Simultaneous extraction and purification of alkaloids from Sophora flavescens Ait. by microwave-assisted aqueous two-phase extraction with ethanol/ammonia sulfate system

Abstract

A rapid and effective method of integrating extraction and purification for alkaloids from Sophora flavescens Ait. was developed by microwave-assisted aqueous two-phase extraction (MAATPE) based on the high efficiency of microwave-assisted extraction (MAE) and the demixing effect of aqueous two-phase extraction (ATPE). The aqueous two-phase system (ATPS), ethanol/ammonia sulfate was chosen from seven combinations of ethanol/salt systems, and its extraction properties were investigated in detail. Key factors, namely, the compositions of ATPS, solvent-to-materials ratio, and the extraction temperature were selected for optimization of the experimental conditions using response surface methodology (RSM) on the basis of the results of the single-factor experiment. The final optimized conditions were, the compositions of ATPS: ethanol 28% (w/w) and (NH 4 ) 2 SO 4 18% (w/w), solvent-to-material ratio 60:1, temperature 90°C, extraction time 5 min, and microwave power 780 W. MAATPE was superior to MAE, the latter using a single solvent, not only in extraction yield but also in impurity content. Moreover, compared with the combination of MAE and ATPE in the two-step mode, MAATP demonstrated fewer impurities, a better yield (63.78 ± 0.45 mg/g) and a higher recovery (92.09 ± 0.14%) in the extraction and purification of alkaloids. A continuous multiphase-extraction model of MAATPE was proposed to explicate the extraction mechanism. MAATPE revealed that the interaction between microwave and ATPS cannot only cause plant cell rupture but also accelerate demixing, improving mass-transfer from solid-liquid extraction to liquidliquid purification. MAATPE simplified procedures also contributed to the lower loss occurrence, better extraction efficiency, and reduced impurity to target constituents.

Optimization of Ultrasonic‐Assisted Aqueous Two‐Phase Extraction of Phloridzin from Malus Micromalus Makino with Ethanol/Ammonia Sulfate System

“…The result indicated that the upper limits of the concentrations of ammonium sulfate solution and ethanol were about 40% and 56% (w/w) for the formation of ethanol/(NH 4 ) 2 SO 4 ATPS, respectively. Our result was similar to those reported in recent investigations (Li and others ; Zhang and others ).…”

“…The investigation of phase diagram of ethanol/ammonium sulfate aqueous 2‐phase region could provide useful information for further optimization of the ATPS compositions for UAATPE. Previous studies showed that the solubility of salt and the phase ratio of the top and bottom phase volume can directly affect the operating feasibility of ATPE (Zhang and others ). In combination of abovementioned factors and our preliminary experiments, an ethanol concentration ranging from 27% to 35% (w/w) and (NH 4 ) 2 SO 4 concentration ranging from 13% to 17% (w/w) were tentatively suitable for extraction and selected for the further optimization single‐factor experiments.…”

“…Aqueous two‐phase extraction (ATPE) has recently gained larger popularity in simultaneous extraction and purification of the natural products such as allicin, anthocyanins, alkaloids, and 2, 3‐butanediol (Li and others ; Wu and others ; Liu and others ; Wu and others ; Zhang and others ; Li and others ). These aqueous two‐phase systems (ATPSs) were improved to rely on short‐chain alcohol (for example, ethanol and n‐propanol) and inorganic salt (for example, ammonia and phosphate sulfate).…”

Microscopic Characters, Phytochemical Screening Focus on Alkaloid and Total Phenolic Content of Uncaria gambir Roxb. and Uncaria sclerophylla Roxb. Leaves

“…Ammonia which is alkaline was added to increase the solubility of alkaloids in the solvent. 19 The same principle is also applied to extract flavonoids which are polyphenol groups. To extract polyphenol compounds such as flavonoids, polar solvents such as ethanol were used.…”

Salt‐assisted dispersive liquid–liquid microextraction for enhancing the concentration of matrine alkaloids in traditional Chinese medicine and its preparations

“…Composite Kushen injection is a common liquid preparation of the extract of Sophorae Flavescentis Radix used in the hospital, and therefore, it is more significant to quantitatively measure the active alkaloids, particularly the lower concentration of active alkaloids in complex matrixes. At present, the sample preparation techniques of enriching matrine alkaloids from herbs and their preparations mainly include membrane extraction , LPME with back extraction , aqueous two‐phase extraction , and dispersive liquid–liquid microextraction (DLLME) . The conventional DLLME involves ternary solvent system including extraction solvent, dispersive solvent, and aqueous sample phase, and it is a method with simplicity of operation, low cost, rapidity of extraction, and high enrichment factor (EF) .…”