Liquid crystal (LC)-forming lipids represent an important class of biocompatible amphiphiles and their application extends to cosmeceutical, dietary, and pharmaceutical technologies. In the present study, we aimed to develop strategies for designing and optimizing oral and topical LC formulations by evaluating their in vitro and in vivo drug absorption performances. C17-Monoglycerol ester (MGE) was used as a LC-forming lipid. p-Amino benzoic acid, methyl PABA, ethyl PABA, and sodium fluorescein were selected as drug models with different physiochemical properties. Various oral and topical LC formulations were designed based on changes in the LC forming lipid contents in the formulations and entrapped with different physiochemical properties of the drugs. The LC phase structures were evaluated using small-angle X-ray scattering (SAXS). The drug-release profiles from LC formulations were determined using a dialysis membrane method. In vivo oral absorption of LC formulations was conducted in Wistar rats. Furthermore, the skin penetration of drugs from LC formulations was investigated by in vitro skin permeation studies. As a result, although the release profile was influenced by changes in MGE concentration, it was more dramatically influenced by changes in the physiochemical properties of the entrapped drugs. Drug absorption after oral and topical administration of LC formulations was dramatically affected by the concentration of MGE. The concentration of LC-forming lipid and the physiochemical properties of entrapped drugs are key issues for good performance of the LC formulations in various pharmaceutical applications. The present results could enable researchers to manipulate LC formulation approaches intended to improve the oral absorption and skin permeation of drugs.
This work was aimed to study the solvent fraction of coconut oil (CNO). The fatty acid and triacylglycerol compositions, solid fat content (SFC) and the crystallization properties of CNO and its solid and liquid fractions obtained from fractionation at different conditions were investigated using various techniques. CNO was dissolved in acetone (1:1 w/v) and left to crystallize isothermally at 10°C for 0.5, 1 and 2 h and at 12°C for 2, 3 and 6 h. The solid fractions contained significantly lower contents of saturated fatty acids of ≤ 10 carbon atoms but considerably higher contents of saturated fatty acids with > 12 carbon atoms with respect to those of CNO and the liquid fractions. They also contained higher contents of high-melting triacylglycerol species with carbon number ≥ 38. Because of this, the DSC crystallization onset temperatures and the crystallization peak temperatures of the solid fractions were higher than CNO and the liquid fractions. The SFC values of the solid fractions were significantly higher than CNO at all measuring temperatures before reaching 0% just below the body temperature with the fraction obtained at 12°C for 2 h exhibiting the highest SFC. On the contrary, the SFC values of the liquid fractions were lower than CNO. The crystallization duration exhibited strong influence on the solid fractions. There was no effect on the crystal polymorphic structure possibly because CNO has β’-2 as a stable polymorph. The enhanced SFC of the solid fractions would allow them to find use in food applications where a specific melting temperature is desired such as sophisticated confectionery fats, and the decreased SFC of the liquid fractions would provide them with a higher cold stability which would be useful during extended storage time.
Virgin olive oils extracted from three principal Tunisian olive cultivars (Chemlali, Chetoui and Zarrazi) and coming from four different regions (Sfax, Beja, Gabes and Medenine) along the Tunisian costs were analysed. The quality indices as well as fatty acids and phenolic acids content of oil samples were examined using univariate and multivariate statistical analysis. The finding demonstrated that significant differences (p < 0.05) were found in quality indices between the different cultivars and that fatty acid content is the most informative in discriminating olive oils from production sites that are different by geographical and climatic parameters. In fact, southern cultivars (Zarrazi Gabes and Zarrazi Medenine) have the best fatty acid combination according to their oxidative effect. Besides, phenolic acids content was not useful in discriminating olive oil samples and could depend not only on geographic location but also on olive variety and agronomic practices. Nevertheless, Principal Component Analysis allowed us to highlight the Chemlali Beja olive oil for its interesting oxidative stability, fatty acid composition and its richness in phenolic acids content.
