Solvent Partition Research Articles

Phytochemical Profile of Andrographis paniculata Extract from Solvent Partition and Precipitation

A rapid and simple method to profile intense phytochemicals in Andrographis paniculata was carried out in this study. The intense phytochemicals could be the main contributors for the previously reported biological activities of the herb. A. paniculata was extracted using 70 % ethanol in a reflux system for 2 hours. The crude extract was further fractionated by organic solvents such as ethyl acetate, butanol and chloroform with the aim to recover terpene derived phytochemicals. The increase of saponin content in the organic fractions could be seen and estimated using vanillin assay catalyzed by strong acids. Data LC-DAD-MS/MS revealed that the solvent systems could recover apigenin glucuronide, andrographolide and dehydroandrographolide dimer, but butanol fraction could recover additional compound for 4-deoxyphloridzin. Although butanol fraction was also found to have the lowest saponin content, the fraction could recover andrographolide and saponin via acetone precipitation effectively. It was found that only apigenin glucuronide could be precipitated if crude extract was directly used in acetone precipitation without solvent partition. The findings of this study could be used as a guideline for those researchers who would like to concentrate the biologically active phytochemicals such as andrographolide and its derivatives in samples for high-end product formulation.

Integrated liquid chromatography-mass spectrometry and nuclear magnetic resonance spectra for the comprehensive characterization of various components in the Shuxuening injection

Shuxuening injection (SXNI) is made from the extract of Ginkgo biloba, and used for curing coronary heart disease, stenocardia and cerebral vasospasm. However, the flavonoids and terpene trilactones (TTLs) only account for about 30% of the dry weight of SXNI according to the current quality control standard. Thus, systematic investigation of the chemical composition of SXNI is needed to guarantee the drug safety. In this study, the integral approach of ultra high performance liquid chromatography-Q Exactive hybrid quadrupole-orbitrap high resolution accurate mass spectrometry (UHPLC-Q-Orbitrap HRMS) and nuclear magnetic resonance (NMR) techniques, combining with the solvent partition, were used for identifying the phytochemical compounds in SXNI. The NMR analysis revealed the possible structure types based on the characteristic chemical shifts, coupling constants, and peak shape, which gave the clues for the further UHPLC-Q-Orbitrap HRMS analysis of previously unknown or uncatalogued compounds. The characteristic ions and structural network of flavonoids and TTLs were generated and used in the UHPLC-Q-Orbitrap HRMS based structure identification. Only 72 compounds could be identified by the direct UHPLC-Q-Orbitrap HRMS analysis of SXNI, while this systematic strategy led to the identification of 133 compounds, which included 73 flavonoids, 5 biflavone, 6 proanthocyanidin, 14 TTLs, 6 fatty acids, 5 fatty amides, 12 organic acids, 1 amino acid, 3 excipients, 2 saccharides and 6 other components. In addition, the presence of steroids and triglycerides were also suggested by NMR. The absence of toxic components in SXNI was also confirmed. In addition, the NMR spectrum also revealed some unknown signals, which need to be further identified. This approach was proved to be useful for the rapid and effective identification of various compounds in the TCM preparations.

Study on the potential ofAaptos aaptos aqueous extract as an antibacterial agent against Vibrio harveyi in tiger shrimp (Penaeus monodon Fabricius) post larvae

