Unveiling the formation capacity of multicomponent oleogels: Performance of lecithin interacting with monostearate derivatives.

Oleogels have been explored as fat substitutes due to their healthier composition compared to trans and saturated fats, also presenting interesting technological perspectives. The aim of this study was to investigate the compositional perspective of multicomponent oleogels. Structuring ability of lecithin (LEC) (20 or 90 wt% of phosphatidylcholine - PC) combined with glycerol monostearate (GMS), sorbitan monostearate (SMS) or sucrose monostearate (SAC) in sunflower oil was evaluated from oleogels properties. The thermal and rheological properties, microstructure and stability of the oleogels were affected by the difference in the chemical composition of LEC and the ratio between LEC and different surfactants. Interestingly, low-phosphatidylcholine LEC (L20) performed better, although systems formed with reduced amounts of LEC tended to be softer (LEC-GMS) and present high oil holding capacity (LEC-SMS). The mixtures of LEC and monostearate-based surfactants showed different behaviors, depending on the surfactant polar head. In LEC-GMS systems, LEC hindered the self-assembly of GMS in sunflower oil, compromising mechanical properties and increasing oil release. When combined with SMS, LEC acted as a crystal habit modifier of SMS, forming a more homogeneous microstructure and producing stronger oleogels with greater oil binding capacity. However, above the threshold concentration, LEC prevented SMS self-assembly, resulting in a weaker gel. A positive interaction was found in LEC-SAC formulations in specific ratios, since SAC cannot act as a single oleogelator. Results show the impact of solubility balance played by LEC and fatty-acid derivatives surfactant when combined and used as oleogelators. This knowledge can contribute to a rational perspective in the preparation and modulation of the properties of edible oleogels.

Verapamil-Loaded Cubosomes for Enhancing Intranasal Drug Delivery: Development, Characterization, Ex Vivo Permeation, and Brain Biodistribution Studies.

Verapamil hydrochloride (VRP), an antihypertensive calcium channel blocker drug has limited bioavailability and short half-life when taken orally. The present study was aimed at developing cubosomes containing VRP for enhancing its bioavailability and targeting to brain for cluster headache (CH) treatment as an off-label use. Factorial design was conducted to analyze the impact of different components on entrapment efficiency (EE%), particle size (PS), zeta potential (ZP), and percent drug release. Various in-vitro characterizations were performed followed by pharmacokinetic and brain targeting studies. The results revealed the significant impact of glyceryl monooleate (GMO) on increasing EE%, PS, and ZP of cubosomes with a negative influence on VRP release. The remarkable effect of Poloxamer 407 (P407) on decreasing EE%, PS, and ZP of cubosomes was observed besides its influence on accelerating VRP release%. The DSC thermograms indicated the successful entrapment of the amorphous state of VRP inside the cubosomes. The design suggested an optimized formulation containing GMO (50% w/w) and P407 (5.5% w/w). Such formulation showed a significant increase in drug permeation through nasal mucosa with high Er value (2.26) when compared to VRP solution. Also, the histopathological study revealed the safety of the utilized components used in the cubosomes preparation. There was a significant enhancement in the VRP bioavailability when loaded in cubosomes owing to its sustained release favored by its direct transport to brain. The I.N optimized formulation had greater BTE% and DTP% at 183.53% and 90.19%, respectively in comparison of 41.80% and 59% for the I.N VRP solution.

Enzymatically produced acylglycerol and glycerin monostearate additives improved the characteristics of gelatin-stabilized omega-3 emulsions and microcapsules.

The impacts of enzymatically produced acylglycerol and glycerin monostearate on the characteristics of gelatin-stabilized omega-3 emulsions and microcapsules were investigated. Tuna oil was enzymatically produced and the resulting acylglycerol was mixed with tuna oil at 12.5% (w/w) to prepare a novel oil phase. This oil phase was stabilized by gelatin to prepare oil-in-water emulsions and subsequent microcapsules via complex coacervation. The tuna oil with glycerin monostearate (GMS) at 1 and 2% (w/w) were used as controls. Results showed that both acylglycerol and GMS significantly reduced the emulsion droplet size and zeta potential, while increasing the viscoelasticity and stability. The diacylglycerol/monoacylglycerol were involved in the oil/water interfacial layer formation by lowering interfacial tension and increasing droplet surface hydrophobicity. Overall, the changed emulsion properties promoted the complex coacervation and contributed to the formation of microcapsules with improved oxidative stability. Therefore, enzymatically produced acylglycerol can develop high-quality stable omega-3 microencapsulated novel food ingredients.

