HAMLET in human milk is resistant to digestion and carries essential free long chain polyunsaturated fatty acids and oleic acid.

The oleic acid/alpha-lactalbumin complex HAMLET (human alpha-lactalbumin made lethal to tumors) is cytotoxic to various cancerous cell lines and is assembled from alpha-lactalbumin (ALA) and free oleic acid (OA). HAMLET is also cytotoxic to normal immature intestinal cells. It remains unclear if HAMLET, experimentally assembled with OA and heat, can spontaneously assemble in frozen human milk over time. To approach this issue, we used a set of timed proteolytic experiments to evaluate the digestibility of HAMLET and native ALA. The purity of HAMLET in human milk was confirmed by ultra high performance liquid chromatography coupled to tandem mass spectrometry and western blot to resolve the ALA and OA components. Timed proteolytic experiments were used to identify HAMLET in whole milk samples. Structural characterization of HAMLET was performed by Fournier transformed infrared spectroscopy and indicated a transformation of secondary structure with increased alpha-helical character of ALA upon binding to OA.

Sophorolipid: a glycolipid biosurfactant as a potential therapeutic agent against COVID-19.

Biosurfactants are natural surfactants produced by a variety of microorganisms. In recent years, biosurfactants have garnered a lot of interest due to their biomedical and pharmaceutical applications. Sophorolipids are glycolipid types of biosurfactants produced by selected nonpathogenic yeasts. In addition to the detergent activity (reduction in surface and interfacial tension), which is commonly utilized by biomedical applications, sophorolipids have shown some unique properties such as, antiviral activity against enveloped viruses, immunomodulation, and anticancer activity. Considering their antiviral activity, the potential of sophorolipids as an antiviral therapy for the treatment of COVID-19 is discussed in this review. Being a surfactant molecule, sophorolipid could solubilize the lipid envelope of SARS-CoV-2 and inactivate it. As an immunomodulator, sophorolipid could attenuate the cytokine storm caused by the SARS-CoV-2 upon infection, and inhibit the progression of COVID-19 in patients. Sophorolipids could also be used as an effective treatment strategy for COVID-19 patients suffering from cancer. However, there is limited research on the use of sophorolipid as a therapeutic agent for the treatment of cancer and viral diseases, and to modulate the immune response. Nevertheless, the multitasking capabilities of sophorolipids make them potential therapeutic candidates for the bench-to-bedside research for the treatment of COVID-19.

Synthesis and in vitro preliminary evaluation of prostate-specific membrane antigen targeted upconversion nanoparticles as a first step towards radio/fluorescence-guided surgery of prostate cancer.

Over the last decade, upconversion nanoparticles (UCNP) have been widely investigated in nanomedicine due to their high potential as imaging agents in the near-infrared (NIR) optical window of biological tissues. Here, we successfully develop active targeted UCNP as potential probes for dual NIR-NIR fluorescence and radioactive-guided surgery of prostate-specific membrane antigen (PSMA)(+) prostate cancers. We designed a one-pot thermolysis synthesis method to obtain oleic acid-coated spherical NaYF4:Yb,Tm@NaYF4 core/shell UCNP with narrow particle size distribution (30.0 ± 0.1 nm, as estimated by SAXS analysis) and efficient upconversion luminescence. Polyethylene glycol (PEG) ligands bearing different anchoring groups (phosphate, bis- and tetra-phosphonate-based) were synthesized and used to hydrophilize the UCNP. DLS studies led to the selection of a tetra-phosphonate PEG(2000) ligand affording water-dispersible UCNP with sustained colloidal stability in several aqueous media. PSMA-targeting ligands (i.e., glutamate-urea-lysine derivatives called KuEs) and fluorescent or radiolabelled prosthetic groups were grafted onto the UCNP surface by strain-promoted azide-alkyne cycloaddition (SPAAC). These UCNP, coated with 10 or 100% surface density of KuE ligands, did not induce cytotoxicity over 24 h incubation in LNCaP-Luc or PC3-Luc prostate cancer cell lines or in human fibroblasts for any of the concentrations evaluated. Competitive binding assays and flow cytometry demonstrated the excellent affinity of UCNP@KuE for PSMA-positive LNCaP-Luc cells compared with non-targeted UCNP@CO2H. Furthermore, the binding of UCNP@KuE to prostate tumour cells was positively correlated with the surface density of PSMA-targeting ligands and maintained after 125I-radiolabelling. Finally, a preliminary biodistribution study in LNCaP-Luc-bearing mice demonstrated the radiochemical stability of non-targeted [125I]UCNP paving the way for future in vivo assessments.

