Category: esters-buliding-blocks

Valencia, L. M. published the artcileInduced damage during STEM-EELS analyses on acrylic-based materials for Stereolithography, SDS of cas: 15625-89-5, the publication is Polymer Degradation and Stability (2022), 110044, database is CAplus.

(Scanning) transmission electron microscopy, (S)TEM, offers a powerful characterization tool based on electron-matter interactions, highly valuable in materials science. However, the possible electron beam induced damage during (S)TEM measurements hinders the anal. of soft materials, such as acrylic resins. Importantly, acrylic resins offer an appealing playground for the development of novel composites with customized properties and convenient processing capabilities for 3D-printing technologies, including Stereolithog. (SLA). There are several factors preventing the optimal performance of TEM measurements applied to acrylic resins, among which we focus on the quality of the analyzed specimen (i.e., compromise between thickness and robustness, to achieve electron transparency while keeping the material integrity), particularly challenging when working with soft materials; the electrostatic charging/discharging effects, resulting in sample drift and related noise/artifacts; and the radiolysis and knock-on electron-induced damage, which directly degrade the material under study. We explore and compare different methodologies to obtain resin specimens suitable for (S)TEM anal., employed for the subsequent study of the electron-beam damage induced during STEM-EELS measurements. Furthermore, we propose likely underlying mechanisms explaining the acrylic resin degradation based on the different EELS monitored signals. On one hand, we assess the evolution of the carbon and oxygen content, as well as the material thinning as a function of the accumulated electron dose. On the other hand, we extract meaningful information from the spectral shape of carbon and oxygen K-edges upon increasing electron doses, unraveling likely degradation pathways. The earned understanding on the electron-beam induced damage and the determination of critical doses provide a useful framework for the implementation of (S)TEM techniques as useful tools to help in the smart engineering of acrylic-based composites for SLA.

Polymer Degradation and Stability published new progress about 15625-89-5. 15625-89-5 belongs to esters-buliding-blocks, auxiliary class Polymerization Reagents,Crosslinkers, name is Trimethylolpropane triacrylate, and the molecular formula is C5H5BrN2, SDS of cas: 15625-89-5.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Fuller, Ioan D. published the artcileChemical diversity of kanuka: Inter- and intraspecific variation of foliage terpenes and flavanones of Kunzea (Myrtaceae) in Aotearoa/New Zealand, Synthetic Route of 103-26-4, the publication is Phytochemistry (Elsevier) (2022), 113098, database is CAplus and MEDLINE.

Kunzea (Myrtaceae) trees and shrubs, generally called kanuka, grow across most of Aotearoa/New Zealand (NZ). With the exception of K. sinclairii, an offshore island endemic, kanuka had been treated as an Australasian species K. ericoides. However, a 2014 taxonomic revision recognized ten species, all endemic to NZ. Kanuka chem. is less studied than that of its closest relative in NZ, manuka (Leptospermum scoparium), which shows very distinct regional foliage chemotypes. We have used a miniaturized method with GC and 1H NMR to analyze foliage chem. of voucher specimens from across the geog. ranges of the ten NZ Kunzea species. We found common mono- and sesquiterpenes, with α-pinene dominant in all samples, but only traces of antimicrobial triketones. Two unusual flavanones, with unsubstituted B-rings and known bioactivity against Phytophthora, did distinguish some of the samples. 5,7-Dihydroxy-6,8-dimethyl flavanone was only found at high concentrations in the three K. sinclairii samples in this study’s sample set, but this compound has sep. been reported in K. robusta samples from a nearby region. Therefore none of the NZ Kunzea species was distinguished by the chem. analyzed in this study, but there is a possibility of regional flavonoid chemotypes cutting across the species boundaries.

Phytochemistry (Elsevier) published new progress about 103-26-4. 103-26-4 belongs to esters-buliding-blocks, auxiliary class Alkenyl,Benzene,Ester,Protease,Tyrosinase,Natural product, name is Methyl 3-phenyl-2-propenoate, and the molecular formula is C10H10O2, Synthetic Route of 103-26-4.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Fugolin, A. P. P. published the artcileProbing stress relaxation behavior in glassy methacrylate networks containing thio-carbamate additives, Product Details of C11H15NO2, the publication is Journal of Materials Chemistry B: Materials for Biology and Medicine (2021), 9(13), 3015-3024, database is CAplus and MEDLINE.

