Total Solvent Volume Research Articles

Enhancing Mycosporine-Like Amino Acids (MAAs) Extraction Yield from Fischerella sp. F5 using Experimental Design

Background: Mycosporine-like amino acids (MAAs) are ultraviolet-absorbing metabolites found in cyanobacteria, fungi, algae, and animals, known for their antioxidant and anti-inflammatory properties. Objectives: This study aimed to optimize MAAs extraction from Fischerella sp. F5 using experimental design techniques. Methods: The central composite design was employed to determine the optimal levels of five factors: Total extraction time, temperature, sonication time, methanol ratio, and solvent volume. Each run involved extracting 100 mg of dried biomass under the specified conditions. Mycosporine-like amino acids content was quantified using high performance liquid chromatography (HPLC), and the antioxidant activity of the extract was assessed using the DPPH radical scavenging test. The best model was selected based on the highest R2 value, and the optimized extraction conditions were determined. Results: Mycosporine-like amino acids content in the final extracts ranged from 27.7% to 89%, with antioxidant activities ranging from 15% to 59.3%. Overall, all factors showed a positive correlation with MAAs content in the final extract. However, no significant model was established to correlate extraction conditions with MAAs purity ratio (MAA%) or extract antioxidant activity. Conclusions: The bioactivity of partially purified MAAs may be influenced by factors such as associated impurities extracted alongside MAAs, which were not investigated in this study. Further research is necessary to identify the exact factors affecting MAAs extraction yield and purity, aiming to obtain partially purified MAAs extracts with optimal bioactivity.

Efisiensi Pakan Larva Ikan Nila (Oreochromis Niloticus) Hasil Maskulinisasi Madu Hutan

Nile tilapia is a superior commodity that has been developed with high production. Male nile tilapia has a growth rate of 2 times faster than female nile tilapia, so the cultivation of male nile tilapia (monosex) is far more profitable. The masculinization using honey will produce monosexual male nile tilapia, through immersion method using honey. Honey contain flavonoids which function to direct male genitals. Honey also contains potassium which triggers steroid hormones in protein metabolism, brings glucose into cells and stimulates the hypothalamus, so that it can trigger appetite in animals and influence the level of consumption and feed efficiency. This study aims to determine the best type of honey in nile tilapia larvae for consumption and feed efficiency. Honey used in this study were; forest honey (from Bontocani, Selayar, Sumbawa) and livestock honey with a dose of 0.2% of the total volume of solvents, through the immersion method. The seven days old nile tilapia larvae were immersed in the treatments for 24 hours, then they were reared for 60 days. Completely Randomized Design (CRD) with 3 replications per treatment was used in this experiment. The results showed that honey from Bontocani forest produced highest feed consumption and forest honey (from Bontocani, Selayar and Sumbawa) produced highest feed efficiency.

Room-temperature aqueous synthesis of MOF-808(Zr) for selective adsorption of dye mixtures

ZrIV-based metal–organic frameworks (MOFs) featuring distinguished water stability, large surface area, and intriguing functionalities have immense potential for practical usage. However, conventional MOF synthesis approaches generally require high reaction temperatures and organic solvents to initiate and template the nucleation and growth, hindering sustainable and cost-effective manufacturing and application of Zr-based MOFs. In this study, a scalable, room-temperature and aqueous synthesis of MOF-808—a Zr-MOF extensively explored as an adsorbent in both academic and industrial sectors—was reported. A rational use of water/formic acid (FA) as a green co-solvent enabled the formation of Zr6-cluster in an aqueous phase, thereby facilitating subsequent coordination with H3BTC to yield well-crystallized MOF-808. The effects of the water/FA volume ratio, the total solvent volume, and reaction time on the physicochemical properties of MOF-808 were studied. The optimized synthesis conditions (FA/water = 2.7:8.1, and reaction time = 24 h) resulted in the synthesis of MOF-808 with good hydrophilicity, excellent stability, high surface area, and weak positive charges. Moreover, this synthesis approach was successfully upscaled, yielding 11.5 g of MOF-808 at a magnification factor of 48. Notably, MOF-808-V10.8 exhibited an impressive adsorption capacity for Congo Red (ca. 1500 mg/g) and demonstrated selective fractionation of dye mixtures, suggesting their potential application in dye wastewater treatment. This methodology is expected to provide guidance for aqueous and scalable fabrication of Zr-MOFs towards water-related environmental applications.