New potential antiproliferative monophosphoester 2-aminoethyl dihydrogen phosphate in K-562 and K-562 MDR+ leukemia cells.

The main obstacle in the treatment of cancer patients has been resistance to multiple drugs, leading to the need to develop molecules with a higher specificity target. The liposomal formulation DODAC/2-AEH2P has antitumor potential, inducing apoptosis in several tumor types. Human chronic myeloid leukemia K-562 and K-562 Lucena (MDR+) cells were treated with the DODAC carrier and the liposomal formulation 2-AEH2P. Viability, cell cycle phases, apoptosis, marker expression and mitochondrial potential were analyzed. Significant reduction in viability was observed for all treatments. Changes in the distribution of the cell cycle phases and expression of markers involved in the apoptosis pathways were observed. Reduction of the mitochondrial electrical potential mediated by Bcl-2, being regulated by the reduction of the MTCH2 protein linked to the progression of myeloid leukemia and an increase in the pro-apoptotic proteins Bad and Bax, dependent on p53. This study demonstrated a significant therapeutic potential through apoptotic effects in leukemic cells, regardless of the molecular resistance profile (MDR+).

Bladder cancer therapy using a conformationally fluid tumoricidal peptide complex.

Partially unfolded alpha-lactalbumin forms the oleic acid complex HAMLET, with potent tumoricidal activity. Here we define a peptide-based molecular approach for targeting and killing tumor cells, and evidence of its clinical potential (ClinicalTrials.gov NCT03560479). A 39-residue alpha-helical peptide from alpha-lactalbumin is shown to gain lethality for tumor cells by forming oleic acid complexes (alpha1-oleate). Nuclear magnetic resonance measurements and computational simulations reveal a lipid core surrounded by conformationally fluid, alpha-helical peptide motifs. In a single center, placebo controlled, double blinded Phase I/II interventional clinical trial of non-muscle invasive bladder cancer, all primary end points of safety and efficacy of alpha1-oleate treatment are reached, as evaluated in an interim analysis. Intra-vesical instillations of alpha1-oleate triggers massive shedding of tumor cells and the tumor size is reduced but no drug-related side effects are detected (primary endpoints). Shed cells contain alpha1-oleate, treated tumors show evidence of apoptosis and the expression of cancer-related genes is inhibited (secondary endpoints). The results are especially encouraging for bladder cancer, where therapeutic failures and high recurrence rates create a great, unmet medical need.

One-step self-assembly of curcumin-loaded zein/sophorolipid nanoparticles: physicochemical stability, redispersibility, solubility and bioaccessibility.

Curcumin, a polyphenolic compound isolated from turmeric, exhibits various biological activities. The application of this nutraceutical in foods, however, is limited due to its extreme hydrophobicity, inferior stability, and poor bioaccessibility. The purpose of this paper is to prepare alcohol-free curcumin-loaded zein/sophorolipid nanoparticles (Cur-Z/SNPs) by one-step self-assembly to overcome the abovementioned challenges of curcumin. In detail, Cur-Z/SNPs were formed by mixing curcumin, zein, and sophorolipid under neutral conditions without any organic reagents or high energy equipment. The encapsulation efficiency and loading capacity of Cur-Z/SNPs were 94.08% and 11.50%, respectively. The spherical shape of Cur-Z/SNPs was observed by using a transmission electron microscope. The self-assembly mechanism involved hydrogen bonding, hydrophobic and electrostatic interactions, and the crystalline nature of curcumin changed to amorphous during self-assembly. Cur-Z/SNPs enhanced the zein denaturation resistance. They exhibited complete redispersibility and improved the aqueous solubility by approximately 246 times compared with free curcumin. The fresh Cur-Z/SNPs exhibited physicochemical stability at pH 5.0-8.0, ionic strength within 250 mM, and storage at 25 °C and 4 °C for 30 days. Notably, Cur-Z/SNPs could achieve excellent storage stability at room temperature as compared to those at refrigeration. Furthermore, lyophilization had a positive effect on storage stability, did not change the pH stability, and slightly reduced the ionic strength stability. Besides, Cur-Z/SNPs increased the 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH˙) scavenging capacity compared to free curcumin. The bioaccessibility of curcumin was increased by about 6 times by Cur-Z/SNPs. These findings provided new insight into the application of hydrophobic nutrients in alcohol-free functional foods.

