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1.
J Virol Methods ; 299: 114305, 2022 01.
Article in English | MEDLINE | ID: mdl-34626684

ABSTRACT

Adenoviruses (AdVs) are used as gene therapy vectors to treat human diseases and as vaccines against COVID-19. AdVs are produced by transfecting human embryonic kidney 239 (HEK293) or PER.C6 virus producer cells with AdV plasmid vectors or infecting these cells withcell lysates containing replication-defective AdV. Cell lysates can be purified further by caesium chloride or chromatographic protocols to research virus seed stocks (RVSS) for characterisation to high quality master virus seed stocks (MVSS) and working virus seed stocks (WVSS) before downstream production of pure, high titre AdV. Lysates are poorly infectious, block filtration columns and have limited storage capability. Aqueous two-phase systems (ATPS) are an alternative method for AdV purification that rapidly generates cleaner RVSS for characterisation to MVSS. After testing multiple ATPS formulations, an aqueous mixture of 20 % PEG 600 and 20 % (NH4)2SO4 (w/w) was found most effective for AdV partitioning, producing up to 97+3% yield of high-titre virus that was devoid of aggregates both effective in vitro and in vivo with no observable cytotoxicity. Importantly, AdV preparations stored at -20 °C or 4 °C show negligible loss of titre and are suitable for downstream processing to clinical grade to support the need for AdV vaccines.


Subject(s)
COVID-19 Vaccines , COVID-19 , Adenoviridae/genetics , Genetic Vectors , HEK293 Cells , Humans , SARS-CoV-2 , Technology
2.
Molecules ; 26(8)2021 Apr 15.
Article in English | MEDLINE | ID: mdl-33920874

ABSTRACT

The detailed metabolite profiling of Laguncularia racemosa was accomplished by high-performance countercurrent chromatography (HPCCC) using the three-phase system n-hexane-tert-butyl methyl ether-acetonitrile-water 2:3:3:2 (v/v/v/v) in step-gradient elution mode. The gradient elution was adjusted to the chemical complexity of the L. racemosa ethyl acetate partition and strongly improved the polarity range of chromatography. The three-phase solvent system was chosen for the gradient to avoid equilibrium problems when changing mobile phase compositions encountered between the gradient steps. The tentative recognition of metabolites including the identification of novel ones was possible due to the off-line injection of fractions to electrospray ionization mass spectrometry (ESI-MS/MS) in the sequence of recovery. The off-line hyphenation profiling experiment of HPCCC and ESI-MS projected the preparative elution by selected single ion traces in the negative ionization mode. Co-elution effects were monitored and MS/MS fragmentation data of more than 100 substances were used for structural characterization and identification. The metabolite profile in the L. racemosa extract comprised flavonoids, hydrolysable tannins, condensed tannins and low molecular weight polyphenols.


Subject(s)
Chromatography, High Pressure Liquid/methods , Spectrometry, Mass, Electrospray Ionization/methods , Tandem Mass Spectrometry/methods , Chemical Fractionation/methods , Countercurrent Distribution/methods , Flavonoids/analysis , Polyphenols/analysis , Solvents/chemistry
3.
J Chromatogr A ; 1581-1582: 80-90, 2018 Dec 21.
Article in English | MEDLINE | ID: mdl-30442474

ABSTRACT

Increasing column/tubing aspect ratio has been shown in a feasibility study to improve column efficiency when operating in reversed phase mode. This paper contains a thorough investigation on how increases in mobile phase flow and centrifugal force field affect stationary phase retention and column efficiency (as measured by the resolution between adjacent peaks) for columns wound with rectilinear tubing of different aspect ratio. The study uses a Mini CCC instrument operating from 1500 to 2100 rpm (126-246 g) to compare three columns with the same cross-sectional area but different aspect ratio - rectangular horizontal (force field perpendicular to the flat side - aspect ratio 3.125); square (aspect ratio 1.0) and rectangular vertical (flat side parallel with force field - aspect ratio 0.32). Columns are compared by measuring stationary phase retention, resolution and normalized resolution for 3 different mobile phase flow rates 2, 4 and 8 ml/min in both normal phase and reversed phase modes. The results with rectilinear tubing are compared to conventional circular tubing with the same cross-sectional area. The results show that resolution increases with aspect ratio and that at the highest aspect ratio the highest flow rate can maintain a high efficiency only if the highest g-field of 246 g is used. When comparing the rectangular horizontal tubing which gave the best results with conventional circular tubing with the same cross-sectional area a 45% improvement was found in reversed phase mode and a 51% improvement in normal phase mode over the conventional circular cross-section tubing. In other words, a rectangular horizontally wound bobbin with half the length of tubing can achieve the same result as a circular one. These are very significant results for halving separation times analytically or enabling designers to produce new instruments of the same capacity with a much-reduced size.


