Chromatography-electron Spray Ionization-mass Spectrometry Research Articles

Development and validation of HPLC-DAD and LC-(ESI)/MS methods for the determination of sulfasalazine, mesalazine and hydrocortisone 21-acetate in tablets and rectal suppositories: In vitro and ex vivo permeability studies

Controlled-release tablets and rectal suppositories of sulfasalazine (SLF) and hydrocortisone 21-acetate (HA) were prepared as recommended dosage forms for the treatment of acute episodes of ulcerative colitis, in patients who do not respond to monotherapy.A High-Performance Liquid Chromatography (HPLC) Diode-array method with a gradient elution mobile phase was developed to evaluate the production quality of both formulations (assay and dissolution profiles in gastric and intestinal fluids). Method's validation was carried out providing good linearity (r ≥ 0.9995), precision (RSD < 1.53%), recovery (96.9% − 103.7%) and limits of detection (LODSLF = 12 ng/mL, LODHA = 15 ng/mL). Experimental design and Plackett-Burman methodology was constructed to study the robustness of the analysis. In all composite substrates, a freezing lipid precipitation approach was used as purification step. The method was optimized by applying Central Composite design mode.The in-vitro/ex-vivo permeability studies of both formulations were evaluated by a Liquid Chromatography-Electron Spray Ionization Mass Spectrometry (LC-ESI/MS) +/- mode. The analysis of sulfamethazine (internal standard, SLM, m/z 279), HA (m/z 449, [M + HCOO]-), SLF (m/z 399) and its active metabolite mesalazine (MSL, m/z 154) was performed using a C18 column and gradient elution. The validation of the method met the requirements of the International Council for Harmonization (ICH) (r ≥ 0.9997, RSD ≤ 4.62%, Recovery > 95%, LODSLF = 1.28 ng/mL, LODHA = 1.07 ng/mL, LODMSL = 3.16 ng/mL). Based on the results, important conclusions were drawn concerning the role of excipients and SLF metabolism.

Characterization of anthocyanin from red sorghum (Sorghum bicolor) bran by liquid chromatography-electron spray ionization mass spectrometry analysis.

In the present study, anthocyanin pigments from red sorghum (Sorghum bicolor) bran were identified and characterized by Liquid Chromatography-Electron Spray Ionization Mass Spectrometry. The individual anthocyanins were identified by comparing their mass spectrometric data and retention times, published data. 3-deoxyanthocyanidins and methyl 3-deoxyanthocyanidins were identified in red sorghum bran. This paper presents complete LCMS profile and MS spectrometric data of red sorghum bran.

Antibacterial activity of Nepalese wild mushrooms against Staphylococcus aureus and Propionibacterium acnes

The present study aims to reveal the antibacterial potential of the wild mushrooms of Nepal. Despite the recognition of the medicinal potential of the natural resources in this country, a systematic study on the bioactivities of the wild mushrooms is still lacking. Therefore, in an attempt to fill this gap, ethanol extracts of 90 Nepalese wild mushroom samples were tested for antibacterial activity against Staphylococcus aureus and Propionibacterium acnes. Staphylococcus aureus was comparatively more susceptible with Inonotus clemensiae exhibiting the least minimum bactericidal concentration (MBC) of 100 μg/mL. The major compound in I. clemensiae was identified to be hispidin using high resolution liquid chromatography–electron spray ionization mass spectrometry (LC–ESI-MS) and nuclear magnetic resonance (NMR) analyses. Furthermore, the minimum inhibitory concentration (MIC) and MBC values of hispidin were determined to be 25 and 100 µg/mL for S. aureus and P. acnes, respectively. These findings show that the Nepalese wild mushrooms have the potential to be a novel addition to the functional ingredients industry due to their strong antibacterial potential.

Boronic acid-functionalized detonation nanodiamond for specific enrichment of glycopeptides in glycoproteome analysis

Here we present the novel functionalization of detonation nanodiamond (dND) with amino-phenyl boronic acid (APBA) assisted by poly-L-lysine (PL) and PEG-diglycolic acid (PEG) (dND-p-APBA). With the assistance of biocompatible poly-L-lysine and PEG, dND-p-APBA particles show good dispersibility in aqueous solution and plentiful boronic acid functional groups on the surface, which make it a novel material promising for glycoproteome. The dND-p-APBA particles demonstrate highly specific and efficient capture of glycopeptides from complex samples. In comparison with direct (or traditional) analysis, the novel method shows better specificity for glycopeptides even when non-glycopeptides are 40 times more than glycopeptides. Besides that, the detection sensitivity of glycopeptides could be increased 50 times by the novel strategy. Additionally, the recovery of glycopeptides is up to 72.2% and the glycopeptides even can be sensitively specifically enriched and detected in the presence of 1 M sodium chloride or 0.1% sodium dodecyl sulfate. Furthermore, in combination with liquid chromatography electronspray ionization mass spectrometry (LC-ESI-MS), the novel approach was successfully applied to characterize one fraction of mouse liver, in which 40 different N-glycosylation peptides within 34 unique glycoproteins have been identified. Accordingly, the usefulness of the functionalized dND might be a promising efficient and specific analytical platform in glycoproteome analysis.

Quantitative Determination of Ticlopidine Hydrochloride in Human Plasma by High-performance Liquid Chromatography-Electronspray Ionization Mass Spectrometry

A sensitive, selective and simple high performance liquid chromatographyelectrospray ionization-mass spectrometry (HPLC-ESI-MS) was developed and validated for the quantification of ticlopidine hydrochloride (CAS 53885-35-1) in human plasma using loratadine (CAS 79794-75-5) as internal standard (IS). Following liquid-liquid extraction, the analyte and the IS were extracted from plasma samples by n-hexane:isopropanol (95:5, v/v), separated by HPLC on a commercially available column (150 mm x 2.0 mm ID, 5 microm) with a mobile phase of acetonitrile: 10 mmol/L ammonium acetate buffer solution (85:15, v/v) and analyzed on a quadrupole mass spectrometer with ESI interface operating in the positive-ion mode. The correlation coefficient of the calibration curve was linear (r2 > 0.99) over the concentration range of 1-1000 ng/mL for ticlopidine hydrochloride. The intra- and inter-batch precisions were less than 15% of the relative standard deviation and the accuracy ranged from 85 to 115% in terms of percent accuracy. The limit of detection (LOD) of ticlopidine hydrochloride was 0.5 ng/mL. The extraction recovery of ticlopidine hydrochloride was more than 80%. The proposed method enables the unambiguous identification and quantification of ticlopidine hydrochloride for pharmacokinetic, bioavailability or bioequivalence studies.