Extrusion as pretreatment for complexation of high-amylose starch with glycerin monostearin: Dependence on the guest molecule.

Low-moisture extrusion (LME) can modify starch structures and enrich their functionality. These LME-made starches may efficiently form inclusion complexes (ICs) with hydrophobic guest molecules, which is profoundly impacted by the guest molecule concentration. In this work, the influence of glycerin monostearin (GMS) concentration on the structure and in vitro digestibility of pre-extruded starch-GMS complexes was investigated. The results showed that LME pretreatment increased the complex index of high-amylose starch with GMS by 13 %. The appropriate GMS concentrations produced ICs with high crystallinity and excellent thermostability. The presence of IC retarded amylose retrogradation and dominated bound water in starches. In addition, highly crystallized ICs were resistant to enzymolysis and had a higher proportion of resistant starch. The acquired knowledge would provide a better understanding of the LME-modified starch and GMS concentration-regulated IC formation.

Counterion optimization for hydrophobic ion pairing (HIP): Unraveling the key factors.

In the present study, various surfactants were combined with insulin (INS), bovine serum albumin (BSA) and horseradish peroxidase (HRP) via hydrophobic ion pairing to increase lipophilicity and facilitate incorporation into self-emulsifying drug delivery systems (SEDDS). Lipophilicity of model proteins was successfully increased, achieving log Dn-butanol/water values up to 3.5 (INS), 3.2 (BSA) and 1.2 (HRP). Hereby, key factors responsible for complex formation were identified. In particular, surfactants with branched alkyl chains or chain lengths greater than C12 showed favorable properties for hydrophobic ion pairs (HIP). Furthermore, flexibility of the carbon chain resulted in higher lipophilicity and suitability of polar head groups of surfactants for HIP decreased in the rank order sulfonate > sulfosuccinate > phosphate = sulfate > carbonate > phosphonic acids = sulfobetaines. Stability studies of formed HIP complexes were performed in various gastrointestinal fluids and their solubility was determined in commonly used SEDDS excipients. Formed complexes were stable in simulated gastrointestinal fluids and could be incorporated into SEDDS formulations (C1: 10% caprylocaproyl polyoxyl-8 glycerides, 20% PEG-40 hydrogenated castor oil, 20% medium-chain triglycerides, 50% n-butanol; C2: 10% caprylocaproyl polyoxyl-8 glycerides, 20% PEG-40 hydrogenated castor oil, 20% medium-chain triglycerides, 40% n-butanol, 10% 1,2-butanediol), resulting in suitable payloads of up to 11.9 mg/ml for INS, 1.0 mg/ml for BSA and 1.6 mg/ml for HRP.

Enzymatic enrichment of acylglycerols rich in n - 3 polyunsaturated fatty acids by selective methanolysis: Optimization and kinetic studies.

n - 3 Polyunsaturated fatty acids (n - 3 PUFA) have special physiological effect, but their contents in natural oils may not meet the growing demand. Lipase-catalyzed selective methanolysis could be used to produce acylglycerols rich in n - 3 PUFA. To explore the kinetics of enzymatic methanolysis, factors affecting the reaction, including reaction system, water content, substrate molar ratio, temperature, lipase loading, and reaction time, were first investigated in the view of optimizing the reaction. Then the effects of triacylglycerol concentrations and methanol concentrations on initial reaction rate were studied. Finally, the key kinetic parameters of methanolysis were determined subsequently. The results showed that under optimal conditions, the n - 3 PUFA content in acylglycerols increased from 39.88% to 71.41%, and the n - 3 PUFA yield was 73.67%. The reaction followed a Ping-Pong Bi Bi mechanism with inhibition by methanol. The kinetic analysis indicated the lipase could selectively remove saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) in acylglycerols. The inhibition constant of methanol to the n - 3 PUFA (KiM , 0.30 mmol/L) was lower than that to the SFA and MUFA (219.64 and 79.71 mmol/L). The combined effects of the fatty acid selectivity of Candida antarctica lipase A and methanol inhibition resulted in an enrichment of n - 3 PUFA in acylglycerols. Overall, the methanolysis reaction catalyzed by the lipase A is a prospective enrichment method. PRACTICAL APPLICATION: This study demonstrated that enzymatic selective methanolysis is a prospective enrichment method to produce acylglycerols rich in n - 3 PUFA. This method is highly efficient, environment-friendly, and simple. n - 3 PUFA concentrates have been widely applied in the food, health-care food, and pharmaceutical industries.

