Biphasic System Research Articles

Membrane-free Zn hybrid redox flow battery using water-in-salt aqueous biphasic electrolytes

In this study, we develop a membrane-free Zn hybrid redox flow battery (RFB) using an unconventional water-in-salt aqueous biphasic system (WIS-ABS). This membrane-free Zn hybrid battery employs soluble ferrocene (Fc) derivative and Zn salt as the active species in the immiscible catholyte and anolyte, respectively. Initially, we demonstrate the potential of using WIS-ABS for a totally aqueous membrane-free Zn battery under static conditions. This static battery operates at a cell voltage of 1.01 V and effectively eradicates the detrimental self-discharge observed in membrane-free batteries, achieving excellent coulombic efficiency (CE) consistently around 100 % over 2000 cycles. However, due to transport limitations in the static configuration, the battery exhibits a low capacity utilization of 17.4 % for the catholyte, ultimately restricting the energy density of the battery. Further improvements in the battery performance are achieved by employing a specially designed RFB cell reactor to operate under real flowing conditions. Impressively, the developed membrane-free Zn hybrid RFB cell significantly shows an improved catholyte utilization, reaching up to 95 %. Furthermore, the membrane-free RFB consistently maintains CE higher than 95 % throughout the cycling process, ultimately achieving a capacity retention as high as 96.5 % after 30 cycles at 100 % depth of discharge. This work highlights the potential of utilizing a water-in-salt aqueous biphasic system to develop a membrane-free Zn hybrid RFB with excellent electrochemical performance, effectively avoiding the undesired self-discharge phenomena.

Modular synthesis of dendritic ionic triphiles and their behavior in three-phase liquid–liquid–liquid system

Triphilic molecules possess unique features due to the presence of chemically distinct domains − oleophilic, hydrophilic, and fluorophilic. In bulk, they can form intriguing crystal structures, while in solutions, they can act as multi-purpose emulsifiers or form assemblies such as multi-compartment micelles applicable in drug delivery. However, their chemico-physical properties are still relatively unexplored. Namely, they have never been studied in a three-phase liquid–liquid–liquid system consisting of organic and fluorous solvents and water. Here we present an adaptive, modular synthesis of a novel type of dendritic ionic triphiles and a study of their solution behavior, with a focus on a three-phase toluene/water/perfluoro(methylcyclohexane) (PMC) system. The synthesis is based on the quaternization of various alkylimidazoles by a previously published type of carbosilane dendritic wedges bearing polyfluorinated chains of varied lengths at their periphery. This approach enables the facile combination of different organic and fluorous blocks and, thus, easy tailoring of final structures according to the results of this work. The distribution of triphiles in the selected three-phase system was mapped in a ternary diagram representing the mass proportions of individual domains. The distribution between toluene and PMC changes gradually depending on the sizes of the corresponding domains and significantly differs from the distribution in a biphasic system where water is absent (i.e., the fluorous partition coefficient). However, at a certain size of the fluorous domain, the molecules completely lose their affinity to the fluorous phase and gain affinity to water even though being still partially soluble in PMC. The results can help understand the structure-affinity relationship of triphilic compounds and can help find a substance with balanced affinities to all three solvents. Moreover, some of the prepared compounds manifested interesting surface activity, namely the emulsification capability on both phase interfaces or the formation of stable nanoparticles in an aqueous environment.

Catalytic conversion of mannose to 5-hydroxymethylfurfural promoted by hydrophobic halloysite-based catalyst in biphasic system

A novel halloysite (Hal) based acidic catalyst was synthesized by anchoring functional alkyl group and Cr site and catalyzed the selective conversion of mannose to 5-hydroxymethylfurfural (HMF) in NaCl-H2O/dimethyl sulfoxide/methyl isobutyl ketone (MIBK) biphasic system. Herein, adjusting the hydrophilicity/hydrophobicity of catalyst by modifying the octyl group can facilitate the HMF yield. The density functional theory (DFT) calculation and in-situ FT-IR results revealed that increasing the hydrophobicity of catalyst surface weakened the interaction between HMF, water molecule and acid sites and inhibited the rehydration of HMF. Moreover, the synergistic effect between Cr and sulfonic group active sites remarkedly promoted the isomerization of mannose to fructose and the dehydration of fructose to HMF, and the 48.1% yield of HMF was obtained. This study provides references for the high value conversion of hemicellulose with the high efficiency reaction system.

