Neopentyl Glycol Research Articles

BASF increases prices for Neopentyl Glycol and 1,6-Hexanediol in Europe

BASF increases prices for Neopentyl Glycol and 1,6-Hexanediol in Europe

Efficient expression, purification, and visualization by cryo-EM of unliganded near full-length HER3.

Biochemical analyses of membrane receptor kinases have been limited by challenges in obtaining sufficient homogeneous receptor samples for downstream structural and biophysical characterization. Here, we report a suite of methods for the efficient expression, purification, and visualization by cryo-electron microscopy (cryo-EM) of near full-length Human Epidermal Growth Factor Receptor 3 (HER3), a receptor tyrosine pseudokinase, in the unliganded state. Through transient mammalian cell expression, a two-step purification with detergent exchange into lauryl maltose neopentyl glycol (LMNG), and freezing devoid of background detergent micelle, we obtained ~6Å reconstructions of the ~60kDa fully-glycosylated unliganded extracellular domain of HER3 from just 30mL of suspension culture. The reconstructions reveal previously unappreciated extracellular domain dynamics and glycosylation sites.

Preparation and properties of bio-lubricants of neopentylglycol esters from various acids

In this work, two different neopentyl glycol (NPG) esters have been synthesized from NPG with 10- undecylenic acid (UDA) and calophyllum fatty acid (CFA) by the esterification process by using para toluene sulfonic acid as a catalyst. The esterification reaction progress has been determined by collecting measured water by using the Dean Stack apparatus. The prepared ester structures have been characterized by NMR, IR and the general physico-chemical behaviors such as density, viscosity, flash point, pour point and copper strip corrosion were determined. Moreover, these prepared ester properties have been compared to commercial ISO VG grade lubes.

Biophysical and functional properties of purified glucose-6-phosphatase catalytic subunit 1

Glucose-6-phosphatase catalytic subunit 1 (G6PC1) plays a critical role in hepatic glucose production during fasting by mediating the terminal step of the gluconeogenesis and glycogenolysis pathways. In concert with accessory transport proteins, this membrane-integrated enzyme catalyzes glucose production from glucose-6-phosphate (G6P) to support blood glucose homeostasis. Consistent with its metabolic function, dysregulation of G6PC1 gene expression contributes to diabetes, and mutations that impair phosphohydrolase activity form the clinical basis of glycogen storage disease type 1a. Despite its relevance to health and disease, a comprehensive view of G6PC1 structure and mechanism has been limited by the absence of expression and purification strategies that isolate the enzyme in a functional form. In this report, we apply a suite of biophysical and biochemical tools to fingerprint the in vitro attributes of catalytically active G6PC1 solubilized in lauryl maltose neopentyl glycol (LMNG) detergent micelles. When purified from Sf9 insect cell membranes, the glycosylated mouse ortholog (mG6PC1) recapitulated functional properties observed previously in intact hepatic microsomes and displayed the highest specific activity reported to date. Additionally, our results establish a direct correlation between the catalytic and structural stability of mG6PC1, which is underscored by the enhanced thermostability conferred by phosphatidylcholine and the cholesterol analog cholesteryl hemisuccinate. In contrast, the N96A variant, which blocks N-linked glycosylation, reduced thermostability. The methodologies described here overcome long-standing obstacles in the field and lay the necessary groundwork for a detailed analysis of the mechanistic structural biology of G6PC1 and its role in complex metabolic disorders.

A SiO2 Microcarrier with an Opal-like Structure for Cross-Linked Enzyme Immobilization.

The opal-like SiO2 microcarriers with different pore diameters named opal-SiO2I and opal-SiO2II were synthesized and utilized as microcarriers to immobilize Rhizopus oryzae lipase (ROL) and Aspergillus oryzae α-amylases (AOA). ROL and AOA can be more stably immobilized on the cross-linked SiO2 opals by neopentyl glycol diglycidyl ether (NGDE), which is the first attempt to use it as a cross-linking agent compared with glutaraldehyde. According to the morphology analysis, multiple layers of SiO2 monodisperse microspheres were regularly packed and formed an opal-like structure, and enzymes were well scattered and immobilized throughout the SiO2 opals. The results showed that the performance of enzymes immobilized on opal-SiO2II with a larger specific surface area was much better than that of opal-SiO2I. The enzyme activity of ROL@opal-SiO2II and AOA@opal-SiO2II cross-linked with 1% NGDE increased 5.32 and 9.32 times compared with their free counterpart, respectively. Furthermore, pH and thermal stability and reusability of ROL/AOA@opal-SiO2II were significantly improved and higher than those of ROL/AOA@opal-SiO2I and free enzymes. This study provides an easily obtained microcarrier opal-SiO2II, which shows potential for efficient different enzyme immobilizations and further industrial applications.

