Methanol Concentration Research Articles

Multi-Omics Analysis of the Co-Regulation of Wood Alcohol Accumulation in Baijiu Fermentation

Methanol, also known as wood alcohol, is a common hazardous by-product of alcoholic beverage fermentation and serves as a crucial indicator for assessing the safety of alcoholic beverages. However, the metabolic mechanisms of methanol production during the solid-state fermentation of Chinese Baijiu remain unclear. In this study, we sought to determine the primary stage of methanol production in Chinese Baijiu by measuring the methanol content at different stages of fermentation. High-throughput multi-omics sequencing techniques were employed to elucidate methanol metabolic pathways and associated microorganisms. In addition, a comprehensive analysis incorporating environmental factors and microbial interactions was conducted to explore their combined effects on methanol production. Methanol was predominantly produced during pit fermentation, with the most significant increase observed within the first seven days. Microorganisms such as Pichia kudriavzevii, Byssochlamys spectabilis, Penicillium, and Aspergillus played a regulatory role in methanol content during the first seven days through their involvement in butyrate and methane metabolic pathways and pectin degradation modules. During Baijiu production, various types of molds and yeasts participate in methanol production. Differences in their abundance within fermentation cycles may contribute to variations in methanol content between stages. Lactobacillus accumulated abundantly in the first seven days in each stage, suppressing methanol-metabolizing microorganisms. In addition, the increased acidity resulting from Lactobacillus metabolism may indirectly promote methanol generation.

Unsupervised Clustering-Assisted Method for Consensual Quantitative Analysis of Methanol-Gasoline Blends by Raman Spectroscopy.

Methanol-gasoline blends have emerged as a promising and environmentally friendly bio-fuel option, garnering widespread attention and promotion globally. The methanol content within these blends significantly influences their quality and combustion performance. This study explores the qualitative and qualitative analysis of methanol-gasoline blends using Raman spectroscopy coupled with machine learning methods. Experimentally, methanol-gasoline blends with varying methanol concentrations were artificially configured, commencing with initial market samples. For qualitative analysis, the partial least squares discriminant analysis (PLS-DA) model was employed to classify the categories of blends, demonstrating high prediction performance with an accuracy of nearly 100% classification. For the quantitative analysis, a consensus model was proposed to accurately predict the methanol content. It integrates member models developed on clustered variables, using the unsupervised clustering method of the self-organizing mapping neural network (SOM) to accomplish the regression prediction. The performance of this consensus model was systemically compared to that of the PLS model and uninformative variable elimination (UVE)-PLS model. Results revealed that the unsupervised consensus model outperformed other models in predicting the methanol content across various types of methanol gasoline blends. The correlation coefficients for prediction sets consistently exceeded 0.98. Consequently, Raman spectroscopy emerges as a suitable choice for both qualitative and quantitative analysis of methanol-gasoline blend quality. This study anticipates an increasing role for Raman spectroscopy in analysis of fuel composition.

Purification, characterization of a plant esterase from red kidney bean and its feasibility for pesticide residue analysis in foods

Plant-derived esterase is a promising alternative enzyme source for pesticide residue analysis. The present study aimed to obtain purified red kidney bean esterase (RKBE), investigate its biochemical properties and application potential in pesticide residue assay. RKBE was extracted and purified by simple aqueous two-phase extraction combined with dextran gel filtration chromatography, with specific activity of 11.845 U/mg and purification fold of 18.952. SDS-PAGE revealed that RKBE has a molecular weight of 33 kDa. Preliminary structural characterization showed the amino acid sequence of RKBE was similar to that of α/β-hydrolase (ESW18998) derived from Phaseolus vulgaris with 19.5% sequence coverage, and the relative contents of β-sheet, β-turn, α-helix, and random coil were 22.69%, 24.19%, 30.12%, and 23.00%, respectively. The optimal pH and temperature of RKBE were 6.5 and 40 °C. Ca2+, Mg2+, Zn2+, and low concentrations of methanol and ethanol stimulated the enzyme activity. The half-life was 138.6 days at −20 °C. Kinetic studies showed that RKBE exhibited a high affinity and catalytic activity towards 1-naphthyl acetate, with a Km of 0.277 mM and a Kcat/Km of 0.455 s−1 mM−1. Enzyme-specific inhibition assay indicated RKBE to be a carboxylesterase. Finally, pesticide susceptibility experiments confirmed that organophosphorus and carbamate pesticides exerted inhibitory effects on RKBE catalytic activity. For methamidophos, methomyl, dichlorvos, and carbaryl, the limit of detection (IC10) values in cabbage were 0.0031, 0.0045, 0.001, and 0.0065 mg/kg, respectively, suggesting that RKBE can serve as a new, widely available and cost-effective enzyme source for pesticide residual assay in foods.

