Preliminary Screening Experiments Research Articles

Porous biochars derived from brewery waste for the treatment of Cr(VI)-contaminated water.

The use of brewery waste for the removal of pollutants such as chromium has rarely been studied. In the present work, the removal of hexavalent chromium (Cr(VI)) from aqueous solutions was evaluated by brewer's spent grain (BSG), brewing sewage sludge (BSS), and their mixture (MIX), which were obtained from the Bedele Brewery Share Company, Ethiopia. BSG with acid and heat treatment at 600 °C was selected during the preliminary screening experiments and further characterized via FTIR, XRD, and SEM. An adsorption experiment was carried out in batches to study the effectiveness of adsorbents in removing Cr(VI) under different conditions. Factors affecting adsorption, including pH, contact time, adsorbent dosage, and initial Cr(VI) concentration, were analyzed and optimized. The best conditions for the highest efficiency in removing Cr(VI) were a contact time of 7 h, initial solution pH of 2, initial Cr(VI) concentration of 40 mg/L, and adsorbent dose of 2 g/L. The pseudo-second-order (PSO) model, which suggests chemisorption of Cr(VI) on the surface of the adsorbent, describes the kinetics of Cr(VI) removal by the adsorbent (R2 = 0.9570). The Freundlich isotherm was a good fit for the experimental equilibrium adsorption data. The BSG biochar was found to have an approximate adsorption capacity of 31.87 mg/g for Cr(VI). The ability to recycle adsorbents suggests that BSG biochar could be effectively used to treat Cr(VI) in wastewater. As a result, converting industrial waste into useful material is cost effective and beneficial for the protection of the environment. More research is recommended to study how well this adsorbent works in real wastewater samples and during the column adsorption process.

Improving Gas Diffusion Electrodes for Electrochemical CO2 Reduction: Influence of the Ionomer

Electrochemical CO2 reduction is a promising way of harnessing greenhouse gas as an abundant resource for the production of value-added hydrocarbons. By employing copper as the catalyst, CO2 can be converted to multi-carbon compounds such as ethylene. Highly porous gas diffusion electrodes (GDEs) enable efficient contacting of gaseous CO2 and the electrolyte. Copper-coated GDEs are commonly manufactured by depositing a mixture of copper nanoparticles and ionomer on a gas diffusion layer. The ionomer not only acts as a binder, but also influences the GDE’s wetting behavior and can improve mass transport within the catalyst layer due to the combination of a hydrophobic PTFE-backbone and hydrophilic ion groups. Thus, optimizing the type and content of ionomer in the catalyst layer is of utmost importance.In this study, we investigate how the composition of catalyst layers affects the faradaic efficiency (FE) toward ethylene during electrochemical CO2 reduction. For this purpose, we fabricate different GDEs with constant copper loading but varied ionomer content and type (Nafion, Sustainion). To assess the performance of the GDEs, we conduct electrolysis experiments in a flow cell (Flex-E-Cell) setup with KHCO3 as the catholyte. Preliminary screening experiments at up to 50 mA cm-2 reveal a strong effect of the Nafion/copper mass ratio (NCR) on the FE toward ethylene. Within the investigated range (NCRs of 0.1, 0.2, 0.3, 0.4 and 0.5), we identify a sweet spot at an NCR of approximately 0.4. We hypothesize that at higher NCRs negative effects, such as decreasing porosity and an increasingly acidic pH, outweigh the improved mass transport. To assess the performance of the different GDEs at industrially relevant conditions, we perform constant current experiments at ≥ 100 mA cm-2. Here, we corroborate the previously observed trend and find that increasing the NCR from 0.2 to 0.4 doubles the maximum observed FE toward ethylene. When replacing Nafion with an anion exchange ionomer such as Sustainion, the total FE toward carbon products remains nearly unchanged. However, the selectivity shifts from ethylene toward single-carbon species such as CO and formic acid. These results highlight that ionomers play a decisive role in hydrogen evolution mitigation and tuning of the product spectrum during electrochemical CO2 reduction. Figure 1