Facile and Rapid Synthesis of Neopentyl Glycol in a Continuous‐Flow Microreactor

AbstractNeopentyl glycol (NPG) synthesis by condensation disproportionation of formaldehyde and isobutyraldehyde (IBD) with sodium hydroxide as catalyst was studied in a continuous‐flow microreactor under various experimental conditions, such as reaction temperature, residence time, and the molar ratio of reactants. All the conditions were determined by Box‐Behnken experimental design and the response surface method based on the preferred range selected by single‐factor experiments. For comparison, NPG was synthesized by condensation disproportionation of the same reactants in a batch reactor. The results showed that higher NPG yield and shorter residence time were achieved in a continuous‐flow microreactor than in a batch reactor when the other experimental conditions were similar.

Production of sustainable two-stroke engine biolubricant ester base oil from palm fatty acid distillate

In this study, palm fatty acid distillate (PFAD) was selected as the feedstock for biolubricant base oil production in two-stroke engine oils’ formulation. PFAD is a low-cost palm refinery by-product with a high free fatty acid (FFA) content (85%). The esterification of PFAD with neopentyl glycol (NPG) was conducted in the presence of a solid acid catalyst (SO42-/Fe2O3/Al2O3) to produce PFAD-NPG ester. Optimization profile indicated that PFAD conversion and PFAD-NPG ester yield were 84% and 82%, respectively, under optimum reaction conditions of 180 °C, 4 h, 2.0 wt% SO42-/Fe2O3/Al2O3 catalyst loading and a 2:1 PFAD to NPG molar ratio. The physicochemical properties of the base oil successfully comply with the Japanese Automotive Standards Organization (JASO) M345:2018 requirements for two-stroke oils in terms of sulfated ash content, kinematic viscosity at 100 °C and flash point. In addition, reusability of solid acid catalyst, SO42-/Fe2O3/Al2O3 was investigated, where PFAD conversion and PFAD-NPG ester yield were found to be excellent at 81% and 80%, respectively, which showed that the catalyst had good consistency after 5 cycles.

Heterogeneous esterification of ricinoleic acid with polyol for the synthesis of polyol ricinoleates as biomass‐based lubricant base oil

AbstractBio‐derived lubricants, especially those derived from vegetable oils, are considered to be promising alternatives to mineral oil‐based lubricants due to the features of sustainability and environmental friendliness. In this work, the polyol ricinoleates were prepared by esterification of ricinoleic acid with trimethylolpropane (TMP), neopentyl glycol (NPG) and pentaerythritol (PE) respectively using Lewis acidic stannous oxide as an efficient heterogeneous catalyst, affording the polyol ricinoleates up to 99.7% yield. Remarkably, the solid catalyst was readily recovered and reused at least for five cycles without significant loss of activity. The resulting polyol ricinoleates products were structurally characterized by Fourier transform infrared spectroscopy (FT‐IR), 1H NMR, 13C NMR, electrospray ionization mass spectra (ESI‐MS); and were stable below 300°C through thermogravimetric analysis (TGA). Furthermore, the physicochemical and lubricating properties of as‐synthesized polyol esters were also evaluated including viscosity at 40 and 100°C, viscosity index (VI), pour point and flash point, thermal stability and wear scar diameter. To our delight, the performance indicators of the target products were comparable or better than the commercial lubricants, showing their potential as lubricant base oil. This work represents an alternative access to useful lubricant products via effective and selective conversion of non‐edible vegetable oil.