Conjugates of 1,3- and 1,2-Acylglycerols with Stigmasterol: Synthesis, NMR Characterization, and Impact on Lipid Bilayers.

The main aim of research was synthesis and spectroscopic characterization of new conjugates in which stigmasterol was linked via carbonate or succinyl linker with 1,3- and 1,2-acylglycerols of palmitic and oleic acid. Acylglycerols containing stigmasterol residue at internal position have been synthesized from 2-benzyloxypropane-1,3-diol or dihydroxyacetone. Their asymmetric counterparts containing stigmasterol residue attached to sn-3 position have been obtained from (S)-solketal. Eight synthesized conjugates were used to create the liposomes as nanocarriers of phytosterols to increase their stability and protect them from degradation during thermal-oxidative treatments. Fluorimetric and ATR-FTIR methods were used to determine the impact of synthesized conjugates on the physicochemical properties of the lipid bilayer. The results indicate that conjugates with palmitic acid are better candidates for use as the potential stigmasterol nanocarriers compared to those with oleic acid because they increase the stiffness of the lipid bilayer and temperature of the main phase transition. The obtained results are the first step in designing of stigmasterol-enriched liposomal carriers with higher thermo-oxidative stability for their potential use in the food industry.

Assessment of glyceride-structured oleogels as an injectable extended-release delivery system of bupivacaine.

This manuscript systematically assesses three different glycerides (tripalmitin, glyceryl monostearate, and a blend of mono-, di- and triesters of palmitic and stearic acids (Geleol™)) as potential gelator structuring agents of medium-chain triglyceride oil to form an oleogel-based injectable long-acting local anesthetic formulation for postoperative pain management. Drug release testing, oil-binding capacity, injection forces, x-ray diffraction, differential scanning calorimetry, and rheological testing were serially performed to characterize the functional properties of each oleogel. After benchtop assessment, the superior bupivacaine-loaded oleogel formulation was compared to bupivacaine HCl, liposomal bupivacaine, and bupivacaine-loaded medium-chain triglyceride oil in a rat sciatic nerve block model to assess in vivo long-acting local anesthetic performance. In vitro drug release kinetics were similar for all formulations, indicating that drug release rate is primarily dependent on the drug's affinity to the base oil. Glyceryl monostearate-based formulations had superior shelf-life and thermal stability. The glyceryl monostearate oleogel formulation was selected for in vivo evaluation. It was found to have a significantly longer duration of anesthetic effect than liposomal bupivacaine and was able to provide anesthesia twice as long as the equipotent bupivacaine-loaded medium-chain triglyceride oil, indicating that the increased viscosity of the oleogel provided enhanced controlled release over the drug-loaded oil alone.

Characterizing the Self-Assembly Properties of Monoolein Lipid Isosteres.