Feeding regulation by oleoylethanolamide synthesized from dietary oleic acid.

Oleoylethanolamide (OEA), a well-known satiety factor, is produced during feeding in the proximal intestine. Enterocytes sense oleic acid in dietary fat via CD36 and convert it to OEA through NAPE-PLD dependent or independent pathways. The satiety function of OEA is known to involve peroxisome proliferator-activated receptor type-α (PPAR-α). OEA stimulates afferent sensory fibers (possibly those of the vagus nerve) and provoke the recruitment of feeding-controlling circuits in the brain that use oxytocin and histamine as neurotransmitters for regulating satiety. Dysfunction of OEA synthesis by high-fat feeding might contribute to increased weight and obesity. Here, we describe the roles played by OEA in the regulation of energy metabolism and food intake by introducing our preliminary data regarding this lipid mediator, and we briefly outline the biosynthesis and deactivation of OEA.

Sustainable and Green Synthesis of Stanol Esters from Oil Wastes.

The recombinant lipase ofOphiostoma piceae (OPEr) is characterized by its prominent sterol esterase activity. The protein was immobilized on magnetic nanoparticles, giving four enzyme variants that have been tested in solvent-free transesterification of methyl oleate and sitostanol. The yields of stanol esters reached 85%, and the catalysts can be reused. Stanol esters were also obtained in a two-step cascade reaction; a mixture of fatty acid methyl esters was enzymatically synthesized from cooking oil wastes and then used for stanol transesterification. An 85% conversion was achieved in 2 h from the second cycle onward, maintaining the activity over 5 cycles. The biocatalysts can be safely used since they don't release toxic compounds for HeLa and A549 cell lines. These procedures comply with the principles of green chemistry and contribute to the sustainable production of these nutraceuticals from secondary raw materials, like the lipid fraction from industrial or agricultural residues.

A novel sophorolipid-producing Candida keroseneae GBME-IAUF-2 as a potential agent in microbial enhanced oil recovery (MEOR).

The biosurfactants have extensive applications in food and petroleum microbiology. The aims of this research were isolation and characterization of thermo-tolerant biosurfactants from highly producing yeast strains. The Bushnell Hass medium was used for screening the biosurfactant-producing yeasts. Biosurfactant presence was evaluated using oil displacement assay and surface tension test. The best biosurfactant-producing strain was named Candida keroseneae GBME-IAUF-2 and its 5.8s-rDNA sequence was deposited in GenBank, NCBI, under the accession number MT012957.1. The thin layer chromatography and Fourier-transform infrared spectroscopy analysis confirmed that the extracted biosurfactant was sophorolipid with a significant surface activity. The purified sophorolipid decreased the surface tension of water from 72 to 29.1 mN/m. Its maximum emulsification index, E24%, was recorded as 60% and preserved 92.06-97.25% of its original activity at 110-120°C. It also preserved 89.11% and 84.73% of its original activity in pH of 9.3 and 10.5, respectively. It preserved 96.66-100% of its original activity in saline extreme conditions. This is the first report of sophorolipid production by the yeast C. keroseneae. According to the high thermal, pH and saline stability, the sophorolipid produced by C. keroseneae GBME-IAUF-2 could be highly recommended for applications in microbial enhanced oil recovery as well as food industries as an excellent emulsifying agent.

Elaidate, a trans fatty acid, suppresses insulin signaling for glucose uptake in a manner distinct from that of stearate.

