Extensive phytochemical investigation of the polar constituents of Diospyros bipindensis Gürke traditionally used by Baka pygmies.

The water maceration and methanolic extract of the stem barks of Diospyros bipindensis, which is a medicinal plant used in Cameroon by Baka pygmies, revealed a complex high-performance liquid chromatography (HPLC) profile primarily composed of coumarin and naphthoquinone glycosides. The methanolic and apolar extracts also exhibited significant antifungal activity on a TLC bioautography assay against Candida albicans. HPLC-microfractionation in 96-well plates combined with bioautography enabled the rapid localization of the antifungal compound that was identified by HPLC-PDA and HPLC-MS analysis as plumbagin.

Isolation and characterization of bioactive compounds from plant resources: the role of analysis in the ethnopharmacological approach.

The phytochemical research based on ethnopharmacology is considered an effective approach in the discovery of novel chemicals entities with potential as drug leads. Plants/plant extracts/decoctions, used by folklore traditions for treating several diseases, represent a source of chemical entities but no information are available on their nature. Starting from this viewpoint, the aim of this review is to address natural-products chemists to the choice of the best methodologies, which include the combination of extraction/sample preparation tools and analytical techniques, for isolating and characterizing bioactive secondary metabolites from plants, as potential lead compounds in the drug discovery process.

Separation and characterisation of beta2-microglobulin folding conformers by ion-exchange liquid chromatography and ion-exchange liquid chromatography-mass spectrometry.

In this work we present for the first time the use of ion-exchange liquid chromatography to separate the native form and a partially structured intermediate of the folding of the amyloidogenic protein beta2-microglobulin. Using a strong anion-exchange column that accounts for the differences in charge exposure of the two conformers, a LC-UV method is initially optimised in terms of mobile phase pH, composition and temperature. The preferred mobile phase conditions that afford useful information were found to be 35 mM ammonium formate, pH 7.

Chemical composition and antimicrobial activity of the volatile fractions from leaves and flowers of the wild Iraqi Kurdish plant Prangos peucedanifolia FENZL.

The volatile fractions isolated from Prangos peucedanifolia FENZL leaves and flowers were investigated for their phytochemical composition and biological properties. Flower and leaf hydrodistillation afforded 3.14 and 0.

Anti-inflammatory, antimicrobial and antioxidant activities of Diospyros bipindensis (Gürke) extracts and its main constituents.

Ethnopharmacological Relevance: Diospyros bipindensis (Gürke) stem bark is used in Cameroon by Baka Pygmies for the treatment of respiratory disorders.

Aim Of The Study: To assess the anti-inflammatory, antibacterial and antioxidant properties of constituents from the bark extracts through bioassay-guided fractionation.

Materials And Methods: The anti-inflammatory activity of extracts, fractions and pure compounds was assessed through the inhibition of the pro-inflammatory mediator nuclear factor-kappa B (NF-κB) transcriptional activity and nitric oxide (NO) production.

Chemical composition and antimicrobial activity of Phyllanthus muellerianus (Kuntze) Excel essential oil.

Ethnopharmacological Relevance: Phyllanthus muellerianus (Kuntze) Excel (family Euphorbiaceae) stem bark is used in Cameroon by Baka pygmies as a remedy for wound healing and tetanus.

Aim Of The Study: To characterize the chemical composition and to evaluate the antimicrobial properties of the essential oil of the plant.

Materials And Methods: The essential oil was extracted from the stem bark by dynamic head space and by hydrodistillation and characterized by GC and GC-MS analyses.

The nutritional risk in oncology: a study of 1,453 cancer outpatients.

Purpose: There is little information about the nutritional status of cancer outpatients because the practice of nutritional screening is rarely performed. This study aims to define the pattern of scores of nutritional risk in 1,453 outpatients and factors associated with a high nutrition risk score, to facilitate the identification of such patients by the oncologists.

Methods: We prospectively screened the nutritional status of cancer outpatients according to the NRS-2002 score which combines indicators of malnutrition and of severity of the disease (1-3 points, respectively).

Antimicrobial properties of stem bark extracts from Phyllanthus muellerianus (Kuntze) Excell.

Ethnopharmacological Relevance: The plants of the genus Phyllanthus (Euphorbiaceae) are widely distributed in most tropical and subtropical countries, and have long been used in folk medicine to treat several diseases. Particularly, Phyllanthus muellerianus (Kuntze) Excell, commonly called "mbolongo" in Cameroon, is used by pygmies baka as a remedy for tetanus and wound infections.

Aim Of The Study: To investigate the antimicrobial properties of Phyllanthus muellerianus (Kuntze) Excell (family Euphorbiaceae) stem bark used in Cameroon by baka pygmies as a remedy for wound healing and tetanus.