The incorporation of thiourethane prepolymer (TU) into either the organic phase or as a surface treatment for filler particles in composites reduces polymerization stress and improves fracture toughness. The aim of this study was to gain insight into the influence of the inclusion of thiourethanes on the resulting network of methacrylate-based materials polymerized via free-radical mechanisms. Dynamic mech. anal. was used to elucidate network parameters and potential stress relaxation behavior of these networks. TU oligomers were synthesized using a combination of trimethylol-tris-3-mercaptopropionate and dicyclohexylmethane 4,4′-diisocyanate and added into composite formulations at 20 wt% replacing part of the organic matrix and/or as TU-silanes used to functionalize filler particles (TU-matrix, TU-Sil or TU-matrix/sil). Materials not containing any form of TU were used as the control (in those cases, 3-(trimethoxysilyl)propyl methacrylate was used as the silane agent). Filler was added at 50 wt%. Degree of conversion was evaluated by near-IR spectroscopy, mech. properties by 3-point bending and rotational rheometry. Dynamic mech. anal. was used to obtain network parameters (glass transition temperature (T_g), storage modulus, crosslink d., and breadth of tan delta a proxy for network homogeneity – temperature sweep experiments) and to evaluate the potential for network relaxation (stress relaxation). TU-containing formulations showed 10% higher DC than the control. The time to reach storage/loss modulus crossover in the rheometer experiments was significantly longer for TU-matrix and TU-matrix/sil in comparison with the control (21.6, 27.9, and 5.1 s, resp.). TU-matrix and TU-matrix/sil presented significant lower T_g than the control (151.5, 153.8, and 161.3°C, resp.). There were no statistical differences among the groups in terms of shear modulus, crosslink d., breadth of tan delta, flexural strength/modulus, and toughness. For at least one group (TU-matrix/sil), the relaxation time was four times faster than for the control at 105°C. The addition of TU additives into dental polymers resulted in a stark reduction in the stress relaxation time. This behavior, in tandem with the network characterization and mech. properties seems to indicate the TU networks undergo a variety of reversible associative and dissociative chem. reactions which facilitate enhanced stress relief.

Journal of Materials Chemistry B: Materials for Biology and Medicine published new progress about 10287-53-3. 10287-53-3 belongs to esters-buliding-blocks, auxiliary class Amine,Benzene,Ester, name is Ethyl 4-dimethylaminobenzoate, and the molecular formula is C11H15NO2, Product Details of C11H15NO2.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Garcia, T. published the artcileOptimization of the enzymic synthesis of isobutyl palmitate using a central composite design, HPLC of Formula: 110-34-9, the publication is Food and Bioproducts Processing (1995), 73(C3), 140-4, database is CAplus.

The process of synthesis of iso-Bu palmitate using the immobilized lipase SP-435L as catalyst has been developed and optimized following factorial design and response surface methodol. A second-order model has been developed to predict ester conversion as a function of temperature and enzyme concentration The model has been found to describe the exptl. results adequately. According to this model, maximum ester conversions are obtained at high enzyme concentration and medium temperature

Food and Bioproducts Processing published new progress about 110-34-9. 110-34-9 belongs to esters-buliding-blocks, auxiliary class Aliphatic hydrocarbon chain,Ester, name is Isobutyl palmitate, and the molecular formula is C20H40O2, HPLC of Formula: 110-34-9.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Pellevoisin, C. published the artcilePre-validation of SENS-IS assay for in vitro skin sensitization of medical devices, Category: esters-buliding-blocks, the publication is Toxicology In Vitro (2021), 105068, database is CAplus and MEDLINE.

According to ISO 10993-1:2018, the skin sensitization potential of all medical devices must be evaluated, and for this endpoint ISO 10993-10:2010 recommends the use of in vivo assays. The goal of the present study was to determine if the in vitro SENS-IS assay could be a suitable alternative to the current in vivo assays. The SENS-IS assay uses the Episkin Large and SkinEthic RHE reconstructed human epidermis models to evaluate marker genes. In our study, the SENS-IS assay correctly identified 13 sensitizers spiked in a non-polar solvent. In a subsequent anal. six medical device silicone samples previously impregnated with sensitizers were extracted with polar and non-polar solvents. The SENS-IS assay correctly identified five of these extracts, while a sixth extract, which contained the weak sensitizer Ph benzoate, was classified as neg. However, when this extract was concentrated, or a longer exposure time was used, the assay was able to detect Ph benzoate. The SENS-IS assay was transferred to a naive laboratory which correctly identified sensitizers in six blinded silicone samples, including the one containing Ph benzoate. In light of these results, we conclude that the SENS-IS assay is able to correctly identify the presence of sensitizers in medical devices extracts

Toxicology In Vitro published new progress about 121-79-9. 121-79-9 belongs to esters-buliding-blocks, auxiliary class Natural product, name is Propyl 3,4,5-trihydroxybenzoate, and the molecular formula is C10H12O5, Category: esters-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Rahman, Shahzad S. published the artcile1,3-Diaminopropan-2-ol Sulfonamides as potent and selective inhibitors of the glycine transporter type 1, HPLC of Formula: 115314-17-5, the publication is Bioorganic & Medicinal Chemistry Letters (2007), 17(6), 1741-1745, database is CAplus and MEDLINE.

