Isolation by pressurised fluid extraction (PFE) and identification using CPC and HPLC/ESI/MS of phenolic compounds from Brazilian cherry seeds (Eugenia uniflora L.).

Brazilian cherry seeds are a waste product from juice and frozen pulp production and, the seeds composition was investigated to valorize this by-product. Compounds separation was performed with ethanol by pressurised fluid extraction (PFE). Here we determine the effect of temperature (T), static time (ST), number of cycles (C), and flush volume (VF) on the yield, composition and total phenolic content (TPC) of the seed extracts.

Pentacyclic triterpenes from Manilkara bidentata resin. Isolation, identification and biological properties.

Three pentacyclic triterpenes were isolated for the first time from resinous plant Manilkara bidentata. Ultrasound-assisted extraction with ethanol was chosen after a comparison of various extraction methods. Analysis of the extract was performed by HPLC with evaporative light scattering detection and semi-preparative HPLC has enabled us to isolate two urs-12-enes (3β-O-acetyl-α-amyrin and 3β-O-trans cinnamyl-α-amyrin) and a lupane-type derivative (3β-O-trans cinnamyl lupeol).

Bioactive molecules in Kalanchoe pinnata leaves: extraction, purification, and identification.

Kalanchoe pinnata (Lam.) Pers. (syn.

Chiral separation of phosphine-containing alpha-amino acid derivatives using two complementary cellulosic stationary phases in supercritical fluid chromatography.

Enantiomeric separations of six amino-acid derivatives have been studied using packed-column supercritical fluid chromatography with two polysaccharide-based enantioselective stationary phases: cellulose tris(3,5-dimethylphenylcarbamate) and cellulose tris(3-chloro-4-methylphenylcarbamate) (Lux Cellulose-1 and -2). The effect of analyte structure on retention and separation was studied. Varied mobile phase compositions were investigated: alcohol modifier percentage was increased from 3 to 40% but smaller amounts were most effective in separating these compounds.

Pilot-scale ion-exchange centrifugal partition chromatography: purification of sinalbin from white mustard seeds.

The purification of p-hydroxybenzylglucosinolate (sinalbin) on a multigram scale from a crude aqueous extract of white mustard seeds (Sinapis alba var. concerta) was successfully achieved by scaling up a strong ion-exchange centrifugal partition chromatography (SIXCPC) laboratory procedure. Thus, the one-step sinalbin purification was performed with 2.

Hyphenation of centrifugal partition chromatography with electrospray ionization mass spectrometry using an active flow-splitter device for characterization of flavonol glycosides.

Online coupling of centrifugal partition chromatography to electrospray ionization mass spectrometry (CPC/ESI-MS) was investigated for the separation and characterization of flavonol glycosides. Structural identification and purification monitoring of analytes on milligram scale were demonstrated to be possible by using an active flow-splitter device which transfers automatically and successively, at discrete frequencies, small aliquots of the chromatographic effluent to an independent auxiliary stream directed to an ESI quadrupole mass spectrometer. The CPC protocol used a biphasic solvent system composed of ethyl acetate/ethanol/water (4.

Selective solid-phase extraction of a triterpene acid from a plant extract by molecularly imprinted polymer.

A molecularly imprinted polymer (MIP) has been prepared by a thermal polymerisation method using methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross-linking agent, chloroform as porogenic solvent and an oleanane triterpene compound (18-beta-glycyrrhetinic acid) as imprinted molecule (template). Equilibrium ligand binding experiments were done to assess the performance of the MIP relative to non-imprinted polymer (NIP). After optimisation of SPE protocol (CHCl3 as washing solvent and MeOH as elution solvent), successful imprinting was confirmed by comparison of the recoveries between NIP (5%) and MIP (97%) cartridges.

Composition and distribution of carrabiose moieties in hybrid kappa-/iota-carrageenans using carrageenases.

Hybrid kappa/iota-carrageeans extracted from Gigartina skottsbergii, Chondracanthus chamissoï, and Chondrus crispus were incubated with Pseudoalteromonas carrageenovora kappa-carrageenase and Alteromonas fortis iota-carrageenase. The degradation products as well as the resistant fraction were fully characterized by chromatography, NMR, and mass spectrometry. The low percentage of degradation observed after treatment by the iota-carrageenase suggests that long segments of iota-carrabiose or block of iota-carrageenan are low in abundance.

Analysis of triacylglycerols on porous graphitic carbon by high temperature liquid chromatography.

The retention behaviour of several triacylglycerols (TAGs) and fats on Hypercarb, a porous graphitic carbon column (PGC), was investigated in liquid chromatography (LC) under isocratic elution mode with an evaporative light scattering detector (ELSD). Mixtures of chloroform/isopropanol were selected as mobile phase for a suitable retention time to study the influence of temperature. The retention was different between PGC and non-aqueous reversed phase liquid chromatography (NARP-LC) on octadecyl phase.

On-line liquid chromatography-electrospray ionisation mass spectrometry for kappa-carrageenan oligosaccharides with a porous graphitic carbon column.

Enzymatically digested oligosaccharides of kappa-carrageenans were separated on a porous graphitic carbon (PGC) column and characterised on-line by electrospray ionisation mass spectrometry (ESI-MS). Two different developing ions were applied. Among them ammonium hydrogencarbonate showed more eluting power as it should on normal anion-exchange stationary phases.

Tandem mass spectrometry for the characterisation of sulphated-phosphorylated analogues of the carbohydrate-protein linkage region of proteoglycans.

