Presence Of Fatty Acid Esters Research Articles

Headspace solid-phase microextraction and on-fiber derivatization for the determination of 3-/2-MCPDE and GE in breast milk and infant formula by gas chromatography tandem mass spectrometry

The presence of fatty acid esters of 3-monochloropropane-1,2-diol (3-MCPDE), 2-monochloropropane-1,3-diol (2-MCPDE) and glycidyl (GE) in foods is a potential concern due to their toxicity, especially for infants. This study proposed a rapid, sensitive and environmentally friendly method for simultaneous determination of the 3-/2-MCPDE and GE in breast milk and infant formula using headspace solid-phase microextraction (SPME) and on-fiber derivatization combined with gas chromatography-tandem mass spectrometry (GC-MS/MS). The approach proved high sensitivity with detection limits of 0.10 μg/L and 0.15 μg/kg for MCPDEs in breast milk and infant formula, respectively. Mean recoveries were obtained ranging from 79.9 to 111.2% for breast milk and from 82.1 to 106.7% for infant formula, with relative standard deviation (RSD) of less than 9.5%. According to the levels of 3-MCPDE and GE determined in 30 breast milk and 23 infant formulas, the exposure to 3-MCPDE and GE may pose a potential health risk for infants from birth to <12 months fed by breast milk and infants from birth to 6 months fed by infant formula.

Hydrothermal liquefaction of spent coffee grounds followed by biocatalytic upgradation to produce biofuel: a circular economy approach

Hydrothermal liquefaction (HTL) of wet spent coffee grounds was performed in a batch reactor for bioenergy production. The effects of spent coffee grounds to water ratio, temperature and reactor volume occupation on product yield were investigated. A maximum 19.1 wt% bio-oil yield with HHV of 38.5 MJ/kg was obtained from wet spent coffee grounds. Subsequently, the bio-oil synthesized via hydrothermal liquefaction was upgraded biocatalytically to bring down the acid value and to convert the bio-oil into a higher quality liquid biofuel. During this process the fatty acids present in the bio-oil were converted into fatty acid methyl esters (biodiesel) using lipase. Novozyme-435 converted ∼ 85% of fatty acids in the bio-oil into fatty acid methyl esters at 35 °C after 14 h, as determined by 1H NMR. In addition, FTIR analysis confirmed the presence of fatty acid esters in the product. The acid number of the bio-oil decreased significantly after the enzymatic reaction. The results shows that lipase is an effective biocatalyst for crude bio-oil upgradation.

Crude extract of the tropical tree Gallesia integrifolia (Phytolaccaceae) for the control of Aedes aegypti (Diptera: Culicidae) larvae

Introduction: Phytoinsecticides are alternatives to control insects in different stages, Gallesia integrifolia (Spreng.) Harms, Phytolacaceae family, popularly known as pau d'alho, garlic tree, and guararema in Brazil, is known due to its strong alliaceous odor because of the presence of sulfur molecules in the plant. This species presents biological activity and potential insecticide effect that is still unexploited. Objective: This study aimed to evaluate the biological activity of the ethanolic crude extract from G. integrifolia leaves, flowers, and fruits on the control of Aedes aegypti third-stage larvae and pupae. Methods: The botanical material was collected in city Umuarama, Paraná, Brazil at the coordinates (23º46’16” S &amp; 53º19’38” WO), and altitude of 442 m, the fruits of G. integrifolia were collected in May and the leaves and flowers in December 2017. The crude extracts of G. integrifolia leaves, flowers, and fruits were prepared by dynamic maceration technique. The chemical composition of the extracts was determined by gas chromatography coupled to a mass spectrometry. The insecticidal activity of the crude extracts of G. integrifolia were carried out on larvae and pupae of A. aegypti in concentrations between 0.001 to 25 000 mg/mL, and afterwards the lethal concentrations that kill 50 % (LC50) and 99.9 % (LC99.9) were determined by probit analysis. Anticholinesterase activity was determined by bioautographic method at concentrations from 0.000095 to 50 mg/mL. Results: The yield of G. integrifolia crude extracts were 8.2, 9.1, and 17.3 % for flowers, fruits, and leaves, respectively. The chemical composition of G. integrifolia extracts was characterized by presence of fatty acid esters, phytosterols, vitamins, oxygenated diterpenes and organosulfur compounds. The flower extract presented the high amount of sulfur compounds (20.2 %) such as disulfide, bis (2-sulfhydryl ethyl) (11.9 %), 2,3,5-trithiahexane (6.2 %), 1,2,4-trithiolane (1.1 %), and 2,4-dithiapentane (1.1 %). Regarding the insecticidal activity, flower extract showed highly active with LC99.9 of 0.032 mg/mL and LC99.9 of 0.969 mg/mL on A. aegypti larvae and pupae, respectively, and the highest inhibition of acetylcholinesterase enzyme (0.00019 mg/mL) ex situ. The flower extract presented anticholinesterase and larvicide activity, respectively, 12.8 % and 35.6 % greater than the control temephos. Conclusions: This study opens new perspectives on the use of extracts from G. integrifolia as a bioinsecticide alternative for the control of A. aegypti larvae and pupae.

