Glycidol Research Articles

Quantification of 2,4-dichlorophenoxyacetic acid in environmental samples using imprinted polyethyleneimine with enhanced selectivity as a selective adsorbent in ambient plasma mass spectrometry

Detection and quantification of various organic chemicals in the environment is critical to track their fate and control their levels. 2,4-Dichlorophenoxyacetic acid (2,4-D) is a widely applied phenoxy herbicide with potential toxicity to fish and other aquatic organisms. In this study, we address the need for improved detection of 2,4-D by introducing a novel analytical method for its quantification. This method relies on the selective extraction of 2,4-D using MIPs and their subsequent direct analysis using ambient plasma mass spectrometry. During the synthesis, MIPs with various degrees of glycidol (GLY) functionalization were obtained. Experimental data showed that MIPs with no GLY functionalization displayed the highest adsorption capacity. Conversely, MIPs with 30% GLY functionalization exhibited the greatest selectivity for 2,4-D, rendering them valuable for extraction of 2,4-D even in the presence of other contaminants. Finally, the obtained MIPs were applied for quantification of 2,4-D in various water samples through direct analysis using a specially designed ambient plasma mass spectrometry setup. This approach improved the detection limits by 200-fold compared to pure solution analysis. The quantification of 2,4-D in river water samples yielded highly satisfactory recoveries, demonstrating the effective utility of the proposed analytical setup for real-life water sample analysis.

Fabrication of hyperbranched-polyglycidol-Fe3O4 nanocomposite labeled with fluorescein isothiocyanate via rapid ligand exchange reaction

Oleic acid, the ligand of Fe3O4 magnetic nanoparticles with the size of 20 nm, prepared from iron oleate via the thermal decomposition method, was rapidly replaced with lactic acid (LA) via heating in tetrahydrofuran within 10 min. The exchange degree was almost quantitative, and the product was easily isolated by magnetic separation. The OH groups of LA on the surface of the Fe3O4 nanoparticles were utilized for the ring-opening polymerization of glycidol (GLYD) to produce the Fe3O4-LA-hyperbranched poly (GLYD) (hbPGLYD) nanocomposite. The thickness of the hbPGLYD layer was easily altered by changing the feed ratio of GLYD to Fe3O4. After converting up to 30 mol% of OH on the hbPGLYD moiety into NH2 functions, the nanocomposite was successfully labeled using fluorescein isothiocyanate.

Suppression of neurogranin expression by disruption of epigenetic DNA methylation in hippocampal mature granule cells after developmental exposure to neurotoxicants in rats

We previously performed comprehensive analyses of genes hypermethylated promoter regions and downregulated transcripts in the hippocampal dentate gyrus (DG) of rats upon weaning at postnatal day (PND) 21 after developmental exposure to 6-propyl-2-thiouracil (PTU), valproic acid, and glycidol (GLY), all of which are known to show irreversible effects on hippocampal neurogenesis in adulthood on PND 77. Here, we selected neurotransmitter and neurogenesis-related genes for validation analysis of methylation and expression. As a result, Nrgn by GLY and Shisa7, Agtpbp1, and Cyp46a1 by PTU underwent DNA hypermethylation and sustained downregulation. Immunohistochemical analysis of candidate gene products revealed that the number of neurogranin (NRGN)+ granule cells was decreased in the ventral DG by GLY on PND 21 and 77 and by PTU on PND 21. Among the samples of developmental or 28-day young adult-age exposure to known developmental neurotoxicants in humans, i.e., lead acetate, ethanol, and aluminum chloride, a decrease of NRGN+ cells by ethanol was also observed on PND 77 after developmental exposure. Double immunohistochemistry analysis revealed that NRGN was expressed in mature granule cells, and a similar immunoreactive cell distribution was found for phosphorylated calcium/calmodulin-activated protein kinase, a NRGN downstream molecule. After developmental PTU exposure, the number of activity-regulated cytoskeleton-associated protein+ granule cells was also profoundly decreased in the ventral DG in parallel with the decrease in NRGN+ cells on PND 21. These results suggest that NRGN is a potential marker for suppression of synaptic plasticity in mature granule cells in the ventral DG.

