Chemical Profile of Lipophilic Fractions of Different Parts of Zizyphus lotus L. by GC-MS and Evaluation of Their Antiproliferative and Antibacterial Activities.

Zizyphus lotus L. is a perennial shrub particularly used in Algerian folk medicine, but little is known concerning the lipophilic compounds in the most frequently used parts, namely, root bark, pulp, leaves and seeds, which are associated with health benefits. In this vein, the lipophilic fractions of these morphological parts of Z. lotus from Morocco were studied by gas chromatography-mass spectrometry (GC-MS), and their antiproliferative and antimicrobial activities were evaluated. GC-MS analysis allowed the identification and quantification of 99 lipophilic compounds, including fatty acids, long-chain aliphatic alcohols, pentacyclic triterpenic compounds, sterols, monoglycerides, aromatic compounds and other minor components. Lipophilic extracts of pulp, leaves and seeds were revealed to be mainly composed of fatty acids, representing 54.3-88.6% of the total compounds detected. The leaves and seeds were particularly rich in unsaturated fatty acids, namely, (9Z,12Z)-octadeca-9,12-dienoic acid (2431 mg kg-1 of dry weight) and (9Z)-octadec-9-enoic acid (6255 mg kg-1 of dry weight). In contrast, root bark contained a high content of pentacyclic triterpenic compounds, particularly betulinic acid, accounting for 9838 mg kg-1 of dry weight. Root bark extract showed promising antiproliferative activity against a triple-negative breast cancer cell line, MDA-MB-231, with a half-maximal inhibitory concentration (IC50) = 4.23 ± 0.18 µg mL-1 of extract. Leaf extract displayed interesting antimicrobial activity against Escherichia coli, methicillin-sensitive Staphylococcus aureus and Staphylococcus epidermis, presenting minimum inhibitory concentration (MIC) values from 1024 to 2048 µg mL-1 of extract. Our results demonstrate that Zizyphus lotus L. is a source of promising bioactive components, which can be exploited as natural ingredients in pharmaceutical formulations.

Characterization of Glucuronosyl-diacyl/monoacylglycerols and Discovery of Their Acylated Derivatives in Tomato Lipid Extracts by Reversed-Phase Liquid Chromatography with Electrospray Ionization and Tandem Mass Spectrometry.

Glucuronic acid containing diacylglycerols (3-(O-α-d-glucuronopyranosyl)-1,2-diacyl-sn-glycerols, GlcA-DAG) are glycolipids of plant membranes especially formed under phosphate-depletion conditions. An analytical approach for the structural characterization of GlcA-DAG in red ripe tomato (Solanum lycopersicum L.) extracts, based on reversed-phase liquid chromatography (RPLC) coupled with electrospray ionization (ESI) and tandem mass spectrometry (MS/MS) using a linear ion trap, is described in this paper. At least 14 GlcA-DAG (R1/R2) species, including four regioisomers, containing three predominant fatty acyl chains C16:0, C18:2, and C18:3, were identified for the first time. Moreover, 29 GlcA-DAG acylated on the glucuronosyl ring (acyl-R3 GlcA-DAG) were discovered, alongside 15 acylated lyso-forms, i.e., acylated 3-(O-α-d-glucuronosyl)monoacylglycerols, abbreviated as acyl-R3 GlcA-MAG (R1/0) or (0/R2). Although many of these acylated lyso-forms were isomeric with GlcA-DAG (i.e., acyl chains with equivalent sum composition), they were successfully separated by reversed-phase liquid chromatography (RPLC) using a solid-core C18 column packed with 2.6 µm particle size. Tandem MS (and eventually MS3) data obtained from sodium adducts ([M + Na]+) and deprotonated molecules ([M - H]-) were fundamental to detect diagnostic product ions related to the glucuronosyl ring and then determine the identity of all investigated glycolipids, especially to recognize the acyl chain linked to the ring. A classification of GlcA-MAG, GlcA-DAG, and acylated GlcA-DAG and GlcA-MAG was generated by an in house-built database. The discovery of acylated derivatives emphasized the already surprising heterogeneity of glucuronic acid-containing mono- and diacylglycerols in tomato plants, stimulating interesting questions on the role played by these glycolipids.

