Amounts Of Fatty Acid Esters Research Articles

Individual Scent-Marks of Nest Entrances in the Solitary Bee, Osmia cornuta (Hymenoptera: Apoidea).

Simple SummaryOsmia cornuta is a solitary mason bee that uses natural pre-existing cavities, such as beetle worm traces or hollow plant stalks, for nest construction. Such nesting opportunities can often be found pretty close to each other, leading to dense aggregations of many nesting bees. Therefore, it is crucial for females returning from collecting flights to localize their own nests’ entrance among many other similar-looking holes. Individual scent marks of entrances were suspected to be used by bees as olfactory cues additional to visual orientation. We used paper sleeves introduced in the nest entrances to identify the substances involved in marking and compared the composition with secretions of the Dufour’s gland and substances present on the body surface. Although the nest marks were found to be ample diverse, tags did not perfectly render individual odor bouquets nor did bees possess private chemicals. Instead, females used an individual mixture of body-derived substances enriched by external components to produce distinguishable tags that alter over time. The smell of the own nest has to be learned continuously by the resident female as a template to identify her own nest at the next arrival from a provision flight.The ability to recognize the own nest is a basic skill in nest constructing solitary bees. Osmia cornuta females use a dual mechanism of visual orientation to approach a nest and olfactory verification of the tube when entering it. Occupied tubular cavities were steadily marked by the resident female. Nest marking substances originate from Dufour’s gland and cuticle, enriched by external volatiles. Scent tags were dominated by alkanes and alkenes in a species-specific mixture enriched by small amounts of fatty acid esters, alcohols, and aldehydes. The individual nest tags are sufficiently variable but do not match perfectly with the nesting female. Furthermore, tags are not consistent over time, although females continue in marking. Besides the correct position of the entrance in space, bees have to learn also the bouquet of the used cavity and update their internal template at each visit to recognize their own nest by its actual smell. Due to the dominance of the species-specific hydrocarbon pattern, nest marks may function not only as an occupied sign but may also provide information on the species affiliation and constitution of the nest owner.

Assessment of changes in blood plasma biochemical indices at hypercholesterol diet with a high fat load

Introduction. It was studied the lipid composition of the blood plasma of rats under the impact of a hyper cholesterol diet with a high fat load. It was carried out the prevention of disturbances in blood plasma biochemical parameters with a lipid complex from the tunic of the marine hydrobiont Halocynthia aurantium. Materials and methods. The experiment was carried outwith outbred male rats weighing 200 ± 3 g.The experimental model of a hyper cholesterol diet with a high fat load with the development of dyslipidemia was set up by feeding the animals with ahigh fat diet consisting of 2% cholesterol and 20% beef fat from the total diet. The animals were divided into the following groups of 10 rats each: group 1 - control (standard diet), group 2 - dyslipidemia (hypercholesterol diet with high fat load), group 3 - dyslipidemia + lipid complex from ascidia. Results. It was shown that the influence of the diet was accompanied by an increase in the amount of total lipids in the blood plasma of rats, cholesterol, low-density lipoproteins (LDL), as well as a decrease in total phospholipids and high-density lipoproteins (HDL), which is considered as an indicator of the formation of dyslipidemia. The contents of phospholipid lysofractions increased due to the activation of phospholipases. The amount of fatty acid esters and cholesterol esters decreased, which indicates the inhibition of esterification processes. The imbalance in the phospholipid spectrum of blood plasma occurred: the amount of metabolically active fractions required for the functioning of membrane-bound enzymes decreased. The addition of a lipid complex from the tunic of ascidian purple into the diet was accompanied by a pronounced prophylactic effect, which manifested itself in the normalization of the studied biochemical parameters. The lipid complex containing a wide range of “sea” phospholipids and polynonsaturated fatty acids of the n-3 type is an important basis for application as prophylactic in the conditions of a hypercholesterol diet with a high-fat load. Conclusion. Application of the lipidic complexes containing the “sea” lipids allocated from a tunic of the ascidian purple can be useful and perspective at a dislipidemiya and a hypercholesterolemia that will allow to carry out effective prevention of violations of metabolic reactions at influence of hyper high-calorie food.

Evaluation of indigenous non-Saccharomyces cider yeasts for use in brewing

The non-Saccharomyces yeasts represent a great richness for the production of new and different types of beers. In this study, the role of eight yeast strains (Saccharomycodes ludwigii, Metchnikowia pulcherrima, Hanseniaspora uvarum, Hanseniaspora osmophila and Brettanomyces bruxellensis) isolated from Asturian cider and belonging to five unconventional species was evaluated. None of the strains could ferment the main wort sugars (maltose and maltotriose). Beers produced by S. ludwigii strains showed the highest ethanol content (21.6 g/L) and interestingly high levels of fusel alcohols, fatty esters and isoamyl acetate. Strains of B. bruxellensis were the only ones that produced ethyl phenols and they also generated the highest concentration of fatty acids and their ethyl esters. Sucrose was not utilised by Metschnikowia and Hanseniaspora strains, resulting in low ethanol formation (4.7 g/L), although these yeasts differed in terms of their synthesis of volatile compounds. Larger amounts of fatty acid esters were detected in beers fermented by H. osmophyla 10, while H. uvarum 62 produced more 2-phenylethyl acetate and ethyl acetate. M. pulcherrima 301 stands out for its low fermentative capacity and production of volatile compounds. These results show the interest of non-Saccharomyces strains in the production of beers with low alcohol content and their potential use in developing new beer styles in sequential or mixed inoculations with S. cerevisiae strains.