The dietary intake of elaidate (elaidic acid), a trans-fatty acid, is associated with the development of various diseases. Since elaidate is a C18 unsaturated fatty acid with a steric structure similar to that of a C18 saturated fatty acid (stearate), we previously revealed that insulin-dependent glucose uptake was impaired in adipocytes exposed to elaidate prior to and during differentiation similar to stearate. However, it is still unknown whether the mechanism of impairment of insulin-dependent glucose uptake due to elaidate is similar to that of stearate. Here, we indicate that persistent exposure to elaidate has particular effects on insulin signaling and GLUT4 dynamics. Insulin-induced accumulation of Akt at the plasma membrane (PM) and elevations of phosphorylated Akt and AS160 levels in whole cells were suppressed in adipocytes persistently exposed to 50 µM elaidate. Interestingly, persistent exposure to the same concentration of stearate has no effect on the phosphorylated Akt and AS160 levels. When cells were exposed to these fatty acids, elaidate suppressed insulin-induced fusion, but not translocation, of GLUT4 storage vesicles in the PM, whereas stearate did not suppress the fusion and translocation of GLUT4 storage, indicating that elaidate has suppressive effects on the accumulation of Akt and fusion of GLUT4 storage vesicles and that both elaidate and stearate vary in the mechanisms by which they impair insulin-dependent glucose uptake.

Oleoyl alanine (HU595): a stable monomethylated oleoyl glycine interferes with acute naloxone precipitated morphine withdrawal in male rats.

RATIONALE: Oleoyl glycine, a little studied fatty acid amide similar in structure to anandamide, interferes with nicotine addiction in mice and acute naloxone-precipitated morphine withdrawal (MWD) in rats. Because endogenous oleoyl glycine is subject to rapid enzymatic deactivation, we evaluated the potential of more stable analogs to interfere with opiate withdrawal. OBJECTIVES: The potential of monomethylated oleoyl glycine (oleoyl alanine, HU595) to interfere with somatic and aversive effects of acute naloxone-precipitated MWD, its duration, and mechanism of action was assessed in male Sprague Dawley rats. The potential of dimethylated oleoyl glycine (HU596) to interfere with the aversive effects of naloxone-precipitated MWD was also investigated. RESULTS: Oleoyl alanine (HU595) interfered with somatic and aversive effects produced by naloxone-precipitated MWD at equivalent doses (1 and 5 mg/kg, i.p.) as we have reported for oleoyl glycine; however, oleoyl alanine produced a longer lasting (60 min) interference, yet did not produce rewarding or aversive effects on its own and did not modify locomotor activity. HU596 was not effective. The interference with aversive effects of naloxone-precipitated MWD by oleoyl alanine was prevented by both a PPARα antagonist and a CB1 receptor antagonist. Accordingly, the compound was found to inhibit FAAH and activate PPARα in vitro. Finally, oleoyl alanine also reduced acute naloxone-precipitated MWD anhedonia, as measured by decreased saccharin preference. CONCLUSIONS: Oleoyl alanine (also an endogenous fatty acid) may be a more stable and effective treatment for opiate withdrawal than oleoyl glycine.

Design of high-oleic tobacco (Nicotiana tabacum L.) seed oil by CRISPR-Cas9-mediated knockout of NtFAD2-2.

