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A sensitive and specific high-performance liquid chromatography–tandem mass spectrometry (LC-MS/MS) method was developed for the determination of Grayanotoxin I (GTX I) and Grayanotoxin III (GTX III) in rat whole blood. Grayanotoxins (GTXs) and clindamycin as internal standard (IS) were extracted from rat blood via solid-phase extraction using PEP solid-phase extraction cartridges. Chromatographic separation of the analytes was achieved on a Kinetex C18 (100 × 2.1 mm, 2.6 µm) reversed-phase column using a gradient elution with the mobile phase of 1% acetic acid in water and methanol at a flow rate of 0.2 mL/min. Electrospray ionization mass spectrometry was operated in the positive ion mode with multiple reaction monitoring. The calibration curves obtained were linear over the concentration range of 1–100 ng/mL with a lower limit of quantification of 1 ng/mL for GTXs. The relative standard deviation of intra-day and inter-day precision was below 6.8% and accuracy ranged from 94.8 to 106.6%. The analytes were stable in the stability studies. The validated method was successfully applied to the quantification and toxicokinetic study of GTXs in rats for the first time after oral administration of 11.52 mg/kg mad honey and 0.35 mg/kg GTX III, respectively. Copyright © 2014 John Wiley & Sons, Ltd.

The ERETIC (Electronic REference To access In vivo Concentrations)2 method is a new qNMR experimental technique to measure analytes based on the signal of the reference compound without additional hardware equipment. In this study, ERETIC 2 method was validated, and we sought to identify whether it would be possible to apply this method to a specific compound analysis of metabolites in plant. The 90° pulse value (P1) and spin -lattice relaxation time ( T 1 ) of each compound were measured for ERETIC 2. The 9 1 H of 3-(trimethylsilyl) propionic -2,2,3,3 -d 4 acid (TSP) was used as a reference peak for ERETIC 2, and then, a suitable solvent and pulse sequence for each compound were selected. Under the NOESY -presat sequence, the relative accuracy e rror for quantitative analyses of primary metabolites was within the range of 5%, with the exception of glucose, which showed • 5% error due to saturation. It showed excellent results for the quantification of glucose by using a 30° pulse sequence, which did not suppress the water peak. In addition, the qua ntitative accuracy for secondary metabolites was extremely accurate, with DQ HUURU ” ZKHQ FRQVLGHULQJ WKH SXULW\ RI WKHstandard sample. The ERETIC 2 method showed outstanding linearity, precision, and accuracy. Keywords qNMR, ERETIC , quantification Introduction Nuclear magnetic resonance (NMR) is a qualitative and quantitative analytical technique. It is the only physical method used routinely that can provide quantitative valuable information at the molecular level. Therefore NMR has found various a pplications in other fields than chemistry, such as metabolomics methodology

Endocrine disrupting chemicals (EDC) are defined as environmental compounds that may result in adverse health problems such as cancer proliferaition and metastasis in humans. Benzophenone-1 (2,4-dihydroxybenzophenone, BP-1) and nonyl-phenol (NP) are known as typical EDCs. They are discharged from numerous industrial products including plastics, pesticides, drugs, detergents, and cosmetics. In this study, we examined the effect of BP-1 and NP on the growth of MCF-7 human breast cancer cells expressing oestrogen receptors (ER) in comparison with E2 to assess their risk in cancer progression. In cell viability assay, BP-1 (10–5, 10–6, and 10–7 M) and NP (10–6 and 10–7 M) were determined to induce the proliferation of MCF-7 cells as well as E2 (10–9 M) was compared to a negative control treated with DMSO (P

Two new guaianolides, 4alpha,10alpha-dihydroxy-1beta(H),5beta(H)-guai-11(13)-en-8alpha,12-olide (2) and 4beta,10beta-dihydroxy-5alpha(H)-1,11(13)-guaidien-8alpha,12-olide (3), from Carpesium macrocephalum were isolated, and their structures were elucidated on the basis of spectroscopic studies.