High throughput screening led to the discovery of a novel series of 1,3-diaminopropan-2-ol sulfonamides, e.g. I, as selective GlyT-1 inhibitors. Structure-activity relationships of this novel series and optimization of the initial hit that led to the identification of I, a potent and selective GlyT-1 inhibitor, are also presented.

Bioorganic & Medicinal Chemistry Letters published new progress about 115314-17-5. 115314-17-5 belongs to esters-buliding-blocks, auxiliary class Epoxides,Chiral,Nitro Compound,Sulfonate,Benzene, name is (R)-Oxiran-2-ylmethyl 3-nitrobenzenesulfonate, and the molecular formula is C9H9NO6S, HPLC of Formula: 115314-17-5.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Nguyen, Khanh Q. published the artcileEffects of Exposure Conditions on Antioxidant Depletion, Tensile Strength, and Creep Modulus of Corrugated HDPE Pipes Made With or Without Recycled Resins, Related Products of esters-buliding-blocks, the publication is Journal of Polymers and the Environment (2022), 30(9), 3959-3973, database is CAplus.

The service lifetime of corrugated high-d. polyethylene (HDPE) pipes used in transportation infrastructure applications has been the subject of several studies over the years. How factors specific to North American climate conditions-such as freeze/thaw cycles, deicing salts, and abrasion-affect pipe service life have not been addressed. In this study, laboratory accelerated-aging tests were conducted to examine the thermo-oxidative degradation as well as tensile strength and creep modulus of HDPE pipes made with or without recycled resins. Specimens were immersed in saline solution (NaCl), acidic solution (H₂SO₄), alk. solution (NaOH) at 60°C, or in water and exposed to freeze/thaw cycles ranging from – 40 to + 40°C. Measuring the oxidative induction time (OIT) at various time intervals quantified the amounts of antioxidants present in the pipes, revealing that the rate of antioxidant depletion depended on the surrounding environment. The depletion rate was faster in the saline solution and slower in the freeze/thaw cycles. For specimens exposed to freeze/thaw cycles, the depletion was 1.12 to 1.91 lower than in the acidic solution, 1.25 to 2.64 times lower than in the alk. solution, and 1.43 to 3.25 times lower than in saline solution Nevertheless, the HDPE pipes all met the OIT requirements of a min. of 20 min. Furthermore, the one-way anal. of variance (ANOVA) and Tukey’s HSD test indicate that the tensile strength and creep modulus values of the recycled and virgin HDPE pipes were unchanged before and after immersion in the different solutions

Journal of Polymers and the Environment published new progress about 31570-04-4. 31570-04-4 belongs to esters-buliding-blocks, auxiliary class Mono-phosphine Ligands, name is Tris(2,4-di-tert-butylphenyl) phosphite, and the molecular formula is C42H63O3P, Related Products of esters-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Pereira, Leonardo Duarte Eiras published the artcileInfluence of resin matrix on the rheology, translucency, and curing potential of experimental flowable composites for bulk-fill applications, Synthetic Route of 10287-53-3, the publication is Dental Materials (2021), 37(6), 1046-1053, database is CAplus and MEDLINE.