BACKGROUND: Tobacco seed oil could be used as an appropriate feedstock for biodiesel production. However, the high linoleic acid content of tobacco seed oil makes it susceptible to oxidation. Altering the fatty acid profile by increasing the content of oleic acid could improve the properties of biodiesel produced from tobacco seed oil. RESULTS: Four FAD2 genes, NtFAD2-1a, NtFAD2-1b, NtFAD2-2a, and NtFAD2-2b, were identified in allotetraploid tobacco genome. Phylogenetic analysis of protein sequences showed that NtFAD2-1a and NtFAD2-2a originated from N. tomentosiformis, while NtFAD2-1b and NtFAD2-2b from N. sylvestris. Expression analysis revealed that NtFAD2-2a and NtFAD2-2b transcripts were more abundant in developing seeds than in other tissues, while NtFAD2-1a and NtFAD2-1b showed low transcript levels in developing seed. Phylogenic analysis showed that NtFAD2-2a and NtFAD2-2b were seed-type FAD2 genes. Heterologous expression in yeast cells demonstrated that both NtFAD2-2a and NtFAD2-2b protein could introduce a double bond at the Δ12 position of fatty acid chain. The fatty acid profile analysis of tobacco fad2-2 mutant seeds derived from CRISPR-Cas9 edited plants showed dramatic increase of oleic acid content from 11% to over 79%, whereas linoleic acid decreased from 72 to 7%. In addition, the fatty acid composition of leaf was not affected in fad2-2 mutant plants. CONCLUSION: Our data showed that knockout of seed-type FAD2 genes in tobacco could significantly increase the oleic acid content in seed oil. This research suggests that CRISPR-Cas9 system offers a rapid and highly efficient method in the tobacco seed lipid engineering programs.

Evaluation of Antioxidant and Antibacterial Activities, Cytotoxicity of Acacia seyal Del Bark Extracts and Isolated Compounds.

Water extract of Acacia seyal bark is used traditionally by the population in Djibouti for its anti-infectious activity. The evaluation of in vitro antibacterial, antioxidant activities and cytotoxicity as well as chemical characterization of Acacia seyal bark water and methanolic extracts were presented. The water extract has a toxicity against the MRC-5 cells at 256 µg/mL while the methanolic extract has a weak toxicity at the same concentration. The methanolic extract has a strong antioxidant activity with half maximal inhibitory concentration (IC50) of 150 ± 2.2 µg/mL using 1-diphenyl-2-picrylhydrazyl (DPPH) and IC50 of 27 ± 1.3 µg/mL using 2,2'-azino-bis 3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical methods. For ferric reducing/antioxidant power (FRAP) assay, the result is 45.74 ± 5.96 µg Vitamin C Equivalent (VCE)/g of dry weight (DW). The precipitation of tannins from methanol crude extract decreases the MIC from 64 µg/mL to 32 µg/mL against Staphylococcus aureus and Corynebacterium urealyticum. However, the antioxidant activity is higher before tannins precipitation than after (IC50 = 150 µg/mL for methanolic crude extract and 250 µg/mL after tannins precipitation determined by DPPH method). By matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, the results showed that the condensed tannins consist of two types of catechin and gallocatechin-based oligomers. The fractionation led to the identification of three pure compounds: two flavanols catechin and epicatechin; one triterpene as lupeol; and a mixture of three steroids and one fatty acid: campesterol, stigmasterol, clionasterol, and oleamide.

Hydroxy-octadecenoic acids instead of phorbol esters are responsible for the Jatropha curcas kernel cake's toxicity.

The toxic kernel cake of Jatropha curcas (KCakeJ) is an emerging health and environmental concern. Although phorbol esters are widely recognized as the major toxin of KCakeJ, convincing evidence is absent. Here, we show that rather than phorbol esters an isomeric mixture of 11-hydroxy-9E-octadecenoic acid, 12-hydroxy-10E-octadecenoic acid and 12-hydroxy-10Z-octadecenoic acid (hydroxy-octadecenoic acids, molecular formula C18H34O3) is the major toxic component. The toxicities of hydroxy-octadecenoic acids on experimental animals, e.g. acute lethality, causing inflammation, pulmonary hemorrhage and thrombi, allergies, diarrhea and abortion, are consistent with those on human/animals caused by Jatropha seed and/or KCakeJ. The hydroxyl group and the double bond are essential for hydroxy-octadecenoic acids' toxicity. The main pathway of the toxicity mechanism includes down-regulating UCP3 gene expression, promoting ROS production, thus activating CD62P expression (platelet activation) and mast cell degranulation. The identification of the major toxin of KCakeJ lays a foundation for establishing an environmentally friendly Jatropha biofuel industry.

Production of 7,10,12-trihydroxy-8(E)-octadecenoic acid from ricinoleic acid by Pseudomonas aeruginosa KNU-2B.