Unveiling the bioactivity of Allium triquetrum L. lipophilic fractions: chemical characterization and in vitro antibacterial activity against methicillin-resistant Staphylococcus aureus.

The lipophilic composition of Allium triquetrum L. bulbs, flowers and leaves was studied for the first time by GC-MS. Sixty compounds were firstly identified in A. triquetrum L. Fatty acids represented the major lipophilic family among the studied extracts, with (9Z,12Z,15Z)-octadeca-9,12,15-trienoic and (9Z,12Z)-octadeca-9,12-dienoic acids being the major constituents of this family. A long chain aliphatic ketone, namely hentriacontan-16-one, was mainly found in flowers and leaves. Flowers and leaves were also found to be rich in long chain aliphatic alkanes and alcohols, respectively. Sterols, monoglycerides, aromatic compounds and long chain aliphatic aldehydes were found in lower amounts. The antibacterial activity of A. triquetrum bulb, flower and leaf extracts against methicillin-resistant Staphylococcus aureus (MRSA) growth was in vitro assessed. Bulb and flower extracts showed significant MRSA growth inhibition. Overall, these valuable findings can contribute to the valorization of A. triquetrum L. as a source of value-added phytochemicals, specifically as antibacterial agents and for nutraceutical applications.

Prediction of oxidative stability in bulk oils using dielectric constant changes.

The effects of amphiphilic compounds on the dielectric constant of bulk oils were determined and the utility of the dielectric constant as a reliable parameter for predicting the oxidative stability of edible oils was evaluated. As the content of monoacylglycerols (MAGs), lecithin, and moisture increased, the dielectric constant of modified corn oil increased at different rates, whereas the addition of free fatty acids, including oleic and linoleic acid, decreased the dielectric constant of modified corn oil. Unoxidized fresh bulk oils showed a wide range of dielectric constants, from 8 for canola oils to 33 for flaxseed oils. The dielectric constant showed a strong correlation with the percentage of unsaturated fatty acids in the bulk oils. Oils with low oxidative stability had a high dielectric constant. Overall, the dielectric constant of bulk oils is strongly correlated with the content of amphiphilic compounds, moisture content, and degree of unsaturation of fatty acids.

Monoacylglycerol and diacylglycerol production by hydrolysis of refined vegetable oil by-products using an immobilized lipase from Serratia sp. W3.

Unlike the synthetic surfactants, mono- and diacylglycerols have the advantage to be biodegradable and non-toxic. In the present work, the hydrolysis of lipid fraction by-products of refined vegetable oils was performed by Serratia sp. W3 lipase immobilized on CaCO3 by combined adsorption and precipitation. This support was selected out of four carriers as it exhibited the finest activity support (950 U/g) and the most satisfactory behavior at use. The immobilized preparation with CaCO3 was stable and active in the whole range of pH (4 to 9) and temperature (37 to 55°C), yielding a 75% degree of hydrolysis at optimal environmental conditions of pH 8.5 and temperature 55°C. Thin-layer chromatography, gas chromatography, and liquid chromatography methods were evaluated to determine the analytical characterization of hydrolysis products. For monoacylglycerols and diacylglycerol fractions identified in the samples, a novel approach by liquid chromatography method was employed, through a homemade linear retention index database and a dedicated software. The adopted approach allowed the use of basic instrumentation set-ups, without the need of sophisticated detectors, such as mass spectrometers. Thus, it could be an effective alternative to produce emulsifiers from cheap vegetable oils.

Production of FAME and FAEE via Alcoholysis of Sunflower Oil by Eversa Lipases Immobilized on Hydrophobic Supports.

