Tag: M.W=100-150

Pisella, Guillaume published the artcileThree-Component Reaction for the Synthesis of Highly Functionalized Propargyl Ethers, Safety of 3-Acetyldihydrofuran-2(3H)-one, the publication is Chemistry – A European Journal (2020), 26(45), 10199-10204, database is CAplus and MEDLINE.

Copper-catalyzed three-component reaction of diazo compounds, alcs. and ethynyl benziodoxole (EBX) reagents for the synthesis of propargyl ethers was reported. Extensive variations of the three partners of the reaction was possible, led to highly functionalized and structurally diverse products under mild conditions. Alkynylation of a copper ylide intermediate was postulated as key step for this transformation.

Chemistry – A European Journal published new progress about 517-23-7. 517-23-7 belongs to esters-buliding-blocks, auxiliary class Tetrahydrofuran,Ketone,Ester, name is 3-Acetyldihydrofuran-2(3H)-one, and the molecular formula is C6H8O3, Safety of 3-Acetyldihydrofuran-2(3H)-one.

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

Maniscalco, Giorgia Teresa published the artcileLong term persistence of SARS-CoV-2 humoral response in multiple sclerosis subjects, SDS of cas: 624-49-7, the publication is Multiple Sclerosis and Related Disorders (2022), 103800, database is CAplus and MEDLINE.

The persistence of the severe acute respiratory syndrome coronavirus (SARS-CoV)-2 pandemic, partly due to the appearance of highly infectious variants, has made booster vaccinations necessary for vulnerable groups. Here, we present data regarding the decline of the SARS-CoV-2 BNT162b2 mRNA vaccine-induced humoral immune response in a monocentric cohort of MS patients.96 MS patients undergoing eight different DMTs, all without previous SARS-CoV-2 infection, were evaluated for anti-Spike IgG levels, 21 days (T1) and 5-6 mo (T2) after the second SARS-CoV-2 BNT162b2 mRNA vaccine dose. The anti-Spike IgG titer from MS subjects was compared with 21 age- and sex-matched healthy controls (HC). When compared with SARS-CoV-2 IgG levels at T2 in HC, we observed comparable levels in interferon-β 1a-, di-Me fumarate-, teriflunomide- and natalizumab-treated MS subjects, but an impaired humoral response in MS subjects undergoing glatiramer acetate-, cladribine-, fingolimod- and ocrelizumab-treatments. Moreover, comparison between SARS-CoV-2 IgG Spike titer at T1 and T2 revealed a faster decline of the humoral response in patients undergoing di-Me fumarate-, interferon-β 1a- and glatiramer acetate-therapies, while those receiving teriflunomide and natalizumab showed higher persistence compared to healthy controls. The prominent decline in humoral response in MS subjects undergoing di-Me fumarate-, interferon-β 1a- and glatiramer acetate-therapies should be considered when formulating booster regimens as these subjects would benefit of early booster vaccinations.

Multiple Sclerosis and Related Disorders published new progress about 624-49-7. 624-49-7 belongs to esters-buliding-blocks, auxiliary class Inhibitor,Natural product, name is Dimethyl fumarate, and the molecular formula is C6H8O4, SDS of cas: 624-49-7.

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

Moore, Gordon G. published the artcilePreparation of hindered esters by the alkylation of carboxylate salts with simple alkyl halides, Category: esters-buliding-blocks, the publication is Journal of Organic Chemistry (1979), 44(14), 2425-9, database is CAplus.

Sterically hindered esters were prepared in excellent yields by the use of anion-exchange resins in both biphase and triphase systems. In addition, quant. yields of a variety of esters were obtained by the displacement reactions of simple aliphatic and aromatic K carboxylate salts and alkyl halides in Me₂CO or aqueous Me₂CO. Esters prepared in quant. yields included Et hexadecanoate in 95% Me₂CO and Et 2,4,6-trimethylbenzoate, 1-methylheptyl 2,4,6-trimethylbenzoate, and Et 9,10-epoxyoctadecanoate in pure Me₂CO. The 2nd-order rate constant for the reaction of K 2,4,6-trimethylbenzoate with iodoethane in 95% acetone was 2.67 × 10^-4 mL^-1s^-1 at 40°.