Mathematical Modelling and Simulations of Active Direct Methanol Fuel Cell

A one dimensional isothermal model is proposed by modelling the kinetics of methanol transport at anode flow channel (AFC), membrane and cathode catalyst layer of direct methanol fuel cell (DMFC). Analytical model is proposed to predict methanol cross-over rate through the electrolyte membrane and cell performance. The model presented in this paper considered methanol diffusion and electrochemical oxidation at the anode and cathode channels. The analytical solution of the proposed model was simulated in a MATLAB environment to obtain the polarization curve and leakage current. The effect of methanol concentration on cell voltage and leakage current is studied. The methanol cross-over has the significant impact on cell performance. The presented model predicts higher leakage current with the increase of methanol feed concentration. The cell performance was predicted at 70°C and various methanol feed concentration. The proposed model was validated with the experimental polarization curve of active DMFC.

The Experimental Investigation of the Effects on the Combustion, Performance, and Emission Characteristics of an RCCI Engine Using Methanol/Diesel Fuel

Reactivity-controlled compression ignition (RCCI) combustion is considered one of the most promising low-temperature combustion (LTC) concepts aimed at reducing greenhouse gases for the transportation and power generation sectors. RCCI combustion mode is achieved by combining different fuel types with low and high temperatures. The aim of this study is to investigate combustion characteristics and reduce nitrogen oxide (NOx) and carbon dioxide (CO2) emissions. In this experimental study, the effects of the RCCI strategy using methanol/diesel fuel on combustion characteristics (ignition delay, combustion duration), engine performance (brake-specific fuel consumption and brake-specific energy consumption), and emissions were examined in a four-cylinder, turbocharged, dual-fuel engine. The experiments were conducted at a constant speed of 1750 rpm at partial loads (40 Nm, 60 Nm, 80 Nm, and 100 Nm). The test results obtained with diesel fuel were compared with the test results obtained with methanol at different mass flow rates. When the results were examined, the minimum ignition delay (ID) occurred at 40 Nm torque, 5.63 crank angle (CA) with M12 fuel, while the maximum ID occurred with M26 fuel at 80 Nm torque, showing an increasing trend as engine load (EL) increased. The highest combustion time (CD) was achieved with M26 fuel at 100 Nm torque, whereas the lowest was achieved with the same fuel (M26) at 40 Nm. While the minimum brake-specific fuel consumption (bsfc) was 45.9 g/kWh for conventional diesel fuel at 40 Nm, the highest bsfc was 104.88 g/kWh for 100 Nm with M26 fuel. Generally, bsfc tends to increase with increasing load. Brake-specific energy consumption (bsec) had the lowest value of 1950.58 kJ/kWh with conventional diesel fuel at 40 Nm and the highest value of 4034.69 kJ/kWh with M26 fuel at 100 Nm. As the methanol content increased, significant improvements were observed in (NOx) and (CO2) emissions, while hydrocarbon (HC) and oxygen (O2) emissions increased as well. Smoke emissions decreased at low loads but tended to increase at high loads.

Evaluation of total flavonoids, total phenolic content and biological activity of Iraqi Lipedium sativum L. crude extract obtained by optimized ultrasound assisted extraction conditions