Subject(s)
Countercurrent Distribution/methods , Acceleration , Countercurrent Distribution/instrumentation
4.
J Chromatogr A ; 1580: 120-125, 2018 Dec 14.
Article in English | MEDLINE | ID: mdl-30429083

ABSTRACT

This paper builds on the fact that high aspect ratio rectilinear tubing columns of the same length and outside dimensions can double column efficiency. It demonstrates that further improvements in efficiency can be made by using rectilinear tubing columns with half the wall thickness thus replacing heavy PTFE with light solvent systems and producing lighter higher capacity columns. Increases in sample loading/throughput of up to 55x are demonstrated by comparing the separation of Honokiol and Magnolol using a Hexane: Ethyl Acetate: Methanol: Water (5:2:5:2) phase system with the new thin wall rectilinear column (56 mL, 30 mL/min, 2.1 g/h in 6.5 min.) with the original optimization performed using a conventional DE-Mini column (18 mL, 0.8 mm bore circular PTFE tubing, 2.5 mL/min, 0.038 g/h in 45 min.). Honokiol is currently going through first phase clinical trials as an anti-lung cancer therapy where preparative countercurrent chromatography was used for its manufacture. To be competitive in the future it is important for the technology to become more efficient. This is the first big step in that direction.


Subject(s)
Chemistry, Pharmaceutical/instrumentation , Chemistry, Pharmaceutical/methods , Countercurrent Distribution , Biphenyl Compounds/chemistry , Biphenyl Compounds/isolation & purification , Hexanes/chemistry , Lignans/chemistry , Lignans/isolation & purification , Methanol/chemistry , Solvents/chemistry , Water/chemistry
5.
Article in English | MEDLINE | ID: mdl-29241086

ABSTRACT

A robust strategy for the automated preparation of aqueous two-phase systems (ATPS) using a liquid handling sample processor was developed using gravimetric methods: to determine the accuracy of preparation. The major robotic control parameters requiring adjustment were; speed of aspiration and dispense; delay times following aspiration and dispense alongside measures to control cross-contamination during phase sampling. In general mixture compositions of both polymer/polymer and polymer/salt mixtures could be prepared with a target bias accuracy of less than 5%. However, we found that the bias accuracy with which systems of defined TLL and MR could be constructed was highly dependent on the tie line length of the ATPS and the geometrical form of the ATPS co-existence curve. For systems with a very low degree of curvature (PEG/salt systems here) increases in bias (accuracy) are appreciable at relatively long tie line lengths. Where the degree of curvature is more pronounced (PEG/dextran systems) closer approach to the critical point was possible without major effect on bias/accuracy. Application of the strategy to the measurement of the partitioning of phosphorylated and dephosphorylated forms of the model protein ovalbumin are reported. Differences in partition of phosphorylated (native) forms and dephosphorylated forms could be demonstrated. In a PEG/salt system this was manifest as a substantial decrease in solubility based on overall protein recovery derived from accurate knowledge of the system mass ratio. In a PEG/dextran system differences in partition coefficient could be demonstrated between phosphorylated and dephosphorylated forms.