The performance of two new commercial low-cost lipases Eversa® Transform and Eversa® Transform 2.0 immobilized in different supports was investigated. The two lipases were adsorbed on four different hydrophobic supports. Interesting results were obtained for both lipases and for the four supports. However, the most active derivative was prepared by immobilization of Eversa® Transform 2.0 on Sepabeads C-18. Ninety-nine percent of fatty acid ethyl ester was obtained, in 3 h at 40 °C, by using hexane as solvent, a molar ratio of 4:1 (ethanol/oil), and 10 wt% of immobilized biocatalyst. The final reaction mixture contained traces of monoacylglycerols but was completely free of diacylglycerols. After four reaction cycles, the immobilized biocatalyst preserved 75% of activity. Both lipases immobilized in Sepabeads C-18 were very active with ethanol and methanol as acceptors, but they were much more stable in the presence of ethanol.

Mass spectrometric imaging of localization of fat molecules in water-in-oil emulsions containing semi-solid fat.

Firstly, we report the localization analysis of the lipid components of a water-in-oil (W/O) semi-solid emulsion by mass spectrometry imaging (MSI). Uniform emulsion droplets were prepared using microchannel emulsification devices with lecithin, stearic acid-binding monoglyceride (St-MAG), and polyglycerol polyricinoleate (PGPR) as emulsifiers. The mass image gives us the localization of phosphatidylcholine (PC) in lecithin, St-MAG, tripalmitin (PPP), medium-chain triglyceride (MCT), and high-melting-point triglyceride tristearin (C18-TAG). PC, St-MAG, and PPP were localized at the interface with the dispersed water droplets. PC and PPP took the same localized position, suggesting an interaction between PC and PPP at the interface. Conversely, PC existed in other regions with St-MAG. MSI revealed multiple target molecules in fat products in a single measurement, and it is expected to reveal fat crystallization at the emulsion interfaces, which will clarify the mechanisms related to the physical properties of high-fat products such as fat spread and butter.

A new methodology capable of characterizing most volatile and less volatile minor edible oils components in a single chromatographic run without solvents or reagents. Detection of new components.

The possibilities offered by a new methodology to determine minor components in edible oils are described. This is based on immersion of a solid-phase microextraction fiber of PDMS/DVB into the oil matrix, followed by Gas Chromatography/Mass Spectrometry. It enables characterization and differentiation of edible oils in a simple way, without either solvents or sample modification. This methodology allows simultaneous identification and quantification of sterols, tocols, hydrocarbons of different natures, fatty acids, esters, monoglycerides, fatty amides, aldehydes, ketones, alcohols, epoxides, furans, pyrans and terpenic oxygenated derivatives. The broad information provided by this methodology is useful for different areas of interest such as nutritional value, oxidative stability, technological performance, quality, processing, safety and even the prevention of fraudulent practices. Furthermore, for the first time, certain fatty amides, gamma- and delta-lactones of high molecular weight, and other aromatic compounds such as some esters derived from cinnamic acid have been detected in edible oils.

Effects of Minor Components of Crude Vegetable Oil on the Enzymatic Method to Analyze Positional Fatty Acid Distributions in Triacylglycerols withCandida antarctica Lipase B.

Crude soybean and rapeseed oils were subjected to the method to determine FA distributions in TAG using Candida antarctica lipase B, giving similar results to those for refined oils. Minor components in crude oils, such as percentages of FFA or phospholipids were indicated not to affect 1(3)-selective transesterification by the lipase and FA compositional analysis of the resulting 2-MAG fraction significantly. Phospholipids were confirmed not to contaminate the 2-MAG fraction. Oxidized soybean oil with a PV of 10 meq/kg also gave similar results to the ones for refined oil. The method was confirmed to be applicable for crude oils and oxidized oils with a PV smaller than 10 meq/kg without prior purification of TAG.

Determination of polar components in frying oils by Fourier-transform near-infrared spectroscopy.

A rapid and convenient method was developed to determine the polar components (PC) of frying oil by Fourier-transform near-infrared (FTNIR) spectroscopy. One hundred twenty six oil samples were used to PC determination by column chromatography and FTNIR spectroscopy combined with partial least-square (PLS) calibration. The optimal PLS calibration was obtained after the Savitzky-Golay smoothing and first derivative treatment performed in the wavelength ranges of 4963 cm(-1) to 4616 cm(-1), 5222 cm(-1) to 5037 cm(-1), and 5688 cm(-1) to 5499 cm(-1). The obtained correlation coefficient (R) was 0.998 and the root mean square error of calibration was 1.0%. The PLS calibration was validated, and the results showed that the highest correlation (R) was 0.997 between reference value and the FTNIR predicted value and the root mean square error of prediction was 1.3%. Therefore, the FTNIR technique can be effectively applied to quantify PC with the advantages of simple operation and no pollution.