Sedative, hypothermic, anxiolytic effects and rapid radical scavenging property of aqueous leaf extract of Vitex doniana (Lamiaceae) in mice

Vitex doniana is used ethnomedicinally for the management of madness, insanity, and epilepsy. This study was undertaken to evaluate the sedative, hypothermic and anxiolytic effects of crude aqueous leaf extract of Vitex doniana (AVD) in mice, as well as its rapid radical scavenging property. Doses of 250, 500, and 1000 mg/kg AVD were adopted for the pharmacological testing in mice of both sexes (n=6). The behavioural effects of the extract in the open field apparatus were determined. AVD was evaluated for its anxiolytic effect, using elevated T- maze, staircase, and hole-board models. While the sedative and hypothermic effects of the extract in mice were determined by assessments of ketamine-induced sleeping time and rectal temperature respectively. AVD was subjected to rapid radical scavenging test using thin-layer chromatography (TLC)-bioautography. The results showed AVD to have an inhibitory effect on CNS in the open field test. AVD demonstrated anxiolytic effect at 250 mg/kg, and sedative effect at 500 and 1000 mg/kg. The sedative effect of AVD at 500 and 1000 mg/kg was further revealed in ketamine-induced sleeping time and rectal temperature. AVD also showed strong free radical scavenging property attributed to the presence of fatty acid esters, terpenes, phenolics, and phenolic glycosides. AVD is acutely non-toxic and it possesses significant sedative, hypothermic and anxiolytic effects, which could in part be due to the presence of rapid free radical scavenging compounds, thus, providing pharmacological justification for its ethnomedicinal uses as a curative for madness and insanity.

Evaluation of Chlorella Minutissima Oil for Biodiesel Production

Abstract Present work is an attempt to focus on screening of microalgae chlorella minutissima, extraction of oil, and conversion of oil into biodiesel. The experimental results are supported by scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDX), high-performance liquid chromatography (HPLC), and gas chromatography-mass spectrometry (GC-MS) analytical techniques. The SEM/EDX results indicate microalgae contain several elements that are required for lipid metabolism, e.g., calcium, magnesium, iron, potassium, and nitrogen. HPLC analysis of hexane extracted oil shows the presence of 74.27 % of free fatty acids, 10.65 % of fatty acid esters, and 13.74 % triglycerides, besides unidentified component 1.34 %. These results are in close agreement with the high acid value of the oil. The presence of fatty acid esters in the oil were also confirmed by GC-MS analysis. Under optimized conditions, of acid catalyzed transesterification &amp;gt;97 % conversion of microalgae oil into FAME is observed. The studies indicate that lower reaction time is favorable for conversion to FAMEs. However, for the purpose of biodiesel feedstock, any increase in the lipid content of the algae will improve the efficiency of the process.