The sponge Aaptos aaptos is known to contain bioactive compounds with bactericidal properties. These compounds could be utilized in shrimp aquaculture to inhibit the growth of Vibrio harveyi, the causative agent of vibriosis. This study aimed to evaluate the antibacterial activity of an aqueous extract of Aaptos aaptos on V. harveyi isolated from diseased shrimp post larvae and identify bioactive compounds active against V. harveyi. An aqueous extract was obtained through solvent partitioning of active Aaptos aaptos extract using methanol with n-hexane and butanol. The bioactive compound was isolated from the aqueous extract through repeated column chromatography with silica gel as stationary phase and a mixture of dichloromethane and methanol as mobile phase. The antibacterial activity of the aqueous extract was tested using a 96 microwell plate with extract concentrations of 10,000, 1,000, 100, 10, 1, and 0 mg/L. An in vitro aqueous extract antibacterial activity challenge test against V. harveyi was conducted using reaction tubes with extract concentrations of 5,000, 500, 50, 5 and 0 mg/L. Antibacterial activity of isolated bioactive compounds was determined through an agar diffusion assay using paper discs with a concentration of 20 μg/disc. Results showed that the Aaptos aaptos aqueous extract displayed strong antibacterial activity with a minimum inhibitory concentration (MIC) of 10 mg/L. V. harveyi colonies treated with aqueous extract at concentrations of 500 and 5,000 mg/L had decreased drastically (5.50 × 103 and 0.83 × 102 CFU/mL respectively) 4 hours post treatment. The orange spot exhibited when sprayed with Dragendorff reagent indicated that one of the compounds successfully isolated belonged to the alkaloid group, with an Rf value of 0.2 (acetonitrile/methanol, 2:8, Q8 TLC Plate).This bioactive compound was one of those responsible for the Aaptos aaptos aqueous extract activity, with an inhibition zone of 22 ± 0.1 mm.

Bioassay-guided isolation and identification of gametocytocidal compounds from Artemisia afra (Asteraceae)

BackgroundOptimal adoption of the malaria transmission-blocking strategy is currently limited by lack of safe and efficacious drugs. This has sparked the exploration of different sources of drugs in search of transmission-blocking agents. While plant species have been extensively investigated in search of malaria chemotherapeutic agents, comparatively less effort has been channelled towards exploring them in search of transmission-blocking drugs. Artemisia afra (Asteraceae), a prominent feature of South African folk medicine, is used for the treatment of a number of diseases, including malaria. In search of transmission-blocking compounds aimed against Plasmodium parasites, the current study endeavoured to isolate and identify gametocytocidal compounds from A. afra.MethodsA bioassay-guided isolation approach was adopted wherein a combination of solvent–solvent partitioning and gravity column chromatography was used. Collected fractions were continuously screened in vitro for their ability to inhibit the viability of primarily late-stage gametocytes of Plasmodium falciparum (NF54 strain), using a parasite lactate dehydrogenase assay. Chemical structures of isolated compounds were elucidated using UPLC-MS/MS and NMR data analysis.ResultsTwo guaianolide sesquiterpene lactones, 1α,4α-dihydroxybishopsolicepolide and yomogiartemin, were isolated and shown to be active (IC50 < 10 μg/ml; ~ 10 μM) against both gametocytes and intra-erythrocytic asexual P. falciparum parasites. Interestingly, 1α,4α-dihydroxybishopsolicepolide was significantly more potent against late-stage gametocytes than to early-stage gametocytes and intra-erythrocytic asexual P. falciparum parasites. Additionally, both isolated compounds were not overly cytotoxic against HepG2 cells in vitro.ConclusionThis study provides the first instance of isolated compounds from A. afra against P. falciparum gametocytes as a starting point for further investigations on more plant species in search of transmission-blocking compounds.

Solvolysis Artifacts: Leucettazoles as Cryptic Macrocyclic Alkaloid Dimers from a Southern Australian Marine Sponge, Leucetta sp.

Chemical analysis of a southern Australian sponge, Leucetta sp., led to the discovery of a pair of solvolysis adducts, leucettazoles A1 (1a) and B1 (2a), as artifacts of an unprecedented family of 15-membered macrocyclic alkaloid dimers featuring a pair of imino bridged 2-aminoimidazoles, together with a putative monomeric precursor, leucettazine A (3). The dimeric alkaloids 1a and 2a, and monomer 3, were identified by detailed spectroscopic analysis, supported by chemical transformations, analytical mass spectrometry, and biosynthetic considerations. Global natural product social networking (GNPS) molecular analysis of crude sponge extracts and solvent partitions, supported by single ion extraction (SIE) and diagnostic MS/MS fragmentations, revealed the associated natural products, leucettazoles A (1) and B (2). This study highlights that the study of natural product artifacts can be useful, and can on occasion serve as a pathway to discover cryptic new classes of natural products.

Solvation Descriptors for Zwitterionic α-Aminoacids; Estimation of Water-Solvent Partition Coefficients, Solubilities, and Hydrogen-Bond Acidity and Hydrogen-Bond Basicity.

