Inhibition of ache by malathion and some structuraly similar compounds

Inhibition of bovine serum acetylcholinesterase by in vitro exposure to malathion, malaoxon, isomalathion and diethyl maleate was investigated to elucidate the mechanism of the enzyme interaction with structurally similar organophosphorus compounds. IC50 (half maximum inhibitory concentrations) were determined by Hill analysis of experimentally obtained inhibition curves. The values (2.87 ± 0.24)x10-6 M, (2.65±0.61)x10-6M, (3.01±0.36)x10-4 M and (5.69 ±0.7)x10-2 M were obtained for malaoxon, isomalathion, malathion and their hydrolysis product diethyl maleate, respectively. The relationship between the structure of the compounds and their potency to inhibit the enzyme activity was discussed.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Supercritical Carbon Dioxide Extraction of Four Medicinal Mediterranean Plants: Investigation of Chemical Composition and Antioxidant Activity

With everyday advances in the field of pharmaceuticals, medicinal plants have high priority regarding the introduction of novel synthetic compounds by the usage of environmentally friendly extraction technologies. Herein, a supercritical CO2 extraction method was implemented in the analysis of four plants (chamomile, St. John’s wort, yarrow, and curry plant) after which the non-targeted analysis of the chemical composition, phenolic content, and antioxidant activity was evaluated. The extraction yield was the highest for the chamomile (5%), while moderate yields were obtained for the other three plants. The chemical composition analyzed by gas chromatographyhigh-resolution mass spectrometry (GC-HRMS) and liquid chromatography- high-resolution mass spectrometry (LC-HRMS) demonstrated extraction of diverse compounds including terpenes and terpenoids, fatty acids, flavonoids and coumarins, functionalized phytosterols, and polyphenols. Voltammetry of microfilm immobilized on a glassy carbon electrode using square-wave voltammetry (SWV) was applied in the analysis of extracts. It was found that antioxidant activity obtained by SWV correlates well to 1, 1-diphenyl-2-picrylhidrazine (DPPH) radical assay (R2 = 0.818) and ferric reducing antioxidant power (FRAP) assay (R2 = 0.640), but not to the total phenolic content (R2 = 0.092). Effective results were obtained in terms of activity showing the potential usage of supercritical CO2 extraction to acquire bioactive compounds of interest

Simply applicable method for microplastics determination in environmental samples

Microplastics (MPs) have gained significant attention in the last two decades and have been widely researched in the marine environment. There are, however, less studies on their presence, routes of entry, and impacts on the biota in the soil environment. One of the main issues in the study of MPs is a lack of standardized methods for their identification in environmental samples. Currently the most commonly used techniques are thermal desorption gas chromatography–mass spectrom etry (GC–MS) methods and pyrolysis followed by GC–MS. In this study, headspace-solid phase microextraction followed by GC–MS is proposed as a simple and widely applicable method for the de termination of commonly present polymer MPs (polyethylene terephthalate, polystyrene, polyvinyl chloride, polyethylene, and polypropylene) in environmental samples, for analytical laboratories with basic equipment worldwide. The proposed method is based on the identification of compounds, which are formed during the well-controlled melting process of specific coarse (1–5 mm) and fine fraction (1 mm–100 µm) MPs. The method was upgraded for the identification of individual polymer type in blends and in complex environmental matrices (soil and algae biomass). The successful application of the method in complex matrices makes it especially suitable for widescale use

Impact of varying degrees of powdery mildew infection (<em>Uncinula necator</em> (Schwein.) Burrill) on the volatile compounds of Chardonnay grapes, must and wine

Aims: The aims of this study are (i) to trace the major components responsible for the unpleasant mushroom, earthy and geranium odour in the transformation from grapes to wine in response to powdery mildew infection intensities, (ii) to determine the impact of an aggressive infection on volatile compounds in grapes and wine, and (iii) to determine their effect on the olfactory-taste evaluation of the resulting Chardonnay wine. Methods and results: A GC-MS technique was used to investigate the impacts of different degrees of oidium infections (0, 10, 50 and 100% of infected grapes) on the presence of volatiles in grapes, musts and wines. The number of volatiles was higher in oidium-infected grapes than in noninfected grapes, especially for terpenes, aldehydes and alcohols, with 1-octen-3-ol, 2-octen-1-ol, 2-heptanol and 2-octenal, the volatiles reminiscent of mushroom-, geranium-, and earthy-like odours, being detected in oidiuminfected grapes only. After overnight clarification, 1-octen-3-ol and 2-heptanol but also methyl-2-furoate were the only mushroom reminiscent volatiles detected in the musts. The infection also caused higher amounts of acetic acid, furfural and some of its derivates (2,5-furandicarboxaldehyde, 5-hydroxymethyl furfural, furaneol), most ethyl esters (except ethyl caprylate), 1-hexanol, maltol and 1-decanol in musts. After alcoholic fermentation the number of esters in young wines increased, whereas that of aldehydes decreased, especially in the wines produced from severely infected grapes. Though it was not detected by sensory analysis, we assume that the intensification of the odours reminiscent of pineapple, banana and coconut in the aged wines produced from infected grapes was likely a consequence of the increased amount of esters. Conclusion: Powdery mildew infection statistically decreased the freshness but enhanced the malty, sweet mouthfeel of Chardonnay wine, and neither the mushroom odour nor taste were perceived, which contradict some previously published findings. Significance and impact of the study: This study gives an answer to the significant problem of wine production from oidium-infected grapes. It reports for the first time the traceability of volatiles highly related to mushroom, earthy and geranium odours from the Chardonnay grapes to the wines. The overnight must clarification decreased the impacts of unpleasant volatiles on must and wine odour. This suggested that the oidium infection of the grapes does not necessarily hinder the production of wine, as no unpleasant odour could be sensory evaluated, not even in the wines made from highly infected grapes