Subject(s)
Automation, Laboratory/methods , Chromatography, Liquid/methods , Liquid-Liquid Extraction/methods , Models, Chemical , Ovalbumin/analysis , Ovalbumin/chemistry , Ovalbumin/isolation & purification , Protein Isoforms/analysis , Protein Isoforms/chemistry , Protein Isoforms/isolation & purification , Recombinant Proteins/analysis , Recombinant Proteins/chemistry , Recombinant Proteins/isolation & purification , Robotics
6.
Faraday Discuss ; 202: 415-431, 2017 09 21.
Article in English | MEDLINE | ID: mdl-28665423

ABSTRACT

Over 8 million tonnes of sugar beet are grown annually in the UK. Sugar beet pulp (SBP) is the main by-product of sugar beet processing which is currently dried and sold as a low value animal feed. SBP is a rich source of carbohydrates, mainly in the form of cellulose and pectin, including d-glucose (Glu), l-arabinose (Ara) and d-galacturonic acid (GalAc). This work describes the technical feasibility of an integrated biorefinery concept for the fractionation of SBP and conversion of these monosaccharides into value-added products. SBP fractionation is initially carried out by steam explosion under mild conditions to yield soluble pectin and insoluble cellulose fractions. The cellulose is readily hydrolysed by cellulases to release Glu that can then be fermented by a commercial yeast strain to produce bioethanol at a high yield. The pectin fraction can be either fully hydrolysed, using physico-chemical methods, or selectively hydrolysed, using cloned arabinases and galacturonases, to yield Ara-rich and GalAc-rich streams. These monomers can be separated using either Centrifugal Partition Chromatography (CPC) or ultrafiltration into streams suitable for subsequent enzymatic upgrading. Building on our previous experience with transketolase (TK) and transaminase (TAm) enzymes, the conversion of Ara and GalAc into higher value products was explored. In particular the conversion of Ara into l-gluco-heptulose (GluHep), that has potential therapeutic applications in hypoglycaemia and cancer, using a mutant TK is described. Preliminary studies with TAm also suggest GluHep can be selectively aminated to the corresponding chiral aminopolyol. The current work is addressing the upgrading of the remaining SBP monomer, GalAc, and the modelling of the biorefinery concept to enable economic and Life Cycle Analysis (LCA).


Subject(s)
Beta vulgaris/metabolism , Carbohydrates/biosynthesis , Pharmaceutical Preparations/metabolism , Beta vulgaris/chemistry , Carbohydrates/chemistry , Pharmaceutical Preparations/chemistry
7.
J Chromatogr A ; 1497: 56-63, 2017 May 12.
Article in English | MEDLINE | ID: mdl-28366567

ABSTRACT

The isolation of component sugars from biomass represents an important step in the bioprocessing of sustainable feedstocks such as sugar beet pulp. Centrifugal partition chromatography (CPC) is used here, as an alternative to multiple resin chromatography steps, to fractionate component monosaccharides from crude hydrolysed sugar beet pulp pectin. CPC separation of samples, prepared in the stationary phase, was carried out using an ethanol: ammonium sulphate (300gL-1) phase system (0.8:1.8v:v) in ascending mode. This enabled removal of crude feedstream impurities and separation of monosaccharides into three fractions (l-rhamnose, l-arabinose and d-galactose, and d-galacturonic acid) in a single step. Throughput was improved three-fold by increasing sample injection volume, from 4 to 16% of column volume, with similar separation performance maintained in all cases. Extrusion of the final galacturonic acid fraction increased the eluted solute concentration, reduced the total separation time by 24% and removed the need for further column regeneration. Reproducibility of the separation after extrusion was validated by using multiple stacked injections. Scale-up was performed linearly from a semi-preparative 250mL column to a preparative 950mL column with a scale-up ratio of 3.8 applied to mobile phase flow rate and sample injection volume. Throughputs of 9.4gL-1h-1 of total dissolved solids were achieved at the preparative scale with a throughput of 1.9gL-1h-1 of component monosaccharides. These results demonstrate the potential of CPC for both impurity removal and target fractionation within biorefinery separations.


Subject(s)
Beta vulgaris/chemistry , Chemical Fractionation/methods , Chromatography, Liquid/methods , Monosaccharides/isolation & purification , Centrifugation , Hexuronic Acids/isolation & purification , Hydrolysis , Pectins/chemistry , Reproducibility of Results
8.
J Chromatogr A ; 1487: 77-82, 2017 Mar 03.
Article in English | MEDLINE | ID: mdl-28110947

