Highly efficient separation of strongly hydrophilic structurally related compounds by hydrophobic ionic solutions

Abstract

The selective separation of strongly hydrophilic structurally related compounds in aqueous solutions is a long‐standing challenge due to a trade‐off between separation selectivity and capacity. This work shows a new method to separate strongly hydrophilic structurally related compounds through hydrophobic ionic solution‐based liquid‐liquid extraction, with L‐ascorbic acid 2‐glucoside (AA‐2G) and L‐ascorbic acid as model compounds. Extraordinary distribution coefficient, superb molecular selectivity, large extraction capacity and good recyclability without using strong acids and salts were all achieved, with a small consumption of phosphonium bromide ionic liquid and aprotic molecular diluent. The essence of this method is the successful combination of both strong hydrogen‐bond basicity and good hydrophobicity along with significant preferential solvation phenomena of the constructed ionic solutions. Even if at a high feed concentration of 100 mg/mL, the purity of AA‐2G could be greatly elevated from 50% to 96.2% with an ultrahigh yield of almost 100% after five‐stage countercurrent extraction. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1373–1382, 2018

A synergistic ‘push and pull’ ionic liquid biphasic system for enhanced extraction separation of cholic acid and deoxycholic acid

“…The separation of structurally similar compounds represents an immense challenge across the fine chemical, pharma-ceutical, food, and natural product industries due to the nearly identical physicochemical properties shared between analogues and derivatives. [1][2][3][4][5][6][7][8] An exemplary case highlighting this persistent challenge is cholic acid (CA) and deoxycholic acid (DCA), two bile acid derivatives vital to various biological functions that differ only by a single hydroxyl group on the 7th carbon of CA (Fig. 1).…”

Identification of Process-Related Impurities and Corresponding Control Strategy in Biocatalytic Production of 2-O-α-d-Glucopyranosyl-l-ascorbic Acid Using Sucrose Phosphorylase

“…Several bioseparation techniques have been applied in the current purification of AA-2G, such as column chromatography purification, 18,19 membrane technologies, 20 and solvent extraction. 21 However, scarce studies have been performed on the impurity formation mechanism and control methods in the manufacturing processes of AA-2G. It is well-recognized that the safety of a drug product is dependent upon not only the toxicology of the active ingredient but also the contained impurities.…”

“…Isolating AA-2G from the reaction mixture has also been a complicated and challenging issue; this is partially due to low utilization efficiency of substrates, a small proportion of the target product (lower than 30%) in a complex mixture, and similar physicochemical and structural properties of byproducts, such as glucose, fructose, and different site-glycosylated products. Several bioseparation techniques have been applied in the current purification of AA-2G, such as column chromatography purification, , membrane technologies, and solvent extraction . However, scarce studies have been performed on the impurity formation mechanism and control methods in the manufacturing processes of AA-2G.…”

Separation of α‐ketoglutaric acid by salting‐out extraction coupled with solar‐driven distillation

“…Due to the complex composition of fermentation broth or biotransformation broth, the low total yield and high separation energy consumption limit the industrial application of distillation 14 . Moreover, the low selectivity of direct crystallization and the complex process of precipitation method affect the yield and purity of the product to a certain extent 15,16 . Although the ion exchange method could achieve a higher yield, it has high operating costs and produces a large amount of waste acid or alkali.…”

“…14 Moreover, the low selectivity of direct crystallization and the complex process of precipitation method affect the yield and purity of the product to a certain extent. 15,16 Although the ion exchange method could achieve a higher yield, it has high operating costs and produces a large amount of waste acid or alkali. The membrane separation method avoids contamination of the target product, but there are problems such as poor membrane regeneration capacity and cleaning difficulties.…”