Journal of Organic Chemistry published new progress about 5340-78-3. 5340-78-3 belongs to esters-buliding-blocks, auxiliary class Aliphatic Chain, name is Ethyltert-butylacetate, and the molecular formula is C8H16O2, Category: esters-buliding-blocks.

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

Portaccio, Emilio published the artcileImpact of COVID-19 on multiple sclerosis care and management: Results from the European Committee for Treatment and Research in Multiple Sclerosis survey, Safety of Dimethyl fumarate, the publication is Multiple Sclerosis Journal (2022), 28(1), 132-138, database is CAplus and MEDLINE.

Background:: The spread of Coronavirus disease-19 (COVID-19) poses unique challenges in the management of people with multiple sclerosis (PwMS). Objectives:: To collect data about the impact of COVID-19 emergency on access to care for PwMS and on MS treatment practices. Methods:: Between March and July 2020, the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) promoted an online survey covering patient access to care, management of relapses and visits, disease-modifying therapy (DMT) and experience with COVID-19. Results:: Three-hundred and sixty neurologists from 52 countries (68from Europe) completed the survey. 98reported COVID-19-related restrictions. Telemedicine was adopted to overcome the limited access to care and was newly activated (73) or widely implemented (17). 70reported changes in DMT management. Interferons and glatiramer were considered safe. No modifications were considered for natalizumab in 64, cladribine in 24, anti-CD20 in 22and alemtuzumab in 17; 18(for alemtuzumab and cladribine) and 43(for anti-CD20) considered postponing treatment. Conclusion:: The ECTRIMS survey highlighted the challenges in keeping standards of care in clin. practice. Telemedicine clearly needs to be implemented. Gathering data on DMT safety will remain crucial to inform treatment decisions.

Multiple Sclerosis Journal published new progress about 624-49-7. 624-49-7 belongs to esters-buliding-blocks, auxiliary class Inhibitor,Natural product, name is Dimethyl fumarate, and the molecular formula is C6H8O4, Safety of Dimethyl fumarate.

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

Rayne, Sierra published the artcileCarboxylic acid ester hydrolysis rate constants for food and beverage aroma compounds, Synthetic Route of 19788-49-9, the publication is Flavour and Fragrance Journal (2016), 31(5), 385-394, database is CAplus.

Aroma compounds in the Flavornet database were screened for potentially hydrolysable carboxylic acid ester functionalities. Of 738 aroma compounds listed in this database, 140 mols. contain carboxylic acid ester groups that may be amenable to hydrolysis in various food and beverage products. Acid- (k_A) and base- (k_B) catalyzed and neutral (k_N) hydrolysis rate constants in pure water at 25°C were calculated for these aroma compounds Where available, good agreement between theor. and exptl. hydrolytic half-lives was obtained at various pH values. Wide ranges and broad frequency distributions for k_A, k_B, and k_N are expected among the various hydrolyzable aroma compounds, with calculated k_A ranging from 3.7 × 10^-8 to 4.7 × 10^-4 M^-1 s^-1, calculated k_B ranging from 4.3 × 10^-4 to 43 M^-1 s^-1, and calculated k_N ranging from 4.2 × 10^-17 to 7.6 × 10^-9 M^-1 s^-1. The resulting hydrolytic half-lives also range widely, from 10 days to 370 years at pH 2.8, 18 days to 4,900 years at pH 4.0, 1.8 days to 470 years at pH 7.0, and 26 min to 5.1 years at pH 9.0. The findings illustrate the importance of considering abiotic hydrolysis and matrix pH when modeling the evolution of sensory characteristics for foods and beverages with carboxylic acid ester based aroma compounds Copyright © 2016 John Wiley & Sons, Ltd.

Flavour and Fragrance Journal published new progress about 19788-49-9. 19788-49-9 belongs to esters-buliding-blocks, auxiliary class Thiol,Aliphatic hydrocarbon chain,Ester, name is Ethyl 2-mercaptopropanoate, and the molecular formula is C5H10O2S, Synthetic Route of 19788-49-9.

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

Rayne, Sierra published the artcilepH dependent partitioning behaviour of food and beverage aroma compounds between air-aqueous and organic-aqueous matrices, Recommanded Product: Ethyl 2-mercaptopropanoate, the publication is Flavour and Fragrance Journal (2016), 31(3), 228-234, database is CAplus.