Lepidium sativum L. also known as garden cress belong to the family Brassicaceae. The plant species composed of various phytochemicals as well as powerful nutraceutical potential and possess several bioactivities like, hepatoprotective, antioxidant, anticancer, antimicrobial, hypoglycemic, gastrointestinal and bone healing activities. This research paper presents an investigation into the total flavonoids (TFC), total phenolic content (TPC) and biological activity of Iraqi Lepidium sativum L. The study aimed to optimize ultrasound-assisted extraction conditions to obtain a crude extract with enhanced bioactive components. Three variables were examined including methanol concentration, extraction time and ultrasound frequency. The optimum yields of extract, TFC and TPC were (3.22 ± 0.049 g/10 g of dry plant), (17.03 ± 0.060 mg RE/g) and (10.96±0.020 mg GAE/g) respectively. The optimal extraction conditions contributed to these values of experiment 2 and 3 were 70% methanol, 10 min and 40 KHz and 70% methanol, 15 min and 40 KHz respectively. The lowest IC50 values of optimized methanolic extracts of Iraqi Lepidium sativum aerial parts against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals were 31.84 µg/mL for TFC and 35.85 µg/mL for TPC . For the first time, the study provided data about the phenolic and flavonoid contents of the Iraqi plant and optimized conditions for extraction by UAE technique using single factor experiment. The plant can be acknowledged as a potential nutraceutical or functional food rich in antioxidants to combat many diseases.

An on-chip microarray platform for material-temperature optimization and gas discrimination

The demand for gases detection has promoted extensive research into gas sensors. Sensor arrays can be used as electronic olfaction units for complex gas detection and identification. However, the gas sensing properties are affected by various factors. The multi-dimensional nature of those interactions is crucial for creating a sensor array with diverse responses, but it is also challenging to fabricate an array considering all these parameters, particularly in miniaturization. In this paper, we present a framework that can take multiple factors into consideration and help to fabricate an optimal array for gas identification. 32 sensors including different MOS materials (SnO2, In2O3, WO3), morphologies (microsphere, nanoparticle, nanoflake), doped/loaded metals (Pd, Pt, Ce, Ru, Rb), and operational temperatures (250℃∼370℃) are discussed. A material-temperature-analyte-response database was then established by storing their response characteristics towards low ppm concentrations of ammonia, ethyl acetate, toluene, methanol, ethanol, and acetone. An optimized array was then constructed out of 10,518,300 possible combinations of materials and operational temperatures. Results showed improvements in discrimination ability and the optimized array integrated into the chip can provide vector signals with high selectivity, completely recognizing all the 6 target gases and even for their multi-component mixture after linear discriminant analysis transformation.

Methanol intoxication in the central region of Saudi Arabia: Five case studies

Outbreaks of methanol poisoning have been described in the medical literature worldwide. However, the few outbreaks that have occurred in Saudi Arabia remain undocumented. This is especially noteworthy in light of the fact that Saudi Arabia is among the countries that explicitly prohibit the usage of alcoholic beverages and recreational drugs. Herein, we describe five cases of methanol poisoning in Saudi Arabia. The first three comprise patients admitted to the emergency room (ER) with signs of methanol toxicity, such as heart palpitations, vomiting, and blurred vision; otherwise, those patients were considered medically free. The remaining two cases were examined postmortem. A headspace gas chromatography-flame ionization detector was used to test blood, vitreous humor, and urine samples for methanol. Specific lethal concentrations of methanol were defined based on published case studies as 23–740 mg/dL in blood and 12–396 mg/dL in vitreous humor. In postmortem cases of our present study, samples exhibited lethal concentrations: 118 and 257 mg/dL in blood, 116.3 and 283 mg/dL in vitreous humor. In ER cases, methanol concentrations in urine samples were lower, at 7.5, 9.1, and 20.9 mg/dL; however, toxic symptoms were still observed. These case studies indicate that it is necessary to raise community awareness about the risk of methanol poisoning in order to minimize future poisoning epidemics.

Optimization of methyl ester synthesis using gas/liquid phase pulsed discharge plasma in a novel oscillatory slug flow reactor

In the present research, an innovative oscillatory slug flow reactor (OSFR) under the treatment of gas–liquid phase pulsed discharge plasma was developed for biodiesel production. The main goal was continuous production of high quality biodiesel at low temperature and pressure. Experimental tests were carried out under the influence of four main operating parameters including applied voltage, molar ratio, reactant flow rate, and catalyst concentration. The response surface method was employed to optimize experimental tests. The results showed that the proposed technology provided 94% production efficiency under the optimal conditions of voltage 19.4 kV, molar ratio 6.4, flow rate 2.7 ml/s, and catalyst 0.9 wt. %. According to the statistical analysis, increasing the applied voltage and reducing the flow rate have a strong effect on the Fatty Acid Methyl Ester yield, while the concentration of potassium hydroxide and methanol have less effect on the overall efficiency. In addition, the characteristics of the produced biodiesel were in accordance with ASTM D6751 standards. Surprisingly, the optimal energy consumption in this system was 95 kJ/l, which is more economically viable. In general, this study showed that the combined system of gas/liquid phase plasma in the OSFR reactor has a high synergistic potential for the transesterification reaction.