Living cells feature lipid compartments which exhibit a variety of shapes and structures that assist essential cellular processes. Many natural cell compartments frequently adopt convoluted nonlamellar lipid architectures that facilitate specific biological reactions. Improved methods for controlling the structural organization of artificial model membranes would facilitate investigations into how membrane morphology affects biological functions. Monoolein (MO) is a single-chain amphiphile which forms nonlamellar lipid phases in aqueous solution and has wide applications in nanomaterial development, the food industry, drug delivery, and protein crystallization. However, even if MO has been extensively studied, simple isosteres of MO, while readily accessible, have seen limited characterization. An improved understanding of how relatively minor changes in lipid chemical structure affect self-assembly and membrane topology could instruct the construction of artificial cells and organelles for modeling biological structures and facilitate nanomaterial-based applications. Here, we investigate the differences in self-assembly and large-scale organization between MO and two MO lipid isosteres. We show that replacing the ester linkage between the hydrophilic headgroup and hydrophobic hydrocarbon chain with a thioesther or amide functional group results in the assembly of lipid structures with different phases not resembling those formed by MO. Using light and cryo-electron microscopy, small-angle X-ray scattering, and infrared spectroscopy, we demonstrate differences in the molecular ordering and large-scale architectures of the self-assembled structures made from MO and its isosteric analogues. These results improve our understanding of the molecular underpinnings of lipid mesophase assembly and may facilitate the development of MO-based materials for biomedicine and as model lipid compartments.

Rheological and thermal properties of reinforced monoglyceride-carnauba wax oleogels.

BACKGROUND: Oleogels can be used in the food industry to reduce the consumption of solid fat in the human diet and diminish some of the industrial-technological issues of using oil instead of fat. Regarding the structural weakness of neat monoglyceride oleogel and the waxy mouthfeel of pure carnauba wax oleogel, as a result of the high melting and crystallization points, the present study aimed to diminish these defects. RESULTS: Carnauba wax (CBW) was used as a co-gelator with distilled monoglyceride (DMG) at different weight ratios (100:0, 85:15, 70:30, 55:45, 40:60, and 0:100) (DMG: CBW) and two total gelator concentrations (50 and 100 g kg-1 ) to improve the DMG oleogel characteristics. The addition of CBW strengthened the DMG network and decreased the polymorphic transition. Thermal analysis showed just co-crystallization at the 85:15 ratio, whereas, in the other combinations, high melting components of CBW crystalized at first. As a result of the crystal homogeneity and long-time development, the oleogel properties improved at the 85:15 ratio. The low concentration of CBW and the formation of the eutectic system were efficient in the waxy mouthfeel reduction of oleogel at the 85:15 ratio in food applications. CONCLUSION: The DMG/CBW oleogel at the 85:15 ratio, with better structural and sensorial properties than DMG and CBW oleogels, respectively, has the potential for use instead of fat in food formulations. © 2023 Society of Chemical Industry.

Structured lipids produced from palm-olein oil by interesterification: A controllable lipase-catalyzed approach in a solvent-free system.

Palm olein (POL) was modified by enzymatic interesterification with different degrees of acyl migration in a solvent-free packed bed reactor. The fatty acid and acylglycerol composition, isomer content, thermodynamic behavior, and relationship between crystal polymorphism, solid fat content (SFC), crystal microstructure, and texture before and after modification were studied. We found that the increase in sn-2 saturation interesterification was not only due to the generated tripalmitin (PPP) but also caused by acyl migration, and the SFC profiles were changed accordingly. The emergence of high melting point acylglycerols was an important factor accelerating the crystallization rate, further shortening the crystallization induction time, leading to the formation of large crystal spherulites, thereby reducing the hardness. The transformation from the ß' to the ß form occurred during post-hardening during storage. The isomer content also affected the physicochemical properties of the modified POL.

Progress in enrichment of n-3 polyunsaturated fatty acid: a review.

n-3 Polyunsaturated fatty acids (n-3 PUFA) has been widely used in foods, and pharmaceutical products due to its beneficial effects. The content of n-3 PUFA in natural oils is usually low, which decreases its added value. Thus, there is an increasing demand on the market for n-3 PUFA concentrates. This review firstly introduces the differences in bioavailability and oxidative stability between different types of PUFA concentrate (free fatty acid, ethyl ester and acylglycerol), and then provides a comprehensive discussion of different methods for enrichment of lipids with n-3 PUFA including physical-chemical methods and enzymatic methods. Lipases used for catalyzing esterification, transesterification and hydrolysis reactions play an important role in the production of highly enriched various types of n-3 PUFA concentrates. Lipase-catalyzed alcoholysis or hydrolysis reactions are the mostly employed method to prepare high-quality n-3 PUFA of structural acylglycerols. Although many important advantages offered by lipases in enrichment of n-3 PUFA, the high cost of enzyme limits its industrial-scale production. Further research should focus on looking for biological enzymes with extraordinary catalytic ability and clear selectivity. Other novel technologies such as protein engineering and immobilization may be needed to modify lipases to improve its selectivity, catalytic ability and reuse.