ABSTRACT

Countercurrent chromatography (CCC) and centrifugal partition chromatography (CPC) are support free liquid-liquid chromatography techniques sharing the same basic principles and features. Method transfer has previously been demonstrated for both techniques but never from one to another. This study aimed to show such a feasibility using fractionation of Schinus terebinthifolius berries dichloromethane extract as a case study. Heptane - ethyl acetate - methanol -water (6:1:6:1, v/v/v/v) was used as solvent system with masticadienonic and 3ß-masticadienolic acids as target compounds. The optimized separation methodology previously described in Part I and II, was scaled up from an analytical hydrodynamic CCC column (17.4mL) to preparative hydrostatic CPC instruments (250mL and 303mL) as a part of method development. Flow-rate and sample loading were further optimized on CPC. Mobile phase linear velocity is suggested as a transfer invariant parameter if the CPC column contains sufficient number of partition cells.


Subject(s)
Anacardiaceae/chemistry , Chemistry Techniques, Analytical/methods , Chromatography, Liquid , Countercurrent Distribution , Chemical Fractionation , Chemistry Techniques, Analytical/standards , Fruit/chemistry , Methanol/chemistry , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Solvents/chemistry , Triterpenes/chemistry , Water/chemistry
9.
J Chromatogr A ; 1481: 92-100, 2017 Jan 20.
Article in English | MEDLINE | ID: mdl-28027839

ABSTRACT

Ampelozizyphus amazonicus Ducke (Rhamnaceae), a medicinal plant used to prevent malaria, is a climbing shrub, native to the Amazonian region, with jujubogenin glycoside saponins as main compounds. The crude extract of this plant is too complex for any kind of structural identification, and HPLC separation was not sufficient to resolve this issue. Therefore, the aim of this work was to obtain saponin enriched fractions from the bark ethanol extract by countercurrent chromatography (CCC) for further isolation and identification/characterisation of the major saponins by HPLC and MS. The butanol extract was fractionated by CCC with hexane - ethyl acetate - butanol - ethanol - water (1:6:1:1:6; v/v) solvent system yielding 4 group fractions. The collected fractions were analysed by UHPLC-HRMS (ultra-high-performance liquid chromatography/high resolution accurate mass spectrometry) and MSn. Group 1 presented mainly oleane type saponins, and group 3 showed mainly jujubogenin glycosides, keto-dammarane type triterpene saponins and saponins with C31 skeleton. Thus, CCC separated saponins from the butanol-rich extract by skeleton type. A further purification of group 3 by CCC (ethyl acetate - ethanol - water (1:0.2:1; v/v)) and HPLC-RI was performed in order to obtain these unusual aglycones in pure form.


Subject(s)
Chromatography, High Pressure Liquid/methods , Countercurrent Distribution/methods , Mass Spectrometry/methods , Rhamnaceae/chemistry , Saponins/chemistry , Saponins/isolation & purification , Butanols/chemistry , Glycosides/chemistry , Hexanes/chemistry , Plant Extracts/chemistry , Plants, Medicinal/chemistry , Saponins/analysis , Solvents/chemistry , Triterpenes/chemistry , Triterpenes/isolation & purification , Dammaranes
10.
J Chromatogr A ; 1476: 19-24, 2016 Dec 09.
Article in English | MEDLINE | ID: mdl-27884427

ABSTRACT

Counter-current chromatography (CCC) has been widely used as a preparative separation method to purify natural products from plant extracts and fermentation broths. Traditionally, throughput optimization in CCC has focused on sample concentration and sample volume. In this paper sample injection was considered as consisting of three variables: injection flow rate, post-injection flow rate and sample solvent. The effects of these parameters were studied using a honokiol purification from a Magnolia officinalis bark extract as a case study aiming to achieve the highest throughput/yield ratio for greater than 99% purity of this potential anti-cancer drug obtained for submission to the Chinese FDA. An injection method was established that increased the throughput of honokiol by 46.5% (from 3.05g/h to 4.47g/h), and decreased the solvent consumption of mobile phase and stationary phase per gram of honokiol by 40.0% (from 0.68L/g to 0.41L/g) and 48.4% (from 0.40L/g to 0.21L/g) respectively. These results show the importance of understanding the whole injection process when optimizing a given CCC separation.