The literature data on solubilities and water–solvent partition coefficients have been used to obtain properties or “Absolv descriptors” for zwitterionic α-aminoacids: glycine, α-alanine (α-aminopropanoic acid), α-aminobutanoic acid, norvaline (α-aminopentanoic acid), norleucine (α-aminohexanoic acid), valine (α-amino-3-methylbutanoic acid), leucine (α-amino-4-methylpentanoic acid), and α-phenylalanine. Together with equations that we have previously constructed, these descriptors can be used to estimate further solubilities and partition coefficients in a variety of organic solvents and in water–methanol and water–ethanol mixtures. It is shown that equations for neutral solutes are inadequate for the description of solubilities and partition coefficients for these α-aminoacids, and our equations developed for use with both neutral and ionic solutes must be used. The Absolv descriptors include those for hydrogen-bond acidity, A, and hydrogen-bond basicity, B. We find that both of these descriptors are far smaller in value than those for compounds that contain the corresponding ionic groups. Thus, A for α-alanine is 0.28, but A for the ethylammonium cation is 1.31; B for α-alanine is 0.83, and yet B for the acetate anion is no less than 2.93. The additional descriptors that we developed for equations that involve ions, J+ and J–, are very significant for the α-aminoacids, although numerically smaller than for ionic species such as EtNH3+ and CH3CO2–.

Self-Assembly of a Midblock-Sulfonated Pentablock Copolymer in Mixed Organic Solvents: A Combined SAXS and SANS Analysis.

Ionic, and specifically sulfonated, block copolymers are continually gaining interest in the soft materials community due to their unique suitability in various ion-exchange applications such as fuel cells, organic photovoltaics, and desalination membranes. One unresolved challenge inherent to these materials is solvent templating, that is, the translation of self-assembled solution structures into nonequilibrium solid film morphologies. Recently, the use of mixed polar/nonpolar organic solvents has been examined in an effort to elucidate and control the solution self-assembly of sulfonated block copolymers. The current study sheds new light on micellar assemblies (i.e., those with the sulfonated blocks comprising the micellar core) of a midblock-sulfonated pentablock copolymer in polar/nonpolar solvent mixturesby combining small-angle X-ray and small-angle neutron scattering. Our scattering data reveal that micelle size depends strongly on overall solvent composition: micelle cores and coronae grow as the fractionof nonpolar solvent is increased. Universal model fits further indicate that an unexpectedly high fraction of the micelle cores is occupied by polar solvent (60-80 vol %) and that partitioning of the polar solvent into micelle cores becomes more pronounced as its overall quantity decreases. This solvent presence in the micelle cores explains the simultaneous core/corona growth, which is otherwise counterintuitive. Our findings provide a potential pathway for the formation of solvent-templated films with more interconnected morphologies due to the greatly solvated micellar cores in solution, thereby enhancing themolecular, ion, and electron-transport propertiesof the resultant films.

Anti-inflammatory property and gas chromatography-mass spectrometry analysis of ethyl acetate fraction of Crateva adansonii DC leaves

Aims: This study was designed to determine the most active anti-inflammatory fraction of C. adansonii leaves and characterize the bioactive compounds. Methods: Dried and pulverized C. adansonii leaves (CAL) were extracted with 70% methanol, followed by successive solvent partitioning into hexane (CALH), ethyl acetate (CALE), butanol (CALB) and aqueous (CALA) leaf fractions. In vitro antioxidant assays carried out on the extract/fractions were DPPH, hydrogen peroxide, ferric reducing antioxidant power (FRAP), nitric oxide scavenging, total antioxidant capacity (TAC), total phenol (TP) and flavonoid (TF) assays. In vitro anti-inflammatory assays investigated were heat-induced bovine serum albumin (BSA) denaturation and human red blood cell (HRBC) membrane stabilization against hypotonicity- induced hemolysis. Formaldehyde-induced inflammation model in rats was carried out, followed by paw edema measurement as well as serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities assays. The ethyl acetate (CALE) fraction was subjected to GC-MS analytical method. Results: CAL extract and fractions substantially inhibited BSA denaturation and stabilized HRBC membrane against hypotonicity-induced hemolysis, however CALE exhibited the highest activity. CALE also suppressed formaldehyde-induced rat paw edema and significantly (p

Characterization of the antibacterial activity of Bald's eyesalve against drug resistant Staphylococcus aureus and Pseudomonas aeruginosa.