Thermal Properties, Microstructure and Crystallization of Blends of Leaf Lard and Cottonseed Oil Stearin.

Blend oils composed by leaf lard (LL) and cottonseed oil stearin (COS) were prepared and the thermal property, microstructure and crystallization of these blends were investigated in the present study. Solid fat content (SFC), thermal behaviors, triacylglycerols composition, crystal structure and morphology of the LL and COS blends were determined by pulsed nuclear magnetic resonance (pNMR), differential scanning calorimetry (DSC), high-performance liquid chromatography (HPLC), X-ray diffractometer (XRD) and polarized light microscope (PLM), respectively. SFC profiles and iso-solid diagrams indicated that SFCs of all blends were almost close to the weighted averages of the fat components at temperatures beyond 20°C; however, below 20°C, SFCs of blends exhibited higher than those of the weighted averages of the fat components. With the content of COS increasing, palmitic acid and linoleic acid in the blends increased, while stearic acid and oleic acid decreased; monounsaturated-disaturated (USS) and triunsaturated (UUU) glycerides in the blends enhanced, while monosaturated-diunsaturated (UUS) glycerides declined. The melting temperature of the blends decreased with the increase of COS content. The crystal forms in LL were ß' and ß, and the packing pattern was double and triple chain length (2L and 3L). With COS in blends increasing, ß' form crystals and 3L pattern reduced. Polarized light micrographs showed that the number of crystal particles in the blends raised with the increase of COS content, meanwhile, the grainsize of the sample gradually decreased. Visual appearances of the blends indicated that blending LL with COS could efficiently reduce the graininess of LL. The addition of COS had a significant effect on the crystallization behavior of LL. LL presented one-step crystallization at 10°C and 20°C, while COS showed two-step crystallization at 10°C and one-step crystallization at 20°C. However, the blends exhibited obvious two-step crystallization at 10°C, one-step or slight two-step crystallization at 20°C.

Solid lipid nanoparticles for phytosterols delivery: The acyl chain number of the glyceride matrix affects the arrangement, stability, and release.

The lipid matrix plays a key role in solid lipid nanoparticles (SLNs) embedding active ingredients. To investigate the influence of lipid matrix structure on arrangement, release, and stability of solid lipid nanoparticles, three phytosterols formulations with different carrier glycerides [glycerol monostearate (GMS), glycerol distearate (GDS), and glycerol tristearate (GTS)] were prepared and evaluated. X-ray diffraction and differential scanning calorimetry revealed the lowest crystallinity of phytosterols in the GMS matrix, corresponding to the maximum bioaccessibility (40.2%) in vitro experiments. Sustained release and better stability were observed from GDS and GTS matrices, which could be attributed to strong molecular interactions or a core-rich structure inside the nanoparticles. Molecular dynamics simulations demonstrated that the affinity between phytosterols and glycerides decreased in the order GDS > GTS > GMS, as well as explaining the release and storage capacities of the three nanoparticles. This study would facilitate the rational design of SLNs in functional foods.

Observations of phase changes in monoolein during high viscous injection.