Screening of fibrillogenesis inhibitors of β2-microglobulin: integrated strategies by mass spectrometry capillary electrophoresis and in silico simulations.

The challenging search of ligands for the amyloidogenic protein β(2)-microglobulin led us to set up an integrated strategy that combines analytical techniques and molecular modelling. Using a chemical library composed of 90 sulphonated molecules and a novel MS screening approach, we initially single out a few new binders. To check for anti-amyloid activity, the best hit obtained was thoroughly studied by docking analysis, affinity and refolding experiments by capillary electrophoresis and in vitro fibrillogenesis Thioflavin T test.

A combined high-resolution mass spectrometric and in silico approach for the characterisation of small ligands of beta2-microglobulin.

Beta(2)-microglobulin (beta(2)-m) is a protein responsible for a severe complication of long-term hemodialysis, known as dialysis-related amyloidosis, in which initial beta(2)-m misfolding leads to amyloid fibril deposition, mainly in the skeletal tissue. Whereas much attention is paid to understanding the complex mechanism of amyloid formation, the evaluation of small molecules that may bind beta(2)-m and possibly inhibit the aggregation process is still largely unexplored mainly because the protein lacks a specific active site. Based on our previous findings, we selected a pilot set of sulfonated molecules that are known to either bind or not to the protein, including binders that are anti-amyloidogenic.

Frontal affinity chromatography-mass spectrometry useful for characterization of new ligands for GPR17 receptor.

The application of frontal affinity chromatography-mass spectrometry (FAC-MS), along with molecular modeling studies, to the screening of potential drug candidates toward the recently deorphanized G-protein-coupled receptor (GPCR) GPR17 is shown. GPR17 is dually activated by uracil nucleotides and cysteinyl-leukotrienes, and is expressed in organs typically undergoing ischemic damage (i.e.

Optimum extraction process of polyphenols from Bridelia grandis stem bark using experimental design.

Euphorbiaceae barks are known to contain an appreciable amount of polyphenolic compounds responsible for several biological activities. Preliminary extraction from Bridelia grandis stem bark afforded high content of polyphenols, determined by spectrophotometric methods such as Folin-Ciocalteu (for total phenols, TP) and n-butanol-HCl (for condensed tannins, CT). A preliminary Plackett-Burman screening design was used to identify the key factors that influence the TP and CT extraction.

The genus Bridelia: a phytochemical and ethnopharmacological review.

Approximately 60 species of Bridelia, (Phyllanthaceae) are found throughout tropical and subtropical regions of the world, mainly in Africa and Asia. Several Bridelia species are used in popular medicines as antiamebic, antianemic, antibacterial, anticonvulsant, anti-diabetic, antidiarrhoeal, antihelmintic, anti-inflammatory, antimalarial, antinociceptive, antiviral, hypoglycemic and for abdominal pain, cardiovascular, gynecological and sexual diseases. The present paper reviews the traditional usage, the biological activities and the correlated chemical compounds of Bridelia species with emphasis on the validation of the ethnopharmacological uses.

Target-based drug discovery: the emerging success of frontal affinity chromatography coupled to mass spectrometry.

Frontal affinity chromatography coupled to mass spectrometry (FAC-MS) has been reported as a potential method for screening compound mixtures against immobilized target proteins. The potentiality of this analytical approach is described and illustrated with a number of examples based on targets of pharmaceutical interest.

CE can identify small molecules that selectively target soluble oligomers of amyloid beta protein and display antifibrillogenic activity.

Soluble and toxic oligomers of amyloid beta (A beta) protein have been identified as the true neurotoxic species involved in Alzheimer's disease and considering them as targets to inhibit A beta aggregation might have a therapeutic value. We previously set up a CE method that enables the separation and quantification of transient oligomers of A beta protein-containing 42 amino acids (A beta(1-42)) along the pathway leading to fibrils and we now demonstrate how this method can be successfully applied to examine the in vitro inhibitory effects of small molecules on A beta oligomerization. To this end, we investigated mitoxantrone and pixantrone, two well-known anticancer drugs, as well as suramin and a suramin-like compound.

Validation of use of a traditional remedy from Bridelia grandis (Pierre ex Hutch) stem bark against oral Streptococci.

Aim Of The Study: Bridelia grandis (Pierre ex Hutch) (Euphorbiaceae) is a medicinal plant traditionally used in Cameroon by pygmies Baka as a remedy for oral cavity affection. Bioassay-guided stem bark extracts were investigated for their in vitro antimicrobial properties as well as their phytochemical constituents.

Materials And Methods: The first extraction was carried out according to the traditional use.

Determination of glycine and threonine in topical dermatological preparations.