On the influence of different alcohol-type biofuels on performance and engine emissions of an SI engine

Greenhouse gas emissions (G.H.G.) from vehicles are the main source of pollution. In this transition period from fossil fuels to the use of synthetic fuels, the diversification of alternative fuels used to fuel internal combustion engines is seen as one of the best alternatives for reducing G.H.G. In Europe, conforming to the stringent emission reduction targets for 2030, as well as trying to fulfil the regulations of the new Euro VII standard will force engine manufacturers to adopt alternative fuel solutions with a low environmental impact. However, fossil fuels will continue to be used but alternative fuels will substantially decrease our dependence on petroleum-derived fuels. Modern simulation software tools make it easy to produce a fairly accurate analysis of how an internal combustion engine works without the need for prototyping. Packages such as Ricardo WAVE or AVL Boost, are relatively cheap and represent accessible tools for developing, designing, and testing modern internal combustion engines. AVL Boost is a widely used engine simulation tool a 1D (one-dimensional) simulation software that allows engineers and researchers to model, simulate, and optimize various internal combustion engines, including spark ignition (SI) engines, diesel engines, and hybrid powertrains. The software also offers a high degree of flexibility in terms of alternative fuel blends. This paper evaluates the influences of using alcohol-based biofuels on performance metrics and pollutant emissions, such as brake power, brake thermal efficiency, and emissions, such as CO, CO2, and NOx in a spark ignition engine. The effects of varying alcohol fractions in the gasoline-alcohol blends on engine performance and emissions are analysed and explained. In this study, several types of ethanol in gasoline blends were simulated (E25, E50, E85). The one-dimensional model of the tested engine was developed based on the design dimensions of the 1.2L TCe H5FT engine produced by Renault. In the context of maintaining constant engine power output, the findings from the simulation results indicate that the utilization of alcohol-based blends with a high volumetric percentage of alcohol (ranging from 70-90%) can result in a substantial increase in fuel consumption, particularly in the case of methanol blends. Consequently, this phenomenon is associated with an elevated emission of carbon dioxide (CO2). However, it should be noted that despite this drawback, there is evidence of an inclination towards reduced emissions of other pollutants due to the enhanced combustion processes facilitated by the higher ratio of oxygenated compounds and a lower peak temperature. Methanol, one of the two alcohols investigated in this study, is not recommended for usage in fuel blends for several reasons. Firstly, the consumption rate of methanol is higher compared to ethanol, which can result in increased fuel usage. Secondly, methanol poses health risks due to its toxicity at certain levels, posing potential hazards in handling and utilization. Moreover, high concentrations of methanol are not easily miscible with gasoline without the addition of co-solvents, further limiting its feasibility as a viable fuel component.

Multi-physics field modeling and electrochemical performance analysis of medium-temperature methanol-fueled proton-conducting solid oxide fuel cell

ABSTRACT A two-dimensional axisymmetric multi-physics field simulation for a methanol-fueled proton-conducting solid oxide fuel cell (CH3OH-SOFC-H) was created in this work. The influence of structural and operating parameters on the performance of the cell was analyzed. Moreover, the cell performance was compared with that of a methanol-oxygen ion-conducting SOFC (CH3OH-SOFC-O) under the same operating conditions. It was found that the anode support enables CH3OH-SOFC-H to exhibit higher performance, with the highest power density being 1493.3 W‧m−2 at 973 K. As the anode flow rate rises, the current density rises and subsequently falls, with a peak of 7623.6 A‧m−2. Meanwhile, as the methanol content in the gas composition and the cathode flow rate increase, so does the current density. CH3OH-SOFC-H has better electrochemical performance at low and medium temperatures, reaching 562.64 W‧m−2 at 773K (66% higher than that of CH3OH-SOFC-O at the same operating conditions). Meanwhile, CH3OH-SOFC-O has better performance at high temperatures. This study provides a theoretical reference for the subsequent application and promotion of CH3OH-SOFC-H.