The versatile CYP74 clan enzyme CYP440A19 from the European lancelet Branchiostoma lanceolatum biosynthesizes novel macrolactone, epoxydiene, and related oxylipins

The present work reports the detection and cloning of a new CYP74 clan gene of the European lancelet (Branchiostoma lanceolatum) and the biochemical characterization of the recombinant protein CYP440A19. CYP440A19 possessed epoxyalcohol synthase (EAS) activity towards the 13-hydroperoxides of linoleic and α-linolenic acids, which were converted into oxiranylcarbinols, i.e., (11S,12R,13S)-11-hydroxy-12,13-epoxy derivatives. The conversion of 9-hydroperoxides produced distinct products. Linoleic acid 9(S)-hydroperoxide (9-HPOD) was mainly converted into 9,14-diol (10E,12E)-9,14-dihydroxy-10,12-octadecadienoic acid and macrolactone 9(S),10(R)-epoxy-11(E)-octadecen-13(S)-olide. In addition, (8Z)-colneleic acid was formed. Brief incubations of the enzyme with 9-HPOD in a biphasic system of hexane–water enabled the isolation of the short-lived 9,10-epoxydiene (9S,10R,11E,13E)-9,10-epoxy-11,13-octadecadienoic acid. The structure and stereochemistry of the epoxyalcohols, macrolactone, (8Z)-colneleic acid (Me), and 9,10-epoxydiene (Me) were confirmed by 1H-NMR, 1H-1H-COSY, 1H-13C-HSQC, and 1H-13C-HMBC spectroscopy. Macrolactone and cis-9,10-epoxydiene are novel products. The 9-hydroperoxide of α-linolenic acid was mainly converted into macrolactone 9(S),10(R)-epoxy-11(E),15(Z)-octadecadiene-13(S)-olide and a minority of divinyl ethers, particularly (8Z)-colnelenic acid. The versatility of enzyme catalysis, as well as the diversity of CYP74s and other enzymes involved in oxylipin biosynthesis, demonstrates the complexity of the lipoxygenase pathway in lancelets.

Enhancing biomarker detection in human serum for lung cancer diagnosis: Aqueous biphasic systems for simultaneous depletion of high-abundance proteins and efficient extraction of CYFRA 21–1

Analysing biomarkers in human serum could be used as an effective and less invasive approach for the diagnosis of lung cancer; however, biomarker detection reliability is highly limited due to matrix effects. Herein, aqueous biphasic systems (ABS) are studied as platforms for human serum pretreatment, allowing the simultaneous depletion of high abundant proteins and biomarker extraction. By using ABS varying the polyethylene glycol (PEG) molecular weight between 400 and 6000 g·mol−1 and adopting phosphate buffer as the other phase-forming component, the depletion of the high abundance serum proteins immunoglobulin G (IgG) and human serum albumin (HSA) is induced at the ABS interphase, through precipitation, forming a three-phase partitioning system (ABS-TPP). Maximum depletion efficiencies of 99 % for IgG and 70 % for HSA were achieved in one step using PEG 1500-based ABS-TPP. On the other hand, lung cancer biomarkers, such as CYFRA 21–1, are extracted to the PEG-rich phase of the same ABS-TPP with recovery yields of 91 %. This work shows that a proper selection of the PEG molecular weight in the ABS composition leads to the efficient depletion of high-abundance proteins and extraction of cancer biomarkers from human serum, in a single step, confirming the potential of ABS for sample pretreatment to improve biomarker analysis.

