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

Abstract

This work proposed to prepare solid acid from phosphorus tailings and successfully convert Dioscorea zingiberensis C.H. Wright (DZW) into diosgenin from the perspective of solid waste resource reuse and clean production. The results showed that SiO 2 −SO 3 H solid acid could catalyze the production of diosgenin from total saponins under solvothermal reaction conditions. In addition, the parameters of a single factor, such as the amount of SiO 2 −SO 3 H, solvent volume, reaction temperature, and reaction time, were optimized to confirm the optimal range of reaction conditions, and the optimal process conditions were determined by the response surface method. The yield of diosgenin was 2.45 ± 0.17% under the optimum conditions, and the yield of diosgenin was increased by 12.90% compared with the traditional acid hydrolysis process. Except the relatively higher catalytic activity, the alcoholysis approach for the production of diosgenin has no waste liquid to discharge. The products were analyzed by highperformance liquid chromatography-mass spectrometry, and the pathway to convert total saponins into diosgenin under SiO 2 − SO 3 H has been proposed. Moreover, the adopted catalyst can be prepared with very low cost from phosphorus tailings. Considering the obvious superiorities, the alcoholysis approach in this work could be a promising strategy for green production of diosgenin as well as a possible utilization pathway of phosphorus tailings.

Synthesis and characterization of novel hercynite@sulfuric acid and its catalytic applications in the synthesis of polyhydroquinolines and 2,3-dihydroquinazolin-4(1H)-ones

“…24 Most solid state acids are heterogenized organic acids and transition metal complexes or acidic ion-exchange polymer resins. [33][34][35][36] Recently, various types of solid-acid catalysts, i.e. silica sulfuric acid (SSA), 37,38 boehmite silica sulfuric acid (boehmite-SSA) 39 and magnetic silica sulfuric acid (Fe 3 O 4 @-SSA), 40 have been developed using Zolgol's method.…”

A Method for Improving Microbial Conversion of Diosgenin and Separation and Identification of the Product

“…However, this method requires high volumes of water and results in severe environmental pollution [9]. In order to explore an environmentally friendly extraction method of diosgenin, Shen et al (2021) proposed the use of phosphorus tailings to prepare solid acid and convert Dioscorea zingiberensis C.H. Wright (DZW) to diosgenin [10].…”

“…In order to explore an environmentally friendly extraction method of diosgenin, Shen et al (2021) proposed the use of phosphorus tailings to prepare solid acid and convert Dioscorea zingiberensis C.H. Wright (DZW) to diosgenin [10]. Zhao et al (2022) developed and synthesized a new solid acid based on TiO 2 as an effective solid acid catalyst by sulfonating the prepared TiO 2 , which can be used to extract diosgenin from saponin [11].…”