Process Optimization for Production of Persimmon Wine with Lower Methanol.

Persimmon wine has various nutritional elements and high commercial potential. However, the high content of methanol, which is derived from the fruit's pectin, always hinders persimmon wine production. To reduce the methanol level in the wine, the effects of persimmon cultivar, starter, pectinase, and pretreatment methods were investigated via single-factor and orthogonal experiments. The persimmon cultivar 'MaoKui' was finally used throughout the study owing to its lowest pectin concentration (24.5 g/kg). The best treatment conditions against the persimmon pulp were pectinase (0.04 g/kg) at 30 °C for 4 h, then boiled at 115 °C for 15 min before fermentation started. The optimized fermentation conditions for wine production were pectinase (0.03 g/kg), 250 mg/kg starter (BO213 and SPARK with equal amounts), at 28 °C for 6 d. The obtained wine had 77.7 mg/L methanol and a 68.4% raw juice yield. The fruit wine had 111.4 mg/L methanol and a 90.6 sensory evaluation score. Forty-nine volatile aromas were identified. Ethyl acetate content was the highest, followed by 3-methyl-1-butanol, 2,3-butanediol, and lactate ethyl ester. The persimmon wine had a unique style with transparent color, elegant aroma, and pure taste.

Study of the Formation of Hydrates with NaCl, Methanol Additive, and Quartz Sand Particles

During deepwater drilling, testing, production, or hydrate mining, the circulating medium in the wellbore may contain solid particles, such as rock chips and sand, in addition to drilling fluids, gas, and water. In the high-pressure, low-temperature conditions of deep water, gas intrusion can easily combine with free water in the drilling fluid to form hydrates, increasing the drilling risk. Therefore, understanding the formation patterns of hydrates in drilling fluids is of significant importance for the prevention and control of hydrates. This study utilized a small-scale high-pressure reactor to investigate the impact of the stirring rate, NaCl, and methanol additives, as well as the sand content on the hydrate formation process and gas consumption. The results indicate that the hydrate formation process can be divided into an induction stage, a rapid formation stage, and a slow formation stage. The induction stage and rapid formation stage durations are significantly reduced under stirring conditions. In NaCl and methanol solutions, hydrate formation is inhibited, with the induction stage duration increasing with higher concentrations of NaCl and methanol. There was no apparent rapid formation stage observed. The final gas consumption decreases substantially with increasing concentrations of NaCl and methanol, reaching no significant hydrate formation at a 20% concentration. The sand content has a significant impact on the slow formation stage, with the final gas consumption increasing within a certain range (in this work, at a sand content of 20%), and being notably higher than in the pure water system under the same conditions.

Polyphenol Content, Antioxidant Properties and Trypsin Inhibition Activity of Methanol Seed Extract and Fractions of White Velvet Bean from Vietnam

Background: White Velvet bean (Mucuna pruriens) is a very valuable plant due to its medical potential. Different parts of the plant have been studied by various researchers. However, the seeds, which contain a lot of bioactive compounds, have been considered of substantial medicinal importance. Methods: The total phenolic content, total flavonoid content, antioxidant and trypsin inhibition properties in the methanol extract of white Velvet bean (WVB) seeds and its fractions (methanol, n-hexane, ethyl acetate, n-butanol and aqueous) were studied. Result: The highest total phenolic content was recorded in the methanol extract (206.3 mg GAE g-1). The highest total flavonoid content was in the n-hexane fraction (7.75 mg rutin g-1). The methanol extract showed the highest total antioxidant potential (261.5 mg AAE g-1). The methanol extract also had the strongest DPPH radical scavenging activity and the highest level of trypsin inhibitory activity compared to the other fractions with an IC50 value (35.3 ìg mL-1).

Expression of VEGFR2 Ligand Binding Domain in Pichia pink™ 4 Cells and Evaluation of Its Interactions with VEGF-A165 Receptor Binding Domain.