Subject(s)
Antineoplastic Agents, Phytogenic/isolation & purification , Biphenyl Compounds/isolation & purification , Countercurrent Distribution/methods , Lignans/isolation & purification , Magnolia/chemistry , Plant Extracts/chemistry , Solvents
11.
J Chromatogr A ; 1466: 76-83, 2016 Sep 30.
Article in English | MEDLINE | ID: mdl-27608619

ABSTRACT

Countercurrent chromatography (CCC) is being widely used across the world for purification of various materials, especially in natural product research. The predictability of CCC scale-up has been successfully demonstrated using specially designed instruments of the same manufacturer. The reality is that the most of CCC users do not have access to such instruments and do not have enough experience to transfer methods from one CCC column to another. This unique study of three international teams is based on innovative approach to simplify the scale-up between different CCC machines using fractionation of Schinus terebinthifolius berries dichloromethane extract as a case study. The optimized separation methodology, recently developed by the authors (Part I), was repeatedly performed on CCC columns of different design available at most research laboratories across the world. Hexane - ethyl acetate - methanol - water (6:1:6:1, v/v/v/v) was used as solvent system with masticadienonic and 3ß-masticadienolic acids as target compounds to monitor stationary phase retention and calculate peak resolution. It has been demonstrated that volumetric, linear and length scale-up transfer factors based on column characteristics can be directly applied to different i.d., volume and length columns independently on instrument make in an intra-apparatus scale-up and inter-apparatus method transfer.


Subject(s)
Anacardiaceae/chemistry , Countercurrent Distribution/methods , Plant Extracts/isolation & purification , Chemical Fractionation , Chromatography, High Pressure Liquid/methods , Countercurrent Distribution/instrumentation , Plant Extracts/chemistry
12.
J Chromatogr A ; 1425: 1-7, 2015 Dec 18.
Article in English | MEDLINE | ID: mdl-26610613

ABSTRACT

The 8th International Conference on Counter-current Chromatography (CCC2014) was held at Brunel University London from July 23rd to 25th, 2014. It has been 14 years since Brunel hosted the first International Conference on CCC (CCC2000) at the beginning of the millennium and therefore, it was a good opportunity to review the progress of this emerging technology and particularly the impact it is having with industry today.


Subject(s)
Countercurrent Distribution , Humans
13.
J Chromatogr A ; 1411: 84-91, 2015 Sep 11.
Article in English | MEDLINE | ID: mdl-26278358

ABSTRACT

A critical step in the bioprocessing of sustainable biomass feedstocks, such as sugar beet pulp (SBP), is the isolation of the component sugars from the hydrolysed polysaccharides. This facilitates their subsequent conversion into higher value chemicals and pharmaceutical intermediates. Separation methodologies such as centrifugal partition chromatography (CPC) offer an alternative to traditional resin-based chromatographic techniques for multicomponent sugar separations. Highly polar two-phase systems containing ethanol and aqueous ammonium sulphate are examined here for the separation of monosaccharides present in hydrolysed SBP pectin: l-rhamnose, l-arabinose, d-galactose and d-galacturonic acid. Dimethyl sulfoxide (DMSO) was selected as an effective phase system modifier improving monosaccharide separation. The best phase system identified was ethanol:DMSO:aqueous ammonium sulphate (300gL(-1)) (0.8:0.1:1.8, v:v:v) which enabled separation of the SBP monosaccharides by CPC (200mL column) in ascending mode (upper phase as mobile phase) with a mobile phase flow rate of 8mLmin(-1). A mixture containing all four monosaccharides (1.08g total sugars) in the proportions found in hydrolysed SBP was separated into three main fractions; a pure l-rhamnose fraction (>90%), a mixed l-arabinose/d-galactose fraction and a pure d-galacturonic acid fraction (>90%). The separation took less than 2h demonstrating that CPC is a promising technique for the separation of these sugars with potential for application within an integrated, whole crop biorefinery.


Subject(s)
Beta vulgaris/chemistry , Countercurrent Distribution/methods , Monosaccharides/isolation & purification , Arabinose/isolation & purification , Galactose/isolation & purification , Hydrolysis , Pectins/isolation & purification
14.
J Chromatogr A ; 1398: 66-72, 2015 Jun 12.
Article in English | MEDLINE | ID: mdl-25931379

ABSTRACT

Countercurrent chromatography (CCC) is a form of liquid-liquid chromatography. It works by running one immiscible solvent (mobile phase) over another solvent (stationary phase) being held in a CCC column using centrifugal force. The concentration of compound in each phase is characterised by the partition coefficient (Kd), which is the concentration in the stationary phase divided by the concentration in the mobile phase. When Kd is between approximately 0.2 and 2, it is most likely that optimal separation will be achieved. Having the Kd in this range allows the compound enough time in the column to be separated without resulting in a broad peak and long run time. In this paper we report the development of quantitative structure activity relationship (QSAR) models to predict logKd. The QSAR models use only the molecule's 2D structure to predict the molecular property logKd.


Subject(s)
Chemistry Techniques, Analytical/methods , Countercurrent Distribution , Models, Theoretical , Molecular Structure , Quantitative Structure-Activity Relationship , Solvents/chemistry
15.
J Chromatogr A ; 1389: 39-48, 2015 Apr 10.
Article in English | MEDLINE | ID: mdl-25757818

ABSTRACT

'Countercurrent chromatography' (CCC) is an ideal technique for the recovery, purification and isolation of bioactive natural products, due to the liquid nature of the stationary phase, process predictability and the possibility of scale-up from analytical to preparative scale. In this work, a method developed for the fractionation of Schinus terebinthifolius Raddi berries dichloromethane extract was thoroughly optimized to achieve maximal throughput with minimal solvent and time consumption per gram of processed crude extract, using analytical, semi-preparative and preparative 'high performance countercurrent chromatography' (HPCCC) instruments. The method using the biphasic solvent system composed of n-heptane-ethyl acetate-methanol-water (6:1:6:1, v/v/v/v) was volumetrically scaled up to increase sample throughput up to 120 times, while maintaining separation efficiency and time. As a fast and specific detection alternative, the fractions collected from the CCC-separations were injected to an 'atmospheric pressure chemical ionization mass-spectrometer' (APCI-MS/MS) and reconstituted molecular weight MS-chromatograms of the APCI-ionizable compounds from S. terebinthifolius were obtained. This procedure led to the direct isolation of tirucallane type triterpenes such as masticadienonic and 3ß-masticadienolic acids. Also oleanonic and moronic acids have been identified for the first time in the species. In summary, this approach can be used for other CCC scale-up processes, enabling MS-target-guided isolation procedures.


Subject(s)
Anacardiaceae/chemistry , Chemical Fractionation/methods , Chromatography, High Pressure Liquid , Countercurrent Distribution , Plant Extracts/isolation & purification , Tandem Mass Spectrometry , Atmospheric Pressure , Plant Extracts/chemistry , Solvents/chemistry , Triterpenes/isolation & purification
16.
J Chromatogr A ; 1380: 29-37, 2015 Feb 06.
Article in English | MEDLINE | ID: mdl-25595533

ABSTRACT

Betalains, natural plant pigments, are beneficial compounds due to their antioxidant and possible chemoprotective properties. A mixture of betalains: betanin/isobetanin, decarboxybetanins and neobetanin from processed red beet roots (Beta vulgaris L.) juice was separated in food-grade, gradient solvent systems using high-performance counter-current chromatography (HPCCC). The decarboxylated and dehydrogenated betanins were obtained by thermal degradation of betanin/isobetanin from processed B. vulgaris L. juice under mild conditions. Two solvent systems (differing in their composition by phosphoric acid and ethanol volume gradient) consisting of BuOH-EtOH-NaClsolution-H2O-H3PO4 (v/v/v/v/v, 1300:200-1000:1300:700:2.5-10) in the 'tail-to-head' mode were run. The flow rate of the mobile phase (organic phase) was 1.0 or 2.0 ml/min and the column rotation speed was 1,600 rpm (20°C). The retention of the solvent system stationary phase (aqueous phase) was ca. 80%. The system with the acid and ethanol volume gradient consisting of BuOH-EtOH-NaClsolution-H2O-H3PO4 (v/v/v/v/v, 1300:200-240:1300:700:2.5-4.5) pumped at 2.0 ml/min was the most effective for a separation of betanin/isobetanin, 17-decarboxy-betanin/-isobetanin, 2-decarboxy-betanin/-isobetanin, 2,17-bidecarboxy-betanin/-isobetanin pairs as well as neobetanin. The pigments were detected by LC-DAD and LC-MS. The results are crucial in the application of completely food-grade solvent systems in separation of food-grade compounds as well, and the systems can possibly be extended to other ionizable and polar compounds with potential health benefits. In particular, the method is applicable for the isolation and purification of betalains present in such rich sources as B. vulgaris L. roots as well as cacti fruits and Amaranthaceae flowering plants due to modification possibilities of the solvent systems polarity.