A simple assay method of recombinant human epidermal growth factor (rhEGF) in a pharmaceutical preparation was studied and validated by capillary electrophoresis (CE) using micellar electrokinetic chromatography (MEKC) techniques. Factors affecting the migration behavior and separation performances of the peptide; type of buffer, pH, buffer concentration, and concentration of sodium dodecyl sulfates (SDS) were investigated to optimize the analytical performance. CE was performed using running buffer, 50.0 mM borate (pH 8.5) containing 12.5 mM SDS at 20 kV of the applied voltage. Calibration curves for the rhEGF showed good linearity (r>0.999) over the wide dynamic range from 1.25 to 100 microg/ml. Sample analysis was performed by using standard addition method to eliminate the matrix effects of dosage vehicle. This method is assumed to be useful for quality control (QC) of various forms of pharmaceutical products of the peptide.

A novel HPLC method with electrochemical detection has been developed for the determination of recombinant human epidermal growth factor (rhEGF) in pharmaceutical products. rhEGF was separated from other components in formulation on a reversed-phase C18 column with 24% acetonitrile in 0.1 M phosphate buffer (pH 4.75). The optimum electrochemical oxidation of EGF was obtained at 0.85 V vs. Ag/AgCl in a glassy carbon working electrode due to electroactive tyrosine, tryptophan, methionine, and arginine residues. The quantitation range was from 1.0 to 200 ng of rhEGF with the linear correlation coefficient greater than 0.999. The method was successfully applied for the quantitation of rhEGF in a pharmaceutical preparation.

It has been shown that oestrogen (E2) up-regulated the expression of components of insulin-like growth factor-1 (IGF-1) signaling pathway and induced the downstream of mitogenic signaling cascades via phosphorylation of insulin receptor substrate-1 (IRS-1). An interaction between oestrogen receptor (ER) and IGF-1 receptor (IGF-1R) signaling pathway plays an important role in proliferation of and resistance to endocrine therapy to oestrogen-dependent cancers (i.e. breast and endometrial cancers). In the present study, we evaluated xenoestrogenic effect of bisphenol A (BPA) and antiproliferative activity of genistein (GEN) in accordance with the influence on this crosstalk. The gene expressions in mRNA and protein levels were examined by semiquantitative RT-PCR and Western blot analysis, in which the primers for ERα, IGF-1R, and GAPDH and the antibodies against pIRS-1, pAkt, and GAPDH were used, respectively. Total RNA and protein samples were isolated from BG-1 cells treated with dimethyl sulfoxide (DMSO), estradiol (E2; 10–9 M), BPA (10–5 M), E2 (10–9 M) + GEN (10–4 M), and BPA (10–5 M) + GEN (10–4 M). The DMSO was used a vehicle of E2, BPA, and GEN in in vitro experiments. All in vitro experiments were done in triplicates. The effects on tumour growth and immunohistologic alterations were identified in in vivo mouse models. The mice were injected subcutaneously with corn oil (vehicle, n = 6), E2 (n = 6), BPA (n = 6), E2+GEN (n = 6), and BPA+GEN (n = 6) for 8 weeks. The BPA treatment resulted in up-regulation of ERα and IGF-1R mRNA, and induced phosphorylation of IRS-1 and Akt proteins compared with a control (DMSO) in BG-1 ovarian cancer cells as E2 did in triplicates. In the mouse model xenografted with BG-1 cells, BPA significantly increased a tumour burden of mice and expressions of ERα, pIRS-1, and cyclin D1 in tumour mass compared with the vehicle (corn oil), indicating that BPA induces ovarian cancer growth by promoting the crosstalk between ER and IGF-1R signals. On the other hand, GEN effectively reversed estrogenicity of BPA by reversing mRNA and protein expressions of ERα, IGF-1R, pIRS-1, and pAkt induced by BPA in cellular model with triplicates. The GEN also significantly decreased tumour growth and in vivo expressions of ERα, pIRS-1, and pAkt in a xenografted mouse model. Also, GEN was confirmed to have an antiproliferative effect by inducing apoptotic signaling cascades. Taken together, these results suggest that GEN effectively reversed the increased proliferation of BG-1 ovarian cancer by suppressing the crosstalk between ER and IGF-1R signaling pathways up-regulated by BPA or E2. This work was supported by a grant from the Next-Generation BioGreen 21 Program (No. PJ009599), Rural Development Administration, Republic of Korea.