Abstract 589: Long-term acclimation of target cell lines to tumor microenvironment culture condition provides mechanistic insights into cell therapy effectiveness

Abstract The tumor microenvironment (TME) has several characteristics that distinguish it from normal tissue, including elevated interstitial fluid pressures and hypoxia. To study the effects of TME culture conditions, commonly used target cell lines were serially passaged under hyperbaric and hypoxic conditions for a period of eight weeks. Conventionally expanded parental cell lines (normoxia) were compared against TME-acclimated tumor cell lines (TACTLs; hyperbaric and hypoxic), using RNAseq, ATACseq, and flow cytometry analysis. Commonly used target cell lines for cell therapy development were selected for TME acclimation (SKOV3, A549, JEKO1, and NALM6). TACTLs were generated using an AVATAR system, with culture conditions set at 1% O2 and 2.0 PSI, and serially passaged twice a week for a minimum of 8 weeks. Cell doubling times were measured weekly and compared against parental lines maintained under normoxic culture conditions in a conventional CO2 incubator. In-depth characterization was performed on TME-Acclimated Tumor Cell Lines (TACTLs), utilizing a multi-omic approach. Differential gene expression analysis was performed using RNAseq datasets, and surface biomarkers/targets used for cell therapy development were assessed via nanostring and flow cytometry. Growth kinetics and cell doubling times of TACTLs were initially inhibited during the first two weeks of culture under TME conditions, but eventually reached parity with their normoxia maintained parental cell lines at 6 to 8 weeks, signaling a successful adaptation of the tumor lines to low oxygen and hyperbaric conditions. RNAseq analysis revealed upregulation in glycolytic pathways and epithelial-to-mesenchymal signaling, accompanied by altered metabolic profiles. Surface target expression showed increased expression of checkpoint ligands, such as PD-L1. Cell therapy targets, such as ROR1 were also upregulated in A549 and JEKO1 cell lines passaged under TME. Preliminary drug screening experiments were conducted using checkpoint inhibitors and CAR-T candidates on TACTLs, revealing significant changes in half maximal inhibitory concentration (IC50) when compared to parental tumor lines maintained under normoxia. In summary, acclimation of tumor cell lines to TME culture conditions can provide unique mechanistic insights that can facilitate drug development efforts. Future studies will incorporate TACTLs for CDX tumor models with the goal of identifying cell therapies that work effectively in the tumor microenvironment. Citation Format: James Lim, Albert Wong, Ann Lu, Candy Garcia, Evan Massi, Yewei Xing, Ningchun Liu, Scott Wise. Long-term acclimation of target cell lines to tumor microenvironment culture condition provides mechanistic insights into cell therapy effectiveness [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 589.

Photo-reforming and degradation of waste plastics under UV and visible light for H2 production using nanocomposite photocatalysts

Plastics are recalcitrant and difficult to be removed from a natural environment. As a result, plastics have accumulated in the environment and food chain, causing adverse effects on living organisms and human health. Photo-reforming, a process of generating H2 from an organic substrate in aqueous solutions using catalysts, is promising to address the challenge of treating plastics and recovering energy from these large-volume waste products. TiO2 nanoparticles doped with Au and Pt and ZnO doped with Pt were studied to enhance the light utilization efficiency and catalytic activity. The preliminary photodegradation screening experiments revealed that 5 % Au-doped TiO2 (Au/TiO2) was the most photoactive catalyst among the developed catalysts. However, Pt/TiO2, Au/TiO2, and Pt/ZnO performed differently in H2 evolution experiments. The change of the Au/TiO2 properties was characterized using a transmission electron microscope (TEM), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. Computational simulation using Quantum ESPRESSO was performed to predict the narrowed bandgap of TiO2 when the surface of nano-TiO2 particles was modified with nano-Au particles.Polyethylene terephthalate (PET) was selected as representative plastic for photo-reforming, which was demonstrated effective for degrading and converting common plastic wastes to H2. The effectiveness of pre-treatment using different KOH concentrations and temperatures was studied to achieve efficient PET hydrolysis. H2 production under the different pretreatment conditions showed that higher temperature and KOH concentration increased hydrogen yield. Further, Pt/TiO2 performed better than Au/TiO2 in H2 production while Pt/ZnO was the lowest hydrogen producer. Microscopic examination and FTIR analysis were conducted to identify the morphology and functionality change during the photo-reforming of PET. The variation of carbonyl index, vinyl index, and band area ratios respective to the C-H band area confirmed the plastic degradability. This study demonstrates that photo-reforming is an attractive, low-cost, easy-to-use clean H2 technology, which improves environmental sustainability by reducing greenhouse gas emissions and removing plastic waste using solar energy.