To propose monomer formulations that show an optimal degree of conversion as a function of depth for bulk-fill applications.Four resin blends were formulated with methacrylate-based monomers: BisGMA + TEGDMA (control); BisEMA + BisGMA + TEGDMA (BisEMA-based); UDMA + BisGMA + TEGDMA (UDMA-based) and BisEMA + UDMA + BisGMA + TEGDMA (BisEMA + UDMA-based). For each material, a photoinitiating system and silanized filler particles were added. The rheol. analyses were performed with a rotational rheometer using the cone/plate geometry. CIELab coordinates were assessed over black and white backgrounds using a bench spectrophotometer (SP60, X-Rite) to calculate the translucency parameter (TP) for samples with 0.5, 4, and 6 mm thickness. The degree of C = C conversion (DC) was determined by IR spectroscopy (FTIR/ATR) at 0.05 mm (top), 4, and 6 mm depths (bottom), and the bottom-to-top ratio was considered. A broad spectrum-based LED was used for light activation. Anal. of variance and Tukey′s test (95%) were performed on the results.The materials tested showed pseudoplastic and thixotropic behavior and a predominance of viscous effects over elastics. The control resin yielded the lowest viscosity for the entire shear rate investigated, followed by the BisEMA-based, BisEMA + UDMA-based, and UDMA-based group, which had the highest viscosity. The UDMA-based material showed the lowest TP as a function of thickness. Both the materials′ formulations and depths significantly influenced the DC. The UDMA-based group promoted the highest DC on the top (71 ± 1%) and 4 mm depth (68 ± 1%) but exhibited lower bottom-to-top DC ratio. The BisEMA + UDMA-based material promoted the highest bottom-to-top DC ratio at 4 mm (99%) and 6 mm (97%). The resin matrix interferes in the rheol. behavior, translucency parameter, and polymerization capacity as a function of depth. The material formulated with the addition of UDMA and BisEMA demonstrated the highest curing potential as a function of depth and can be useful for bulk-fill applications.

Dental Materials published new progress about 10287-53-3. 10287-53-3 belongs to esters-buliding-blocks, auxiliary class Amine,Benzene,Ester, name is Ethyl 4-dimethylaminobenzoate, and the molecular formula is C11H15NO2, Synthetic Route of 10287-53-3.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Grosheva, Daria published the artcileKetene Aminal Phosphates: Competent Substrates for Enantioselective Pd(0)-Catalyzed C-H Functionalizations, Computed Properties of 126613-06-7, the publication is ACS Catalysis (2017), 7(11), 7417-7420, database is CAplus.

Nonracemic siloxy- and alkoxybinaphthyl diphenylphospholanes such as I were prepared; in the presence of I, palladium(II) pivalate, pivalic acid, (diarylmethyl)oxodihydropyridinyl phosphates (ketene aminal phosphates) such as II underwent enantioselective C-H activation and cyclization mediated by Cs₂CO₃ in toluene to yield fused indolizinones such as phenylpyridoisoindolinone III in 59-91% yields and in 73:27-97:3 er. Diaryloxodihydropyridinyl phosphates underwent enantioselective cyclization to give mixtures of regioisomeric products in 88:12-98:2 er and 1.1:1-1.3:1 regioselectivities. The structures of I and of a (chlorophenyl)chloropyridoisoindolinone were determined by X-ray crystallog.

ACS Catalysis published new progress about 126613-06-7. 126613-06-7 belongs to esters-buliding-blocks, auxiliary class Chiral Diphenols, name is (R)-[1,1′-Binaphthalene]-2,2′-diyl bis(trifluoromethanesulfonate), and the molecular formula is C22H12F6O6S2, Computed Properties of 126613-06-7.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Narjes, Frank published the artcileDiscovery of (7R)-14-Cyclohexyl-7-{[2-(dimethylamino)ethyl](methyl) amino}-7,8-dihydro-6H-indolo[1,2-e][1,5]benzoxazocine-11-carboxylic Acid (MK-3281), a Potent and Orally Bioavailable Finger-Loop Inhibitor of the Hepatitis C Virus NS5B Polymerase, Recommanded Product: (R)-Oxiran-2-ylmethyl 3-nitrobenzenesulfonate, the publication is Journal of Medicinal Chemistry (2011), 54(1), 289-301, database is CAplus and MEDLINE.

Infections caused by hepatitis C virus (HCV) are a significant world health problem for which novel therapies are in urgent demand. The polymerase of HCV is responsible for the replication of viral genome and has been a prime target for drug discovery efforts. Here, we report on the further development of tetracyclic indole inhibitors, binding to an allosteric site on the thumb domain. Structure-activity relationship (SAR) studies around an indolo-benzoxazocine scaffold led to the identification of compound 33 (MK-3281), an inhibitor with good potency in the HCV subgenomic replication assay and attractive mol. properties suitable for a clin. candidate. The compound caused a consistent decrease in viremia in vivo using the chimeric mouse model of HCV infection.

Journal of Medicinal Chemistry published new progress about 115314-17-5. 115314-17-5 belongs to esters-buliding-blocks, auxiliary class Epoxides,Chiral,Nitro Compound,Sulfonate,Benzene, name is (R)-Oxiran-2-ylmethyl 3-nitrobenzenesulfonate, and the molecular formula is C9H9NO6S, Recommanded Product: (R)-Oxiran-2-ylmethyl 3-nitrobenzenesulfonate.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics