Analytical Investigation of the Profile of Human Chorionic Gonadotropin in Highly Purified Human Menopausal Gonadotrophin Preparations.

Highly purified human menopausal gonadotropin (HP-hMG [Menopur, Ferring Pharmaceuticals, Saint-Prex, Switzerland]) contains a 1:1 ratio of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). This analysis aimed to assess gonadotropin (FSH, LH and hCG) abundance in HP-hMG and clarify the source of hCG by assessing the presence of sulfated glycans, which are diagnostic for pituitary hCG forms due to their distinct glycosylation patterns. Additionally, the purity of each sample, their specific components, and their oxidation levels were assessed.

Characterization by LC-MS/MS of oxidized products identified in synthetic peptide somatostatin and cetrorelix submitted to forced oxidative stress by hydrogen peroxide: Two case studies.

In a broader scenario, the forced degradation studies provided by the ICH guidelines for Q1A, Q1B, and Q2B degradation studies allow to know the CQA of the molecule used as a drug product, to determine the appropriate analytical methods, excipients, and storage conditions ensuring the quality of the drug, its efficacy, and patient safety. In this study, we focused our attention on understanding how oxidative stress is performed by H O -impacted small synthetic peptides that do not contain residues susceptible to oxidation such as methionine. Among the amino acids susceptible to oxidation, methionine is the most reactive and depending on the structure of the protein where it is exposed, it tends to oxidize by converting into methionine sulfone or methionine sulfoxide by oxidation of its sulfur atom.

Capillary methacrylate-based monoliths by grafting from/to γ-ray polymerization on a tentacle-type reactive surface for the liquid chromatographic separations of small molecules and intact proteins.

Capillary methacrylate-based monoliths were prepared for the high performance liquid chromatography (HPLC) separation of both small molecules and large biomolecules. An efficient grafting from/to synthetic approach was adopted introducing a network of activated sites in the inner wall surface using the new silanization agent (N-trimethoxysilylpropyl)-polyethylenimine. Copolymerization of lauryl methacrylate monomer and 1,6-hexanediol dimethacrylate cross-linker in the presence of porogenic solvents was obtained under continuous γ-ray exposure with high conversion yield.

Separation of intact proteins on γ-ray-induced polymethacrylate monolithic columns: A highly permeable stationary phase with high peak capacity for capillary high-performance liquid chromatography with high-resolution mass spectrometry.

Polymethacrylate-based monolithic capillary columns, prepared by γ-radiation-induced polymerization, were used to optimize the experimental conditions (nature of the organic modifiers, the content of trifluoroacetic acid and the column temperature) in the separation of nine standard proteins with different hydrophobicities and a wide range of molecular weights. Because of the excellent permeability of the monolithic columns, an ion-pair reversed-phase capillary liquid chromatography with high-resolution mass spectrometry method has been developed by coupling the column directly to the mass spectrometer without a flow-split and using a standard electrospray interface. Additionally, the high working flow and concomitant high efficiency of these columns allowed us to employ a longer column (up to 50 cm) and achieve a peak capacity value superior to 1000.

Revealing the fine details of functionalized silica surfaces by solid-state NMR and adsorption isotherm measurements: the case of fluorinated stationary phases for liquid chromatography.

The structural and chromatographic characterization of two novel fluorinated mesoporous materials prepared by covalent reaction of 3-(pentafluorophenyl)propyldimethylchlorosilane and perfluorohexylethyltrichlorosilane with 2.5 μm fully porous silica particles is reported. The adsorbents were characterized by solid state (29)Si, (13)C, and (19)F NMR spectroscopy, low-temperature nitrogen adsorption, elemental analysis (C and F), and various chromatographic measurements, including the determination of adsorption isotherms.

Analysis of bovine milk caseins on organic monolithic columns: an integrated capillary liquid chromatography-high resolution mass spectrometry approach for the study of time-dependent casein degradation.

Casein proteins constitute approximately 80% of the proteins present in bovine milk and account for many of its nutritional and technological properties. The analysis of the casein fraction in commercially available pasteurized milk and the study of its time-dependent degradation is of considerable interest in the agro-food industry. Here we present new analytical methods for the study of caseins in fresh and expired bovine milk, based on the use of lab-made capillary organic monolithic columns.

Efficient organic monoliths prepared by γ-radiation induced polymerization in the evaluation of histone deacetylase inhibitors by capillary(nano)-high performance liquid chromatography and ion trap mass spectrometry.

New monolithic HPLC columns were prepared by γ-radiation-triggered polymerization of hexyl methacrylate and ethylene glycol dimethacrylate monomers in the presence of porogenic solvents. Polymerization was carried out directly within capillary (250-200 μm I.D.

Stereolability of dihydroartemisinin, an antimalarial drug: a comprehensive kinetic investigation. Part 2.