Design and synthesis of SO3H-based ionic liquids for direct catalytic conversion of straw to levulinic acid

The utilization of ionic liquids (ILs) in the conversion of lignocellulose to levulinic acid (LA) is a significant pathway in the field of bio-refinery. In this study, a series of sulfonic-based ILs with elongated alkyl chains were synthesized using density functional theory. These ILs were then utilized for the conversion of straw into LA in a single reaction vessel. The yield of LA was compared between a single solvent (water) and a biphasic system comprising water and methyl isobutyl ketone (MIBK). Among the investigated ILs, [C3SO3HEim]Cl exhibited a higher yield of LA, reaching up to 11.3 wt% in the aqueous phase and 17.8 wt% in the MIBK-water biphasic system. Furthermore, [C3SO3HEim]Cl displayed a high catalytic efficiency (90.4%) and a yield of LA (16.3 wt%) after 5 cycles. These findings suggest that the elongation of alkyl side chains in ILs enhances the solubility of cellulose and increases the yield of LA. The MIBK-water biphasic system promotes the rehydration of hydroxymethylfurfural (HMF) and reduces the residence time of LA in the aqueous phase, thereby optimizing its yield. This innovative approach involving ILs and the MIBK-water biphasic system presents a novel perspective for the production of LA from biomass.

Exceptional functionalized ionic liquid@metal–organic framework: A high-efficiency desulfurization platform for organic sulfide oxidation by reactive oxygen species

There is a challenge with designing catalysts that simultaneously possess active sites for catalyzing the generation of reactive oxygen species (ROSs) and effectively overcoming mass transfer resistance in oil–water biphasic systems. In this study, a novel, highly efficient oxidative desulfurization (ODS) strategy is proposed that uses an ILs-loaded metal–organic framework (MOF) coupled material as a catalyst. The IL@MOF ([Hnmp]HSO4@MIL-125(Ti)) coupled material prepared by loading [Hnmp]HSO4 onto MIL-125(Ti) has catalytic-adsorption synergistic capability. It demonstrated outstanding oxidative desulfurization performance by achieving nearly a 100 % removal of dibenzothiophene (DBT) from model oil with a dosage of 0.04 g IL@MOF per 10 mL of model fuel under mild conditions (50 °C, 10 min). By comparing the experimental results with the characterization data, it is suggested that [Hnmp]HSO4@MIL-125(Ti) converts superoxide radicals (•O2−) into 1O2 through oxygen vacancies (Ov) and that the catalytic action of Ti on the oxidation of DBT is primarily based on a 1O2-driven non-free radical mechanism. [Hnmp]HSO4@MIL-125(Ti) serves as a favorable medium for contact to be made between ROSs and sulfides, which indicates an efficient catalytic-adsorption synergy.

Sustainable recovery of cobalt and lithium from lithium-ion battery cathode material by combining sulfate leachates and aqueous biphasic systems based on tetrabutylphosphonium-ionic liquids

The consistent expansion of the lithium-ion battery (LIB) market, coupled with their relatively brief lifespan, necessitates the development of efficient and sustainable LIB recycling strategies. Recycling is crucial not only for the recovery of critical metals like Co(II) and Li(I) from the cathode material as a secondary resource but also from an environmental perspective. This study explores the use of a series of aqueous biphasic systems (ABS) with synthesized tetrabutylphosphonium ionic liquids (ILs) and ammonium sulfate as extraction platforms for metals from LIB cathode. Firstly, liquid–liquid equilibrium phase diagrams for each ABS were established, and partitioning experiments were conducted to assess the Co(II), Ni(II), Mn(II), and Li(I) recovery efficiencies. We observed distinct partitioning behaviors for the metals, with tetrabutylphosphonium diethylenetriaminepentaacetate, [TBP][DTPA], showing recovery efficiencies exceeding 98% for Co(II), Ni(II), and Mn(II). At the same time, Li(I) was predominantly retained in the aqueous salt-rich phase. By fine-tuning ABS operational parameters such as pH, temperature, system composition, and phase ratio, we identified optimal conditions for extracting metals from the cathode material of lithium-cobalt-oxide (LCO) batteries using sulfate lixiviate. Introducing [TBP][DTPA] after the leaching process induced ABS, achieving remarkable recovery efficiency over 95% for Co(II) in the IL-rich phase, with all Li(I) remaining in the lower phase. Cobalt was subsequently extracted using oxalic acid to precipitate as Co-oxalate from concentrate, while Li(I) was isolated from the aqueous phase using ammonium carbonate. After the “cleaning” of the IL-rich phase, the [TBP][DTPA] was recovered and reused in four consecutive cycles, with small detected losses on the recovery efficiency of Co(II) and Li(I). Therefore, our innovative strategy combines sulfate-based lixiviants with IL-ABS technology, thereby enhancing selectivity and sustainability within one of the most efficient lixiviant systems widely employed in the industry. This technological advancement presents a promising pathway for the recycling of spent batteries, offering substantial environmental advantages within the well-established and extensively utilized realm of metal recovery technology in the industry.

