Micellar Extraction

[Nikita Desjardins]

Thesite is secure.

The ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

New developments in the area of downstream processing are, hopefully, to fulfill the promises of modern biotechnology. The traditional separation processes such as chromatography or electrophoresis can become prohibitively expensive unless the product is of high value. Hence, there is a need to develop efficient and cost-effective downstream processing methods. Reverse micellar extraction is one such potential and a promising liquid-liquid extraction technique, which has received immense attention for isolation and purification of proteins/enzymes in the recent times. This technique is easy to scale-up and offers continuous operation. This review, besides briefly considering important physico-chemical and biological aspects, highlights the engineering aspects including mass transfer, mathematical modeling, and technology development. It also discusses recent developments in reverse micellar extraction such as affinity based separations, enzymatic reactions in reverse micelles coupled with membrane processes, reverse micellar extraction in hollow fibers, etc. Special emphasis has been given to some recent applications of this technique.

Plasmid DNA as an active pharmaceutical ingredient (API) is gaining more and more importance. For the production of multigram quantities of this substance robust and scalable processes comprising several purification steps have to be designed. One main challenge is the initial separation of plasmid DNA and RNA in such a purification scheme. In this study we investigated the distribution of plasmid DNA and RNA in reverse micellar two-phase systems which is considered to be the basis for the development of an extractive purification step that can easily be integrated into common processes. For this purpose the distribution of the 4.6kb plasmid pUT649 and Escherichia coli RNA in systems comprising isooctane, ethylhexanol, and the surfactant methyltrioctylammoniumchloride (TOMAC) under the influence of different salts was studied. Anion concentrations at which the partitioning behaviour for nucleic acids inverted (inversion point) were identified. Systems capable of separating RNA from plasmid DNA were further analysed and applied to extract RNA from plasmid DNA out of a preconditioned cleared lysate. The capability of reverse micellar systems for plasmid form separation was also shown by capillary and agarose gel electrophoresis.

FMT (Fig. 1), [3-(((2-((aminoiminomethyl)amino)-4-thiazolyl)-methyl)thio)-N-(aminosulfonyl)propanimidamide], is applied in daily doses of 40 mg [13]. About 20% of FMT binds to plasma proteins and is metabolized to famotidine S-oxide. A large amount of unchanged drug is excreted with urine [14, 15]. FMT creates two polymorphic forms: aliphatic structure A (is more stable thermodynamically) and cyclic B [16, 17]. FMT exhibits basic properties (pK a = 6.7) and is soluble in water and polar organic solvents [13]. This drug is able to form an ion-pair complex with acidic dyes and to coordinate transition metal ions due to the presence of thiazole nitrogen, thioether sulfur, guanidine and amine groups in its molecular structure [17,18,19].

The present paper describes a newly elaborated micellar extraction procedure for the concentration of FMT from surface-water samples. The separation process was performed with a mixture of surface-active agents: anionic surfactant sodium dodecylsulfate (SDS) together with Triton X-114 (TX-114). This nonionic surfactant, with a cloud point of 25 C, is representative of t-octylphenoxy polyoxethylene ethers [25, 26]. The determination of FMT was performed by spectrophotometric and HPLC methods with an ultraviolet detection system.

Surface water samples were collected from a local river (hospital region, Podlaskie Voivodeship in Poland). Aqueous samples were taken according to analytical sampling requirements on about 1/3 river depth about 50 cm from the river bank into polyethylene flasks. Before conducting experiments, samples of water were filtered through the paper filters to remove solid particles. The micellar extraction (procedure 2.3) was used for the determination of FMT in natural aqueous samples. The developed isolation method allows preconcentration of FMT. The final volume of micellar extracts dissolved in methanol was equal to 2 mL. Afterwards, the analysis of river water was performed by applying the elaborated extraction process and preconcentration of real samples.

The primary studies showed that the used surfactant was able to bind FMT in micelles. It was observed that the addition of the non-ionic surface active agent: Triton X-114 enhanced the efficiency of micellar extraction. Absorption spectra of applied solutions of surfactants and the studied analyte (FMT) are shown in Fig. 2 while the spectra of micellar extract of FMT and a blank solution of used surfactants without the analyte are presented in Fig. 3. A micellar extract of FMT exhibits an intense band at 275 nm. This wavelength was subsequently used for the measurements of absorbance in optimization of the best parameters for the micellar extraction.