Box-Behnken experimental design for optimizing process parameters in carbonate-promoted direct thiophene carboxylation reaction with carbon dioxide

A feasible synthesis route is developed for achieving the direct carboxylation of thiophene and CO 2 in a relatively mild solvent-free carboxylate-assisted carbonate (semi) molten state. The effects of reaction factors on the carboxylate yield are investigated in the preliminary screening experiments, and the phase behavior analysis of the reaction medium is detected through the thermal characterization analysis of in-situ high temperature X-ray diffraction measurement ( in-situ XRD). The application of response surface methodology (RSM) based on the Box-Behnken design (BBD) is conducted to investigate the effect of the reaction parameters, such as reaction temperature, carbonate proportion, CO 2 pressure and thiophene amount, on the product yield. The regressed second-order polynomial model equation well correlates all the independent variables. The analysis of variance (ANOVA) results reveal that the quadratic effect of reaction temperature is the most effective parameter in this carboxylation reaction owing to it’s the highest contribution to the sum of square (30.18%). The optimum reaction conditions for maximum product yield are the reaction temperature of 287 ℃, carbonate proportion of 32.20%, CO 2 pressure of 10 bar and thiophene amount of 9.35 mmol. Operating under these selected experimental conditions, a high product yield (50.98%) can be achieved.

Separation of glatiramer acetate and its constituent amino acids using aqueous two-phase systems composed of maltodextrin and acetonitrile

Glatiramer acetate (GA), FDA-approved therapeutic for multiple sclerosis (MS), is a random-sized synthetic polypeptide composed of four amino acids: tyrosine, glutamic acid, alanine, and lysine. This work aims to design an efficient protocol for the separation of GA from its broth. For this purpose, the feasibility of a carbohydrate-based aqueous two-phase system (ATPS) for separation of GA from the amino acids was investigated. Initially, the binodal curve and tie-lines for the ATPS composed of maltodextrin and acetonitrile were determined. Next, preliminary screening experiments for determining optimum conditions were conducted by introducing GA and amino acids into the ATPS individually and the effect of pH and carbohydrate concentration on partition coefficient were investigated. Results revealed that glutamic acid and alanine were migrated toward the acetonitrile rich phase while GA, tyrosine, and lysin showed the opposite trend. Besides, the partitioning of amino acids was correlated with their physicochemical and structural properties. The preliminary results suggested that the system composed of maltodextrin 15 wt%, acetonitrile 35 wt%, at pH = 6 can be considered as the optimum feed. In the next step, the partitioning of GA and amino acids broth was investigated in the optimum feed. Under these conditions, the partition coefficient and selectivity of GA were obtained to be 1.17 and 62%, respectively. Additionally, circular dichroism spectroscopy results proved that the structure of GA remains unchanged during the separation steps. Finally, a recovery method was proposed where the acetonitrile was evaporated and maltodextrin was precipitated by the addition of methanol.

Inhibitory effects of quercetin and its major metabolite quercetin-3-O-β-D-glucoside on human UDP-glucuronosyltransferase 1A isoforms by liquid chromatography-tandem mass spectrometry.

Quercetin is a flavonoid that is widely present in plant-derived food. Quercetin-3-O-β-D-glucoside (Q3GA) is a predominant metabolite of quercetin in animal and human plasma. The inhibitory effects of the UDP-glucuronosyl transferases (UGTs) caused by herbal components may be a key factor for the clinical assessment of herb-drug interactions (HDIs). The present study aimed to investigate the inhibitory profile of quercetin and Q3GA on recombinant UGT1A isoforms in vitro. The metabolism of the nonspecific substrate 4-methylumbelliferone (4-MU) by the UGT1A isoforms was assessed by liquid chromatography-tandem mass spectrometry. Preliminary screening experiments indicated that quercetin exhibited stronger inhibitory effects on UGT1A1, UGT1A3, UGT1A6 and UGT1A9 enzymes than Q3GA. Kinetic experiments were performed to characterize the type of inhibition caused by quercetin and Q3GA towards these UGT isoforms. Quercetin exerted non-competitive inhibition on UGT1A1 and UGT1A6, with half maximal inhibitory concentration (IC50) values of 7.47 and 7.07 µM and inhibition kinetic parameter (Ki) values of 2.18 and 28.87 µM, respectively. Quercetin also exhibited competitive inhibition on UGT1A3 and UGT1A9, with IC50 values of 10.58 and 2.81 µM and Ki values of 1.60 and 0.51 µM, respectively. However, Q3GA displayed weak inhibition on UGT1A1, UGT1A3 and UGT1A6 enzymes with IC50 values of 45.21, 106.5 and 51.37 µM, respectively. In the present study, quercetin was a moderate inhibitor of UGT1A1 and UGT1A3, a weak inhibitor of UGT1A6, and a strong inhibitor on UGT1A9. The results of the present study suggested potential HDIs that may occur following quercetin co-administration with drugs that are mainly metabolized by UGT1A1, UGT1A3 and UGT1A9 enzymes.

N-nitrosoethylenethiourea formation at environmentally-relevant concentrations of ethylenethiourea in a pooled groundwater sample

N-nitroso compounds form from the interaction between nitrosatable precursors and nitrite under acidic conditions. A majority of N-nitroso compounds tested show evidence of carcinogenicity in animal models. Formation of N-nitroso compounds may occur from exposure to precursors in drinking water, but the extent of formation depends on a number of factors, including concentration of substrates, presence of catalysts and inhibitors, and pH. The objective of this study was to examine these factors in pesticide-associated N-nitroso (PANN) compound formation in drinking water. In preliminary screening experiments, nine nitrosatable pesticides and degradation products were individually reacted at environmentally-relevant concentrations (≤ 20 μg L‐−1) with sodium nitrite (NaNO2) and hydrochloric acid (HCl) in ultra-pure water. Only ethylenethiourea (ETU) showed evidence of PANN compound formation in initial experiments and was further tested for N-nitrosoethylenethiourea (N-ETU) formation in a pooled groundwater sample (comprised of five tap water samples combined into one homogenous sample) collected from an agricultural region of Prince Edward Island in Canada, where nitrate contamination is a known concern. Evidence of N-ETU formation in the groundwater sample was observed within 30 min at concentrations 7.5, 10, and 20 μg L−1. Analysis of target compounds and semi-target PANN compounds was performed using ultra-high pressure liquid chromatography coupled with high resolution orbital ion trap mass spectrometry. These preliminary experiments serve to inform about potential PANN compound formation in groundwater. The results of this study suggest that ETU is capable of forming potentially carcinogenic N-ETU in water containing nitrite/nitrate at trace concentrations under acidic conditions. Thus, these findings suggest that N-ETU formation may be a concern for individuals exposed to low concentrations of ETU in groundwater.

A methodology employing retention modeling for achieving control space in liquid chromatography method development using quality by design approach

This study reports the application of retention modeling and quality by design practices for reverse-phase liquid chromatographic method development of a new chemical entity. Prior to the retention modeling, preliminary screening experiments were performed for the selection of stationary phase, organic modifiers, and method parameters. Based on the results of preliminary method conditions, tG-T (gradient time - temperature) 2-D modeling with 4 input runs, and tG-T-tc (gradient time-temperature-ternary composition) 3-D modeling with 12 input runs were designed to build a model for achieving the optimized separation. Modeling of reverse phase separations was based on the measurement of both retention times and peak areas. A design space with appropriate input variables and control strategy was established prior to optimization and robustness evaluation following the quality by design framework. DryLabⓇ was used to predict the optimized gradient profile and separation temperature. The robustness evaluation was carried out using the multiple factors at a time approach and the control space was established. The interdependence of control space and the control strategy was demonstrated by evaluating method robustness using two levels of system suitability criteria. The predictive accuracy of the retention modeling was established through experimental verification of the in-silico predictions. The quality by design based method development approach demonstrated the in-silico optimization as an integral component of reverse-phase chromatographic method development to evaluate the interplay of factors such as organic modifiers, separation temperature and gradient time, which greatly integrated and enhanced method robustness during method development.

Simultaneous Separation and Quantification of Vitamins by Microemulsion Liquid Chromatography.

Microemulsion eluents have been found to have excellent potential uses in high-performance liquid chromatography (HPLC). Here, a novel, environmentally benign and simple method using concentration/flow-rate double-gradient elution using a microemulsion eluent was used to separate water- and fat-soluble vitamins simultaneously and rapidly. Preliminary screening experiments were performed to determine the optimum column type, surfactant concentration, co-surfactant to surfactant ratio, oil, mobile phase pH and microemulsion concentration. The resolution and analysis time were simultaneously optimized using concentration/flow-rate double-gradient elution. The optimized method simultaneously separated water- and fat-soluble vitamins using a Venusil ASB C8 column and a combination of isocratic and linear gradient elution modes using a microemulsion mobile phase (solvent A) consisting of 3.5% (w/w) sodium dodecyl sulfate, 10.5% (w/w) n-butanol, 0.8% (w/w) n-octanol and 85.2% (w/w) water and water (solvent B) at pH2.50. The optimum detection wavelength was 283nm. The method was validated and used to analyze a solid pharmaceutical sample.

Investigation of the Role of Manganese Transport Repressor DR2539 in Mn/Fe Homeostasis

Mn and Fe ions are necessary for fundamental cellular processes, where they serve as enzyme cofactors or impart structural stability to proteins. However, Mn and Fe are toxic in excess. For example, dysregulation of Mn/Fe homeostasis results in manganism, a neurological disorder with symptoms similar to Parkinson’s disease. Therefore, tight regulation of intracellular Mn/Fe ratios is critical. Understanding the mechanisms used to regulate Mn/Fe homeostasis has both medical and bioremediation implications. D. radiodurans is particularly successful at establishing maintaining a high Mn/Fe ratio, making it an ideal model to investigate. DR2539, a metal ion dependent transcription factor of the DtxR family, plays a major role in maintaining the intracellular ratio of manganese to iron within D. radiodurans. DR2539 has been shown to bind to the promoter of the Mn importer protein, MntH and repress it in a Mn‐ and Fe‐ dependent manner. 64 other genes are either up‐ or downregulated in the absence of functional DR2539. To further elucidate the role of DR2539 in Mn homeostasis, we recombinantly expressed DR2539 from E. coli and purified it to homogeneity. Preliminary differential light scattering (DLS) and differential scanning fluorimetry (DSF) results suggest DR2539 can bind to Mn, and Mn binding induced oligomerization of the protein. Comparative modeling suggest the Mn‐induced oligomer is either a homodimer or a homotetramer with a similar structure to other members of the DtxR family. Preliminary crystallization screening experiments have identified potential conditions which may lead to samples suitable for high‐resolution structural studies. In total these experiments represent a first step toward elucidating the molecular basis of DR2539 function.Support or Funding InformationNSF HRD 1547757 Grant

Gelatin nanoparticles for NSAID systemic administration: Quality by design and artificial neural networks implementation.