Determination of n-3 fatty acids in shrimp using a mini-scale extraction method and GC-FID analysis

Crustaceans are low in fat but rich in omega-3 (n-3) fatty acids (FA). In this study, a mini-scale extraction method was optimized based on the Bligh and Dyer method for the determination of n-3 fatty acids, i.e., alpha-linolenic acid (LNA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), in shrimp samples followed by gas chromatography with flame ionization detection. The optimal extraction conditions were determined through a 23 factorial design with a center point. The optimized method extracted comparable amounts of n-3 FA as the original Bligh and Dyer method but was 45 times faster and used 30 times less chloroform and sample and 11 times less total solvent volume. Additionally, the optimized method was successfully applied for the extraction of fatty acid, mainly n-3 fatty acid, from various shrimp species. Thus, the n-3 mini-scale extraction method can be considered a suitable alternative to traditional methods for the extraction of n-3 fatty acid from shrimp.

Green Optimization of the First Steps for the Synthesis of a Novel Surfactant: Towards the Elimination of CMR Solvents and the Drastic Reduction of the Used Solvent Volume

AbstractIn this report, the first steps of the synthesis of a novel surfactant have been described. Each stage has been optimized to abide by the principles of green chemistry. The replacement of CMR (Carcinogenic, Mutagenic, Reprotoxic) solvents by 4‐MTHP (4‐methyltetrahydropyran) led to the improvement of the overall yield and to the drastic reduction of the total organic solvent volume used in the process.

Water‐insoluble cosolvent in aqueous two‐phase system improved the extraction of paeonol from cortex moutan

AbstractBackgroundAqueous two‐phase extraction has advantages of green extraction, high yield, good product purity and low cost. However, conventional aqueous two‐phase systems (ATPSs) are limited in extraction/separation due to high polarity. Some researchers tuned the hydrophobicity of ATPSs by addition of hydrophobic ionic liquids or polymers. We aimed to tailor the hydrophobicity of a solvent–salt–water ATPS using cosolvent for extraction of paeonol from cortex moutan.ResultsTie‐line length and compositions in the ATPS were employed for qualitative evaluation of polarity and polarity difference between the two phases. Conditions such as pH, salt type and concentration, total solvent volume fraction and cosolvent fraction were optimized. Ethyl acetate (EA) as cosolvent in ethanol–NaH2PO4–H2O (EtPO) system did not alter the first‐order kinetic extraction model, but it improved the kinetic constant and boosted the partition coefficient from 36.7 to 58.8. For both EtPO and EtPO–EA systems, both the extraction yields and partition coefficients increased when temperature increased from 11 to 37 °C. The optimized EtPO–EA system demonstrated higher extraction yield than EtPO and 70% (v/v) ethanol systems by 25.4 and 19.5%, respectively.ConclusionsThe hydrophobicity of an ATPS was successfully tuned with cosolvent for paeonol extraction. The cosolvent–salt–water two‐phase systems are promising in extraction of weakly polar components from herbs. © 2019 Society of Chemical Industry

SLTCAP: A Simple Method for Calculating the Number of Ions Needed for MD Simulation.

An accurate depiction of electrostatic interactions in molecular dynamics requires the correct number of ions in the simulation box to capture screening effects. However, the number of ions that should be added to the box is seldom given by the bulk salt concentration because a charged biomolecule solute will perturb the local solvent environment. We present a simple method for calculating the number of ions that requires only the total solute charge, solvent volume, and bulk salt concentration as inputs. We show that the most commonly used method for adding salt to a simulation results in an effective salt concentration that is too high. These findings are confirmed using simulations of lysozyme. We have established a web server where these calculations can be readily performed to aid simulation setup.

Lipid Extraction from Tetraselmis sp. Microalgae for Biodiesel Production Using Hexane-based Solvent Mixtures

Lipid extraction is a critical step in the downstream processing of biodiesel production from microalgae. Solvent extraction using mixtures of non-polar and polar solvents is one of the most well-known processes for this purpose. Hexane is the most common solvent of choice for large-scale lipid extractions due to its technical and economic advantages, especially its high selectivity toward lipids and low cost. In this study, extractions using mixtures of hexane and polar solvents were evaluated for their performance in order to develop a more efficient method for large-scale lipid extraction from microalgae. The combination of hexane and methanol resulted in the highest fatty acid methyl ester (FAME) yield for lipids from Tetraselmis sp. The effects of extraction conditions, including proportions of methanol to hexane, ratios of total solvent volume to dry biomass, and extraction time, on extraction yields were evaluated to determine optimum conditions providing higher lipid and FAME yields. The optimal conditions were as follows: proportion of hexane to methanol of 1:1, ratio of total solvent volume to dry biomass of 10 mL/g, and extraction time of 120 min. Finally, the selected solvent mixture and optimal conditions were applied to larger scale extraction experiments with scale-up factors of 10, 50, and 100. FAME yields of large-scale extractions were almost completely consistent with increasing scale-up factors. The results of this study suggest that a hexane and methanol mixture is a promising solvent for large-scale lipid extraction from microalgae.