Thorough elucidation of synthesis and structure of poly(glycerol) functionalized nanodiamonds

Poly(glycerol) (PG) is one of the most promising platforms for the surface modification of nanomaterials especially for in vivo applications. Since the “grafting-from” process is facile to functionalize the nanomaterial surface covalently through the ring-opening polymerization of glycidol (GD), it has been applied to a variety of nanomaterials. The resulting numerous hydroxy groups in the hyperbranched structure serve as scaffolds for further functionalization and provide good dispersibility under physiological conditions. On the other hand, nanodiamond (ND) is a nanomaterial most intensely worked with PG because of its prominent properties including fluorescence from color centers. Despite the wide-spread use, the process has not been extended to be scalable and controllable. In addition, the structural details of PG chain on ND surface are yet elusive. In this work, we develop more scalable and safer PG functionalization of NDs by dropwise-addition of GD to ethylene glycol (EG) suspension of ND. The resulting PG amount can be controlled or even estimated by the reaction conditions (weights of GD, ND and EG) and the ND properties (diameter and oxygen content). The structure of PG chain was qualitatively and quantitatively analyzed by 13C nuclear magnetic resonance (NMR) and dynamic light scattering (DLS) measurements. Based on these results, the structure of PG is elucidated.

Bifunctional Oxidation Catalysis of New Titanium-Silicon Molecular Sieve (HTS-1) Based on the Reaction of Allyl Alcohol and Hydrogen Peroxide

The HTS-1 (Hollow Titanium silicalite molecular sieve) catalyst with bifunctional catalysis showed superior catalytic activity in the epoxidation of olefins and the oxidation of alcohols. The competitive oxidation law of enols in the HTS-1/H2O2 oxidation system was studied. The effects of various reaction conditions, such as the reaction temperature, solvent, catalyst type, and the amount of additive, were examined. The results indicated that the HTS-1 catalyst preferentially catalyzes AA epoxidation to produce glycidol (GLY) efficiently and selectively using polar proton solvent and proper temperature. Using alkaline additives can greatly improve the catalytic activity of HTS-1 and selectivity of glycidol. Under optimal conditions, the conversion of AA can rate to 77%, and the selectivity of GLY can also achieve 91%.

Effect of hydrophilic or hydrophobic interactions on the self-assembly behavior and micro-morphology of a collagen mimetic peptide

Peptide self-assembles with bionic properties have been widely utilized for bioactive drugs and biomedical materials. Collagen mimetic peptide (CMP) gains more attention due to its unique advantages in biosecurity and function. Unfortunately, the self-assembly mechanism of CMP, particularly the effect of intermolecular forces on its self-assembly behavior and morphology, is still unrecognized. Herein, the hydrophilic glycidol (GCD) and hydrophobic Y-glycidyl ether oxypropyl trimethoxysilane (GLH) were grafted onto the side chains of CMP through the ring-opening reaction (GCD/CMP, GLH/CMP). Subsequently, the effects of hydrophilic and hydrophobic interactions on the self-assembly behavior and morphology of CMP were further studied. The results substantiated that the GCD/CMP and GLH/CMP self-assembly followed “nucleation-growth” mechanism, and the supererogatory hydrophilic and hydrophobic groups prolonged the nucleation and growth time of CMP self-assembly. Noted that the hydrophilic interaction had stronger driving effects than hydrophobic interaction on the self-assembly of CMP. The GCD/CMP and GLH/CMP self-assembles exhibited fibrous 3D network and microsphere morphology, respectively. Furthermore, the GLH/CMP self-assembles had better resistance to degradation. Consequently, the microtopography and degradation properties of CMP self-assembles could be controlled by the hydrophilic and hydrophobic interactions between CMP, which would further provide a way for subsequent purposeful design of biomedical materials.Graphical abstract

Identification of gene targets of developmental neurotoxicity focusing on DNA hypermethylation involved in irreversible disruption of hippocampal neurogenesis in rats.

We have previously found that maternal exposure to 6‐propyl‐2‐thiouracil (PTU), valproic acid (VPA), or glycidol (GLY) has a sustained or late effect on hippocampal neurogenesis at the adult stage in rat offspring. Herein, we searched for genes with hypermethylated promoter region and downregulated transcript level to reveal irreversible markers of developmental neurotoxicity. The hippocampal dentate gyrus of male rat offspring exposed maternally to PTU, VPA, or GLY was subjected to Methyl‐Seq and RNA‐Seq analyses on postnatal day (PND) 21. Among the genes identified, 170 were selected for further validation analysis of gene expression on PND 21 and PND 77 by real‐time reverse transcription‐PCR. PTU and GLY downregulated many genes on PND 21, reflecting diverse effects on neurogenesis. Furthermore, genes showing sustained downregulation were found after PTU or VPA exposure, reflecting a sustained or late effect on neurogenesis by these compounds. In contrast, such genes were not observed with GLY, probably because of the reversible nature of the effects. Among the genes showing sustained downregulation, Creb, Arc, and Hes5 were concurrently downregulated by PTU, suggesting an association with neuronal mismigration, suppressed synaptic plasticity, and reduction in neural stem and progenitor cells. Epha7 and Pvalb were also concurrently downregulated by PTU, suggesting an association with the reduction in late‐stage progenitor cells. VPA induced sustained downregulation of Vgf and Dpysl4, which may be related to the aberrations in synaptic plasticity. The genes showing sustained downregulation may be irreversible markers of developmental neurotoxicity.