An efficient and mild fractionation of corn stover via 2-phenoxyethanol and silicotungstic acid biphasic pretreatment for biomass valorization

Developing an efficient and facile pretreatment is of great importance to comprehensive utilization of lignocellulosic biomass. Herein, a biphasic system of 2-phenoxylethanol (EPH) and silicotungstic acid (STA) was employed for fractionation of corn stover. The EPH/STA biphasic system demonstrated remarkable fractionation efficiency to remove 90.23 % of xylan and 88.54 % of lignin, while retaining 85.60 % of cellulose under the mild pretreatment conditions of 130 °C for 90 min with 7/3 of EPH/STA and 40 mM of STA. The xylose of 52.93 % and lignin of 88.01 % were recovered in aqueous phase and organic phase by EPH/STA biphasic pretreatment, respectively. In the further process, 94.27 % of saccharification was achieved by enzymatic hydrolysis of cellulose-rich solid residue, and 106.17 mg/g of xylonic acid was obtained by oxidation of xylose in aqueous phase. Additionally, the recovered lignin in organic phase could be fabricated to lignin-based films with good mechanical properties. Notably, acid solvent in biphasic system had an important role in fractionation efficiency of corn stover. The STA had the best effect among the different acid solvents. This work provided a promising route to full components utilization of corn stover for biomass valorization.

Stepwise processing strategy for efficient and comprehensive utilization of sugarcane bagasse via enzymatic hydrolysis and catalytic conversion to produce 5-hydroxymethylfurfural

To achieve the goal of “no waste” in circular bioeconomy on the basis of waste-to-energy conversion, the development of efficient technology for sustainable treatment and utilization of lignocellulosic biomass is significant yet challenging. In this study, a stepwise processing strategy based on enzymatic hydrolysis and catalytic conversion was proposed for comprehensive utilization of sugarcane bagasse (SCB) to produce value-added products. Mechanical activation (MA) pretreatment was adopted to disrupt the recalcitrant structure of SCB for improving enzymatic hydrolysis of polysaccharides to produce reducing sugars, obtaining a high yield (392 mg/g SCB) of target sugars (TS; i.e., cellobiose and glucose). The enzymolysis residue and Al(NO3)3·9 H2O were treated by MA and then calcinated to construct the biochar (BC)-based catalyst (denoted as MA-Al/BC) with Brønsted–Lewis dual-acidic sites, which effectively catalyzed the conversion of TS to produce 5-hydroxymethylfurfural (5-HMF). A TS conversion of 94.5% and a 5-HMF yield of 77.6% were achieved at 190 °C for 4 h in the biphasic system. MA-Al/BC exhibited excellent universality for efficient catalytic conversion of various carbohydrates. This study offers a promising approach for value-added exploitation of agricultural wastes within circular bioeconomy principles.

An amino acid ionic liquid-based biphasic solvent with low viscosity, small rich-phase volume, and high CO2 loading rate for efficient CO2 capture