Vascular endothelial growth factor A165 (VEGF-A165) and VEGF receptor 2 (KDR) are important mediators of angiogenesis. We aimed to express the soluble KDR ligand-binding domain (sKDR1-3) and evaluate its interaction with the VEGF-A165 receptor-binding domain (VEGFA165-RBD). sKDR1-3 DNA was designed and subcloned into pPinkα-HC plasmid. The cassette was transfected into the Pichia pink™ 4 genome by homologous recombination. We optimized the expression of sKDR1-3 under the induction of different methanol concentrations. VEGFA165-RBD was expressed in E. coli BL21 harboring pET28a( +)─VEGFA165-RBD vector under induction with IPTG with/without lactose. Interaction and biological activity of sKDR1-3 and VEGFA165-RBD were investigated by ELISA and anti-proliferation tests. sKDR1-3 migrated on SDS-PAGE gel as a 35-180kDa protein due to glycosylation. The relative expression level of sKDR1-3 under 1% methanol was higher than 0.5% and 4% methanol induction. IPTG and cysteine were suitable for induction and refolding of VEGFA165-RBD. 25ng sKDR1-3 and 20ng VEGFA165-RBD showed strong binding. sKDR1-3 bound to VEGFA165-RBD and VEGF-A165 with dissociation constants of 0.148 and 0.2nM, respectively. 4-10nM concentrations of sKDR1-3 inhibited the proliferation of HUVE cells induced by 5nM VEGFA165-RBD. In consideration, sKDR1-3 in the nanomolar concentration range, is a promising anticancer drug to inhibit angiogenesis.

Development of a Microwave Sensor for Real-Time Monitoring of a Micro Direct Methanol Fuel Cell

Micro direct methanol fuel cells (μDMFCs) are a promising power source for microelectronic devices and systems. As the operating state and performance of a μDMFC is generally determined by both electrochemical polarization and methanol crossover, it is important to monitor the methanol concentration in μDMFCs. Here, we design and fabricate a microwave sensor and integrate it with a μDMFC for the online detection of methanol concentration in a nonintrusive way. The sensing area is set at the bottom of the anode chamber of a μDMFC which exhibits a maximum output power density of 28.8 mW cm−2 at 30 °C. With a square ring structure, the dual-mode microwave sensor shows a sensitivity of 9.5 MHz mol−1 L. Furthermore, the importance of methanol concentration monitoring is demonstrated in the long term. A relatively smooth methanol decline curve was obtained, which indicated a normal and stable operating status of the μDMFC. Derived from real-time recording data, fuel utilization was additionally calculated as 28.5%.

Integration of jackfruit seed-derived carbon dots and electronic nose for a sensitive detection of formaldehyde vapor

The preparation of carbon dots from jackfruit seeds through a pyrolysis method at 280℃ and their use for the detection of formaldehyde were reported. The as-prepared carbon dots showed a high fluorescence efficiency with a quantum yield of 12.7% and excellent photostability and dispersibility in aqueous solution with a zeta potential of ‒62.5 mV. The integration of carbon dot thin film and a home-made optical electronic nose system possessed sensitivity towards formaldehyde vapor with a detection limit of 24.7%v/v across a linear range of 25%v/v to 100%v/v. Furthermore, the sensor showed the highest sensitivity towards formaldehyde against other volatile organic compounds through a strong interaction between the carbonyl groups and the carbon dots. Additionally, principal component analysis (PCA) was conducted to achieve quantitative measurements of formaldehyde content in different formaldehyde volume ratios with substantial variance. Due to the significance of methanol as a typical chemical precursor for the industrial manufacturing of formaldehyde, the quantitative analytical method is essential to determining formaldehyde or methanol concentration. The sensing ability of carbon dot film-integrated electronic nose towards formaldehyde in formaldehyde/methanol mixtures was measured to be 10.74%v/v in a linear range of 25%v/v to 100%v/v. The PCA showed orderly linear combinations of the data set, which can be potentially utilized to analyze formaldehyde and methanol content in industrial processes. The results indicate the significant potential of carbon dots and optical electronic nose system as an effective formaldehyde sensing platform. Potential applications include the quantification of formaldehyde from methanol conversion and determination of methanol contaminant in formaldehyde.