Impact of different deacidification methods on quality characteristics and composition of olein and stearin in crude red palm oil.

Crude red palm oil of 8.7% free fatty acid content was deacidified using enzyme (lipase from Rhizomucor miehei), solvent (ethanol) and chemical (aqueous Sodium hydroxide) and its impact on chemical characteristics and composition were evaluated. Deacidification of oil using enzyme showed nearly 100% product yield. The neutral lipid loss after ethanol and sodium hydroxide deacidification of the oil was 13.6% and 19.5% respectively. The enzyme deacidified oil has shown a higher value in unsaponifiable matter (0.91%), monoacylglycerols (2.8%) and diacylglycerols (18.7%) contents as compared to the other two methods of deacidification. Also it showed a higher retention of nutraceuticals such as carotenoids (94%), phytosterols (57%), total tocopherols (71%), squalene (72%), coenzyme Q10 (99%) and total phenolics (69%) with IC50 value of 19.7 mg of oil/ml. Stearin content increased in the oil after deacidification with enzyme (47.4%) compared to the stearin content of crude red palm oil (28.6%). The olein fraction contained less saturated fatty acids (41.6%) than the fraction obtained by other two methods (47.2%). The enzyme catalyzed the esterification reaction of free fatty acids in crude red palm oil with added glycerol at 63°C with a rotation speed of 150 rpm under vacuum of 5 mmHg for the period of 12 h showed that enzyme based deacidification can be effectively utilized for the preparation of low acidic nutraceutical retained red palm oil.

Enrichment and quantification of monoacylglycerols and free fatty acids by solid phase extraction and liquid chromatography-mass spectrometry.

Quantification of monoacylglycerols (MAG) and free fatty acids (FA) is of interest in biological systems, in food, cosmetic and pharmaceutical products. This manuscript describes and validates a reversed phase liquid chromatography-tandem mass spectrometry based approach for simultaneous quantification of these analytes in fats and oils. Purification and concentration of MAG/FA were performed using cation exchange solid phase extraction, which allowed elimination of the abundant triacylglycerols. Following cleanup and concentration, the analytes were separated and detected with the aid of volatile ammonium-formate buffer. MAG were detected in positive ion mode, while FA were detected in negative ion mode. The method was validated by the method of standard additions and using stable isotope labeled internal standards. The results confirm the feasibility of quantifying these two classes of analytes simultaneously without any chemical derivatization. The obtained main quantitative features include: (1) lower limits of quantification 1-30ppm for MAG analytes, (2) lower limits of quantification 90-300ppm for FA analytes, (3) averaged inter-batch precision 6%, and (4) averaged bias -0.2% for MAG and 0.5% for FA. Various animal fat and vegetable oil samples were characterized for their MAG/FA profile indicating the usefulness of the method to address quality and authenticity of fats and oils.

Chemical composition and antioxidative activity of Echinophora platyloba DC. essential oil, and its interaction with natural antimicrobials against food-borne pathogens and spoilage organisms.