The present work deals with comparison of microwave assisted extraction to that of conventional solvent extraction for the extraction of rice bran oil (RBO); focusing on extraction yield and oil composition. Microwave assisted extraction act as a green process over other method and proved that it is effective method for extraction of oil. The investigation also focuses on the study of functional group and component present in oil. Natural antioxidant component; its activity was confirmed by DPPH assay. The oryzanol content was also determined by measuring the optical density of the sample at 315 nm in n-heptane using UV visible spectrophotometer.
An offline solid-phase extraction (SPE) approach combined with a large-volume injection (LVI)-gas chromatography-flame ionization detector (LVI-GC-FID) is improved for routine analysis of mineral oil saturated hydrocarbons (MOSH) in vegetable oils. The key procedure of the method consists in using offline SPE columns for MOSH purification. The SPE column packed with 1% Ag-activated silica gel was used to separate MOSH from triglycerides and olefins in variety of vegetable oils. The eluent of MOSH fraction was only 3 mL and the concentration step was quick with little evaporation loss. The limit of quantification (LOQ) of the method was 2.5 mg/kg and the linearity ranged from 2 to 300 mg/kg. The accuracy was assessed by measuring the recoveries from spiked oil samples and was higher than 90%. Twenty-seven commercial vegetable oils were analyzed, and different levels of MOSH contamination were detected with the highest being 259.4 mg/kg. The results suggested that it is necessary to routinely detect mineral oil contamination in vegetable oils for food safety.
In the present work, direct enzyme-catalysed esterification of medium chain fatty acids (MCFA) from three different sources (Medium chain triacylglycerols, MCT; saponified MCT and a mixture of free MCFA) was evaluated to obtain structured mono- and diacylglycerols. The esterifications were carried out mixing the different sources of MCFA with glycerol at two weight ratios (1:1 and 4:1, w/w), using three immobilized lipases: Novozym 435, Lipozyme RM IM and Lipozyme TL IM; different reaction times (t = 0, 15, 30, 60, 120 min); enzyme loadings (5, 10 or 15% with respect to the total weight of substrates). The extent of esterification was determined by gas chromatography (GC) analysis of the acylglycerols produced. The highest incorporation of free MCFA into glycerol was obtained for a 1:1 (w/w) glycerol to free MCFA ratio, 5% of Novozym 435, at 50°C, 300 rpm, 10% of molecular sieves and a commercial MCFA mixture as starting material. Under these conditions, incorporation of at least 90% of MCFA into glycerol was achieved after 30 min of reaction.
We report new lecithin reverse wormlike micelles with high viscoelasticity formed using lecithin/polyglycerol fatty acid monoester (PGLFA)/oil systems. In this study, the influence of the amphiphilicity (i.e., hydrophile-lipophile balance, HLB) of PGLFA on the phase behavior and rheological properties of reverse wormlike micelles was investigated in detail. PGLFAs with degrees of polymerization of polyglycerol varying between 6-40 and constituent fatty acids with chains between 6-18 carbon atoms long were used. Partial phase diagrams of the lecithin/PGLFA/n-decane systems indicated that the appropriate PGLFA could change the lecithin/oil solution into a highly viscoelastic solution comprising reverse wormlike micelles. Rheological measurements showed that all systems that formed reverse wormlike micelles exhibited an unusual phenomenon called “shear-thickening”. Furthermore, reverse wormlike micelles grew as the PGLFA concentration increased and the zero-shear viscosity (η0) of the solution rapidly increased. Our results indicate that the magnitude of the maximum η0 depends on the degree of polymerization of the constituent polyglycerol in the PGLFA, while the size of the reverse micellar region and the highly viscous region in the phase diagram depends on the HLB value of the PGLFA.