Carbohydrate-protein linkage region of proteoglycans is a key oligosaccharide structure because their sulphated and/or phosphorylated analogues control the biosynthesis of glucosaminoglycans or galactosaminoglycans. Therefore, synthesised sulphated and/or phosphorylated analogues were characterised by tandem mass spectrometry in the negative-ion mode. Results demonstrated that the product ion profile was characterised by glycosidic and cross-ring cleavages depending on the position and the type of the charged group (sulphate, phosphate or carboxylate).

Characterization of a new methylated Beta-cyclodextrin with a low degree of substitution by electrospray ionization mass spectrometry and liquid chromatography/mass spectrometry.

A new methylated beta-cyclodextrin (Me-beta-CD) with a low degree of substitution (DS) was characterized by electrospray ionization mass spectrometry (ESI-MS) and liquid chromatography coupled with ESI-MS (LC/ESI-MS). For ESI-MS analyses, the composition of the infused sample solution was optimized in order to obtain only singly charged ammoniated CDs without fragmentation. The DS value (i.

Characterization of a new methylated beta-cyclodextrin with a low degree of substitution by matrix-assisted laser desorption/ionization mass spectrometry and liquid chromatography using evaporative light scattering detection.

A new methylated beta-cyclodextrin with a low degree of substitution was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and high-performance liquid chromatography (HPLC) with evaporative light scattering detection. Using alpha-cyano-4-hydroxycinnamic acid as the matrix and the thin layer method as the deposition procedure, MALDI-TOF-MS revealed that the mixture was composed of CDs bearing from 2 to 8 methyl groups with an average degree of substitution (DS) of 0.7 (i.

Development and validation of a hydrophilic interaction chromatography-mass spectrometry assay for taurine and methionine in matrices rich in carbohydrates.

A new procedure based on hydrophilic interaction chromatography coupled to tandem mass spectrometry (ionisation process by pneumatically assisted electrospray in negative ion mode), is developed and validated for the simultaneous determination of underivatised taurine and methionine in beverages rich in carbohydrates such as energy drinks. No initial clean-up procedure and no sample derivatisation are required. Satisfactory analysis was obtained on an Astec apHera NH2 (150 mm x 4.

Matrix-assisted laser desorption/ionisation mass spectrometry for the direct analysis of enzymatically digested kappa- iota- and hybrid iota/nu-carrageenans.

Enzymatically digested oligosaccharides of kappa-, iota- and hybrid iota/nu-carrageenans were analysed using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry in the negative-ion mode. nor-Harmane was used as matrix. Depending on the stock concentration and the laser intensity applied, the oligosaccharides exhibited losses of sulphate units (neutralised by the Na+ ion, and thus non-stable), leaving the primary backbone structure in most cases with only the deprotonated sulphate groups (carrying the negative charge, stable).

On-line liquid chromatography electrospray ionization mass spectrometry for the characterization of kappa- and iota-carrageenans. Application to the hybrid iota-/nu-carrageenans.

An on-line liquid chromatography electrospray ionization mass spectrometry (MS) method was developed for the characterization of polymers of kappa- (extracted from Kappaphycus alvarezii), iota-, and hybrid iota-/nu-carrageenans (both extracted from Eucheuma denticulatum) enzymatically digested with specific carrageenase enzymes. Applying either CID MS/MS or in-source fragmentation mechanisms, the results demonstrated that none of the polymers of kappa- or iota-carrageenans existed with their ideal repeating units. On the polymer of kappa-carrageenan, the nonideal structures identified consisted of iota-neocarrabiose sulfate units.

Liquid chromatography analysis of monosubstituted sulfobutyl ether-beta-cyclodextrin isomers on porous graphitic carbon.

The retention behaviour of the three positional isomers of monosubstituted sulfobutyl ether-beta-cyclodextrin was investigated on a porous graphitic carbon (PGC) column. The influence of the mobile phase composition (nature and concentration of organic and electronic modifiers) was studied as well as the effect of column temperature. These hydrophilic and anionic analytes were highly retained on the PGC stationary phase compared to octadecyl bonded phases.

Rapid analysis of triterpenic acids by liquid chromatography using porous graphitic carbon and evaporative light scattering detection.

An original system which uses Porous Graphitic Carbon as support and a mixture of organic solvents as mobile phase is proposed for the analysis of triterpenic acids by liquid chromatography. The separation of betulinic acid, ursolic acid, oleanolic acid, and 18alpha- and 18beta-glycyrrhetinic acids was carried out within a short time and monitored by evaporative light scattering detection as universal detection method. Molecular modelling studies show that the main contribution to the selectivity comes from the electrostatic interaction characterised by the dipole moment of the products.

Validation of a real-time monitoring method for aniline in freshwater by high-performance liquid chromatography on porous graphitic carbon/electrospray ionization tandem mass spectrometry.

Aniline is an anthropogenic organic compound widely used in polymer, rubber, pharmaceutical and dye industries but also used in biodegradability assays of chemical compounds as a positive biodegradation standard. By the two approaches, the rapid determination of aniline is necessary because of the high toxicity of aniline on hemoglobin. A high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) method for the determination of aniline in water is described here.

Isolation of kappa-carrageenan oligosaccharides using ion-pair liquid chromatography--characterisation by electrospray ionisation mass spectrometry in positive-ion mode.

Oligo-kappa-carrageenans participate as elicitors in the cell-cell recognition process in marine plants. Analytical methods can be usefully applied to gain insight into the biochemistry of these biological processes. Therefore, enzymatically digested oligomers of kappa-carrageenans have been separated and isolated on a Spherisorb ODS1 (250 x 4 mm i.