Aroma compounds in the Flavornet database were screened for ionizable functional groups such as carboxylic acids, aliphatic and aromatic amines, phenols, alcs. and thiols. Of the 738 aroma compounds listed in this database, 101 mols. have ionizable moieties with estimated monomeric aqueous pK_a values ranging between 1.75 and 10.97. pH dependent effective air/water partitioning coefficients (K_aw,eff) and n-octanol/water partitioning coefficients (D_ow) were estimated for all ionizable aroma compounds over the pH range from 0 to 14. The ionizable aroma compounds display a broad range of K_aw,eff (1.8 × 10^-23 to 6.1 atm M^-1) and log D_ow (-6.2 to +7.2 units) values. For many aroma compounds, pH dependent ionization will have a significant effect on K_aw,eff and D_ow, leading to variations in these physico-chem. properties by up to 11 orders of magnitude over the composite pH range of common foods and beverages. Changes in food and beverage pH affect not only the relative contributions of neutral vs. charged forms of ionizable aroma compounds (which directly affects analyte volatility and olfactory reception), but also partitioning between freely dissolved and sorbed forms of the analyte in solution (which indirectly affects analyte volatility). Copyright © 2015 John Wiley & Sons, Ltd.

Flavour and Fragrance Journal published new progress about 19788-49-9. 19788-49-9 belongs to esters-buliding-blocks, auxiliary class Thiol,Aliphatic hydrocarbon chain,Ester, name is Ethyl 2-mercaptopropanoate, and the molecular formula is C5H10O2S, Recommanded Product: Ethyl 2-mercaptopropanoate.

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

Liu, Hengrui published the artcileCharacterization of a patient-derived variant of GPX4 for precision therapy, Product Details of C6H8O4, the publication is Nature Chemical Biology (2022), 18(1), 91-100, database is CAplus and MEDLINE.

Glutathione peroxidase 4 (GPX4), as the only enzyme in mammals capable of reducing esterified phospholipid hydroperoxides within a cellular context, protects cells from ferroptosis. We identified a homozygous point mutation in the GPX4 gene, resulting in an R152H coding mutation, in three patients with Sedaghatian-type spondylometaphyseal dysplasia. Using structure-based analyses and cell models, including patient fibroblasts, of this variant, we found that the missense variant destabilized a critical loop, which disrupted the active site and caused a substantial loss of enzymic function. We also found that the R152H variant of GPX4 is less susceptible to degradation, revealing the degradation mechanism of the GPX4 protein. Proof-of-concept therapeutic treatments, which overcome the impaired R152H GPX4 activity, including selenium supplementation, selective antioxidants and a deuterated polyunsaturated fatty acid were identified. In addition to revealing a general approach to investigating rare genetic diseases, we demonstrate the biochem. foundations of therapeutic strategies targeting GPX4.

Nature Chemical Biology published new progress about 624-49-7. 624-49-7 belongs to esters-buliding-blocks, auxiliary class Inhibitor,Natural product, name is Dimethyl fumarate, and the molecular formula is C6H8O4, Product Details of C6H8O4.

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

Huang, Ya Nan published the artcileExternal Stress-Free Reversible Multiple Shape Memory Polymers, Computed Properties of 517-23-7, the publication is ACS Applied Materials & Interfaces (2019), 11(34), 31346-31355, database is CAplus and MEDLINE.

The present work is focused on developing external stress-free two-way triple shape memory polymers (SMPs). Accordingly, a series of innovative approaches are proposed for the material design and preparation Polyurethane prepolymers carrying crystalline polytetrahydrofuran (PTMEG) and poly(ε-caprolactone) (PCL) as the switching phases are resp. synthesized in advance and then crosslinked to produce the target material. The stepwise method is believed to be conducive to manipulation of the relative contribution of PCL and PTMEG. Moreover, the chain extender, 2-amino-5-(2-hydroxyethyl)-6-methylpyrimidin-4-ol (UPy), is incorporated to establish hydrogen bonds among the macromols. By straightforward stretching treatment at different temperatures, the hydrogen bond networks are successfully converted into an internal stress provider, which overcomes the challenge of stress relaxation of the melted low melting temperature polymer (i.e., PTMEG) and increases the efficiency of stress transfer. Meanwhile, the contraction force of the switching phases is tuned to match the internal tensile stress. As a result, the internal stress provider can closely collaborate with melting/recrystallization of the crystalline domains, leading to the repeated multiple shape memory effects. The crosslinked polyurethane is thus able to reversibly morph among three shapes and displays its potentials as soft robot and actuator. The strategy reported here has the advantages of easily accessible raw materials, simple reaction, and facile programing/deprograming/reprograming, so that it possesses wide applicability.