This study was undertaken to determine the chemical composition and antioxidative capacity of Echinophora platyloba DC. essential oil, and its antimicrobial potency against Listeria monocytogenes, Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Salmonella typhimurium, Escherichia coli O157:H7, Pseudomonas aeruginosa, Candida albicans, Candida tropicalis, Rhodotorula rubra, and Rhodotorula mucilaginosa. The essential oil was analyzed by GC and GC-MS; and evaluated for its antioxidative and antimicrobial (singly or in combination with chitosan, nisin, monolaurin, or amphotericin B) activity. Thirty-three components were characterized representing 95.69% of the total oil composition in which thymol, trans-ocimene, carvacrol, and (E)-sesqui-lavandulol were the major constituents. The oil exhibited high scavenging (IC(50): 49.7 ± 2.3 µg/mL) and relative antioxidative activity (RAA%: 85.21 ± 0.4) in 1,1-diphenyl-2-picrylhydrazyl radicals and ß-carotene/linoleic acid bleaching assays, respectively. The oil showed antimicrobial activity against L. monocytogenes, B. cereus, B. subtilis, S. aureus, S. typhimurium, E. coli O157:H7, P. aeruginosa, C. albicans, C. tropicalis, R. Rubra, and R. mucilaginosa. Moreover, R. mucilaginosa and P. aeruginosa were the most susceptible and most resistant organisms, respectively. Regarding the checkerboard data, 47 fractional inhibitory concentration index (FICIs) (≤ 0.5) indicated synergistic, whereas 7 FICIs (>0.5 to 1) indicated additive effect. Consequently, E. platyloba DC. essential oil could be used as a recommended natural antioxidant and antimicrobial substance for food preservation.

Minor components in food oils: a critical review of their roles on lipid oxidation chemistry in bulk oils and emulsions.

Food oils are primarily composed of triacylglycerols (TAG), but they may also contain a variety of other minor constituents that influence their physical and chemical properties, including diacylglycerols (DAG), monoacylglycerols (MAG), free fatty acids (FFA), phospholipids (PLs), water, and minerals. This article reviews recent research on the impact of these minor components on lipid oxidation in bulk oils and oil-in-water emulsions. In particular, it highlights the origin of these minor components, the influence of oil refining on the type and concentration of minor components present, and potential physicochemical mechanisms by which these minor components impact lipid oxidation in bulk oils and emulsions. This knowledge is crucial for designing food, pharmaceutical, personal care, and other products with improved stability to lipid oxidation.

Identification and quantitation of reaction intermediates and residuals in lipase-catalyzed transesterified oils by HPLC.

A high-performance liquid chromatography (HPLC) unit equipped with size exclusion column and a refractive index detector was used for simultaneous monitoring, identification, and quantitation of the reaction components from lipase-catalyzed transesterification of three oils. The procedure simultaneously separated and detected the unreacted triacylglycerols (TAG), diacyl-, and monoacyl-glycerol (DAG and MAG) co-products, residual alcohol as well as free fatty acid (FFA) based on retention times. The chromatograms showed well separated and resolved peaks. The elution of the components from the transesterification reaction in increasing order was: TAG < DAG < FFA < MAG. Generally, higher alcohol ratios decreased the conversion of TAG in all the oils studied with between 14% and 94% of TAG remaining at all the treatment combinations. Higher amount of salmon skin oil (SSO) TAG was generally converted to DAG than Rothsay composite (RC) and olive oil (OO) TAG. Relatively higher amount of OO DAG was converted to MAG than SSO and RC with only 5-14% DAG remaining in OO. RC and OO generally accumulated less MAG, and this was reflected as lower MAG levels in RC (<6%) and OO (<14%) compared with SSO (<27%). For the various treatment combinations and the three oils used in this study, the least amount of FFA was recorded in transesterified OO with a maximum of approximately 4%. This HPLC method can be used as a simple and fast technique to analyze the reaction components and products of transesterification reactions without the need for additional derivatization steps.

Effects of monoacylglycerols on the oxidative stability of olive oil.

BACKGROUND: The study of pro- and anti-oxidant compounds is important for their influence on the shelf-life and nutritional value of food. The aim of this research was to evaluate the activity of monoacylglycerols (MAG), obtained by partial saponification of a purified olive oil, added in increasing amounts to the same oil and submitted to the Rancimat test and oven test at 60 °C. Besides routine analyses, high-performance size exclusion chromatography analysis of polar compounds was performed. RESULTS: The addition of MAG led in all cases to a significant slowdown of the oxidative processes. These trends were more evident as the oxidation went on. The purified oil added with 30 g kg(-1) of MAG after 9 days of oven test at 60 °C presented a level of oxidative degradation significantly lower than the control after only 4 days. CONCLUSION: The data showed a marked antioxidant effect of MAG in purified olive oil, contrary to what has been observed by other authors, who noticed either a pro-oxidant or a non-antioxidant activity of these compounds in soybean oil. A different behaviour of MAG during oxidation could depend on the different fatty acid composition of the oil matter they are added to.