Optimisation of β-cyclodextrin inclusion complexes with natural antimicrobial agents: thymol, carvacrol and linalool

Beta-cyclodextrin (β-CD) inclusion complexes with naturally derived antimicrobial (AM) agents: thymol, carvacrol and linalool were prepared using a co-precipitation technique. Conditions including solvent composition, temperature, reaction time and total solvent volume were investigated to optimise the inclusion efficiency (IE) and yield. Electrospray ionisation mass spectrometry was used to confirm the formation of the thymol/β-CD complex and gas chromatography was used to quantify the amount AM agent that was encapsulated, absorbed onto the surface, or remaining in the filtered solvent. The systematic optimisation of the conditions improved both the yield of the complex and the IE of the AM agents compared to previously reported methods that have been applied to other agents. Using a 1:1 mole ratio of the AM agent to β-CD, the optimised parameters resulted in maximum yields of 87, 84 and 86% (w/w) for thymol, carvacrol and linalool, respectively, with IE’s close to 100% (w/w) for each agent.

Graphene reflux: improving the yield of liquid-exfoliated nanosheets through repeated separation techniques

Scalable production of graphene through liquid-phase exfoliation has been plagued by low yields. Although several recent studies have attempted to improve graphene exfoliation technology, the problem of separating colloidal nanosheets from unexfoliated parent material has received far less attention. Here we demonstrate a scalable method for improving nanosheet yield through a facile washing process. By probing the sedimentation of liquid-phase exfoliated slurries of graphene nanosheets and parent material, we found that a portion of exfoliated graphene is entrapped in the sediment, but can be recovered by repeatedly washing the slurry of nanosheet and parent material with additional solvent. We found this process to significantly increase the overall yield of graphene (graphene/parent material) and recover a roughly constant proportion of graphene with each wash. The cumulative amount of graphene recovered is only a function of total solvent volume. Moreover, we found this technique to be applicable to other types of nanosheets such as boron nitride nanosheets.

Greener solvent systems for copper wire-mediated living radical polymerisation

Copper wire-mediated living radical polymerisation (LRP) is a powerful tool that provides numerous opportunities for the development of new materials. It requires very low catalyst loading and mild reaction conditions; however, it typically involves the use of organic solvents. The authors have investigated the use of greener solvent systems to replace traditional volatile organic solvents without detrimentally affecting polymerisation. The effects of these alternative solvents on the control over polymerisation and polymer characteristics were investigated for the polymerisation of methyl acrylate initiated by ethyl 2-bromoisobutyrate. Copper wire-mediated LRP was conducted in dimethyl sulfoxide (DMSO), polyethylene glycol (PEG) and polypropylene glycol (PPG) and binary mixtures of PEG–DMSO, PEG–ethanol, PPG–DMSO and PPG–ethanol with total solvent volume fractions of 33 and 50%. Secondary solvent fractions in the binary mixtures were examined at 10 and 25% of the total solvent volume. The two most effective greener solvent systems were 33% v/v of 75% PEG–25% ethanol and 33% v/v of 75% PPG–25% ethanol. Both were shown to provide excellent control over polymerisation and a high degree of livingness. The poly(methyl acrylate) produced in these solvent systems retained high bromine chain-end functionality (>90%) and low dispersity (∼1·1).

Lixiviación y secado de hojuelas de nim (Azadirachta indica) para obtener un insecticida botánico

El objetivo de este trabajo es estudiar experimentalmente la viabilidad de mejorar el procesamiento de hojuelas de nim en columnas, mediante la realización de la lixiviación del insecticida sin la remoción intermedia del solvente no-polar; y mediante la simultánea realización de ambas etapas de lixiviación. El secado de los solventes remanentes en las hojuelas de nim también se estudió experimentalmente. En la parte de lixiviación, los parámetros estudiados fueron tiempo de lixiviación, grosor de hojuelas, relación de volumen de solventes y volumen total de solventes. Estos parámetros mostraron tener una gran influencia en el rendimiento de los compuestos insecticidas, pero la influencia de la relación de solventes fue la más importante. Se demostró que más metanol que hexano tuvo que ser empleado para obtener un mayor rendimiento de compuestos insecticidas. El rendimiento de aceite fue influenciado principalmente por el grosor de las hojuelas. En la parte de secado, la temperatura del flujo de aire entrante tiene influencia en el proceso. Conclusiones sobre el tiempo de secado o la velocidad de secado no son posibles de realizar a partir de los resultados de los experimentos. Las variaciones en el tiempo de secado son demasiadas grandes y la velocidad de secado parece ser independiente de las condiciones de la etapa de lixiviación anterior.