In order to achieve efficient CO2 capture, a novel biphasic solvent based on diethylenetriamine serine ionic liquid/polyethylene glycol dimethyl ether/water ([DETA][SER]/NHD/H2O) was developed. This study achieved low viscosity by weakening the hydrogen bonding and van der Waals interactions within the pure ionic liquid (IL) by adding NHD and H2O to [DETA][SER]. Additionally, due to the low polarity and fewer hydrogen bonds formed by NHD, it is separated. The formation of a tight hydrogen bond network in the rich-phase after the reaction enables the enrichment of the product. Based on this, the optimal mass ratio of [DETA][SER]/NHD/H2O is determined to be 20 wt%/40 wt%/40 wt%. The viscosity of this solvent is 7.82 mPa·s, with a total absorption load of 1.26 mol·mol−1 IL, where the rich-phase load accounts for 99 % of the total load and occupies only 37 % of the volume. The mechanism of CO2 capture was investigated using 13C NMR, revealing the formation of zwitterions from the reaction of the primary amines on [DETA]+ and [SER]− with CO2. Subsequently, proton transfer and hydrolysis of the carbamate esters were observed. Notably, NHD was found to promote phase separation without participating in chemical reactions. These findings demonstrate the potential of this biphasic solvent system as a high-capacity solution for CO2 capture.

One-pot direct conversion of raw straw to furan chemicals simultaneously in a choline chloride-lactic acid/methyl isobutyl ketone biphasic system

One-pot direct conversion of raw straw to furan chemicals simultaneously in a choline chloride-lactic acid/methyl isobutyl ketone biphasic system

Boosting one-step degradation of shrimp shell waste to produce chitin oligosaccharides at smart nanoscale enzyme reactor with liquid-solid system

Chitin oligosaccharides (CTOS) possess potential applications in food, medicine, and agriculture. However, lower mass transfer and catalytic efficiency are the main kinetic limitations for the production of CTOS from shrimp shell waste (SSW) and crystalline chitin. Chemical or physical methods are usually used for pretreatment to improve chitinase hydrolysis efficiency, but this is not eco-friendly and cost-effective. To address this challenge, a chitinase nanoreactor with the liquid-solid system (BcChiA1@ZIF-8) was manufactured to boost the one-step degradation of SSW and crystalline chitin. Compared with free enzyme, the catalytic efficiency of BcChiA1@ZIF-8 on colloidal chitin was significantly improved to 142 %. SSW and crystalline chitin can be directly degraded by BcChiA1@ZIF-8 without any pretreatments. The yield of N, N′-diacetylchitobiose [(GlcNAc)2] from SSW and N-acetyl-D-glucosamine (GlcNAc) from crystalline chitin was 2 times and 3.1 times than that of free enzyme, respectively. The reason was that BcChiA1@ZIF-8 with a liquid-solid system enlarged the interface area, increased the collision frequency between enzyme and substrate, and improved the large-substrates binding activity of chitinase. Moreover, the biphasic system exhibited excellent stability, and the design showed universal applicability. This strategy provided novel guidance for other polysaccharide biosynthesis and the conversion of environmental waste into carbohydrates.

TEMPO-Grafted Polystyrene/Polymethacrylate Organosiloxane Janus Nanohybrids as Efficient Pickering Interfacial Catalyst for Selective Aerobic Oxidation of Cinnamyl Alcohol.

The novel 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) groups immobilized on functional polymers or nanoparticles emerged as potential Pickering interfacial catalysts (PICs) for effective catalysis in biphasic systems. In this study, a snowman-shaped Janus-structured polymer with TEMPO-anchored nanohybrid particles (SM-JPP-TEMPO) was prepared and employed as a potential PIC in the Anelli-Montanari system for the selective oxidation of alcohol. The amphiphilic character of SM-JPP-TEMPO particles plays a dual role as an emulsifier and catalyst in the Pickering emulsion. As a result, it enables smaller droplets (102 μm) at the water-in-oil (W/O) interface and reduces the interfacial tension from 26.58 to 17.38 mN/m, which improves the stability of the Pickering emulsion system. This constructed Pickering emulsion microreactor offers a larger interface contact area and shortens the mass transfer distance of the substrate of cinnamyl alcohol, which significantly enhances the catalytic conversion at the Anelli-Montanari oxidation system, thus achieving remarkable conversion efficiency of (92.3%) with excellent selectivity (99%) in static (stirring-free) condition. It was found that the Janus nanohybrid catalyst (SM-JPP-TEMPO) enhanced 1.29-fold catalytic efficiency compared to the TEMPO grafted spherical polystyrene nanoparticle (PS-NPs-TEMPO) catalyst (72%). Moreover, after seven consecutive cycles, the Janus nanocatalyst (SM-JPP-TEMPO) maintained the conversion significantly. Hence, these results collectively highlight that the amphiphilic SM-JPP-TEMPO catalyst provides an efficient and eco-friendly strategy for the intensification of liquid-liquid biphasic reaction systems for potential applications in industries.