Comparison of indirect and direct quantification of esters of monochloropropanediol in vegetable oil

The presence of fatty acid esters of monochloropropanediol (MEs) in food is a recent concern raised due to the carcinogenicity of their hydrolysable moieties 2- and 3-monochloropropanediol (2- and 3-MCPD). Several indirect methods for the quantification of MEs have been developed and are commonly in use until today, however significant discrepancies among analytical results obtained are challenging their reliability. The aim of the present study was therefore to test the trueness of an indirect method by comparing it to a newly developed direct method using palm oil and palm olein as examples. The indirect method was based on ester cleavage under acidic conditions, derivatization of the liberated 2- and 3-MCPD with heptafluorobutyryl imidazole and GC–MS determination. The direct method was comprised of two extraction procedures targeting 2-and 3-MCPD mono esters (co-extracting as well glycidyl esters) by the use of double solid phase extraction (SPE), and 2- and 3-MCPD di-esters by the use of silica gel column, respectively. Detection was carried out by liquid chromatography coupled to time of flight mass spectrometry (LC–ToF-MS). Accurate quantification of the intact compounds was assured by means of matrix matched standard addition on extracts. Analysis of 22 palm oil and 7 palm olein samples (2- plus 3-MCPD contamination ranged from 0.3 to 8.8μg/g) by both methods revealed no significant bias. Both methods were therefore considered as comparable in terms of results; however the indirect method was shown to require less analytical standards, being less tedious and furthermore applicable to all type of different vegetable oils and hence recommended for routine application.

Structural diversity of dietary fatty esters of chloropropanols and related substances

AbstractRecently the presence of fatty acid esters of 3‐mono‐chloro‐1,2‐propanediol (3‐MCPD esters) has been reported in various types of foods and food ingredients, especially in refined vegetable oils. Although no evidence is available indicating any adverse effects, the safety significance of these substances in food is difficult to appreciate because of the lack of data. In addition, it is increasingly acknowledged that the safety of chloropropanol‐esters in food cannot be established through the consideration of 3‐MCPD esters in isolation. These chemicals are formed over processing together with other structurally related and toxicologically relevant molecules. Risk assessment has to consider all of them. This triggers significant analytical and toxicological challenges. Setting priorities, such as on precautionary mitigation, is likely to be necessary.

Fatty acid esters of chloropropanols and related compounds in food: Toxicological aspects

AbstractThe presence of fatty acid esters of 3‐monochloro‐1,2‐propanediol (3‐MCPD esters) has been reported in various types of foods and food ingredients, especially in refined vegetable oils. More recently, it has been acknowledged that 3‐MCPD esters are formed during processing together with a number of other structurally related and toxicologically relevant chemicals such as 2‐monochloro‐1,3‐propanol esters (2‐MCPD esters) and glycidyl esters. Although no evidence is available of any adverse effects of dietary exposure to these esters, the actual human health significance of these compounds is difficult to appreciate due to the lack of toxicological and exposure data. An indirect concern has been raised by the potential release of free chloropropanols (e.g., 3‐MCPD, 2‐MCPD) and glycidol resulting from the action of lipases, which may hydrolyze the esters in the gut.