MmpL3, the trehalose monomycolate transporter, is stable in solution in several detergents and can be reconstituted into peptidiscs

Mycobacteria possess a complex and waxy cell wall comprising a large panel of glycolipids. Among these, trehalose monomycolate (TMM) represents abundant and crucial components for the elaboration of the mycomembrane. TMM is synthesized in the cytoplasmic compartment and translocated across the inner membrane by the MmpL3 transporter. Inhibitors impeding TMM transport by targeting MmpL3 show great promises as new antimycobacterials. The recent X-ray or Cryo-EM structures of MmpL3 complexed to TMM or its inhibitors have shed light on the mechanisms of TMM transport and inhibition. So far, purification procedures mainly involved the use of n-Dodecyl-ß-d-Maltopyranoside to solubilize and stabilize MmpL3 from Mycobacterium smegmatis (MmpL3Msm) or Lauryl Maltose Neopentyl Glycol for MmpL3 from Mycobacterium tuberculosis. Herein, we explored the possibility to solubilize and stabilize MmpL3 with other detergents. We demonstrate that several surfactants from the ionic, non-ionic and zwitterionic classes are prone to solubilize MmpL3Msm expressed in Escherichia coli. The capacity of these detergents to stabilize MmpL3Msm was evaluated by size-exclusion chromatography and thermal stability. This study unraveled three new detergents DM, LDAO and sodium cholate that favor solubilization and stabilization of MmpL3Msm in solution. In addition, we report a protocol that allows reconstitution of MmpL3Msm into peptidiscs.

Neopentyl Glycol as a Scaffold to Provide Radiohalogenated Theranostic Pairs of High In Vivo Stability.

The high in vivo stability of 2,2-dihydroxymethyl-3-[18F]fluoropropyl-2-nitroimidazole ([18F]DiFA) prompted us to evaluate neopentyl as a scaffold to prepare a radiotheranostic system with radioiodine and astatine. Three DiFA analogues with one, two, or without a hydroxyl group were synthesized. While all 125I-labeled compounds remained stable against nucleophilic substitution, only a 125I-labeled neopentyl glycol was stable against cytochrome P450 (CYP)-mediated metabolism and showed high stability against in vivo deiodination. 211At-labeled neopentyl glycol also remained stable against both nucleophilic substitution and CYP-mediated metabolism. 211At-labeled neopentyl glycol showed the biodistribution profiles similar to those of its radioiodinated counterpart in contrast to the 125I/211At-labeled benzoate pair. The urine analyses confirmed that 211At-labeled neopentyl glycol was excreted in the urine as a glucuronide conjugate with the absence of free [211At]At-. These findings indicate that neopentyl glycol would constitute a promising scaffold to prepare a radiotheranostic system with radioiodine and 211At.

Saturated Vapor Pressures and Enthalpies of Vaporization of Diesters of Neopentyl Glycol and Linear C2–C6 Acids

Saturated Vapor Pressures and Enthalpies of Vaporization of Diesters of Neopentyl Glycol and Linear C2–C6 Acids

Development of Methods for the Synthesis of Neopentyl Glycol by Hydrogenation of Hydroxypivaldehyde.

Neopentyl glycol (NPG) is a precursor for the manufacture of many valuable products of industrial importance such as polyester, polyurethane and alkyd resins, synthetic lubricants, hydraulic fluids, drugs, etc. The structure of NPG provides the resins with excellent hydrolytic stability, resistance to weather conditions, good flexibility-hardness balance, and outstanding functional properties. The paper presents a literature review on the development of methods for NPG preparation, focusing primarily on the synthesis of NPG by hydrogenation of hydroxypivaldehyde, which is obtained by the crossed aldol condensation of isobutyraldehyde and formaldehyde. Preparation of the substrates, catalysts, technical and apparatus solutions, and NPG purification were discussed.

Synergistic effect of intumescent flame retardant and zinc borate on linear low‐density polyethylene

AbstractA series of novel intumescent flame retardant (IFR) based on melamine, neopentyl glycol, and aluminum diethylphosphinate were prepared and tested. In addition, the synergistic effect of the novel IFR and zinc borate (ZB) on the flame retardancy of LLDPE composites was investigated. The structures of novel IFR and ZB were characterized by X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The limiting oxygen index (LOI) increased from 19.3% for the pure LLDPE to 27% for the 25 wt% IFR/5 wt% ZB composites and the composites achieved the desired V‐0 rating in the UL‐94 test. Thermogravimetric analysis showed that the addition of IFR/ZB reduced the pyrolysis rate of the LLDPE composites at high temperatures and increased the amount of the char residues, and the char residue of LLDPE‐5 reached 12.1 wt% at 700°C. Cone calorimetry (CCT) data showed that the peak of total heat release, heat release rate, and fire growth index were comparatively reduced, indicating that the addition of IFR/ZB decreased the fire hazard of LLDPE composites. The formation of a compact and thermally stable char layer on the surfaces of LLDPE composites was revealed from the scanning electrone microscopy images and digital photographs of the char residue after the CCT tests.

