Day: October 14, 2022

Chung, Sang J.; Chung, Suhman; Lee, Hyun Soo; Kim, Eun-Jung; Oh, Kyung Seok; Choi, Hyuk Soon; Kim, Kwang S.; Kim, Yeoun Jin; Hahn, Jong Hoon; Kim, Dong H. published the artcile< Mechanistic Insight into the Inactivation of Carboxypeptidase A by α-Benzyl-2-oxo-1,3-oxazolidine-4-acetic Acid, a Novel Type of Irreversible Inhibitor for Carboxypeptidase A with No Stereospecificity>, Category: tetrahydrofurans, the main research area is carboxypeptidase A inactivation oxazolidine derivative.

On the basis of the active site topol. and enzymic catalytic mechanism of carboxypeptidase A (CPA), a prototypical zinc-containing proteolytic enzyme, α-benzyl-2-oxo-1,3-oxazolidine-4-acetic acid (1), was designed as a novel type of mechanism-based inactivator of the enzyme. All four possible stereoisomers of the inhibitor were synthesized in an enantiomerically pure form starting with optically active aspartic acid, and their CPA inhibitory activities were evaluated to find that surprisingly all of the four stereoisomers inhibit CPA in a time dependent manner. The inhibited enzyme did not regain its enzymic activity upon dialysis. The inactivations were prevented by 2-benzylsuccinic acid, a competitive inhibitor that is known to bind the active site of the enzyme. These kinetic results strongly support that the inactivators attach covalently to the enzyme at the active site. The anal. of ESI mass spectral data of the inactivated CPA ascertained the conclusion from the kinetic results. The values of second-order inhibitory rate constants (kobs/[I]o) fall in the range of 1.7-3.6 M-1 min-1. The lack of stereospecificity shown in the inactivation led us to propose that the ring cleavage occurs by the nucleophilic attack at the 2-position rather than at the 5-position and the ring opening takes place in an addition-elimination mechanism. The tetrahedral transition state that would be generated in this pathway is thought to be stabilized by the active site zinc ion, which was supported by the PM3 semiempirical calculations In addition, α-benzyl-2-oxo-1,3-oxazolidine-5-acetic acid (18), a structural isomer of 1 was also found to inactivate CPA in an irreversible manner, reinforcing the nucleophilic addition-elimination mechanism. The present study demonstrates that the transition state for the inactivation pathway plays a critical role in determining stereochem. of the inactivation.

Journal of Organic Chemistry published new progress about Enzyme inhibition kinetics. 137105-97-6 belongs to class tetrahydrofurans, and the molecular formula is C9H15NO4, Category: tetrahydrofurans.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Henschel, Henning; Andersson, Alfred T.; Jespers, Willem; Mehdi Ghahremanpour, Mohammad; van der Spoel, David published the artcile< Theoretical Infrared Spectra: Quantitative Similarity Measures and Force Fields>, Electric Literature of 97-99-4, the main research area is IR spectrum similarity force field database.

IR spectroscopy can provide significant insight into the structures and dynamics of mols. of all sizes. The information that is contained in the spectrum is, however, often not easily extracted without the aid of theor. calculations or simulations. We present here the calculation of the IR spectra of a database of 703 gas phase compounds with four different force fields (CGenFF, GAFF-BCC, GAFF-ESP, and OPLS) using normal-mode anal. Modern force fields increasingly use virtual sites to describe, e.g., lone-pair electrons or the σ-holes on halogen atoms. This requires some adaptation of code to perform normal-mode anal. of such compounds,the implementation of which into the GROMACS software is briefly described as well. For the quant. comparison of the obtained spectra with exptl. reference data, we discuss the application of two different statistical correlation coefficients, Pearson and Spearman. The advantages and drawbacks of the different methods of comparison are discussed, and we find that both methods of comparison give the same overall picture, showing that present force field methods cannot match the performance of quantum chem. methods for the calculation of IR spectra.

Journal of Chemical Theory and Computation published new progress about Alcohols Role: PRP (Properties). 97-99-4 belongs to class tetrahydrofurans, and the molecular formula is C5H10O2, Electric Literature of 97-99-4.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Nam, Ki-Ho; Jin, Jeong-un; Lee, Dong Hoon; Han, Haksoo; Goh, Munju; Yu, Jaesang; Ku, Bon-Cheol; You, Nam-Ho published the artcile< Towards solution-processable, thermally robust, transparent polyimide-chain-end tethered organosilicate nanohybrids>, Formula: C8H4O6, the main research area is polyimide nanohybrid optical elec thermal property.