Application of Co-Al Catalysts in Hydrogenation of Glycidol to 1,3-Propanediol

Application of Co-Al Catalysts in Hydrogenation of Glycidol to 1,3-Propanediol

IMPROVING THE CATALYTIC FEATURES OF THE LIPASE FROM Rhizomucor miehei IMMOBILIZED ON CHITOSAN-BASED HYBRID MATRICES BY ALTERING THE CHEMICAL ACTIVATION CONDITIONS

The lipase from Rhizomucor miehei (RML) has been immobilized on chitosan-based hybrid (sodium alginate or carrageenan) matrices activated with glycidol (GLY), epichlorohydrin (EPI) or glutaraldehyde (GLU) groups. Then, the properties of the different biocatalysts have been evaluated and compared with the soluble RML. Thermal stability (at pH 7.0 and 60 °C) was significantly increased when compared to the soluble enzyme: 154-fold for chitosan 5.0% - GLU, 80-fold for chitosan 2.5% - carrageenan 2.5% - GLY and 93-fold for chitosan 2.5% - alginate 2.5% - EPI. The best biocatalyst preparation, which was 154-fold more stable than the soluble enzyme, was obtained when RML was immobilized on chitosan activated with glutaraldehyde 5.0% v/v. According to the results, it was concluded that RML immobilization on chitosan-based hybrid matrices using different chemistries greatly produced biocatalysts with different properties.

Crystalline LaCoO3 perovskite as a novel catalyst for glycerol transesterification

LaCoO3 perovskite was synthesized using sol-gel method by nitrate and acetate precursors of La and Co with varying molar ratios of La and Co (1:1, 1:2 and 2:1). This was found to be an unique strategy to obtain highly crystalline LaCoO3 perovskite material without using any chelating agent. The variation of precursors was found to influence their crystallinity however, variation in molar ratio in the range of 0.5–2, did not affect the formation of perovskite framework. The formation of pure perovskite phase (around or >80%) could be achieved by combination of acetate and nitrate precursors while, the combination of acetate- acetate or nitrate- nitrate precursors resulted in low phase purity for the perovskite due to the formation of secondary phases like La2O3 and Co3O4. Very interestingly, such combination of perovskite and pure oxide phases contributed to enhancement of basic sites which catalyzed the glycerol transestrifiaction with DMC (dimethyl carbonate) to GC (glycerol carbonate) and GD (glycidol). Among all the catalysts studied, NAP-2 showed highest efficiency in terms of 98% glycerol conversion and 77% GC and 22% GD selectivities. The highlight of this work is that first step glycerol transesterification with DMC required basic sites of either metal oxide or perovskite but for cascade reaction involving decarboxylation required both metal oxide as well as LaCoO3 perovskite phase.

Монохлорпропандиолы, глицидол и их эфиры в детском питании

Монохлорпропандиолы, глицидол и их эфиры в детском питании

Synthesis of glycerol carbonate over porous La-Zr based catalysts: The role of strong and super basic sites

As important glycerol derivatives, glycerol carbonate (GC) and glycidol (GD) have attracted increasing attention in recent years. In the present work, a series of new solid base catalysts were developed to catalyze the conversion of glycerol to afford GC and GD. These catalysts were prepared by loading KF on the porous La-Zr solid base catalyst and characterized using a series of methods. A large number of various basic sites were generated upon loading KF onto the La-Zr-600 support. The weak basic sites were assigned to the surface hydroxyl groups produced during the formation of LaOF, while the strong and super basic sites were related to the Lewis base produced due to the interaction between KF and the La-Zr-600 support. A glycerol conversion of 91.77% and a GC selectivity of 99% were obtained over 0.3KF/La-Zr, which displayed the best catalytic performance under the optimal reaction conditions. The excellent activity of these catalysts was attributed to the presence of the strong and super basic sites, which favor the transesterification of glycerol with dimethyl carbonate. The production of GD from GC decarbonylation was unfeasible at low temperature using the newly developed catalysts. A plausible reaction mechanism has been proposed based on the experimental results and characterization.