In the present study, a single HPLC method was developed for the determination of glycine and threonine in cicatrizants. Two different preparations of a cream and an ointment, and the corresponding bandages, onto which the formulations were applied, were studied. The method involved matrix solubilisation with dichloromethane, liquid-liquid isolation of gly and thr with aqueous 1N NaOH, and derivatization with phenylisothiocyanate.

Sulfonated molecules that bind a partially structured species of beta2-microglobulin also influence refolding and fibrillogenesis.

Human beta2-microglobulin (beta2-m) is a small amyloidogenic protein responsible for dialysis-related amyloidosis, which represents a severe complication of long-term hemodialysis. A therapeutic approach for this amyloidosis could be based on the stabilization of beta2-m through the binding to a small molecule, to possibly inhibit protein misfolding and amyloid fibril formation. The search of a strong ligand of this protein is extremely challenging: by using CE in affinity and refolding experiments we study the effect that previously selected sulfonated molecules have on the equilibrium between the native form and an ensemble of conformers populating the slow phase of beta2-m folding.

Integrated analytical strategies for the study of phosphorylation and glycosylation in proteins.

The post-translational modification (PTM) of proteins is a common biological mechanism for regulating protein localization, function, and turnover. The direct analysis of modifications is required because they are not coded by genes, and thus are not predictable. Different MS-based proteomic strategies are used for the analysis of PTMs, such as phosphorylation and glycosylation, and are composed of a structural simplification step of the protein followed by specific isolation step to extract the classes of modified peptides (also called "sub-proteomes") before mass spectrometry.

Development of an integrated chromatographic system for on-line digestion and characterization of phosphorylated proteins.

The development of an integrated chromatographic system for complete phosphoprotein analysis is described. The digestion of phosphoproteins with trypsin- or pronase-based monolithic bioreactors is carried out on-line with selective enrichment on a TiO(2) trap and separation of the produced phosphopeptides by reversed-phase liquid chromatography-multiple mass spectrometry (RPLC/MS(n)). A detailed study on the selective extraction of peptides with different degrees of phosphorylation on TiO(2) cartridges is discussed.

Determination of the threshold odor concentration of main odorants in essential oils using gas chromatography-olfactometry incremental dilution technique.

An essential oil, obtained by steam distillation of Clinopodium tomentosum (Kunth) Govaerts (Lamiaceae), collected in Ecuador, was analyzed by gas chromatography-olfactometry (GC-O) and GC-MS techniques. To our knowledge, the composition of this essential oil is described here for the first time, both from the chemical and olfactometric viewpoints. A preliminary analysis by GC-MS and using Kovats' retention indexes, lead to characterize and quantify the oil constituents, while GC-O was then applied for the identification of the main odorants.

Development and integration of an immunoaffinity monolithic disk for the on-line solid-phase extraction and HPLC determination with fluorescence detection of aflatoxin B1 in aqueous solutions.

The development and characterization of an anti-aflatoxin B1 (anti-AFB1) immunoaffinity monolithic disk is reported. Polyclonal anti-AFB1 was covalently immobilized in batch on an epoxy-activated monolithic Convective Interaction Media (CIM) disk (12 mm x 3 mm i.d.

Pronase-immobilized enzyme reactor: an approach for automation in glycoprotein analysis by LC/LC-ESI/MSn.

An automated analytical approach is proposed for simultaneous characterization of glycan and peptide moieties in pronase-generated glycopeptides. The proposed method is based on the use of a new pronase-immobilized enzyme reactor for the on-line rapid digestion of the target glycoprotein. By coupling the bioreactor to a Hypercarb chromatographic trap column, on-line selective glycopeptide enrichment prior to normal-phase liquid chromatography-mass spectrometry was obtained.

Trypsin-based monolithic bioreactor coupled on-line with LC/MS/MS system for protein digestion and variant identification in standard solutions and serum samples.

The applicability of a trypsin-based monolithic bioreactor coupled on-line with LC/MS/MS for rapid proteolytic digestion and protein identification is here described. Dilute samples are passed through the bioreactor for generation of proteolytic fragments in less than 10 min. After digestion and peptide separation, electrospray ionization tandem mass spectrometry is used to generate a peptide map and to identify proteolytic peptides by correlating their fragmentation spectra with amino acid sequences from a protein database.

Capillary electrophoresis studies on the aggregation process of beta-amyloid 1-42 and 1-40 peptides.

The possibility to monitor, in solution, the steps of beta-amyloid (Abeta) nucleation and therefore to describe this dynamic process by using capillary electrophoresis and under optimized experimental conditions is described. Striking differences in the electrophoretic patterns of Abeta 1-42 and Abeta 1-40 over time are here shown, and different aggregation states are elucidated, which reflect the very diverse oligomerization behavior of two very similar peptides. The isolation of one aggregated species of high molecular weight by ultracentrifugation allowed us to assess its role as toxic oligomer.