Subject(s)
Beta vulgaris/chemistry , Betacyanins/isolation & purification , Solvents , Chromatography, High Pressure Liquid , Countercurrent Distribution , Plant Extracts/chemistry , Spectrometry, Mass, Electrospray Ionization
17.
Food Chem ; 170: 154-9, 2015 Mar 01.
Article in English | MEDLINE | ID: mdl-25306330

ABSTRACT

For the provision of oleocanthal (OLC), a phenolic compound with very promising pharmacological properties, isolation from olive oil is a very important option. Due to the compound's sensitivity to decomposition upon exposure to oxygen and light, a very gentle isolation method has been developed under use of high performance countercurrent chromatography (HPCCC). By partition of olive oil between hexane and methanol, an extract enriched in phenolics was prepared and subjected to a two-step HPCCC separation under use of heptane-EtOAc-MeOH-H2O mixtures in normal-phase and reverse phase mode, respectively. With this method, the isolation of tyrosol, hydroxytyrosol, and the mixture of (3S,4E)- and (3S,4Z)-OLC was achieved in approx. 70 min for each step. By one- and two-dimensional NMR-experiments and LC-MS, the equilibrium of (3S,4E)- and (3S,4Z)-OLC in such olive oil extracts has unambiguously been proven for the first time.


Subject(s)
Aldehydes/chemistry , Countercurrent Distribution/methods , Olive Oil/analysis , Phenols/chemistry , Phenylethyl Alcohol/analogs & derivatives , Plant Oils/analysis , Chromatography, High Pressure Liquid/methods , Cyclopentane Monoterpenes , Phenylethyl Alcohol/chemistry , Plant Oils/chemistry
18.
Sci Total Environ ; 503-504: 22-31, 2015 Jan 15.
Article in English | MEDLINE | ID: mdl-24951181

ABSTRACT

SOLUTIONS (2013 to 2018) is a European Union Seventh Framework Programme Project (EU-FP7). The project aims to deliver a conceptual framework to support the evidence-based development of environmental policies with regard to water quality. SOLUTIONS will develop the tools for the identification, prioritisation and assessment of those water contaminants that may pose a risk to ecosystems and human health. To this end, a new generation of chemical and effect-based monitoring tools is developed and integrated with a full set of exposure, effect and risk assessment models. SOLUTIONS attempts to address legacy, present and future contamination by integrating monitoring and modelling based approaches with scenarios on future developments in society, economy and technology and thus in contamination. The project follows a solutions-oriented approach by addressing major problems of water and chemicals management and by assessing abatement options. SOLUTIONS takes advantage of the access to the infrastructure necessary to investigate the large basins of the Danube and Rhine as well as relevant Mediterranean basins as case studies, and puts major efforts on stakeholder dialogue and support. Particularly, the EU Water Framework Directive (WFD) Common Implementation Strategy (CIS) working groups, International River Commissions, and water works associations are directly supported with consistent guidance for the early detection, identification, prioritisation, and abatement of chemicals in the water cycle. SOLUTIONS will give a specific emphasis on concepts and tools for the impact and risk assessment of complex mixtures of emerging pollutants, their metabolites and transformation products. Analytical and effect-based screening tools will be applied together with ecological assessment tools for the identification of toxicants and their impacts. The SOLUTIONS approach is expected to provide transparent and evidence-based candidates or River Basin Specific Pollutants in the case study basins and to assist future review of priority pollutants under the WFD as well as potential abatement options.


Subject(s)
Conservation of Natural Resources/methods , Water Pollutants, Chemical/analysis , Water Pollution, Chemical/prevention & control , Water Resources/statistics & numerical data , Ecosystem , Environmental Monitoring , Environmental Policy , European Union , Hazardous Substances/analysis , Risk Assessment , Water Pollution, Chemical/statistics & numerical data
19.
Molecules ; 19(7): 8773-87, 2014 Jun 25.
Article in English | MEDLINE | ID: mdl-24968333

ABSTRACT

High performance countercurrent chromatography (HPCCC) was successfully applied for the separation of nostotrebin 6 from cultivated soil cyanobacteria in a two-step operation. A two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (4:5:4:5, v/v/v/v) was employed for the HPCCC separation. In the first-step operation, its neutral upper phase was used as stationary phase and its basic lower phase (1% NH3 in lower phase) was employed as mobile phase at a flow rate of 1 mL/min. In the second operation step, its neutral upper phase was used as stationary phase, whereas both its neutral lower phase and basic lower phase were employed as mobile phase with a linear gradient elution at a flow rate of 0.8 mL/min. The revolution speed and temperature of the separation column were 1,000 rpm and 30 °C, respectively. Using HPCCC followed by clean-up on Sephadex LH-20 gel, 4 mg of nostotrebin 6 with a purity of 99% as determined by HPLC/DAD-ESI-HRMS was obtained from 100 mg of crude extract. The chemical identity of the isolated compound was confirmed by comparing its spectroscopic data (UV, ESI-HRMS, ESI-HRMS2) with those of an authentic standard and data available in the literature.


Subject(s)
Cholinesterase Inhibitors/isolation & purification , Cyclopentanes/isolation & purification , Nostoc/chemistry , Acetates/chemistry , Cholinesterase Inhibitors/chemistry , Chromatography, High Pressure Liquid , Countercurrent Distribution , Cyclopentanes/chemistry , Hexanes/chemistry , Methanol/chemistry , Soil Microbiology , Solvents/chemistry , Spectrometry, Mass, Electrospray Ionization , Water/chemistry
20.
Article in English | MEDLINE | ID: mdl-24184837

ABSTRACT

Two mixtures of decarboxylated and dehydrogenated betacyanins from processed red beet roots (Beta vulgaris L.) juice were fractionated by high performance counter-current chromatography (HPCCC) producing a range of isolated components. Mixture 1 contained mainly betacyanins, 14,15-dehydro-betanin (neobetanin) and their decarboxylated derivatives while mixture 2 consisted of decarboxy- and dehydro-betacyanins. The products of mixture 1 arose during thermal degradation of betanin/isobetanin in mild conditions while the dehydro-betacyanins of mixture 2 appeared after longer heating of the juice from B. vulgaris L. Two solvent systems were found to be effective for the HPCCC. A highly polar, high salt concentration system of 1-PrOH-ACN-(NH4)2SO4 (satd. soln)-water (v/v/v/v, 1:0.5:1.2:1) (tail-to-head mode) enabled the purification of 2-decarboxy-betanin/-isobetanin, 2,17-bidecarboxy-betanin/-isobetanin and neobetanin (all from mixture 1) plus 17-decarboxy-neobetanin, 2,15,17-tridecarboxy-2,3-dehydro-neobetanin, 2-decarboxy-neobetanin and 2,15,17-tridecarboxy-neobetanin (from mixture 2). The other solvent system included heptafluorobutyric acid (HFBA) as ion-pair reagent and consisted of tert-butyl methyl ether (TBME)-1-BuOH-ACN-water (acidified with 0.7% HFBA) (2:2:1:5, v/v/v/v) (head-to-tail mode). This system enabled the HPCCC purification of 2,17-bidecarboxy-betanin/-isobetanin and neobetanin (from mixture 1) plus 2,15,17-tridecarboxy-2,3-dehydro-neobetanin, 2,17-bidecarboxy-2,3-dehydro-neobetanin and 2,15,17-tridecarboxy-neobetanin (mixture 2). The results of this research are crucial in finding effective isolation methods of betacyanins and their derivatives which are meaningful compounds due their colorant properties and potential health benefits regarding antioxidant and cancer prevention. The pigments were detected by LC-DAD and LC-MS/MS techniques.


Subject(s)
Beta vulgaris/chemistry , Betalains/isolation & purification , Countercurrent Distribution/methods , Plant Extracts/chemistry , Solvents/chemistry , Chromatography, High Pressure Liquid , Indicators and Reagents/chemistry
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