C 35-apocarotenoids in the yellow mutant Neurospora crassa YLO

The Neurospora crassa mutant YLO exhibits a yellow phenotype instead of the red-orange pigmentation of the wild type. Recently, it was shown that the mutant YLO is defective in a specific aldehyde dehydrogenase which catalyses the last step of carotenogenesis to the formation of neurosporaxanthin [Estrada, A.F., Youssar, L., Scherzinger, D., Al-Babili, S., Avalos, J., 2008. The ylo-1 gene encodes an aldehyde dehydrogenase responsible for the last reaction in the Neurospora carotenoid pathway. Mol. Microbiol. 69, 1207–1220]. Since different carotenoid compositions between wild type and YLO have been reported in earlier publications, the carotenoids of YLO were analyzed and unknown carotenoids identified. Fractionation of carotenoid extracts from YLO revealed in the less polar fraction two major carotenoids of low polarity which were found only in trace amounts in the wild type. Both carotenoids could be hydrolyzed with KOH to more polar products indicating the presence of fatty acid esters. The fatty acid moiety was identified as myristic acid by gas chromatography. Optical and mass spectra as well as co-chromatography with a synthesized authentic standard identified the free alcohols as 4′-apolycopene-4′-ol and 4′-apo-γ-carotene-4′-ol which assigns the dominating carotenoids in the YLO mutant as 4′-apolycopene-4′-myristate and 4′-apo-γ-carotene-4′-myristate. We can attribute the accumulation of these two carotenoids in YLO to the substantial mutation of the neurosporaxanthin-forming aldehyde dehydrogenase. However, the aldehyde intermediates 4′-apo-γ-carotene-4′-al and 4′-apo-lycopene-4′-al do not accumulate substantially but are reduced instead to the corresponding alcohols, 4′-apolycopene-4′-ol and 4′-apo-γ-carotene-4′-ol, and both further esterified with mainly myristic acid yielding 4′-apolycopene-4′-myristate and 4′-apo-γ-carotene-4′-myristate.

Raman Spectra of Proteinaceous Materials Used in Paintings: A Multivariate Analytical Approach for Classification and Identification

This work presents Raman spectra obtained from thin films of protein materials which are commonly used as binding media in painted works of art. Spectra were recorded over the spectral range of 3250-250 cm(-1), using an excitation wavelength of 785 nm, and several bands have been identified in the fingerprint region that correspond to the various proteins examined. Differences in the C-H vibrations located between 3200 and 2700 cm(-1) can be accounted for with reference to the amino acid composition of the protein-based binding media as well as the presence of fatty acid esters, in the case of egg yolk. In addition, the discrimination of different proteins on the basis of variations in spectra between 3200 and 2700 cm(-1) can be achieved following multivariate analysis of a large data set of spectra, providing a novel and nondestructive alternative based on Raman spectroscopy to other methods commonly used for the analysis of proteins.

Relationship between chlorophyll a and β-carotene in a lipid-containing model system during illumination

The relationship between chlorophyll a (Chl a) and β-carotene during illumination in the presence of fatty acid esters, methyl stearate methyl oleate and methyl linoleate was studied. Mixtures of Chl a, β-carotene and fatty acid esters were exposed to a 40 w light for 3 h. Isomerization and degradation reations of Chl a and β-carotene were monitored using HPLC with diode array detection Three isomers of Chl a and four cis isomers of β-carotene were separated and detected. Both the degradations of total amount of Chl a and β-carotene fit the first-order model. The degradation rate of total amount of β-carotene was highest in methyl stearate, followed by in methyl oleate and in methyl linoleate, while a reverse order was observed for the degradation rate of total amount of Chl a. In the presence of three fatty acid esters, Chl a is more susceptible to isomerization and degradation than β-carotene, and the degradation rates for both Chl a and β-carotene are significantly different ( p < 0.05).

Relationship between chlorophyll a and β-carotene in a lipid-containing model system during heating

The relationship between chlorophyll a (Chl a) and β-carotene during heating in the presence of fatty acid esters, methyl stearate, methyl oleate and methyl linoleate, was studied. Mixtures of Chl a, β-carotene and fatty acid esters were heated at 60°C and 120°C for varied lengths of time. Isomerization and degradation reactions of Chl a and β-carotene were monitored using HPLC with diode array detection. Three isomers of Chl a and four cis isomers of β-carotene were detected. Both the degradations of total amounts of Chl a and β-carotene during heating fit the first-order model. The degradation rates of total amounts of Chl a and β-carotene were highest in methyl stearate, followed by in methyl oleate and methyl linoleate. In the presence of fatty acid esters Chl a is more susceptible to isomerization and degradation than β-carotene during heating.