Lipase‐mediated synthesis of neopentyl glycol diester using a combination of reduced and standard pressure

AbstractNeopentyl glycol (NPG) diester is a biodegradable lubricant used in the machinery industry as it is suitable for the low‐temperature environment. NPG diester was successfully synthesized with fatty acid and NPG using immobilized lipase. Immobilization was carried out with a liquid enzyme, Eversa® Transform 2.0 (from Thermomyces lanuginosus) and Lewatit VP OC 1600 as a carrier. The Eversa immobilized lipase prepared in this study was compared with commercial lipases, such as Novozym 435, Lipozyme RM IM, and Lipozyme TL IM. The Eversa immobilized lipase was the most effective biocatalyst for the synthesis of NPG diesters. The effects of enzyme loading and temperature on conversion were explored at a standard pressure of 101.3 kPa. And then, the effect of reduced pressure was investigated in the range of 1.3 to 40.0 kPa under optimum conditions obtained at standard pressure. The maximum conversion of ca. 63% was achieved at the optimal temperature of 50°C and the enzyme loading of 5% (based on the total weight of the substrate) at standard pressure after 10 h. However, the conversion to NPG diester increased markedly up to 97% after 10 h, even though reduced pressure as low as 26.7 kPa was applied. No significant differences in the conversion to NPG diester between the reactions at constant reduced pressure and the combined reaction of reduced pressure and standard pressure were observed. This pressure combination method employed in this study demonstrated a novel, energy‐saving strategy for the synthesis of NPG diester.

Mechanosensitive channel gating by delipidation

The mechanosensitive channel of small conductance (MscS) protects bacteria against hypoosmotic shock. It can sense the tension in the surrounding membrane and releases solutes if the pressure in the cell is getting too high. The membrane contacts MscS at sensor paddles, but lipids also leave the membrane and move along grooves between the paddles to reside as far as 15 Å away from the membrane in hydrophobic pockets. One sensing model suggests that a higher tension pulls lipids from the grooves back to the membrane, which triggers gating. However, it is still unclear to what degree this model accounts for sensing and what contribution the direct interaction of the membrane with the channel has. Here, we show that MscS opens when it is sufficiently delipidated by incubation with the detergent dodecyl-β-maltoside or the branched detergent lauryl maltose neopentyl glycol. After addition of detergent-solubilized lipids, it closes again. These results support the model that lipid extrusion causes gating: Lipids are slowly removed from the grooves and pockets by the incubation with detergent, which triggers opening. Addition of lipids in micelles allows lipids to migrate back into the pockets, which closes the channel even in the absence of a membrane. Based on the distribution of the aliphatic chains in the open and closed conformation, we propose that during gating, lipids leave the complex on the cytosolic leaflet at the height of highest lateral tension, while on the periplasmic side, lipids flow into gaps, which open between transmembrane helices.

In-situ synthesis and thermal properties of biobased Poly(neopentyl glycol 2,5-furandicarboxylate)/multi-walled carbon nanotubes composites

The in-situ synthesis and thermal properties of biobased poly(neopentyl glycol 2,5-furandicarboxylate) (PNF)/multi-walled carbon nanotubes (MWCNTs) composites were studied in this research. The chemical structure, thermal stability, crystallization behavior, and crystal structure of PNF/MWCNTs composites were extensively investigated and compared with those of PNF. Scanning electron microscopy image revealed that MWCNTs uniformly dispersed in PNF matrix. In the composites, MWCNTs slightly improved the thermal stability of PNF, while the crystallization of PNF was obviously enhanced by MWCNTS under both the nonisothermal and isothermal crystallization conditions as the heterogeneous nucleating agent. Only 0.5 wt% of MWCNTs obviously increased the melt crystallization temperature from 132.9 °C for neat PNF to 141.2 °C for the composite and decreased the crystallization half-time from 3.1 min for neat PNF to 1.9 min for the composite at 165 °C. In addition, MWCNTs did not modify the crystal structure of PNF.