Production of glycerol carbonate using crude glycerol from biodiesel production with DBU as a catalyst

Abstract The biodiesel production technology catalyzed by 1,8-diazabicycloundec-7-ene (DBU) is developed in this work. Crude glycerol containing DBU and DBU/glycerol/CO2 (DGC) ionic compounds reacts directly with dimethyl carbonate (DMC) to produce high value-added glycerol carbonate (GC) catalyzed by DBU and DGC. The catalytic performance of DBU and DGC, as well as the kinetics of the reaction catalyzed by DBU, were investigated. The results show that DGC has a weak catalytic effect on the transesterification of glycerol and DMC. When the temperature is higher than 60 °C, DGC catalyzes the reaction jointly with DBU, which is produced from the decomposition of DGC. DBU has a good catalytic effect on the reaction between glycerol and DMC, with 90% conversion of glycerol and 84% selectivity to GC under the following conditions: DMC-to-glycerol molar ratio of 3:1, 4.0% DBU (based on glycerol mass), reaction time of 60 min, and reaction temperature of 40 °C. The apparent kinetics results show that the activation energies are 30.95 kJ·mol− 1 and 55.16 kJ·mol− 1 for the forward and reverse GC generation reactions, respectively, and the activation energy of the decomposition reaction of GC to glycidol (GD) is 26.58 kJ·mol− 1.

Aliphatic–Aromatic Polyols by Thiol–Ene Reactions

Aliphatic–aromatic polyols were synthesized by thiol–ene reactions (photochemical or thermal) using mercaptanized starting materials from bio-based compounds: limonene dimercaptan, thioglycerol, mercaptanized castor oil and isosorbide (3-mercaptopropyl) ether. Aromatic starting materials were phenols containing double bonds; ortho-allyl phenol (OAP, petrochemical-based) and eugenol (EUG, bio-based). The phenolic hydroxyl groups were blocked by alkoxylation with propylene oxide (PO) or glycidol (GLY) prior to use in thiol–ene reaction. The aromatic rings were attached to the mercaptans by reacting thiol groups with the double bonds of alkoxylated OAP (OAP–PO and OAP–GLY) and alkoxylated EUG (EUG–PO and EUG–GLY). These synthesized aliphatic–aromatic polyols were utilized for preparation of rigid polyurethane foams whose physical–mechanical properties were superior to those made only from bio-based aliphatic polyols. These rigid PU foams can be used in a wide range of applications; such as thermal insulation of freezers, buildings, pipes and storage tanks for food and chemical industries, as wood substitute, packaging materials and flotation materials.

The Kinetics and Mechanism of the Reaction between Barbituric Acid and Glycidol, Part I: The Products Analysis

ABSTRACTThe hydroxyalkyl derivatives of barbituric acid (BA) were formed in the reaction between BA and glycidol (GL). The reaction was performed at BA:GL 1:1, 1:2, and 1:4 molar ratios in DMF or without solvent. The progress of reaction was monitored by determination of the epoxide number and IR and NMR spectroscopy. It was found that primary reactive site of BA was C5 and further nitrogen ring atoms. BA was always involved in keto‐enol equilibrium, the latter form being less reactive. The isolated hydroxyalkyl derivatives are useful precursors of oligoetherols with the pyrimidine ring.

Tandem Synthesis of Glycidol via Transesterification of Glycerol with DMC over Ba-Mixed Metal Oxide Catalysts

Glycerol carbonate (GC) and glycidol (GD) are commercial products possible from glycerol transformation, which has become a subject of great importance. Among several basic catalysts screened in this work, BaO showed the highest glycerol conversion of 71% with almost complete selectivity to GC. A tandem synthesis of GD with a selectivity as high as 80% with 98% glycerol conversion could be achieved with mixed oxides of Ba and lanthanides (La and Ce) prepared by the coprecipitation method. Although BaO alone showed the highest basicity as measured by CO2 TPD, tuning of basicity by incorporation of CeO2 resulted in the formation of GD. Incorporation of Ba into the ceria matrix induced oxygen vacancies in the cerium oxide material. The presence of u″/v″ doublets at 888.7 and 903.2 eV, respectively, in XPS of the Ba–Ce sample also confirmed the oxygen vacancies in the lattice. In this tandem approach to GD, the subsequent decarboxylation of initially formed GC was due to the presence of a CeO2 lattice with de...