The present study evaluates the preparation of systemic administrated NSAID gelatin nanoparticles with the aid of quality by design and artificial neural networks (ANNs). Specifically, two different preparation techniques (i.e. nanoprecipitation and two-step desolvation) were implemented for the formulation of diclofenac sodium (DLC) gelatin nanoparticles (GNs). Preliminary screening experiments showed that in the case of nanoprecipitation the best compromise (in terms of achieving both small particle size and high encapsulation efficiency) was the use of poloxamer 407 (as stabilizer) and acetone (as non-solvent), while in the case of two-step desolvation significant effect had the use of acetone, gelatin type and bloom number (type B with bloom 150 was selected for further evaluation). Implementation of a central composite experimental design (CCD), showed that in the case of nanoprecipitation the optimum formulation can be achieved at high poloxamer, high gelatin and moderate to high glutaraldehyde (GTA used for crosslinking) concentrations, while in the case of two-step desolvation high gelatin and GTA concentrations are needed. Artificial neural networks (ANN) implementation showed significantly improved prediction ability compared to MLR, while verification experiments showed good agreement between the ANN predicted and the experimentally obtained results. SEM analysis of the optimum suggested formulations showed nanoparticles with smooth surface, while powder X-ray diffraction (XRD) analysis showed the formation of amorphously dispersed systems, and Fourier transform infrared spectroscopy (FTIR) revealed the presence of molecular interactions irrespectively of the preparation method followed. A slightly faster release profile was observed in the case of nanoprecipitation based GNs, while all formulations followed biphasic release profile.

Circulating long non-coding RNAs HULC and ZNFX1-AS1 are potential biomarkers in patients with gastric cancer.

Long non-coding RNAs (lncRNAs) have been demonstrated to be involved in different types of cancer, including gastric cancer. Although altered lncRNAs profiles have been observed in or around gastric cancer tissues, the diagnostic value of circulating lncRNAs in gastric cancer remains unclear. In the present study, a number of highly expressed lncRNAs, including uc001lsz, GACAT2, ABHD11-AS1, GACAT3, SUMP1P3, CHET1, TUG1, SNHG12, GAS5, PVT1, LINC00152, HOTAIR, CCAT1, H19, HULC and ZNFX1-AS1, were investigated as potential minimally invasive biomarkers for this tumor. Preliminary screening experiments revealed that ZNFX1-AS1 and HULC were differentially expressed in the plasma of gastric cancer patients and healthy control subjects. The study further examined the relative expression of ZNFX1-AS1 and HULC in the plasma of 50 matching preoperative and postoperative patients, 50 gastrointestinal stromal tumor (GIST) patients, 50 gastritis/peptic ulcer patients and 50 healthy control subjects through reverse transcription-quantitative polymerase chain reaction. The correlation of lncRNA relative expression with the general characteristics and clinicopathological factors was analyzed. It was observed that the levels of ZNFX1-AS1 and HULC in the plasma of preoperative patients were markedly higher compared with those in the plasma of GIST patients, gastritis/peptic ulcer patients and healthy control subjects, while no significant difference was detected among these three groups. Receiver operating characteristic curve analysis was also conducted to distinguish gastric cancer patients from healthy control subjects. The area under the curve was 0.85 and 0.65 for ZNFX1-AS1 and HULC, respectively. In conclusion, the results indicated that the lncRNAs ZNFX1-AS1 and HULC are promising in the clinical diagnosis of gastric cancer.