Fatty acid esters of glycidol in refined fats and oils

AbstractDiscrepancies in the analysis of 3‐chloropropane‐1,2‐diol (3‐MCPD) esters can be explained by the hypothesis that in some refined oils significant amounts of fatty acid esters of glycidol (glycidyl esters) are present in addition to 3‐MCPD esters. Glycidyl esters were separated from triacylglycerols by gel permeation chromatography (GPC) and detected by gas chromatography‐mass spectrometry (GC‐MS). Six samples of palm oil and palm oil‐based fats were analyzed by GPC and GC‐MS. In chromatograms of all samples, significant peaks, retention time and mass spectra in conformity with self‐synthesized glycidyl palmitate and glycidyl oleate were detectable. Quantification of individual glycidyl esters was not possible because of a lack of pure standards. Concentration of ester‐bound glycidol in different samples of fats and oils was estimated using an indirect difference method. Glycidyl esters could be detected only in refined, but not in crude or native, fats and oils. The highest concentrations were detected in palm oil and palm oil‐based fats. In a palm oil sample, glycidyl ester concentration varied according to different deodorization parameters, temperature, and time, while 3‐MCPD ester concentration was relatively constant, indicating that mitigation of glycidyl esters possibly may be achieved by optimizing refining parameters.

In vitro metabolism of beclomethasone dipropionate, budesonide, ciclesonide, and fluticasone propionate in human lung precision-cut tissue slices

BackgroundThe therapeutic effect of inhaled corticosteroids (ICS) may be affected by the metabolism of the drug in the target organ. We investigated the in vitro metabolism of beclomethasone dipropionate (BDP), budesonide (BUD), ciclesonide (CIC), and fluticasone propionate (FP) in human lung precision-cut tissue slices. CIC, a new generation ICS, is hydrolyzed by esterases in the upper and lower airways to its pharmacologically active metabolite desisobutyryl-ciclesonide (des-CIC).MethodsLung tissue slices were incubated with BDP, BUD, CIC, and FP (initial target concentration of 25 μM) for 2, 6, and 24 h. Cellular viability was assessed using adenosine 5'-triphosphate content and protein synthesis in lung slices. Metabolites and remaining parent compounds in the tissue samples were analyzed by HPLC with UV detection.ResultsBDP was hydrolyzed to the pharmacologically active metabolite beclomethasone-17-monopropionate (BMP) and, predominantly, to inactive beclomethasone (BOH). CIC was hydrolyzed initially to des-CIC with a slower rate compared to BDP. A distinctly smaller amount (approximately 10-fold less) of fatty acid esters were formed by BMP (and/or BOH) than by BUD or des-CIC. The highest relative amounts of fatty acid esters were detected for BUD. For FP, no metabolites were detected at any time point. The amount of drug-related material in lung tissue (based on initial concentrations) at 24 h was highest for CIC, followed by BUD and FP; the smallest amount was detected for BDP.ConclusionThe in vitro metabolic pathways of the tested ICS in human lung tissue were differing. While FP was metabolically stable, the majority of BDP was converted to inactive polar metabolites. The formation of fatty acid conjugates was confirmed for BMP (and/or BOH), BUD, and des-CIC.

On-line Extraction−Reaction of Canola Oil with Ethanol by Immobilized Lipase in SC-CO2

On-line extraction−reaction was carried out in supercritical carbon dioxide (SC-CO2) in the temperature range from 308 to 328 K and the pressure range from 24 to 35 MPa. Fatty acid ethyl esters were synthesized from extracted canola oil with ethanol by using the immobilized lipase (Lipozyme IM). The effects of ethanol amount, enzyme load, and operational conditions on the amount of fatty acid esters (FAE), free fatty acids (FFA), and mono-, di-, and triglycerides (MG, DG, and TG, respectively) present in the product were investigated. The results show that it is possible to synthesize fatty acid ethyl esters efficiently at high temperature. Finally, a new process operating at different extractor and reactor temperatures was proposed.

Quantitative and non-destructive analyses of fatty acid esters and cholesterol in brain tissues by Fourier transform infrared spectroscopy

Brain tissues obtained from rats were examined with Fourier transform infrared spectroscopy using a beam condenser apparatus to determine quantitatively and non-destructively the amount of fatty acid esters and cholesterol in the small specimens. For the analysis of fatty acid esters we calculated the ratio between the peak intensities of the fatty ester C  O (1730 cm −1) or methylene CH (2850 cm −1) stretches and amide II band (1550 cm −1), and compared it with the amount of fatty acid esters per mg protein determined chemically by a routine method. For analysis of cholesterol we measured the second derivative spectra between 1300 and 1400 cm −1 and the intensity of a band at 1366 cm −1 in the second derivative spectrum was compared with that of the amide II band in the normal absorption spectrum. This infrared analysis of cholesterol was compared and showed good correlations with the chemically defined data. These results suggest that the infrared technique can provide non-destructively quantitative data for the content of fatty acid esters and cholesterol in biological tissues.

Performance of a high-sensitivity chromatographic argon lonization system as determined by calibration with a pulse technique using a solid sample injector

The response of a small argon detector to varied amounts of fatty acid esters injected onto GLC columns is examined. In the field intensified current region, the ionization current increase of the detector is strictly linear with the concentration of the solute moving through the cell up to a generated peak height current of about 3 nA (Tables 1 and 2, as well as Figure 2). Small quantities of substances with homologous structures and of similar size give rise to current responses that correspond to their molar concentrations. Larger solute concentrations elicit a detector response following an exponential saturation function, as had become previously evident in a steady-state calibration study with propane-argon gas mixtures. A procedure for converting the present peak to the prior established time-invariant detector responses is out-lined. We thus demonstrated that the response for argon detectors, deduced from measurements of varying concentrations of propane, is also applicable to peak currents resulting from slug-injections of high-boiling solutes onto standard GLC columns.