Interfacial assembly and properties of amphiphilic polymer-grafted nanoparticles: Effect of chemical design and density of grafted polymers

Despite extensive research conducted on the polymer-grafted nanoparticle (PGNP) systems for the development of emulsifiers with enhanced performance, little is known about the effects of the grafting architecture and density on the interfacial assembly and interfacial tension reduction behavior of the oil/water (O/W) interface at the molecular level. We performed coarse-grained molecular simulations of both biphasic and emulsion droplet systems with emulsifiers, including Janus (grafting of hydrophilic (HI) and hydrophobic (HO) homopolymers onto two regions of the surface), HI–HO (grafting of diblock polymers with HI monomers as inner blocks and HO monomers as outer blocks), and HO–HI PGNPs, for various graft densities and volume fractions of PGNPs. Compared with the diblock PGNPs, the grafted HI and HO homopolymers of Janus PGNPs penetrate the oil or water phase, rather than assembling at the O/W interface. The depletion of the interface of grafted polymers increases the interfacial tension; consequently, the Janus PGNPs are not effective in reducing the interfacial tension for all the investigated graft densities. The interfacial assembly behavior of the HI–HO and HO–HI PGNPs, whose insoluble blocks have asymmetric interactions with the O/W phases, depends on the graft density and volume fraction. This is particularly the case for their dispersibility, which is an important factor for the interfacial tension. At low graft density, we observe a uniform distribution of HO–HI PGNPs at the O/W interface, resulting in an effective reduction in interfacial tension. At high volume fractions of PGNPs with high graft density, a more tightly packed distribution is observed between HO–HI PGNPs than between HI–HO PGNPs, and their changes in assembly behavior reverse the rate of decrease in the interfacial tension of HO–HI and HI–HO PGNPs. Our results indicate that the grafting architectures of diblock polymers have a significant influence on the assembly behavior at the interface and interfacial tension, and that the appropriate grafting architecture for effective emulsifiers that stabilize the interfaces is different depending on the graft density and volume fraction of the PGNPs. This study also provides new insights into the relation between the interfacial assembly and the stability of emulsion droplets covered by the PGNPs. We observe that the diblock PGNPs, which have the insoluble block as the inner block, are more promising candidates for stabilizing emulsions compared with Janus PGNPs. In the opposite case, the insoluble blocks become the “sticky” points for the adhesion of emulsion droplets, resulting in droplet–droplet coalescence even for effective emulsifiers in reducing interfacial tension. The findings of this study offer a theoretical guide for designing optimal PGNPs for specific volume fractions and optimal graft densities and volume fractions for the grafting architectures of synthesizable PGNPs, and they support the progression from the trial-and-error empirical approaches for developing improved emulsifiers.

Optimization of Chlorophyll Extraction from Ulva Sp. with Ultrasound-Assisted Liquid Biphasic Systems Method

Ulva sp. is a type of green algae that is easily found in the shallow seas of Indonesia and contains various bioactive compounds. Chlorophyll is a bioactive compound that functions as a natural dye, free radical scavenger, and antioxidant in the body. Chlorophyll extraction with conventional methods requires a relatively long time and large amount of solvent. In this research, chlorophyll extraction from Ulva sp. with the Ultrasound-Assisted Liquid Biphasic System (UALBS) method. Ulva sp. as much as 2.5 grams mixed in acetone solvent, added K2HPO4 solution, and carried out the sonification process in a dark room. The extraction process performs at a parameter range of 5-15 minutes, ratio 0.05-0.1 g/mL, and 60-100 mesh particle size. The extracted filtrate was added with petroleum ether and distilled water to form a biphasic condition. The extracted chlorophyll was analyzed with chromatography and spectrophotometry method. Antioxidant activity was analyzed using the DPPH method. The optimum result of Ulva sp. chlorophyll extraction at an extraction time of 10 minutes, the ratio of solids to solvent was 0.1, the particle size of 60 mesh produced a yield of 1.88% with chlorophyll a 20.13664%, chlorophyll b 21.58672% and total chlorophyll 41.71012%, and the percentage inhibition 45.32%.