Brönsted Catalyzed Hydrolysis of Microcystin-LR by Siderite

Six naturally occurring minerals were employed to catalyze the hydrolysis of microcystin-LR (MC-LR) in water. After preliminary screening experiments, siderite stood out among these minerals due to its higher activity and selectivity. In comparison with kaolinite, which is known to act as a Lewis acid catalyst, siderite was found to act primarily as a Brönsted acid catalyst in the hydrolysis of MC-LR. More interestingly, we found that the presence of humic acid significantly inhibited catalytic efficiency of kaolinite, while the efficiency of siderite remained high (∼98%). Reaction intermediates detected by LC-ESI/MS were used to indicate cleavage points in the macrocyclic ring of MC-LR, and XPS was used to characterize siderite interaction with MC-LR. Detailed analysis of the in situ ATR-FTIR absorption spectra of MC-LR indicated hydrogen bonding at the siderite-water-MC-LR interface. A metastable ring, involving hydrogen bonding, between surface bicarbonate of siderite and an amide of MC-LR was proposed to explain the higher activity and selectivity toward MC-LR. Furthermore, siderite was found to reduce the toxicity of MC-LR to mice by hydrolyzing MC-LR peptide bonds. The study demonstrates the potential of siderite, an earth-abundant and biocompatible mineral, for removing MC-LR from water.

Optimization of hydrolysis conditions for minimizing ammonia accumulation in two-stage biogas production process using kitchen waste for sustainable process development

Accumulation of ammonia produced by deamination of proteins during anaerobic digestion of kitchen waste for biogas production is a critical issue since ammonia is a potential inhibitor of biomethanation process. This work deals with optimization of hydrolysis for minimum ammonia accumulation by controlling the physico-chemical conditions viz. temperature, pH and aeration. The hydrolysis experiments were carried out using kitchen waste slurry (5% w/v) in an agitated fermenter of 1.5L working volume. The study was conducted based on statistically designed experimental sets, to find out the optimum conditions required for maximizing ammonia removal during kitchen waste digestion. Preliminary screening experiments were carried out based on a full factorial design to get key information regarding the system performance and to further, extend into the Box-Behnken design for process optimization. The developed model had R2 of 0.9677 and 0.9406 for % total and free ammoniacal nitrogen removal respectively. The results suggested minimized ammoniacal nitrogen accumulation during hydrolysis (net removal up to 75%) with 3589±469mg/L soluble COD and 1419±136mg/L TVFA concentration at pH 7.2 to 7.5, temperature 43–48°C, Aeration 0.19–0.22 vvm. This leads to reduction in ammonia accumulation up to 66% operated under optimized hydrolysis conditions compared to other operating condition in methanogenic phase. Operating the biogas digesters under these optimum conditions may help to overcome the problem of ammoniacal nitrogen accumulation during anaerobic digestion of kitchen waste for biogas production.

An efficient microwave-assisted extraction of anthraquinones from Rheum emodi: Optimisation using RSM, UV and HPLC analysis and antioxidant studies

Rheum emodi—a culinary plant used across the world, is known to contain bioactive anthraquinoids which find extensive use in the chemical, pharmaceutical and cosmetic industry and exhibit diverse pharmacological actions. The current work envisages development of a microwave assisted extraction (MAE) for extraction of total anthraquinones (AQs) and five 1,8-dihydroxyanthraquinones (DHAQs) from Rheum emodi. In the initial part of the work, a rapid and facile method was developed for determining total AQs using UV spectroscopy. Preliminary screening experiments were performed to select choice of solvent, extraction time, microwave power and solvent: sample ratio. Subsequently, optimum conditions for MAE were determined using RSM by employing a Box-Behnken design. Extraction rate of total AQs and five DHAQs reached maximum at time 7.5min, microwave power 490W, solvent: sample ratio 15: 0.1ml/g and concentration of aqueous NaOH solution 0.255M. Furthermore, MAE offered significantly higher yields for total AQs and five DHAQs and also a high DPPH-scavenging and hydrogen peroxide scavenging potential than the extracts obtained by conventional extraction methods. The proposed method was fast, energy-saving, environment-friendly and can find a potential industrial use in the extraction of the bioactive DHAQs.

Assessment of conventional and novel extraction techniques on extraction efficiency of five anthraquinones from Rheum emodi.