Preparation of mixed esters of starch or use of an external plasticizer: two different ways to change the properties of starch acetate films

In view of the brittleness of acetylated starch-based materials, we investigated the possibility of obtaining internal plasticization of such products by preparing mixed esters of starch with both acetate groups and fatty-acid ester chains. We prepared such compounds and determined their compositions by use of quantitative solid-state NMR. The method detailed in this work is not usually used in the area of modified polysaccharides. The presence of fatty-acid esters is shown to decrease the glass transition temperature. External plasticization of starch acetate by triacetin is also studied. A wide range of polymer-plasticizer compositions was investigated, and the variation of glass transition temperature is found to follow a Couchman law. The mechanical behaviour of mixed esters is also investigated. The introduction of fatty-acid esters is shown to depress the glass transition temperature and the α relaxation associated with the glass transition, corresponding to a plasticizing effect. The introduction of these substituents is shown to suppress the β relaxation, corresponding to a local antiplasticizing effect. However, the strength modulus of mixed esters remains almost unchanged compared to that of starch acetate, and the materials remain brittle in spite of internal plasticization. This is due to a decrease of glass transition temperature, which is not sufficient to produce a soft material. In contrast, external plasticization resulted in an increased flexibility, when sufficient amounts of plasticizer were used.

Evidence of extensive phospholipid fatty acid methylation during the assumed selective methylation of plasma free fatty acids by diazomethane

We compared a conventional method (Method I) for measuring plasma free fatty acid (FFA) concentrations with two more rapid procedures (Method II and Method III). Method I required total lipid extraction, separation of FFA by thin-layer chromatography, methylation, and gas-liquid chromatographic analysis of the fatty acid (FA) methyl esters. Method II was a colorimetric procedure. Method III relied upon diazomethane's presumed ability to selectively methylate FFA even in the presence of FA esters. The three methods were compared using plasma from fasted and from fed nude mice, tumor-bearing mice (MX-1 and ZR-75-1 human mammary carcinomas), and controls. Method II, was less reliable than Method I, but both gave similar mean values for plasma FFA levels in fasted mice. Both Methods I and II also showed similar lowering of plasma FFA levels after feeding previously fasted mice. Method III consistently gave values that were far greater than those obtained using Methods I and II. Moreover, highly significant differences between fasted and fed mice were obscured by direct methylation of plasma FFA with diazomethane (Method III). The excess FA methyl esters formed in Method III were derived from plasma phospholipids, but not from plasma triacylglycerols. After feeding fasted mice, plasma free palmitic acid and oleic acid levels fell (Method I); by contrast, the excess "FFA" formed by methylation of plasma phospholipid FA increased two-fold and fourteen-fold, respectively. Caution is therefore advised in the use of direct methylating agents when measuring total and individual plasma FFA levels.

Presence of fatty acid esters of pregnenolone in follicular fluid from women undergoing follicle stimulation

In the following investigation the presence of lipoidal pregnenolone derivatives in the preovulatory follicular fluid obtained from women undergoing in vitro fertilization was established. Concentrations of lipoidal pregnenolone proved to be at least twofold greater than those of the unconjugated counterpart. Indirect identification of these lipoidal pregnenolone derivatives was achieved by comparing the C-18 column, thin-layer silica gel (TLC), high performance liquid chromatography (HPLC), and gas chromatography/mass spectrometry (GC/MS) Chromatographic properties of the endogenous lipoidal pregnenolone derivatives in follicular fluid with those of synthetic acyl pregnenolone esters. Lipoidal pregnenolone derivatives recovered after HPLC subfractionation were treated with alkali to hydrolyze the acyl group thus liberating non-conjugated pregnenolone. Concentrations of this steroid were then measured using radioimmunoassay upon which analysis of HPLC and gas chromatograms permitted the calculation of the individual pregnenolone ester contributions within the samples. Five lipoidal pregnenolone derivatives constituted more than 90% of the total lipoidal pregnenolone concentration observed, these derivatives being: pregnenolone oleate (30.7%), linoleate (20.7%), palmitate (20.1%), linolenate (14.8%), and palmitoleate (7.1%).