) (St‐SAA), and its activity test for extracting diosgenin from Dioscorea Zingiberensis C.H. Wright (DZW). The solid acid was synthesized by the radical polymerization of styrene and sodium allyl sulfonate in water/ethanol solution, followed by the acidification. The prepared solid acid was characterized by infrared spectrum (FTIR), thermogravimetric analysis (TGA), X‐ray photoelectron spectroscopy (XPS), element analysis, and scanning electron microscope. The solid acid catalyst was used to extract diosgenin from DZW. It was found that the alcoholysis activity of the solid acid was higher than the hydrolysis activity of sulfuric acid with the same mass under the same conditions. Besides, the solid acid can be separated from the reaction mixture for the recycling extraction of diosgenin, and the solid acid has no loss of mass and no decrease of alcoholysis activity after repeated cycles.

Polymer‐based solid acid catalyst for the green production of diosgenin

“…The content of diosgenin was determined by UV-vis spectrophotometry, and the calculation formula was the same as that in our previous report. 20 In addition, diosgenin was qualitatively analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS). Agilent extend-C18 column (1.8 um, 2.1 mm 50 mm) was used to separate the products.…”

“…The results showed that the alcoholysis method is a green approach with no waste liquid discharging. 20 To further improve our research work, a novel solid acid catalyst was developed and applied to the extraction of diosgenin from DZW in this work (shown in Scheme 1). The catalyst was obtained by the polymerization of sodium allylsulfonate (SAS) and N, N 0 -methylenebisacrylamide (MBA) in an aqueous solution, followed by acidification with hydrochloric acid.…”

Green Conversion of Saponins to Diosgenin in an Alcoholysis System Catalyzed by Solid Acid Derived from Phosphorus Tailings

“…In recent years, solid acid as a cleaner production catalyst has achieved excellent performance in various research fields . Prior to this, we also successfully used solid acid to extract diosgenin from saponins of DZW. − The studies showed that the alcoholysis method is a green approach to produce diosgenin from DZW, which does not have liquid waste discharging in the process of alcoholism; however, the cost of the solid acid greatly affects the production efficiency. Low cost for the preparation of the solid acid is the key factor to realize the potential applications.…”