Bald’s eyesalve is an Anglo-Saxon medicinal remedy that has been used through ancient times to treat eye sty infections and may represent a source of ancientbiotics. This study assessed the efficacy of Bald’s eyesalve against several strains of Staphylococcus aureus and Pseudomonas aeruginosa, including a multi-drug resistant phenotype, and identified the principal compound conveying antibacterial activity. Bald’s eyesalve formulations were produced by combining garlic, onion or leek, wine, bovine bile, and brass, with specific ingredient omissions in several formulations, followed by incubation at 4 °C for 9 days. Bald’s eyesalve formulation ES-GBBr exhibited the greatest antibacterial activity against S. aureus and P. aeruginosa. Fractionation of ES-GBBr using molecular size exclusion and organic solvent partitioning isolated its antibacterial activity to the small molecule nonpolar fraction, and 1D 1H NMR revealed the identity of the antibacterial agent to be allicin. Depletion of allicin from this fraction by addition of exogenous cysteine established that all observable growth inhibition originated from allicin. Quantification of allicin demonstrated that its concentration was significantly greater in ES-GBBr compared to the ES-O formulation; however, this was not due to greater yield. The antibacterial activity of allicin against S. aureus was antagonized by other ingredients within Bald’s eyesalve, whereas they were additive or synergistic against P. aeruginosa. These results suggest that neither leek nor onion is necessary for the antibacterial efficacy of Bald’s eyesalve against S. aureus or P. aeruginosa, and while allicin was identified as the principal antibacterial agent present, its activity is influenced differentially in the presence of additional Bald’s eyesalve ingredients when used against S. aureus compared to P. aeruginosa. Ancientbiotics may provide a source of promising antibacterials; however, identifying the source of activity and assessing distinct formulations for cooperative effects are essential to using ancient remedies, such as Bald’s eyesalve, effectively against drug resistant pathogens.

Challenges with prediction of battery electrolyte electrochemical stability window and guiding the electrode – electrolyte stabilization

Progress in development of novel battery chemistries critically depends on the stabilization of electrode – electrolyte interfaces. Battery electrolytes are commonly selected to either be electrochemically stable at the electrode, current collector, and conductive additive surfaces or to decompose at these interfaces electrochemically and form a kinetically protective ionically-conducting but electronically-insulating passivation film. Increasing energy density of electrical double layer (EDL) capacitors, or supercapacitors, also requires electrolytes with an extended electrochemical stability window. Quantum chemistry (QC) calculations of the representative electrolyte clusters or electrolyte components reacting with the electrode surfaces provide molecular scale understanding of the key electrolyte decomposition pathways under reductive or oxidative conditions. Moreover, QC calculations show that the electrolyte reduction and oxidation stability depends on the solvent and salt partitioning within EDL near electrolytes and the number of lithium cations complexing anions or solvents. Thus, an electrolyte electrochemical stability could be controlled by adjusting salt concentration, salt aggregation and preferential solvent or anion partitioning within EDL, opening new opportunities for enabling aggressive battery chemistries and EDL capacitors with improved energy densities.

Gibberellic Acid Content of Spinach in Relation to Photoperiod, Temperature, and Flower Induction