In this work, the synthesis of oleoyl-lysophosphatidylcholine by lipase-catalyzed esterification of glycerophosphocholine (GPC) and free oleic acid in a reaction medium without solvent is presented. The complete solubilisation of GPC, which is a crucial issue in non-polar liquids such as melted free fatty acids, was reached by heating the GPC/oleic acid mixture at high temperature during a short time. The immobilized lipase from Rhizomucor miehei (Lipozyme RM-IM) was shown to catalyze the reaction more efficiently than the immobilized lipases from Thermomyces lanuginosus (Lipozyme TL-IM) and Candida antarctica (Novozym 435). The condition reactions leading to the highest yield were as follows: substrate ratio: 1/20 (GPC/oleic acid); amount of catalyst: 10% (w/w of substrates); temperature: 50°C. Under these conditions, a yield of 75% of oleoyl-lysophosphatidylcholine was achieved in 24 h under stirring and almost no dioleoyl-lysophosphatidylcholine was produced. Unlike other studies dealing with the esterification of GPC with free fatty acids, the removal of the water produced while the reaction proceeds was not necessary to reach high yields.
Diarrhea often occurs during enteral nutrition. Recently, several reports showed that diarrhea improves by adding egg yolk lecithin, an emulsifier, in an enteral formula. Therefore, we evaluated if this combination could improve diarrhea outcomes. We retrospectively investigated the inhibitory effects on watery stools by replacing a polymeric fomula with that containing egg yolk lecithin. Then, we investigated the emulsion stability in vitro. Next, we examined the lipid absorption using different emulsifiers among bile duct-ligated rats and assessed whether egg yolk lecithin, medium-chain triglyceride, and dietary fiber can improve diarrhea outcomes in a rat model of short bowel syndrome. Stool consistency or frequency improved on the day after using the aforementioned combination in 13/14 patients. Average particle size of the egg yolk lecithin emulsifier did not change by adding artificial gastric juice, whereas that of soy lecithin and synthetic emulsifiers increased. Serum triglyceride concentrations were significantly higher in the egg yolk lecithin group compared with the soybean lecithin and synthetic emulsifier groups in bile duct-ligated rats. In rats with short bowels, the fecal consistency was a significant looser the dietary fiber (+) group than the egg yolk lecithin (+) groups from day 6 of test meal feedings. The fecal consistency was also a significant looser the egg yolk lecithin (–) group than the egg yolk lecithin (+) groups from day 4 of test meal feeding. The fecal consistency was no significant difference between the medium-chain triglycerides (–) and egg yolk lecithin (+) groups. Enteral formula emulsified with egg yolk lecithin promotes lipid absorption by preventing the destruction of emulsified substances by gastric acid. This enteral formula improved diarrhea and should reduce the burden on patients and healthcare workers.
The study is aimed to investigate the combination of nanocrystalline γ- and χ- alumina that displays the attractive chemical and physical properties for the catalytic dehydration of ethanol. The correlation between the acid density and ethanol conversion was observed. The high acid density apparently results in high catalytic activity, especially for the equally mixed γ- and χ- phase alumina (G50C50). In order to obtain a better understanding on how different catalysts would affect the ethylene yield, one of the most powerful techniques such as X-ray photoelectron spectroscopy (XPS) was performed. Hence, the different O 1s surface atoms can be identified and divided into three types including lattice oxygen (O, 530.7 eV), surface hydroxyl (OH, 532.1 eV) and lattice water (H2O, 532.9 eV). It was remarkably found that the large amount of O 1s surface atoms in lattice water can result in increased ethylene yield. In summary, the appearance of metastable χ-alumina structure exhibited better catalytic activity and ethylene yield than γ- alumina. Thus, the introduction of metastable χ- alumina structure into γ- alumina enhanced catalytic activity and ethylene yield. As the result, it was found that the G50C50 catalyst exhibits the ethylene yield (80%) at the lowest reaction temperature ca. 250°C among other catalysts.