Development of direct conversion method for microalgal biodiesel production using wet biomass of Nannochloropsis salina

In this work, the effects of several factors, such as temperature, reaction time, and solvent and acid quantity on in situ transesterification yield of wet Nannochloropsis salina were investigated. Under equivalent total solvent volume to biomass ratio, pure alcohol showed higher yield compared to alcohol–chloroform solvent. For esterifying 200mg of wet cells, 2ml of methanol and 1ml of ethanol was sufficient to complete in situ transesterification. Under temperatures of 105°C or higher, 2.5% and 5% concentrations of sulfuric acid was able to successfully convert more than 90% of lipid within 30min when methanol and ethanol was used as solvents respectively. Also, it was verified that the optimal condition found in small-scale experiments is applicable to larger scale using 2L scale reactor as well.

Retro operation on the Trp-cage miniprotein sequence produces an unstructured molecule capable of folding similar to the original only upon 2,2,2-trifluoroethanol addition.

Amino acid sequence and environment are the most important factors determining the structure, stability and dynamics of proteins. To evaluate their roles in the process of folding, we studied a retroversion of the well-described Trp-cage miniprotein in water and 2,2,2-trifluoroethanol (TFE) solution. We show, by circular dichroism spectroscopy and nuclear magnetic resonance (NMR) measurement, that the molecule has no stable structure under conditions in which the Trp-cage is folded. A detectable stable structure of the retro Trp-cage, with the architecture similar to that of the original Trp-cage, is established only upon addition of TFE to 30% of the total solvent volume. The retro Trp-cage structure shows a completely different pattern of stabilizing contacts between amino acid residues, involving the guanidinium group of arginine and the aromatic group of tryptophan. The commonly used online prediction methods for protein and peptide structures Robetta and PEP-FOLD failed to predict that the retro Trp-cage is unstructured under default prediction conditions. On the other hand, both methods provided structures with a fold similar to those of the experimentally determined NMR structure in water/TFE but with different contacts between amino acids.

Determination of polychlorinated biphenyls in fish: Optimisation and validation of a method based on accelerated solvent extraction and gas chromatography–mass spectrometry

A simple and robust method for the determination of 18 polychlorinated biphenyls (PCBs) in fish was developed and validated. A mixture of acetone/n-hexane (1:1, v/v) was selected for accelerated solvent extraction (ASE). After the digestion of fat, the clean-up was carried out using solid phase extraction silica cartridges. Samples were analysed by GC–MS in selected ion monitoring (SIM) using three fragment ions for each congener (one quantifier and two qualifiers). PCB 155 and PCB 198 were employed as internal standards.The lowest limit of detection was observed for PCB 28 (0.4ng/g lipid weight). The accuracy of the method was verified by means of the Certified Reference Material EDF-2525 and good results in terms of linearity (R2>0.994) and recoveries (80–110%) were also achieved. Precision was evaluated by spiking blank samples at 4, 8 and 12ng/g. Relative standard deviation values for repeatability and reproducibility were lower than 8% and 16%, respectively.The method was applied to the determination of PCBs in 80 samples belonging to four Mediterranean fish species.The proposed procedure is particularly effective because it provides good recoveries with lowered extraction time and solvent consumption; in fact, the total time of extraction is about 12min per sample and, for the clean-up step, a total solvent volume of 13ml is required.

The effect of guest molecules on the conformation and molecular assembly of the fac-[RuCl3(NO)(dppb)] complex

This paper describes the occurrence of two crystalline solvate forms of the nitrosyl ruthenium complex fac-[RuCl3(NO)(dppb)] (dppb=1,4-bis(diphenylphosphino)butane), and the role of acetone and chloroform inclusions on molecular conformations and molecular assemblies. These two crystal forms were identified by X-ray diffraction and infrared spectroscopy, and compared with the known crystal structure of the complex, without the solvent. Using the FT-IR technique, it was possible to assign the bands characteristics of the nitrosyl stretching and the solvents. An interesting structural aspect occurring in both solvate forms is that the solvent inclusion modifies the molecular conformation of the dppb ligand and the molecular assembly. Due to the similar total volume of guest solvents, the unit cell parameters are similar, resulting in an isostructural arrangement with small differences in the intermolecular interactions, with caged guest solvents, that interact with the complex by hydrogen bonds.