Analysis of monoglycerides, diglycerides, sterols, and free fatty acids in coconut (Cocos nucifera L.) oil by 31P NMR spectroscopy.

Phosphorus-31 nuclear magnetic resonance spectroscopy ( (31)P NMR) was used to differentiate virgin coconut oil (VCO) from refined, bleached, deodorized coconut oil (RCO). Monoglycerides (MGs), diglycerides (DGs), sterols, and free fatty acids (FFAs) in VCO and RCO were converted into dioxaphospholane derivatives and analyzed by (31)P NMR. On the average, 1-MG was found to be higher in VCO (0.027%) than RCO (0.019%). 2-MG was not detected in any of the samples down to a detection limit of 0.014%. On the average, total DGs were lower in VCO (1.55%) than RCO (4.10%). When plotted in terms of the ratio [1,2-DG/total DGs] versus total DGs, VCO and RCO samples grouped separately. Total sterols were higher in VCO (0.096%) compared with RCO (0.032%), and the FFA content was 8 times higher in VCO than RCO (0.127% vs 0.015%). FFA determination by (31)P NMR and titration gave comparable results. Principal components analysis shows that the 1,2-DG, 1,3-DG, and FFAs are the most important parameters for differentiating VCO from RCO.

Compositional study on rice bran oil after lipase-catalyzed glycerolysis and solvent fractionations.

Rice bran oil (RBO) was modified through lipase-catalyzed glycerolysis. After 48 h reaction, the reactant (RBO-G, solved in hexane) containing 0.14 mg/mL of MAG, 0.19 mg/mL of DAG, and 0.93 mg/mL of TAG was obtained. Extending the reaction to 72 h resulted in 0.37 mg/mL of DAG with concomitant reduction in TAG (0.68 mg/mL). Two solvent fractionation methods, independent and sequential fractionation, were performed with acetone and hexane at 0, -8, -14, or -35 degrees C. The fraction with most unsaturated fatty acids (Sigma UFA) was liquid fraction from independent fractionation at -35 degrees C (-35 In) from hexane, showing 88.3%Sigma UFA content. Nevertheless, when yield (wt%) was considered, the highest amount of UFA was obtained from 0 In (liquid fraction from independent fractionation at 0 degrees C) with hexane, resulting in 82.3%Sigma UFA with 97.9 wt% recovery. Normal-phase HPLC was conducted for the compositional study of RBO-G. Overall, solid fractions from sequential fractionation at 0 degrees C (0 SeSo) and independent fractionation at -35 degrees C (-35 InSo) with hexane contained the high concentration of total MAG and DAG, ranging from 0.94 to 1.35 (mg/mL).

Original normal-phase high-performance liquid chromatographic separation of monoacylglycerol classes from extra virgin olive oil triacylglycerols for their stereospecific analysis.

An innovative procedure to separate the 3 isomeric sn-monoacylglycerols (MAG) classes (sn-1-, sn-2-, sn-3-MAG) is described. MAGs, obtained by chemical deacylation of triacylglycerols (TAGs), have been derivatized with (S)-(+)-1-(1-naphtyl)ethyl-isocyanate, and the resulting urethane derivatives have been separated by normal-phase high-performance liquid chromatography. This procedure allows resolution as diasteroisomers of the 2 enantiomeric classes (sn-1-MAG and sn-3-MAG), without the need of a chiral column, and to separate also the isomeric sn-2-MAG class; moreover, by introducing a chromophoric moiety, this reagent makes possible the ultraviolet detection of the analyte molecules. This procedure has been used to obtain the stereospecific analysis of the TAG fraction of extra virgin olive oil samples. The use of a nondestructive detector permitted the collection of the individual urethane classes; the fatty acid composition of each was determined by high-resolution gas chromatography, obtaining directly from the data the fatty acid distribution within each sn- position of TAGs. To validate this new method, the results have been compared with those obtained by 2 other procedures for TAG stereospecific analysis, and the obtained results were satisfactory since the proposed method gave data very similar to the other procedures.