The hypothesis that gibberellic acid is involved in the regulation of spinach flowering was tested. The two-fold objectives of the present study were, first, to isolate and identify gibberellic acid present in induced and non-induced spinach (Spinacia oleracea L., cv. Bloomsdale) tissues and, second, to quantify levels of this compound during the ontogeny of flower induction. Plants were initially grown in a growth chamber under short photoperiod conditions (8 h of light at 25°C and 16 h of darkness at 18°C) for 7 weeks and then half of the plants were transferred to a long photoperiod growth chamber (16 h of light at 30°C and 8 h of darkness at 20°C). Harvest of plants began 48 hours later and over a period of 12 days with 2-day intervals. Plants were subjected to a purification procedure involving preparatory solvent partitioning and reversed-phase high-performance liquid chromatography. The purified gibberellic acid was then identified and quantified using combined gas chromatography-mass spectrometry. When plants were transferred from floral non-inducing to inducing conditions, the gibberellic acid content increased progressively 2- to 6-fold during the 12-day sampling period. Two additional and independent experiments were performed in which the above photoperiodic regime was employed and temperature was kept constant at 30°C and 20°C throughout each experiment. These two experiments showed similar trends of decreasing gibberellic acid content under non-inducing conditions and, conversely, increasing under flower inducing conditions. Our study establishes a correlation between increased gibberellic acid level and flowering of spinach.

From the Front or Back Door? Quantitative analysis of direct and indirect extractions of α-mangostin from mangosteen (Garcinia mangostana).

The pulp and pericarp of mangosteen (Garcinia mangostana) fruit are popular food, beverage and health products whereby 60% of the fruit consist of the pericarp. The major metabolite in the previously neglected or less economically significant part of the fruit, the pericarp, is the prenylated xanthone α-mangostin. This highly bioactive secondary metabolite is typically isolated using solvent extraction methods that involve large volumes of halogenated solvents either via direct or indirect extraction. In this study, we compared the quantities of α-mangostin extracted using three different extraction methods based on the environmentally friendly solvents methanol and ethyl acetate. The three solvent extractions methods used were direct extractions from methanol (DM) and ethyl acetate (DEA) as well as indirect extraction of ethyl acetate obtained via solvent partitioning from an initial methanol extract (IEA). Our results showed that direct extraction afforded similar and higher quantities of α-mangostin than indirect extraction (DM: 318 mg; DEA: 305 mg; IEA: 209 mg per 5 g total dried pericarp). Therefore, we suggest that the commonly used method of indirect solvent extraction using halogenated solvents for the isolation of α-mangostin is replaced by single solvent direct extraction using the environmentally friendly solvents methanol or ethyl acetate.

Chemical Study, Antioxidant and Cytotoxic Activities of Oil Seeds of Spondias tuberosa (Anacardiaceae)

ABSTRACTSpondias tuberosa Arr. Cam (Anacardiaceae) is a tree which fruits are popularly known as “umbu”. The crude methanolic extract of S. tuberosa was subjected to a solvent partition, obtaining different organic soluble portions. Chloroform and ethyl acetate soluble fractions proved to be moderately toxic in lethality test compared to Artemia salina. Regarding antioxidant activity, the ethyl acetate fraction proved to be the most active. From the crude hexane extract, a mixture of triglycerides was obtained and, from the chloroform fraction, mixture of free fatty acids and sitosterol and stigmasterol were obtained. From ethyl acetate fraction’s chromatographic procedures, 5-hydroxymethyl-2-furfuraldehyde was isolated.

Significance of combination therapy between Euclea crispa (Thunb.) (leaf and stem bark) extracts and standard antibiotics against drug resistant bacteria

This study evaluates the probable effect of combination therapy between the extracts of Euclea crispa and standard antibiotics against selected resistant strains of bacterial isolates. The crude extracts were partitioned using a solvent partitioning system. The isolates were screened via determination of minimum inhibitory concentrations (MICs) using broth micro-dilution method and the combination assessment was carried out via time-kill assay to determine the probable synergisms. The MICs by the plant extracts range from 310 to 630 μg/ml (leaf extract) and from 630 to 1250 μg/ml (stem bark extract). The MICs by erythromycin and chloramphenicol range between 31 and 250 μg/ml, while that of ampicillin is between 63 and 500 μg/ml. The range exhibited by streptomycin and tetracycline is between 8 and 250 μg/ml and 6 and 100 μg/ml respectively. Out of 130 different combination tests between the leaf extract and antibiotics, 91.5% express synergy while 8.5% are indifferent. On the other hand, 88.5% of the same number of combination tests show synergism between the stem bark extract and standard antibiotics with no record of antagonism in both cases. The leaf and stem bark extracts of E. crispa have been confirmed, in the course of this study, to possess some bioactive principles which may serve to enhance potency of the available antibiotics against multidrug resistant organisms. Thus, it indicates a source of alternative therapy in combating infectious diseases.