1-Octen-3-ol, known as mushroom alcohol, is a natural product extracted from fungi and plants. Its antimicrobial activities against five common food-related bacteria and two pathogenic fungi were evaluated in this paper, including Staphylococcus aureus, Bacillus subtilis, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Fusarium tricinctum and Fusarium oxysporum. The results showed that 1-octen-3-ol had a strong antibacterial activity against the tested bacteria, especially against Gram-positive bacteria, and it can also inhibit fungal growth and spore germination. The minimum inhibitory concentrations (MICs) for Gram-positive bacteria and Gram-negative bacteria were 1.0 and 2.0 mg/mL, respectively. The minimum bactericidal concentrations (MBCs) for Gram-positive bacteria and Gram-negative bacteria were 4.0 and 8.0 mg/mL, respectively. The completely inhibitory concentrations for fungal growth and spore germination were 8.0 and 2.0 mg/ml, respectively. Cell constituents’ leakage and scanning electron microscope assays indicated that 1-octen-3-ol changed the permeability of the cell membrane. Discrepant antimicrobial activity between 1-octen-3-ol and 1-octen-3-one indicated that hydroxyl may play a decisive role in antimicrobial activity. It is suggested that 1-octen-3-ol, with attractive mushroom aroma and antimicrobial activity, has potential applications in control of pathogens.
In this study, the effect of rate-limiting enzymes involved in degradation of hepatic adenosine and intracellular sorbitol was investigated in rats exposed to haloperidol (HAL) and treated with functional oil (FO), containing principal active phytochemicals from black seed. Animals were divided into six groups (n=10): Distilled water, HAL 15 mg/kg, pre-administration/HAL 15 mg/kg, co-administration/HAL 15 mg/kg, post-administration/HAL 15 mg/kg, FO 150 mg/kg. The results of this study revealed that the activities of ectonucleotidase and aldose-reductase were significantly increased in HAL-treated rats when compared with the control (p < 0.05). However, differential treatments (pre, co and post) with FO depleted the activities of these enzymes compared with HAL-treated rats. Furthermore, therapeutic HAL administration increased the levels of key hepatic biomarkers (ALT, AST, and ALP) and malondialdehyde level with a concomitant decrease in functional hepatic cellular ATP. However, differential treatment with FO increases hepatic ATP and non-enzymatic antioxidant status, with a concomitant decrease in the levels of malondialdehyde and liver biomarkers. Therefore, results of this finding underlined the importance of aldose-reductase and econucleotidase activities in HAL induced toxicity and suggest some possible mechanisms of action by which FO prevent HAL-induced hepatic toxicity in rats.
Matrix assisted laser desorption ionization (MALDI) high-resolution mass spectrometry (HRMS) and the recently introduced high-resolution Kendrick mass defect (HRKMD) analysis are combined to thoroughly characterize non-ionic surfactants made of a poly(ethylene oxide) (PEO) core capped by esters of fatty acids. A PEO monostearate surfactant is first analyzed as a proof of principle of the HRKMD analysis conducted with a fraction of EO as the base unit (EO/X with X being an integer) in lieu of EO for a regular KMD analysis. Data visualization is greatly enhanced and the distributions detected in the MALDI mass spectrum are assigned to a pristine (H, OH)-PEO as well as mono- and di-esterified PEO chains with palmitate and stearate end-groups in HRKMD plots computed with EO/45. The MALDI-HRMS/HRKMD analysis is then successfully applied to the more complex case of ethoxylated hydrogenated castor oil (EHCO) found to contain a large number of hydrogenated ricinoleate moieties (up to 14) in its HRKMD plot computed with EO/43, departing from the expected triglyceride structure. The exhaustiveness of the MALDI-HRMS/HRKMD strategy is validated by comparing the so-obtained fingerprints with results from alternative techniques (electrospray ionization MS, size exclusion and liquid adsorption chromatography, ion mobility spectrometry). Finally, aged non-ionic surfactants formed upon hydrolytic degradation are analyzed by MALDI-HRMS/HRKMD to easily assign the degradation products and infer the associated degradation routes. In addition to the hydrolysis of the ester groups observed for EHCO, chain scissions and new polar end-groups are observed in the HRKMD plot of PEO monostearate arising from a competitive oxidative ageing.