Rheum emodi is principally known to consist 1,8-dihydroxyanthraquinones (DHAQs) that find immense use in the chemical, pharmaceutical, cosmetic industries and in herbal medication and food sector. The aim of this study was to compare non-conventional and classical methods for extraction of anthraquinones from R. emodi. Optimisation of the extraction parameters for various methods was done and their extraction efficiency was evaluated. In preliminary screening experiments, choice of solvent and solid : solvent ratio was optimised. Comparison of extraction efficiency for classical methods like maceration, heat-reflux, soxhletion and non-conventional methods like ultra-sonication and sublimation was done for five DHAQs - aloe emodin, rhein, emodin, chrysophanol and physcion using HPLC-UV and fluorescence detection in native and acid hydrolysed samples. It was observed that ethanol was the best solvent for extraction of anthraquinones with a solid : solvent ratio of 1:20. A prior acid hydrolysis led to significant increase in anthraquinone extraction. Among the extraction methods heat reflux for 45min was the most prominent extraction method with highest recovery of the DHAQs. In ultrasonic assisted extraction, an increase in the anthraquinone extraction was seen till 45min after which the concentration declined. A novel, solvent-free, green and selective method of extraction by sublimation was found to be effective for extraction of anthraquinones.

Simplified the Screening and In Vitro Appraisal of Antioxidant, Cytotoxic, Thrombolytic, Antimicrobial and Membrane Stabilizing Activities of Lablab Purpures at a Time

To simplify the different biological investigation of the methanolic extract and solvent-solvent partitioning of Lablab purpures (L. purpures) bark. In-vitro anti-oxidant study was determined using total DPPH radical scavenging assay. In vitro antimicrobial study was measured by observing zone of inhibition. The cytotoxic activity was studied using brine shrimp lethality bioassay and thrombolytic activity by clot disruption method. The antioxidant potential was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Folin-Ciocalteau reagents using butylated hydroxytolune (BHT) and ascorbic acid as standards. The Aqueous soluble fraction revealed the highest free radical scavenging activity (IC50 = 48.76 µg/mL). The antimicrobial screening of the bark of L. purpures exhibited mild to moderate activity in test microorganisms. The CSF showed the maximum relative percentage inhibition against Salmonella parathyphi (34.2%) for bacteria and C. albicans (28.8%) for fungi whereas, lowest relative percentage inhibition against Sarcina lutea (22.0%) for bacteria and Aspergillus niger (24.4%) for fungi. In the brine shrimp lethality bioassay, The LC50 values of Carbon tetrachloride and N-Hexane soluble fraction were found 92.18 µg/mL, and 68.95 µg/mL respectively while the LC50 values of standard Vincristine sulphate was 1.37 µg/mL. The methanolic extract and its organic soluble fractions of Lablab purpureus at concentration 2.0 mg/mL, significantly protected the lysis of erythrocyte membrane induced by hypotonic solution and heat as compared to the standard, acetyl salicylic acid (0.10 mg/mL). The MSF and AQSF produced 61.48 % and 53.75% inhibition of hemolysis of RBC caused by hypotonic solution respectively, whereas acetyl salicylic acid (0.10 mg/mL) showed 76.42%. Ethanol extract of L. purpures and all of its different partitions exhibited moderate thrombolytic activity of 37.25%-2.40%. Very good preliminary screening and simplified experiments were able to show the different biological activity of methanolic extract and its soluble fractions of L. purpures at a time.

Unexplored hypersaline habitats are sources of novel actinomycetes.

Unexplored hypersaline habitats are sources of novel actinomycetes.

Effect of Arginine on Carbon Dioxide Capture by Potassium Carbonate Solution

Preliminary screening experiments of carbon dioxide (CO2) absorption into aqueous 35 wt % equivalent potassium carbonate (K2CO3) solution with different additives were performed in a wetted-wall column at 322 K. Arginine was found as an effective promoter to enhance the absorption rate in aqueous K2CO3 solution. The effect of arginine concentration and CO2 loading on the absorption rate into carbonate solutions is discussed. The vapor–liquid equilibrium of 35 wt % equivalent K2CO3 with 0–5 wt % arginine was obtained in the temperature range from 323 to 343 K using inert-gas stripping method. Desorption curves of the unpromoted and arginine-promoted carbonate solutions are also discussed.