Discovery of new antidepressant agents: In vivo study on Anthemis wiedemanniana Fisch. & Mey

Ethnopharmacological relevanceMany of the currently available antidepressants have serious adverse effects and are also expensive. Traditional medicines are major sources of original drugs, and their role in effective treatment is remarkable. In Turkish folk medicine, decoctions and infusions are prepared from the flowers of Anthemis wiedemanniana Fisch. & Mey. They exert antispasmodic and sedative effects and are also used for treating urinary inflammations. The present study was designed to evaluate the antidepressant activity of A. wiedemanniana, which is used against central nervous system disorders in Turkish folk medicine. Materials and methodsn-Hexane, ethyl acetate, and methanol (MeOH) extracts were prepared from the flowers of the plant. The antidepressant potentials of these extracts were evaluated in mouse models using the forced swimming test, tail suspension test, and antagonism of tetrabenazine-induced ptosis, hypothermia, and suppression of locomotor activity. The results were compared with those in control and reference groups, and active constituents of the plant were determined. The MeOH extract of A. wiedemanniana was subjected to various chromatographic separation techniques, leading to the isolation and identification of the active component(s). ResultsAfter confirmation of the antidepressant activity, the MeOH extract was subjected to successive solvent partitioning using solvents of increasing polarity, yielding four subextracts. Each subextract was tested on the same biological activity models. Fraction B was found to have the highest activity and subjected to further chromatographic separation. Isolated germacronolide-type sesquiterpene lactones were elucidated as tatridin A (1) and tanachin (1-epi-tatridin B) (2), which were responsible for the antidepressant activity of the flowers. ConclusionsThis study explored the antidepressant potential of A. wiedemanniana. Using bioassay-guided fractionation and isolation techniques, tatridin A and tanachin (1-epi-tatridin B) were determined as the main active components of the flowers. Further antidepressant mechanistic studies should be conducted for exploring the activity of these compounds against depression. This study can be an important step in the discovery of newer antidepressants.

Lipid peroxidation diminishing perspective of isolated theaflavins and thearubigins from black tea in arginine induced renal malfunctional rats

BackgroundRecently oxidative stress induced maladies have amplified owing to sedentary lifestyle and monotonous diet. Introduction of plant based biomolecules may be a suitable strategy to cope with the lipid peroxidation. In this context, black tea polyphenols (theaflavin & thearubigins) are in fame among the scientific community as cost effective therapeutic agents owing to their safety, economics, structural diversity and ability to modulate various lipid peroxidation responses by halting the expression of different metabolic targets.MethodsThe mandate of present investigation was to first time check the synergism among the isolated theaflavins & thearubigins against lipid peroxidative indicators both in vitro and in vivo. Purposely, theaflavins and thearubigins were isolated from black tea through solvent partition methods by using different solvents (Aqueous ethanol, Aqueous methanol & Water) and time intervals (30, 60 & 90 min) and subjected to in vitro characterization through different antioxidant indices to access the in vitro lipid peroxidation shooting effect of these bioactive moieties. Moreover, individual theaflavins contents also estimate through HPLC. For evaluation of in vivo antioxidant effect, renal malfunction was induced through arginine and forty rats were divided in four groups (10 each after power analysis) and 04 types of diets were given i.e. T0 (control diet without supplementation), T1 (Basic experimental Diet+ theaflavins supplementation @ 1 g), T2 (Basic experimental Diet+ Thearubigins supplementation @ 1 g) & T3 (Basic experimental Diet+ Supplementation of theaflavins+ thearubigins @ 0.5 + 0.5 g, respectively) for the period of 56 days. Alongside, a control study was also carried out for comparison by involving normal rats fed on arginine free diet. The body weight, lipid profile, glycemic responses, Renal function test, liver function test, antioxidant indices and hematological parameters were estimated at the termination of study.ResultsThe results indicated that theaflavins and thearubigins isolation was significantly affected by time of extraction and solvent. In this context, aqueous ethanol at 60 min extraction interval caused maximum extraction. Likewise, theaflavins isolate exhibited more antioxidant activity as compared to thearubigins. Moreover, the theaflavins and thearubigins based experimental diets imparted significant reduction in Lipid profile, glucose content, renal function tests and TBARS with enhancement in insulin, HDL and hematological parameters. In this context, theaflavin based diet caused maximum reduction in lipid profile and TBARS better as compared to thearubigins and theaflavins + thearubigins based. However, theaflavin+ thearubigins based diet caused highest glucose, urea & creatinine decline and maximum insulin increase & antioxidant indices as compared to other nutraceuticals.ConclusionsIt was deduced that theaflavins & thearubigins have strong antioxidative potential both in in vitro as well as in vivo to tackle the menace associated with lipid peroxidation.