Separation of ochratoxins by centrifugal partition chromatography

The present research work was dedicated to developing an efficient method based on liquid-liquid chromatography (centrifugal partition chromatography, CPC) applicable to routine purifications of ochratoxins (OT) from the liquid culture of the strain A. albertensis SZMC 2107. The crude extract contained numerous components in addition to OTA (90.1 %,) and OTB (1.1 %,) according to HPLC examinations. For the separation of OTs by CPC, several tertiary systems based on acetonitrile, acetone, and short-chain alcohols were examined to find the most applicable biphasic system. The hexane/i-propanol/water 35:15:50 system supplemented with 0.1 % acetic acid was found to be the most efficient for use in CPC separation. Using liquid–liquid instrumental separation, the two OTs, namely OTA (2.23 mg) and OTB (0.031 mg), were successfully isolated with 96.3 % and–72.8 % purity, respectively, from 1 L ferment broth. The identities and purities of the purified components were confirmed and the performance parameters of each separation step and the whole procedure were determined. The developed method could be used effectively to purify OTs for analytical or toxicological applications.

2,2,5,5-Tetramethyloxolane as a Nonperoxide-Forming Alternative Solvent for Microwave-Assisted Glucose Conversion to 5-Hydroxymethylfurfural in a Biphasic System

2,2,5,5-Tetramethyloxolane as a Nonperoxide-Forming Alternative Solvent for Microwave-Assisted Glucose Conversion to 5-Hydroxymethylfurfural in a Biphasic System

Model-based design of gradient elution in liquid-liquid chromatography: Application to the separation of cannabinoids

Liquid-liquid chromatography (LLC) is a separation technique that utilizes a biphasic solvent system as the mobile and stationary phases. The components are separated solely due to their different distributions between the two liquid phases. Gradient change in the mobile phase composition during the chromatographic process is a powerful method for improving the resolution of separation or shortening the process time. Gradient elution readily applies to LLC with biphasic solvent systems in which the stationary phase composition remains nearly constant when the mobile phase composition changes. This work proposes a model-based approach to optimize gradients in LLC and circumvent tedious trial-and-error experiments. The solutes’ distribution constant depends on the mobile phase composition. Thus, the distribution constants were described as a function of the content of one of the solvents (= modifier) in the mobile phase. The dispersive and mass-transfer effects in the tubing and the column are modeled with a stage model. Only a few experiments are required to determine the model parameters. After the validation of the model and its parameters, the model can be used for LLC gradient optimization. The proposed approach was demonstrated for a gradient LLC separation of a mixture of four cannabinoids. Two different gradient shapes, one-step and linear gradient, were considered. For a pre-selected minimal purity requirement, the gradient was optimized for maximum process efficiency, defined as the product of productivity and yield. An experiment conducted with the optimized gradient conditions was in good agreement with the simulation, showing the potential of the proposed method.

Efficient preparation of icariin from epimedin C by recyclable biphasic enzymatic hydrolysis

Icariin is the most bioactive ingredient of Epimedium L. and a quality marker of Herba Epimedii. Conventional methods for production of Icariin are known to be inefficient, resulting in low yields and significant environmental pollution. This study aimed to develop a sustainable and effective biphasic enzymatic hydrolysis system for the efficient conversion of epimedin C to icariin. The biphasic system was created using butyl acetate and phosphate buffer (pH 4.5) at a ratio of 3:1 (V/V) along with α-L-rhamnosidase/epimedin C (2 U/1 mg) at 50 °C for 12 h. Consequently, 98.21% of epimedin C was hydrolysed to icariin, with 95.62% of the product being transferred to the organic phase. Even after four cycles of use, the conversion ratio remained high at 75.28%. Furthermore, this novel strategy was also used for the conversion of Epimedium brevicornu Maxim. extracts. The biphasic system represents a sustainable and effective method for icariin production, offering potential benefits for industrial applications.