The electrochemical and statistical evaluation of isolation of mellitin and apamin from honey bee (Apis Mellifera) venom.

We present in this manuscript for the first time the electrochemical and statistical evaluation of FPLC isolation of mellitin and apamin from honey bee (Apis mellifera) venom. Venoms are extremely complex blends of diverse substances that target a myriad of receptors or ion channels. Therefore, toxins, isolated from venomous organisms can be a valuable tool with diverse biological applications. In this study we decided to optimize the purification of honey bee venom by using fast protein liquid chromatography, to obtain biologically active peptide - melittin (2846.46 Da). Due to a presence of other compounds with similar molecular weight (apamin 2027.34 Da), we optimized a differential pulse voltammetry method with adsorptive transfer technique (AdT DPV), utilizing Brdicka supporting electrolyte for measurements. Typical voltammograms - fingerprints for each substance were obtained and numerical projections of voltammograms were employed to propose an artificial neural network. Our suggested neural network can simply predict the content of each peptide in fraction with following performance: 100 % for training and 100 % for testing

Biogenic amines and hygienic quality of lucerne silage

This experiment examined the influence of two different silage additives of biological (Lactococcus lactis, Lactobacillus plantarum, Enterococcus faecium, enzyme xylanase) and chemical (43% formic acid, 30% ammonium formate, 10% propionic acid, 2% benzoic acid) types on biogenic amines concentration, nutrient content, fermentation process, and microbiologic indicators in lucerne (Medicago sativa) silage after 90 days of fermentation. The biological additive significantly (P < 0.05) increased putrescine (+51%), lactic acid (+11%) and protein content (+11%) in comparison with control silage. It significantly decreased cadaverine (−29%), histamine (−57%), spermidine (−15%), spermine (−55%), acetic acid (−40%), ethanol (−55%), ammonium (−25%) and ash (−9%). After the chemical-additive treatment, greater amounts of histamine and tyramine were recorded. Significant decrease was observed in the concentrations of putrescine (−18%), cadaverine (−55%), spermidine (−47%), spermine (−45%), lactic acid (−16%), acetic acid (−46%), ammonium (−59%), ash (−13%) and fat (−24%). Populations of bacteria associated with lactic acid fermentation, moulds, yeasts, enterobacteria and total microorganisms count were also influenced. Both biological and chemical additives can be highly recommended for producing high-quality silages meeting hygienic requirements. In lucerne silage, the chemical preservative showed a stronger effect in achieving the health safety of silage compared to the biological inoculant

Flow Injection Analysis with Electrochemical Detection for Rapid Identification of Platinum-Based Cytostatics and Platinum Chlorides in Water

Platinum-based cytostatics, such as cisplatin, carboplatin or oxaliplatin are widely used agents in the treatment of various types of tumors. Large amounts of these drugs are excreted through the urine of patients into wastewaters in unmetabolised forms. This phenomenon leads to increased amounts of platinum ions in the water environment. The impacts of these pollutants on the water ecosystem are not sufficiently investigated as well as their content in water sources. In order to facilitate the detection of various types of platinum, we have developed a new, rapid, screening flow injection analysis method with electrochemical detection (FIA-ED). Our method, based on monitoring of the changes in electrochemical behavior of analytes, maintained by various pH buffers (Britton-Robinson and phosphate buffer) and potential changes (1,000, 1,100 and 1,200 mV) offers rapid and cheap selective determination of platinum-based cytostatics and platinum chlorides, which can also be present as contaminants in water environments

Ion Exchange Chromatography and Mass Spectrometric Methods for Analysis of Cadmium-Phytochelatin (II) Complexes

In this study, in vitro formed Cd-phytochelatin (PC2) complexes were characterized using ion exchange chromatography (IEC) and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. The ratio of both studied compounds as well as experimental conditions were optimized. The highest yield of the complex was observed under an applied concentration of 100 µg·mL−1 PC2 and 100 µg·mL−1 of CdCl2. The data obtained show that IEC in combination with MALDI-TOF is a reliable and fast method for the determination of these complexes

The free radical contents in <i>E</i>. <i>fetida</i> immediately after the termination of the test.

<p>The error bars indicate standard deviations. The asterisks indicate significant differences (<i>p</i><0.05) compared with the control groups.</p

Schematic depiction of E₂ metabolites.

<p>The E₂ ratios to (<b>A</b>) 4-OHE₂ and (<b>B</b>) the final metabolite (E₂)-3,4-Q represents the conversions over time. In control samples, no E₂, 4-OHE₂ or (E₂)-3,4-Q was found. To evaluate the conversion ratios, the following mass weights were utilized: [E₂ + H]⁺<i>m/z</i> 273.38 Da, [4-OHE₂ + H]⁺<i>m/z</i> 289.38 Da and [(E₂)-3,4-Q + H]⁺ at <i>m/z</i> 287.36 Da. The values are presented as the means of three independent replicates (<i>n</i> = 3). The vertical bars indicate standard error.</p

Examination of <i>E</i>. <i>fetida</i> cross sections after E₂ exposure.

<p>H&E-stained cross sections of <i>E</i>. <i>fetida</i> exposed to E₂ (100 μg/L), collected in the (<b>A</b>) 0^th (control), (<b>B</b>) 1^st, (<b>C</b>) 3^rd, (<b>D</b>) 5^th and (<b>E</b>) 8^th weeks of the experiment. The collected individuals were scanned (<b>a</b>) and employed for the MALDI-IMS analysis of (<b>b</b>) the final metabolites of E₂—[(E₂)-3,4-Q + H]⁺ at <i>m/z</i> 287.36 Da ± 0.05%, (<b>c</b>) [PC₂ and PC₃+ H]⁺ merge at <i>m/z</i> 541.61 Da ± 0.05% (red) and 773.91 Da ± 0.05% (green), respectively, (<b>d</b>) [GSSG + H]⁺ at <i>m/z</i> 613.64 Da ± 0.05% and (<b>e</b>) [MT₁ + H]⁺ at <i>m/z</i> 4798.00 Da ± 0.05% (red) and [MT₂ + H]⁺ at m/z 7412.01 Da (green). Matrix HCCA was used. The following conditions were used to acquire the MALDI spectra: 500 shots per raster spot, 45% laser energy and 50-μm spatial resolution. The length of scale bar is 500 μm.</p

The levels of antioxidant molecules in <i>E</i>. <i>fetida</i> after exposure to E₂ (0–100 μg/L).

<p>(<b>A</b>) The levels of metallothionein, determined using DPV. (<b>B</b>) The ratio between GSH and GSSG, determined using HPLC-ED. The antioxidant molecules were analysed in the 1^st; 3^rd; 5^th and 8^th weeks of the experiment. The values are presented as the means of three independent replicates (<i>n</i> = 3). The vertical bars indicate standard errors. The asterisks indicate significant differences (<i>p</i>.05) compared with the control groups.</p

Determination of GPx activity after exposure to E2 (0–100 μg/kg).

<p>The enzymatic activity was examined in the 1^st; 3^rd; 5^th and 8^th weeks of the experiment. The values are presented as the means of three independent replicates (<i>n</i> = 3). The vertical bars indicate the standard error. The asterisks indicate significant differences (<i>p</i> < .05) compared with the control groups.</p