Modeling water partition in composite gels of BSA with gelatin following high pressure treatment

Changes in the structural properties of hydrogels made with gelatin and bovine serum albumin mixtures were recorded following exposure to high pressure at 300 MPa for 15 min at 10 and 80 °C. Dynamic oscillation, SEM, FTIR and blending law modelling were utilised to rationalise results. Pressurization at the low temperature end yielded continuous gelatin networks supporting discontinuous BSA inclusions, whereas an inverted dispersion was formed at the high temperature end with the continuous BSA network suspending the discontinuous gelatin inclusions. Lewis and Nielsen equations followed the mechanical properties of the composites thus arguing that solvent partition between the two phases was always in favour of the polymer forming the continuous network. As far as we are aware, this is the first attempt to elucidate the solvent partition in pressurised hydrogel composites using blending law theory. Outcomes were contrasted with earlier work where binary mixtures were subjected only to thermal treatment.

Hypoglycemic activity of Chenopodium formosanum Koidz. components using a glucose uptake assay with 3T3-L1 adipocytes

Abstract Djulis (Chenopodium formosanum Koidz.) is a cereal plant native to Taiwan. In this study, the hypoglycemic activity of djulis was investigated using a glucose uptake assay with 3T3-L1 adipocytes. Dehusk seeds (SD) or husks (HD) of djulis were extracted using 6 solvents with different polarities (i.e., water, hexane, acetone, ethyl acetate, methanol and ethanol). The crude water extract of husk of djulis (WHD) showed the highest increase in glucose uptake with 3T3-L1 adipocytes. Thus, it was further separated by solvent partition, XAD-7 gel column chromatography, and HPLC. Two hypoglycemic components (P1 and P2) were isolated from WHD. They showed hypoglycemic activity at 5–10 ppm. P1 might have a synergistic effect with insulin. P2, however, did not enhance insulin-stimulated glucose uptake, which might mean it is an insulin mimic. The results suggested that djulis is a potential anti-diabetes functional food ingredient.

(Invited) Recent Progress in Understanding Battery Electrolyte Electrochemical Stability and Its Relationship with Electrolyte Structural Properties