Artemisinin or qinghaosu has now largely given way to the more potent dihydroartemisinin (DHA, 1) and its derivatives in the treatment of drug-resistant malaria, in combination with other classical antimalarial drugs. DHA is obtained by NaBH(4) reduction of artemisinin and contains a stereochemically labile center at C-10, which provided two lactol hemiacetal interconverting epimers, namely 1α and 1β. In the solid state, the drug consists exclusively of the β-epimer; however, upon dissolution, the two epimers equilibrate, reaching different solvent-dependent ratios with different rates.

Stereolability of dihydroartemisinin, an antimalarial drug: a comprehensive thermodynamic investigation. Part 1.

Artemisinin (Qinghaosu, 1) is a sesquiterpene lactone endoperoxide isolated from Artemisia annua L. that Chinese herbalists have traditionally used to treat malaria. Reduction of artemisinin by NaBH(4) produced dihydroartemisinin (DHA, 2) and yielded a new stereochemically labile center at C-10, which in turn provided two lactol hemiacetal interconverting epimers, namely, 2α and 2β.

Analysis of aluminium content and iron homeostasis in nipple aspirate fluids from healthy women and breast cancer-affected patients.

Aluminium is not a physiological component of the breast but has been measured recently in human breast tissues and breast cyst fluids at levels above those found in blood serum or milk. Since the presence of aluminium can lead to iron dyshomeostasis, levels of aluminium and iron-binding proteins (ferritin, transferrin) were measured in nipple aspirate fluid (NAF), a fluid present in the breast duct tree and mirroring the breast microenvironment. NAFs were collected noninvasively from healthy women (NoCancer; n = 16) and breast cancer-affected women (Cancer; n = 19), and compared with levels in serum (n = 15) and milk (n = 45) from healthy subjects.

Iron-binding proteins and C-reactive protein in Nipple Aspirate Fluids: role of Iron-driven inflammation in breast cancer microenvironment?

Breast cancer, a worldwide disease with increasing incidence, develops from ductal/lobular epithelium. Nipple aspirate fluid (NAF), secreted from the breast ducts and lobules, can be analyzed to assess metabolic activity in breast microenvironment. Premalignant and malignant cell alterations may produce biochemical signals that deliver inflammatory proteins to the site.

Hybrid polyacrylamide chiral stationary phases for HPLC prepared by surface-initiated photopolymerization.

Two hybrid polyacrylamide chiral stationary phases (CSPs) for HPLC have been synthesized by a new surface-initiated photo-induced radical polymerization approach of enantiopure N,N'-diacryloyl derivatives of (1R,2R)-diaminocyclohexane (CSP1) and (1R,2R)-diphenylethylenediamine (CSP2). This system is based on the activation of mesoporous silica microparticles by chemically bonded trichloroacetyl groups and dimanganese decacarbonyl as catalyst. UV irradiation was performed using a lab-made quartz photochemical reactor, ad hoc designed for the photo-induced polymerization process on the surface of microparticles.

Detection of superoxide dismutase-1 in nipple aspirate fluids: a reactive oxygen species-regulating enzyme in the breast cancer microenvironment.

Introduction: Analysis of nipple aspirate fluid (NAF) allows the noninvasive identification of both cellular and biomolecular markers of human breast cancer, the most common female malignancy in developed countries. Cytosolic superoxide dismutase (SOD-1) represents a detoxifying enzyme able to regulate the balance between oncogenic and oncosuppressor reactive oxygen species.

Patients And Methods: We analyzed SOD-1 expression in 126 NAF samples collected from 67 women with and 59 without breast cancer, using enzyme-linked immunosorbent assay, immunoprecipitation, Western blotting, and immunocytochemistry.

Transition from enantioselective high performance to ultra-high performance liquid chromatography: A case study of a brush-type chiral stationary phase based on sub-5-micron to sub-2-micron silica particles.

Three brush-type chiral stationary phases (CSPs) differing in the particle size of the starting silica particles have been prepared by covalent grafting of the pi-acidic bis-(3,5-dinitrobenzoyl)-derivative of trans-1,2-diaminocyclohexane (DACH-DNB). Starting silica particles of 4.3, 2.

On-column epimerization of dihydroartemisinin: an effective analytical approach to overcome the shortcomings of the International Pharmacopoeia monograph.

We developed a cryo-HPLC/UV method for the simultaneous determination of artemisinin (1), alpha-dihydroartemisinin (2alpha), beta-dihydroartemisinin (2beta), and a ubiquitous thermal decomposition product of 2 (designated as diketoaldehyde, 3), starting from the International Pharmacopoeia monograph on dihydroartemisinin. The method takes for the first time the on-column epimerization process of 2 into consideration. Chromatographic separation was obtained under reversed-phase conditions on a Symmetry C18 column (3.