The impact of thermomechanical pulp fiber modifications on thermoplastic lignin composites

Cellulose and lignin are abundant renewable biopolymers that can be used for the manufacture of new, environmentally friendly materials. The objective of this study was to produce composites of kraft lignin, which were reinforced with cellulosic thermomechanical pulp (TMP) fibers. Furthermore, the fibers were chemically modified resulting in cross-linking or increased hydrophobicity. Ideally, these modifications improve interaction between the components in the composite. The effects of the modifications on the tensile strength and thermal properties of the composites were investigated, and the interactions between components were examined by infrared spectroscopy and scanning electron microscopy. When the fibers were cross-linked with polyethylene glycol diglycidyl ether (PEGDE), the tensile strength properties of the composite were significantly improved. Depending on the amount of PEGDE added, tensile strength was increased by 16–34%, and Young's Modulus by 6–18%, but at the same time the strain at break remained the same. Similarly, by using PEGDE, the amount of free plasticizer (PEG) could be reduced, which also improved the water-resistance of the composite. According to scanning electron microscopy, all chemical treatments improved the compatibility of the fibers with the lignin matrix. However, the increase in compatibility was highest when the fibers were cross-linked with a combination of glyoxal and neopentyl glycol (GL/NPG) or by increasing hydrophobicity through acetylation (AC), although the tensile strength properties were the best in case of cross-linking with PEGDE.

Degradation of Brominated Organic Compounds (Flame Retardants) by a Four-Strain Consortium Isolated from Contaminated Groundwater

Biodegradation of pollutants in the environment is directly affected by microbial communities and pollutant mixture at the site. Lab experiments using bacterial consortia and substrate mixtures are required to increase our understanding of these processes in the environment. One of the deficiencies of working with environmental cultures is the inability to culture and identify the active strains while knowing they are representative of the original environment. In the present study, we tested the aerobic microbial degradation of two brominated flame retardants, tribromo-neopentyl alcohol (TBNPA) and dibromo neopentyl glycol (DBNPG), by an assembled bacterial consortium of four strains. The four strains were isolated and plate-cultured from a consortium enriched from the impacted groundwater underlying the Neot Hovav industrial area (Negev, Israel), in which TBNPA and DBNPG are abundant pollutants. Total degradation (3–7 days) occurred only when the four-strain consortium was incubated together (25 °C; pH −7.2) with an additional carbon source, as both compounds were not utilized as such. Bacterial growth was found to be the limiting factor. A dual carbon–bromine isotope analysis was used to corroborate the claim that the isolated strains were responsible for the degradation in the original enriched consortium, thus ensuring that the isolated four-strain microbial consortium is representative of the actual environmental enrichment.

Experimental Investigation on CNT-Enhanced Neopentyl glycol Solid–Solid PCM for Applications of Thermal Control in Spatial Remote Sensing Instruments

Experimental Investigation on CNT-Enhanced Neopentyl glycol Solid–Solid PCM for Applications of Thermal Control in Spatial Remote Sensing Instruments

Combustion Performance of Spherical Propellants Deterred by Energetic Composite Deterring Agents.

In order to achieve ideal burning progressivity and reduce harmful phenomena such as muzzle flame and smoke, energetic composite deterring agents (ECDAs) deterring spherical propellants were designed and prepared. The combustion performance of ECDA-deterred propellants was characterized by a closed vessel, and the interior ballistic performance was studied by a ballistic gun. High-speed photography and a smoke box were employed to capture muzzle flames and smoke. The results showed that triethylene glycol dinitrate (TEGDN) had a slight deterring effect weaker than that of poly(neopentyl glycol adipate) (PNA) on the propellants. The maximum pressure in the closed vessel bore of the ECDA-deterred propellants was 2.29 MPa higher than that of the dibutyl phthalate (DBP)-deterred propellants, though the L–B curve of the ECDA-deterred propellants was slightly lower and its combustion time was 0.44 ms longer. For ECDA containing 5 wt % PNA and 3.2 wt % TEGDN, 80 °C and 150 min are the best deterring conditions. The average velocity of the bullet propelled by ECDA-deterred propellants was increased by 93.4 m·s–1, while the average maximum pressure in the gun bore was decreased by 19 MPa, compared with the original propellants. The muzzle flame and smoke of the ECDA-deterred propellants were significantly reduced compared with the DBP-deterred propellants, where the smoke concentration was reduced by up to 44.5%.