Designing compatible electrochemical interfaces is paramount for enabling energy storage devices from batteries to electric double layer capacitors as electrolytes should be either electrochemically stable at the electrode and current collectors surfaces or form a stable electronically insulating but ionically conducting solid electrolyte interphase (SEI). Electrical double layer capacitors with narrow pores cannot rely on the SEI to extend their operating window placing more stringent requirements on electrolyte intrinsic electrochemical stability compared to batteries. In this presentation I will discuss a molecular scale insight into the initial mechanisms of battery electrolyte electrochemical degradation on the active and non-active electrodes obtained from a coordinated density functional theory (DFT) study and non-reactive molecular dynamics (MD) simulations of bulk and interfacial properties of electrolytes and the relationship between them. In the first part of the presentation, I will focus on understanding of electrolyte oxidation reactions on active and non-active electrodes. While HOMO screening for redox shuttle molecules was previously successful for quantitatively predicting trends, such screening is often not sufficient for traditional battery electrolyte solvents including cycling and linear carbonates, phosphates and sulfones.(1) Instead, quantum chemistry calculations have shown that the majority of battery solvents with the exception of the solvents with unsaturated functionalities such C=C double bonds do not undergo direct oxidation within typical operating range, instead their oxidation is coupled with the H-transfer to another solvent or oxygen of the electrode surface. Analogously, on the anode the F-transfer and LiF formation during anion and semi-fluorinated solvent reduction occurs at higher potentials compared to direct reduction of isolated anions and solvents.(2) Local ion and solvent environment influences both oxidation and reduction stability and initial decomposition reactions of electrolytes making electrolyte electrochemical stability dependent on the salt concentration and ion and solvent partitioning with the double layer that is in turn is dependent on the applied potential. Highly concentrated aqueous and non-aqueous electrolytes were found in MD simulations to exclude the solvent molecules from directly interacting with the positive electrode surface providing an additional mechanism for extending the electrolyte oxidation stability in addition to the widely discussed elimination of the “free” solvent from the electrolytes by increasing salt concentration.(3) In this presentation, I will give multiple examples on how changes in the double layer partitioning could be beneficial or detrimental to improving the electrode – electrolyte compatibility with aqueous and non-aqueous electrolytes. (4) References Borodin, O.; Olguin, M.; Spear, C. E.; Leiter, K.; Knap, J., Towards High Throughput Screening of Electrochemical Stability of Battery Electrolytes. Nanotechnology 2015, 26, 354003.Borodin, O.; Olguin, M.; Spear, C.; Leiter, K.; Knap, J.; Yushin, G.; Childs, A.; Xu, K., Challenges with Quantum Chemistry-Based Screening of Electrochemical Stability of Lithium Battery Electrolytes. ECS Transactions 2015, 69, 113-123.Vatamanu, J.; Borodin, O., Ramifications of Water-in-Salt Interfacial Structure at Charged Electrodes for Electrolyte Electrochemical Stability. J. Phys. Chem. Lett. 2017, 8, 4362-4367.Borodin, O. ; Ren, X.; Vatamanu, J.; Cresce, A. von Wald; Knap, J.; Xu, K. "A Modeling Insight into Battery Electrolyte Electrochemical Stability and Interfacial Structure" Acc. Chem. Res. 2017 (ASAP)

Alkaloid Fraction of Alstonia Boonei Stem Bark Demonstrate Antiobesity Potential on High Fat Diet Induced Obesity in Male Sprague‐Dawley Rats

The aim of this study was to investigate the anti‐obesity potential of alkaloid fraction of Alstonia boonei stem bark on high fat diet (HFD) induced obesity in male Sprague‐dawley rats.Preparation of neutral alkaloid fraction (NAF) was done through solvent partitioning of the methanol extract of Alstonia boonei stem bark, and NAF was subjected to LCMS‐MS analysis. To induce obesity, rats were fed with HFD (60% fat content) for 12 weeks preceding oral treatment with 125 and 250 mg/kg body weight of NAF for 4 weeks. Experimental procedures involving rats followed the European Community guidelines (EEC Directive of 1986; 86/609/EEC) for animal use.The major compounds found in NAF includes: Ajmalicine, 16‐Methoxy‐2,3‐dihydro‐3‐hydroxytabersonine, Vincamine, Aspidofractine, 3‐Hydroxyquinidine, 16‐Methoxytabersonine, Mitraphylline, 18‐Hydroxyyohimbine and Catharanthine. NAF significantly (p &lt; 0.05) decreased body weight, white adipose tissue, triglycerides, total cholesterol, low density lipoprotein cholesterol, very low density lipoprotein cholesterol, leptin, insulin and dopamine levels, but increased significantly (p &lt; 0.05) the high density lipoprotein cholesterol, cortisol, serotonin and noradrenaline levels in the treated groups compared to HFD control. However, there were no significant (p &gt; 0.05) changes in food intake, blood glucose, thyroxine, triiodothyronine and thyroid stimulating hormone levels in animals given NAF when compared to HFD control. The photomicrograph of liver of the rats treated with NAF showed slight fat changes unlike that of the HFD obese controls which showed presence of numerous prominent fat deposits on the livers.The findings in this study suggests that the alkaloid fraction of A. boonei possess antiobesity properties as indicated in improved lipid profile, leptin sensitivity, and decreased body weight of animals.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.