34 A pH-sensitive polymer enhances the specificity and therapeutic efficiency of liposomal DOX in vitro

Background Lipid nanoparticles (LNPs) were eagerly anticipated as promising delivery systems for cancer drugs due to their biocompatibility and tendency to accumulate in tumor tissues. 3-Methylglutarylated poly (glycidol) (MGluPG) was insert into LNPs to form pH-sensitive polymer-modified liposomes which can delivery doxorubicin (DOX) into tumor cells by membrane fusion under relatively acidic conditions. In this study, we report that MGluPG-modified liposomal DOX can efficiently promote antitumor activity and target binding compared to non-MGluPG-modified liposomes. Methods Briefly, eggPC, MGluPG, cholesterol and DOTAP were dissolved in chloroform and dried to a thin membrane on a rotary evaporator. The dried lipid mixture was further hydrated in a low-pH solution (6 mM ammonium sulphate, pH 5.5) under a vortex mixer to form polydispersity vesicles. The liposomes were then extruded through a polycarbonate membrane with a pore size of 80 nm to reduce particle size and dialyzed in a neutral buffer (pH 7.4) to establish the pH gradient. DOX was loaded by incubating with preformed liposomes at 60° C for 30 min with intermittent vortexing and finally the mixture was eluted using a Sepharose CL-4B gel-filtration column to remove free DOX. Results The LNPs synthesized in this procedure had a particle size of 168 ± 10.6 nm and a ζ potential of 5 ± 0.78 mV. Drug encapsulation efficiency (EE) was over 85%, meaning most DOX was encapsulated into the liposomes. The release of MGluPG-modified liposomal DOX in phosphate buffer (pH 5.3) was significantly higher than in PBS (pH 7.4) after 24 hours of incubation at 37° C. The MTT test further demonstrated that the IC 50 of MGluPG-modified liposomes induced significantly less cytotoxicity. Data from the inhibition of tumour growth revealed MGluPG-modified liposomal DOX was both safe and inhibited tumor growth efficiently.

Cashew apple bagasse as a support for the immobilization of lipase B from Candida antarctica: Application to the chemoenzymatic production of (R)-Indanol

Lipase B from Candida antarctica lipase expressed in Aspergillus niger has been covalently immobilized on cashew apple bagasse, and it stability and performance in the chemoenzymatic synthesis of (R)-Indanol has been evaluated. The cashew apple bagasse (CAB) has been treated with alkaline hydrogen peroxide and activated with glycidol (GLY) to obtain glyoxyl groups, in addition to ethylenediamine and further activation with glutaraldehyde (GEG).The maximum loading of the support was 10mg protein/g support, and its thermal and solvent stability was much higher than that of the soluble enzyme. The CAB-GEG preparation (with 95% yield of immobilization and 124% activity recovery) was used in the hydrolysis of ethyl rac-indanyl acetate using an enzyme/substrate ratio of 2: 1 and a pH value of 7.0 at 30°C for 24h. The conversion attained was 50% of conversion and e.e. of 99%. The reusability studies showed maintenance of conversion and e.e. during five cycles. The results suggest that the new CAB support may be an excellent alternative for lipase immobilization and stabilization.

New method of synthesis of oligoetherols with pyrimidine ring from barbituric acid and glycidol (Rapid Communication)

Barbituric acid (BA) cannot be used for synthesis of oligoetherols in a straightforward reaction with ethylene oxide (EO) or propylene oxide (PO) or alkylene carbonates because it undergoes tautomeric conversion into the tri-enolic form. The latter is insoluble in oxiranes and alkylene carbonates and does not react with them further. This obstacle was eliminated by initial functionalization of BA with glycidol (GL) leading to hydroxyalkyl derivatives of BA. The hydroxyalkyl derivatives of BA dissolve easily in oxiranes or in alkylene carbonates like ethylene (EC) or propylene (PC) carbonates and react with them to give oligoetherols with enhanced thermal stability.

Unsaturated Polyesters with Pendant Double Bonds and Investigation of their Self Curable Activity

In this paper, the self-curable unsaturated polyester was put forward as a new solution to air pollution problems caused by the cross-linking monomer’s volatilization in unsaturated polyesters (UP) industry. Two kinds of unsaturated polyesters with the vinyl double bonds at the side chain were synthesized with Itaconic acid (IA) or Itaconic anhydride (ITA) as raw materials. The first one was prepared with IA, isophthalic acid and propylene glycol (IPP-UP), and the second one was synthesized with glycidol (GL) and ITA (IG-UP). Investigation demonstrates that the latter UP resin could be self-cured through the nucleophilic addition reaction of hydroxyl groups with double bonds or the free-radical homopolymerization of double bonds when they were heated without cross-linking monomers. However, the former couldn’t. Factors on self-crosslinking activity and crosslinking mechamism of pendant vinyl bonds from IA or ITA were explored.1H-NMR and FT-IR were used to characterize.