ACS Applied Materials & Interfaces published new progress about 517-23-7. 517-23-7 belongs to esters-buliding-blocks, auxiliary class Tetrahydrofuran,Ketone,Ester, name is 3-Acetyldihydrofuran-2(3H)-one, and the molecular formula is C6H8O3, Computed Properties of 517-23-7.

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

Liu, Zhimeng published the artcileIn Situ-Formed Novel Elastic Network Binder for a Silicon Anode in Lithium-Ion Batteries, HPLC of Formula: 517-23-7, the publication is ACS Applied Materials & Interfaces (2021), 13(39), 46518-46525, database is CAplus and MEDLINE.

High energy d. lithium-ion batteries with preferable cycling stability are critical for the development of all-elec. vehicles. Silicon (Si) has demonstrated a remarkable potential for application as anode materials due to its superior capacity performance and worldwide abundance. However, Si intrinsically undergoes substantial volume fluctuation during repeated lithiation/delithiation processes, which pulverizes the Si particles and undermines the integrity of the electrode structures, thus resulting in frustrating cycling stability. We developed a polymer binder with a highly stretchable and elastic network structure that can accommodate volume variation of Si. This was realized by an in situ crosslinking of polyacrylic acid (PAA) with isocyanate-terminated polyurethane oligomers that consist of polyethylene glycol (PEG) chains and 2-ureido-4-pyrimidinone (UPy) moieties through the reaction between isocyanate and carboxyl during the electrode preparation process. In this binder network, PAA could strongly adhere to the Si particles by forming hydrogen bonding with the surface hydroxyl groups. The PEG chains induce the flexibility of the polymer network, while the UPy moieties endow the polymer network with desirable mech. strength through the formation of reversible and strong quadruple H-bonding cross-linkers. This binder not only can sufficiently accommodate the volume change of Si but can also provide a strong mech. support to effectively sustain the integrity for the Si anode, consequently enhancing cycle stability and rate performance.

ACS Applied Materials & Interfaces published new progress about 517-23-7. 517-23-7 belongs to esters-buliding-blocks, auxiliary class Tetrahydrofuran,Ketone,Ester, name is 3-Acetyldihydrofuran-2(3H)-one, and the molecular formula is C6H8O3, HPLC of Formula: 517-23-7.

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

Wang, Yun-Peng published the artcileAn efficient approach to angular tricyclic molecular architecture via Nazarov-like cyclization and double ring-expansion cascade, HPLC of Formula: 30414-53-0, the publication is Nature Communications (2022), 13(1), 2335, database is CAplus and MEDLINE.

A modular and efficient method for constructing angular tri-carbocyclic architectures containing quaternary carbon center(s), e.g., I (R = Me) from 1,3-dicycloalkylidenyl ketones, e.g., II is established, which involves an unconventional synergistic cascade of a Nazarov cyclization and two ring expansions. It features high selectivity, mild conditions and convenient operation, wide scope and easy availability of substrate. Substitution at the 4πe-system with electron-donating group favors this reaction, while that with electron-withdrawing group or proton disfavors. The electron-donating group directs the initial ring expansion at its own site, while the p-π- or n-π- associated substituent favors selectively the later ring expansion near its location because of the beneficial maintenance of an original conjugated system. The stereoselectivity has proved to be governed by either the steric effect at the expanded rings, or the migration ability of the migrating atom. D. Functional Theory calculation suggests that the initial Nazarov cyclization would be the rate-determining step. A racemic total synthesis of the natural (±)-waihoensene is realized in 18 steps by use of this methodol.

Nature Communications published new progress about 30414-53-0. 30414-53-0 belongs to esters-buliding-blocks, auxiliary class Aliphatic hydrocarbon chain,Ketone,Ester, name is Methyl 3-oxovalerate, and the molecular formula is C15H14O, HPLC of Formula: 30414-53-0.

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