Separation of isopropyl alcohol–water mixtures by pervaporation using copolymer membrane: Analysis of sorption and permeation

Membrane made from copolymer of acrylonitrile and methyl acrylate designated as PANMA was used for pervaporative dehydration of isopropyl alcohol (IPA) over the concentration range of 75–100wt% IPA in water. Sorption of the membrane was evaluated in terms of thermodynamic interaction parameters based on Flory–Huggins lattice model. Engaged species induced clustering (ENSIC) model was also used to explain swelling of the membranes. Coupling in sorption was explained by activity coefficient of water and IPA in feed and membrane using Flory–Hugging thermodynamics and also by interpolating ENSIC parameters. Intrinsic membrane properties like partial permeability and membrane selectivity was also determined. Total solvent volume fraction (TSVF) model was used to determine diffusion coefficient and plasticization coefficient of the solvents. The membrane was found to show very high water selectivity (3540) and good flux (3.3kg/m2hμm) for highly concentrated (99.8wt%) IPA at 30°C temperature.

The granulation of binary mixtures: the effects of the composition of the granulating solution and the initial particle size of one component on granule properties.

The effect of total solvent volume and the presence of dissolved material (other than binder) in the granulating solution, on the properties of granules prepared from lactose: boric acid mixtures has been studied. The total volume of binder solution available to powder mixtures during massing determines the ultimate average size of granules produced. Part-dissolution of powders being granulated contributes significantly to the average granule size by increasing the total solution volume and reducing the amount of powder to be wetted. Although the amount of PVP (binder) dissolved in the granulating solution contributed very little to granule size at the concentration examined, the combined effect of total volume of solution and amount of PVP present in the granulating solution determines granule strength and porosity. The effect of the initial particle size of lactose in a binary mixture with boric acid differs from its effect reported for single component systems.

A new way to prepare tin oxide precursor polymeric gels

Transparent tin oxide gels are elaborated in the isopropoxide/toluene/isopropanol system. The gelation occurs at room temperature without any acid or base additions. The formation of the SnO2 precursor gels polymeric network is evidenced by Fourier transform infrared spectroscopy. The gelation time is studied as a function of the complexing ratio R = [acac]/[Sn(OR)4], the hydrolysis ratio W = [H2O]/[Sn(OR)4], the concentration of tin oxide precursor C = [Sn(OR)4], and the volume fraction of toluene P = (toluene volume) / (total solvent volume).

Screening of Complex Natural Extracts by Countercurrent Chromatography Using a Parallel Protocol

In countercurrent chromatography (CCC) the choice of the liquid system is the heart of any separation. It corresponds to the selection of the mobile phase and the stationary phase at the same time. Any change in one phase composition induces a change in the other phase composition which renders the choice of the appropriate liquid system difficult and lengthy. A scale of compositions of the heptane-ethyl acetate-methanol-water quaternary liquid system was referred to by letters from A to Z and called the Arizona (AZ) liquid system. Each composition of the AZ system has the same heptane/ethyl acetate and methanol/water volume ratios. It is shown that there is a continuous polarity change from the hydrophilic A composition (ethyl acetate-water) to the hydrophobic Z (heptane-methanol) mixture by measuring the distribution constant K(D) of a known test mixture. For all compounds, the log K(D) is linearly increasing with the water content of the lower aqueous phase of the composition used. The slopes of the log K(D) versus percent H(2)O have very different values which means that the chromatographic selectivity changes with liquid system compositions. The AZ system was associated to the elution-extrusion method to design a procedure to identify rapidly the appropriate solvent composition able to fractionate correctly a complex natural extract. With the use of an integrated three-coil CCC column (40 mL each coil) able to test three AZ compositions in parallel, it is shown that the optimum AZ composition is found in half a day using less than a liter total volume of solvents. Two natural extracts are rapidly screened using the proposed protocol. An extract of Piper longum L. of intermediate polarity was fractionated in five usable portions using the 3/2/3/2 (Q) composition of the AZ system. A polar extract of Polygonum cuspidatum was also separated in five fractions using the 1/6/1/6 (D) composition. In both cases, a 140 mL CCC column was used for a direct scale-up transfer with the same liquid system. Purified fractions were subjected to an antioxidant activity assay and liquid chromatography with UV and mass spectrometry detection (LC-UV/MS) analysis to determine the molecular weight, number, and quantity of compounds in the active fractions. Four fractions of P. cuspidatum showed excellent antioxidant activity. They were rapidly produced at the milligram level by the 140 mL CCC column and fractionated by semipreparative high-performance liquid chromatography (HPLC) in individual compounds that were each identified by NMR and MS and reevaluated for confirmation of bioactivity. The rapid screening CCC protocol associated to the preparative capability of CCC allows for a fast identification and characterization of active compounds in natural products.