Serial crystallography of membrane proteins often employs high-viscosity injectors (HVIs) to deliver micrometre-sized crystals to the X-ray beam. Typically, the carrier medium is a lipidic cubic phase (LCP) media, which can also be used to nucleate and grow the crystals. However, despite the fact that the LCP is widely used with HVIs, the potential impact of the injection process on the LCP structure has not been reported and hence is not yet well understood. The self-assembled structure of the LCP can be affected by pressure, dehydration and temperature changes, all of which occur during continuous flow injection. These changes to the LCP structure may in turn impact the results of X-ray diffraction measurements from membrane protein crystals. To investigate the influence of HVIs on the structure of the LCP we conducted a study of the phase changes in monoolein/water and monoolein/buffer mixtures during continuous flow injection, at both atmospheric pressure and under vacuum. The reservoir pressure in the HVI was tracked to determine if there is any correlation with the phase behaviour of the LCP. The results indicated that, even though the reservoir pressure underwent (at times) significant variation, this did not appear to correlate with observed phase changes in the sample stream or correspond to shifts in the LCP lattice parameter. During vacuum injection, there was a three-way coexistence of the gyroid cubic phase, diamond cubic phase and lamellar phase. During injection at atmospheric pressure, the coexistence of a cubic phase and lamellar phase in the monoolein/water mixtures was also observed. The degree to which the lamellar phase is formed was found to be strongly dependent on the co-flowing gas conditions used to stabilize the LCP stream. A combination of laboratory-based optical polarization microscopy and simulation studies was used to investigate these observations.

Digestion of lipid excipients and lipid-based nanocarriers by pancreatic lipase and pancreatin.

The digestion behaviour of lipid-based nanocarriers (LNC) has a great impact on their oral drug delivery properties. In this study, various excipients including surfactants, glycerides and waxes, as well as various drug-delivery systems, namely self-emulsifying drug delivery systems (SEDDS), solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) were examined via the pH-stat lipolysis model. Lipolysis experiments with lipase and pancreatin revealed the highest release of fatty acids for medium chain glycerides, followed by long chain glycerides and surfactants. Waxes appeared to be poor substrates with a maximum digestion of up to 10% within 60 min. Within the group of surfactants, the enzymatic cleavage decreased in the following order: glycerol monostearate > polyoxyethylene (20) sorbitan monostearate > PEG-35 castor oil > sorbitan monostearate. After digestion experiments of the excipients, SEDDS, SLN and NLC with sizes between 30 and 300 nm were prepared. The size of almost all formulations was increasing during lipolysis and levelled off after approximately 15 min except for the SLN and NLC consisting of cetyl palmitate. SEDDS exceeded 6000 nm after some minutes and were almost completely hydrolysed by pancreatin. No significant difference was observed between comparable SLN and NLC but surfactant choice and selection of the lipid component had an impact on digestion. SLN and NLC with cetyl palmitate were only digested by 5% whereas particles with glyceryl distearate were decomposed by 40-80% within 60 min. Additionally, the digestion of the same SLN or NLC, only differing in the surfactant, was higher for SLN/NLC containing polyoxyethylene (20) sorbitan monostearate than PEG-35 castor oil. This observation might be explained by the higher PEG content of PEG-35 castor oil causing a more pronounced steric hindrance for the access of lipase. Generally, digestion experiments performed with pancreatin resulted in a higher digestion compared to lipase. According to these results, the digestion behaviour of LNC depends on both, the type of nanocarrier and on the excipients used for them.

Chitosan film containing antifungal agent-loaded SLNs for the treatment of candidiasis using a Box-Behnken design.

The aim of this study was to combine fluconazole (FZ)-loaded solid lipid nanoparticles (FZ-SLNs) and chitosan films (C-films) for the potential administration of FZ across the buccal mucosa using a Box-Behnken design. The chitosan films containing FZ-SLNs (C-FS-films) and C-films were prepared using a film casting method. The ATR-FTIR analysis confirmed the presence of hydrogen bonds between the NH3+ groups of chitosan and the OH or COO- groups of glyceryl monostearate in the films. Additionally, FESEM analysis of the morphology of C-FS-films revealed the presence of FZ-SLNs in the films. Permeation studies using porcine buccal mucosa demonstrated that FZ from the C-FS-films was more permeable than in C-films. The antifungal activity of the C-FS-films was evaluated against Candida albicans, and inhibition zones were observed. Thus, C-FS-films represent an exciting drug carrier for the treatment of candidiasis via the buccal mucosa.

Antioxidant-containing monoolein aqueous dispersions: a preliminary study.