Microbial production of hydroxy fatty acids (HFAs) was widely studied because of important biological properties of HFAs. Among microorganisms producing HFAs, Pseudomonas aeruginosa PR3 was well known to produce various HFAs from different unsaturated fatty acids. Recently, a new variant species of P. aeruginosa PR3 was isolated and characterized, showing improved efficiency for producing 7,10-dihydroxy-8(E)-octadecenoic acid from oleic acid. In this study, we report the production of 7,10,12-trihydroxy-8(E)-octadecenoic acid (TOD) from ricinoleic acid by the newly isolated P. aeruginosa KNU-2B. TOD was efficiently produced from ricinoleic acid by KNU-2B with the maximum conversion yield of 56.7% under the optimum reaction conditions of pH 8.0 and 48-h incubation at 27 °C, 150 rpm. Under optimized reaction conditions, maximum TOD production reached 340.3 mg/100 mL of the culture. However, requirement of nutritional factors by KNU-2B for production of TOD were considerably different from those by PR3 strain.

Developing protein arginine methyltransferase 1 (PRMT1) inhibitor TC-E-5003 as an antitumor drug using INEI drug delivery systems.

Injectable implants with the ability to form in situ are one of the most promising carriers for the delivery of chemotherapeutic drugs to tumor sites. We have reported a novel injectable in situ-forming implant system composed of n-butyl-2-cyanoacrylate (NBCA), ethyl oleate, along with the sol-gel phase transition. The chemotherapeutic drug-loaded injectable NBCA ethyl oleate implant (INEI) exhibited excellent therapeutic efficacy for local chemotherapy. Herein, we utilize this INEI to carry N, N'-(Sulfonyldi-4,1-phenylene)bis(2-chloroacetamide) (TE-C-5003), which is a selective protein arginine methyltransferase 1 (PRMT1) inhibitor, to treat the lung cancer mice model. The in vitro experiment shows that TE-C-5003 has a good anti-tumor effect on lung cancer (IC50 = 0.7022 µM for A549; IC50 = 0.6844 µM for NCL-H1299) and breast cancer (IC50 = 0.4128 µM for MCF-7; IC50 = 0.5965 µM for MDA-MB-231). Anti-tumor experiments in animal models showed that the average growth inhibition rate of xenografted human lung cancer cells by the TE-C-5003-loaded INEI (40% NBCA) was 68.23%, which is far more than TC-E-5003 alone (31.76%). Our study further confirms that INEI is an effective technique to improve the anti-tumor effect. The druggability of small molecule compounds can be improved with the help of the mentioned technology. Also, TC-E-5003 may be developed as a broad spectrum anti-tumor drug.

Preparation and evaluation of self-microemulsifying delivery system containing 5-demethyltangeretin on inhibiting xenograft tumor growth in mice.

5-Demethyltangeretin (5-DTAN), a polymethoxylated flavone found in citrus peels, exhibits highly potent anti-cancer activity. However, 5-DTAN is a hydrophobic compound with poor aqueous solubility, which limits its oral bioavailability and efficacy. In this study, we aimed to develop and characterize an optimal self-microemulsifying delivery system (SMEDS) formulated for 5-DTAN and to assess its anticancer activity in a xenograft model. SMEDS is a lipid-based formulation and typically comprises oil, surfactant, and co-surfactant. The results from our solubility and compatibility test revealed that ethyl oleate and d-limonene were appropriate for use as an oil phases. The optimal formulation comprised ethyl oleate/d-limonene (10%/5%), Cremophor® EL (59.5%), and PEG 400 (25.5%). With this optimal formulation, the mean particle size was 97.1 ± 6.50 nm with the highest 5-DTAN loading (3.01 ± 0.38 mg/mL) determined by photon correlation spectroscopy. The transmission electron microscopy (TEM) morphology of 5-DTAN microemulsion droplets demonstrated a spherical shape and uniform size. Our findings suggest that using 5-DTAN loading SMEDS is an effective approach for inhibiting tumor growth in colon cancer xenograft mice. In summary, this study is the first to successfully demonstrate that oral administration of 5-DTAN-loaded SMEDS serves as a promising nutraceutical for cancer prevention.