Simultaneous quantification of 4-hydroxytamoxifen and hesperidin in liposomal formulations: Development and validation of a RP-HPLC method

Breast cancer treatment options are diverse, with tamoxifen commonly used as a selective estrogen receptor modulator (SERM) for hormone receptor-positive breast cancer. However, tamoxifen can have adverse systemic effects. Local transdermal therapy offers a potential solution by delivering the drug directly to the breast and minimizing systemic exposure. Hesperidin, a flavonoid, exerts synergistic effects when combined with anticancer agents. This combination therapy may be a more effective approach to breast cancer management. Analytical methods have been developed to quantify 4-Hydroxytamoxifen (4-HT) and hesperidin separately; however, no method currently exists for their simultaneous quantification in pharmaceutical formulations. This study aimed to develop and validate a reverse-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous quantification of 4-HT and hesperidin in liposomal formulations. A Design of Experiments (DoE) approach was employed using a Box-Behnken design (BBD) to optimize the RP-HPLC method. BBD allowed for a reduction in the number of required tests by creating a statistical model to estimate the significance of various factors and interactions. The methanol concentration, flow rate, and injection volume were considered as independent variables for optimization. A mobile phase (90:10 ratio of methanol: 0.1% v/v orthophosphoric acid) with a flow rate of 0.4 mL/min, and an injection volume of 10 μL was selected as optimized chromatographic condition. 4-HT showed a retention time (Rt) of 5.05 min and hesperidin showed an Rt of 7.11 min using an optimized analytical method and was detected at 275 nm. The developed RP-HPLC method was validated according to the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines, confirming its accuracy, precision, linearity, selectivity, and robustness. The validated method was then successfully applied to determine the entrapment efficiency and permeation of 4-HT and hesperidin into loaded liposomes. This study fills a gap in the literature by providing a simple and reliable RP-HPLC method for the simultaneous quantification of 4-HT and hesperidin in liposomal formulations.

Production of biliverdin by biotransformation of exogenous heme using recombinant Pichia pastoris cells

Biliverdin, a bile pigment hydrolyzed from heme by heme oxygenase (HO), serves multiple functions in the human body, including antioxidant, anti-inflammatory, and immune response inhibitory activities. Biliverdin has great potential as a clinical drug; however, no economic and efficient production method is available currently. Therefore, the production of biliverdin by the biotransformation of exogenous heme using recombinant HO-expressing yeast cells was studied in this research. First, the heme oxygenase-1 gene (HO1) encoding the inducible plastidic isozyme from Arabidopsis thaliana, with the plastid transport peptide sequence removed, was recombined into Pichia pastoris GS115 cells. This resulted in the construction of a recombinant P. pastoris GS115-HO1 strain that expressed active HO1 in the cytoplasm. After that, the concentration of the inducer methanol, the induction culture time, the pH of the medium, and the concentration of sorbitol supplied in the medium were optimized, resulting in a significant improvement in the yield of HO1. Subsequently, the whole cells of GS115-HO1 were employed as catalysts to convert heme chloride (hemin) into biliverdin. The results showed that the yield of biliverdin was 132 mg/L when hemin was added to the culture of GS115-HO1 and incubated for 4 h at 30 °C. The findings of this study have laid a good foundation for future applications of this method for the economical production of biliverdin.Graphical

Structural Optimization of Reactor for the Enhancement of CO2 Electrochemical Reduction Based on Gas–Liquid Mixing Flow Model

The CO2 electrochemical reduction reaction (CO2ERR) is heralded for carbon dioxide and renewable energy utilization. However, complexities in catalyst optimization and reactor structure research hinder its practical application. Herein, rather than traditional catalyst optimization, emphasis is placed on refining the reactor structure to enhance gas–liquid mixing. The goal is to raise the CO2 concentration in the reaction zone and extend its residence refining CO2ERR. Building on prior reactor designs, this work introduces the N‐reactor (the nozzle‐type reactor) with a ring electrode suited for gas–liquid mixing and reaction interplay. Through finite element simulations using the gas–liquid flow model, compared with the S‐reactors (the wide‐straight‐type reactor and the narrow‐straight‐type reactor), the N‐reactor's ring electrode shows a 12.99% CO2 concentration rise in the electrode zone and a 67.11% surge at the cathode exit. As a consequence, the total concentration of the product methanol is increased by 6.37%, with a maximum concentration increase of 26.96% and a concentration increase of 49.08% at the cathode outlet. These results validate the feasibility of optimizing the reaction from the perspective of gas–liquid mixing flow and provide novel methods and ideas for further optimization of CO2ERR, contributing to the practical application of the technology.