The present study describes a preliminary study on the use of monoolein aqueous dispersions (MADs) as delivery systems for antioxidant molecules, namely, ascorbyl palmitate (AP) and alpha-tocopherol (AT). MAD, produced by emulsifying monoolein (4.5% w/w) in water and poloxamer 407 (0.5% w/w) as emulsifier, was characterized in terms of size, morphology, and antioxidant activity by mean of PCS, cryo-TEM, and (2,2-diphenyl-1-picrylhydrazyl) assay. MAD-AP or MAD-AT gave rise to a bimodal size distribution with mean size around 200 nm. All the preparations stored at 25 °C showed quite stable size at least up to 90 days. Cryo-TEM images confirmed MAD size distribution and indicated different MAD morphologies as a function of the loaded antioxidant molecule. Indeed, in the case of MAD-AP, vesicles and cubosomes with the typical inner cubic structure were observed, while vesicles and hexosomes were shown for MAD-AT. The encapsulation efficiency of both antioxidants reached more than 90% with respect to the total amount of drug used for MAD preparation. Moreover, AP and AT antioxidant activity was retained after encapsulation, and in vitro Franz cell experiments showed that the MAD enabled to better control the drug release. These preliminary results suggest that MAD formulations could be further investigated as a potential delivery system for antioxidant supplementation in dietary or cosmetic fields.

1-, 2- and 3-AG as substrates of the endocannabinoid enzymes and endogenous ligands of the cannabinoid receptor 1.

2-Arachidonoylglycerol (2-AG) is the most potent and abundant endocannabinoid that acts as a full agonist at the cannabinoid 1 (CB1) and 2 (CB2) receptors. It serves as a substrate for several serine hydrolases, including monoacylglycerol lipase (MGL), α/ß hydrolase domain 6 (ABHD6) and fatty acid amide hydrolase (FAAH). However, 2-AG's rapid conversion to 1-AG (the S stereoisomer) and 3-AG (the R stereoisomer) complicates in vivo signaling. Here, we present the interaction profiles of 2-AG and its isomerization products, 1- and 3-AG, with the endocannabinoid MGL, ABHD6 and FAAH enzymes as well as the CB1 receptor. The 1- and 3-AG enantiomers are less prone to isomerization, and their affinities to endocannabinoid enzymes and potencies at CB1 receptor are quite different compared to 2-AG. Although MGL is the principal hydrolytic enzyme of 2-AG, 3-AG (the R isomer) appears to be the best substrate for hMGL. Contrarily, 1-AG (the S isomer) demonstrates the worst substrate profile, indicating that the stereochemistry of 1(3)-monoacylglycerols is very important for MGL enzyme. On the other hand, both 1- and 3-AG (the sn1 monoacylglycerols) are efficiently hydrolyzed by hABHD6 without preference, while 2-AG (the sn2 monoacylglycerol) has the lowest rate of hydrolysis. FAAH, the principal hydrolytic enzyme for arachidonoylethanolamide (anandamide, AEA), catalyzes the hydrolysis of all three isomers with similar efficiencies. In a functional cAMP assay at CB1 receptor, all three isomers behaved as agonists, with 2-AG being the most potent, followed by 3-AG then 1-AG. The presented data provides stereochemical insights to design chemically stable AG analogs with preferential stability against enzymes of interest.

Virucidal effect of monogalactosyl diacylglyceride from a green microalga, Coccomyxa sp. KJ, against clinical isolates of SARS-CoV-2 as assessed by a plaque assay.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19) and is capable of human-to-human transmission and rapid global spread. Thus, the establishment of high-quality viral detection and quantification methods, and the development of anti-SARS-CoV-2 agents are critical. METHODS: Here, we present the rapid detection of infectious SARS-CoV-2 particles using a plaque assay with 0.5% agarose-ME (Medium Electroosmosis) as an overlay medium. RESULTS: The plaques were capable of detecting the virus within 36-40 h post-infection. In addition, we showed that a monogalactosyl diacylglyceride isolated from a microalga (Coccomyxa sp. KJ) could inactivate the clinical isolates of SARS-CoV-2 in a time- and concentration-dependent manner. CONCLUSIONS: These results would allow rapid quantification of the infectious virus titers and help develop more potent virucidal agents against SARS-CoV-2.