It was observed that an addition of an electrolyte influenced the isolation process of the studied compound. The addition of salt increases the density of the aqueous layer and enhances the separation of the two phases.

The effect of sodium chloride concentration on the absorbance of FMT using a mixture of surfactants (SDS and TX-114). The large data point indicates the condition chosen during optimization of micellar extraction of FMT

The influence of shaking and centrifugation times on the micellar extraction of FMT was studied. The isolation process of the analyte was performed using the optimized concentrations of the surfactants and the electrolyte, applying variable shaking and centrifugation times during the micellar extraction. It was observed that 15 min of shaking and 10 min of centrifugation of the samples is adequate for the micellar extraction of FMT. The application of a time shorter than the optimal value caused difficulty in mixing the sample components and separating the phases. A longer time of shaking (more than 15 min) and the centrifugation (more than 10 min) resulted in a decrease in the efficiency of the isolation process of FMT.

The examined organic substances, cysteine, glucose, lactose, chloramine, citric acid, tartaric acid and other biologically active compounds, such as olanzapine, cimetidine, ranitidine, carbamazepine and lovastatin, do not influence the results of the determination of the studied analyte.

The proposed micellar extraction procedure using a mixture of the surfactants was applied to the determination of FMT in surface water. The samples were obtained from the local rivers (Podlaskie Voivodeship, Poland).

This work was financially supported by the Ministry of Science and Higher Education (Grant: NN305189435). Author Ilona Kiszkiel-Taudul was a beneficiary of the project Scholarships for PhD students of Podlaskie Voivodeship. The project was co-financed by European Social Fund, Polish Government and Podlaskie Voivodeship.

This study sought to evaluate the possibility of using grape pomace, a waste material from wine production, for the preparation of cosmetic components. Following the existing clear research trend related to improving the safety of cleansing cosmetics, an attempt was made to determine the possibility of preparing model shower gels based on grape pomace extract. A new method for producing cosmetic components named loan chemical extraction (LCE) was developed and is described for the first time in this paper. In the LCE method, an extraction medium consisting only of the components from the final product was used. Thus, there were no additional substances in the cosmetics developed, and the formulation was significantly enriched with compounds isolated from grape pomace. Samples of the model shower gels produced were evaluated in terms of their basic parameters related to functionality (e.g., foaming properties, rheological characteristics, color) and their effect on the skin. The results obtained showed that the extracts based on waste grape pomace contained a number of valuable cosmetic compounds (e.g., organic acids, phenolic compounds, amino acids and sugars), and the model products basis on them provided colorful and safe natural cosmetics.

In biotechnology there is a need for new purification and concentration processes for biologically active compounds such as proteins, enzymes, nucleic acids, or cells that combine a high selectivity and biocompatibility with an easy scale-up. A liquid-liquid extraction with a reversed micellar phase might serve these purposes owing to its capacity to solubilize specific biomolecules from dilute aqueous solutions such as fermentation and cell culture media. Reversed micelles are aggregates of surfactant molecules containing an inner core of water molecules, dispersed in a continuous organic solvent medium. These reversed micelles are capable of selectively solubilizing polar compounds in an apolar solvent. This review gives an overview of liquid-liquid extraction by reversed micelles for a better understanding of this process.

Abstract - In biotechnology there is a need for new purification and concentration processes for biologically active compounds such as proteins, enzymes, nucleic acids, or cells that combine a high selectivity and biocompatibility with an easy scale-up. A liquid-liquid extraction with a reversed micellar phase might serve these purposes owing to its capacity to solubilize specific biomolecules from dilute aqueous solutions such as fermentation and cell culture media. Reversed micelles are aggregates of surfactant molecules containing an inner core of water molecules, dispersed in a continuous organic solvent medium. These reversed micelles are capable of selectively solubilizing polar compounds in an apolar solvent. This review gives an overview of liquid-liquid extraction by reversed micelles for a better understanding of this process.

3a8082e126