New Insight on the Study of the Kinetic of Biobased Polyurethanes Synthesis Based on Oleo-Chemistry.

Nowadays, polyols are basic chemicals for the synthesis of a large range of polymers, such as polyurethane foams (PUF), which are produced with several other compounds, such as polyisocyanates. During the last decades, the oleo-chemistry has developed several routes from glycerides to polyols for the polyurethanes (PU) industry to replace mainly conventional fossil-based polyols. A large range of biobased polyols can be now obtained by epoxidation of the double bonds and ring-opening (RO) of the subsequent epoxides with different chemical moieties. In preliminary studies, the RO kinetics of an epoxidized model molecule (methyl oleate) with ethanol and acetic acid were investigated. Subsequently, polyols that were derived from unsaturated triglycerides were explored in the frame of e.g., PUF formulations. Different associations were studied with different mono-alcohols derived from epoxidized and ring-opened methyl oleate while using several ring-openers to model such systems and for comparison purposes. Kinetic studies were realized with the pseudo-first-order principle, meaning that hydroxyls are in large excess when compared to the isocyanate groups. The rate of isocyanate consumption was found to be dependent on the moiety located in ß-position of the reactive hydroxyl, following this specific order: tertiary amine >> ether > ester. The tertiary amine in ß-position of the hydroxyl tremendously increases the reactivity toward isocyanate. Consequently, a biobased reactive polyurethane catalyst was synthesized from unsaturated glycerides. These approaches offer new insights regarding the replacement of current catalysts often harmful, pungent, and volatile used in PU and PUF industry, in order to revisit this chemistry.

The human milk protein-lipid complex HAMLET disrupts glycolysis and induces death in Streptococcus pneumoniae.

HAMLET is a complex of human α-lactalbumin (ALA) and oleic acid and kills several Gram-positive bacteria by a mechanism that bears resemblance to apoptosis in eukaryotic cells. To identify HAMLET's bacterial targets, here we used Streptococcus pneumoniae as a model organism and employed a proteomic approach that identified several potential candidates. Two of these targets were the glycolytic enzymes fructose bisphosphate aldolase (FBPA) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Treatment of pneumococci with HAMLET immediately inhibited their ATP and lactate production, suggesting that HAMLET inhibits glycolysis. This observation was supported by experiments with recombinant bacterial enzymes, along with biochemical and bacterial viability assays, indicating that HAMLET's activity is partially inhibited by high glucose-mediated stimulation of glycolysis but enhanced in the presence of the glycolysis inhibitor 2-deoxyglucose. Both HAMLET and ALA bound directly to each glycolytic enzyme in solution and solid-phase assays and effectively inhibited their enzymatic activities. In contrast, oleic acid alone had little to no inhibitory activity. However, ALA alone also exhibited no bactericidal activity and did not block glycolysis in whole cells, suggesting a role for the lipid moiety in the internalization of HAMLET into the bacterial cells to reach its target(s). This was verified by inhibition of enzyme activity in whole cells after HAMLET but not ALA exposure. The results of this study suggest that part of HAMLET's antibacterial activity relates to its ability to target and inhibit glycolytic enzymes, providing an example of a natural antimicrobial agent that specifically targets glycolysis.

Effect of alpha-lactalbumin and lactoferrin oleic acid complexes on chromatin structural organization.

This work focuses on the study of multimeric alpha-lactalbumin oleic acid and lactoferrin oleic acid complexes. The purpose of the research is to study possible mechanisms involved in their pro-apoptotic activities, as seen in some tumor cell cultures. Complexes featuring oleic acid (OA) with human alpha-lactalbumin (hAl) or with bovine alpha-lactalbumin (bAl), and human lactoferrin (hLf) were investigated using small-angle neutron scattering (SANS). It was shown that while alpha-lactalbumin protein complexes were formed on the surface of polydisperse OA micelles, the lactoferrin complexes comprised a monodisperse system of nanoscale particles. Both hAl and hLf complexes appeared to interact with the chromatin of isolated nuclei affecting chromatin structural organization. The possible roles of these processes in the specific anti-tumor activity of these complexes are discussed.