The main challenge to developing future display substrates is to synthesize flexible substrate materials that also have excellent optical and thermal properties, and low thermal expansion number In this study, a novel trifluoromethylated asym. aromatic diamine, 4-[[4-(4-amino-2-trifluoromethylphenoxy)phenyl]sulfonyl-3-(trifluoromethyl)]benzenamine (AFPSFB), was synthesized through nucleophilic substitution. Conventional two-step polycondensation of AFPSFB with com. available tetracarboxylic dianhydrides enabled the fabrication of fully or semi-aromatic polyimides (PIs). The resulting PIs were highly soluble in polar aprotic solvents with good optical and thermal properties. Next, polyhedral oligomeric silsesquioxane containing an amine group (NH2-POSS) was reacted with the resulting soluble PI. All the PI-POSS nanohybrids displayed excellent optical properties, including high transparency (>91% at 400 nm), low refractive index (<1.5589), and very small birefringence (<0.0025 at 637 nm). End-capping of the POSS and chem. bonding between the POSS and PIs significantly enhanced the thermal and elec. properties. The results provide useful information for designing mol. architectures for manufacturing high-performance flexible substrates in future display devices. Composites, Part B: Engineering published new progress about Additive polymerization. 4415-87-6 belongs to class tetrahydrofurans, and the molecular formula is C8H4O6, Formula: C8H4O6.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Wang, Chenguang; Liu, Yong; Cui, Zhibing; Yu, Xiaohu; Zhang, Xinghua; Li, Yuping; Zhang, Qi; Chen, Lungang; Ma, Longlong published the artcile< In Situ Synthesis of Cu Nanoparticles on Carbon for Highly Selective Hydrogenation of Furfural to Furfuryl Alcohol by Using Pomelo Peel as the Carbon Source>, Recommanded Product: (Tetrahydrofuran-2-yl)methanol, the main research area is copper nanoparticle carbon hydrogenation furfural furfuryl alc.

A facile approach was developed to directly synthesize carbon-supported metal nanoparticles with pomelo peel as the carbon source and metal nitrate solution as the metal source. Fe/C, Co/C, Ni/C, and Cu/C catalysts were prepared after calcination in N2 without further reduction The metal nanoparticles and formation mechanism were investigated by multiple techniques such as XRD, HRTEM, XPS, FTIR spectra, SEM, and TG-MS thermal anal. In the case of furfural hydrogenation, Cu/C catalyst exhibited the best activity and exclusive selectivity to produce furfuryl alc. with complete conversion, and excellent selectivity can be maintained at a higher temperature of 240°C. The particle size of Cu nanoparticles can be tuned by the calcination temperature and metal loading for improving catalytic activity. The excellent performance of Cu nanoparticles was also studied by d. functional theory calculation, agreeing well with the experiments A green and facile approach to in situ synthesis of metal nanoparticles on carbon for exclusively selective hydrogenation of furfural.

ACS Sustainable Chemistry & Engineering published new progress about Calcination. 97-99-4 belongs to class tetrahydrofurans, and the molecular formula is C5H10O2, Recommanded Product: (Tetrahydrofuran-2-yl)methanol.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Adeline, Naomi Joan Faray; Geue, Claudia; Hermami, Mohsen Rezaei published the artcile< Cost-effectiveness of treating hepatitis C in Seychelles.>, Application of C9H13N2O9P, the main research area is Hepatitis C; cost-effectiveness; direct-acting antiviral.

INTRODUCTION: approximately eighty million people around the world are living with hepatitis C, and 700,000 people die every year, due to hepatitis C related complications. In Seychelles, a total of 777 cases of hepatitis C were reported from 2002 to 2016, but up to mid of 2016, the cases were not being treated. Treatment with Harvoni, a combination of sofosbuvir and ledipasvir (SOF/LDV), is now being offered on the condition that the patient does not, or has stopped, injecting drugs. This paper is the first to establish the cost effectiveness of treating all cases of hepatitis C in Seychelles with Harvoni, as compared to no treatment. METHODS: data extracted from literature was used to populate an economic model to calculate cost-effectiveness from Seychelles’ government perspective. The model structure was also informed by the systematic review and an accompanying grading of economic models using the Consolidated Health Economic Evaluation Reporting Standard (CHEERS) checklist. A Markov model was developed, employing a lifetime horizon and costs and benefits were analysed from a payer’s perspective and combined into incremental cost effectiveness ratios (ICERs). RESULTS: the direct-acting antiviral (DAA), Harvoni, was found to be cost-saving in Seychelles hepatitis C virus (HCV) cohort, as compared to no treatment, with an ICER of € 753.65/QALY. The treatment was also cost-saving when stratified by gender, with the ICER of male and female being € 783.74/QALY and € 635.20/QALY, respectively. Moreover, the results obtained from acceptability curves showed that treating patients with Harvoni is the most cost-effective option, even for low thresholds. CONCLUSION: treating hepatitis C cases in Seychelles is cost-saving. It is worth developing a treatment programme to include all cases of hepatitis C, regardless of status of drug injection.

The Pan African medical journal published new progress about 58-97-9. 58-97-9 belongs to class tetrahydrofurans, and the molecular formula is C9H13N2O9P, Application of C9H13N2O9P.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Mironenko, R. M.; Belskaya, O. B.; Likholobov, V. A. published the artcile< Carbon Black as a Support in Palladium Catalysts for Hydrogenation of Organic Compounds>, Application In Synthesis of 97-99-4, the main research area is palladium carbon black catalyst hydrogenation.

The possibility of using carbon black (CB) as a support of palladium catalysts for the selective hydrogenation of organic compounds is considered. The advantages of Pd/CB catalysts are demonstrated by examples of liquid-phase hydrogenation of aromatic aldehydes and nitro compounds The combination of high catalytic parameters (activity, selectivity, and stability) achieved by these catalysts in hydrogenation reactions indicates that they are promising for use on an industrial scale, in particular in the syntheses of fine chems.

Solid Fuel Chemistry published new progress about Aldehydes Role: NUU (Other Use, Unclassified), USES (Uses). 97-99-4 belongs to class tetrahydrofurans, and the molecular formula is C5H10O2, Application In Synthesis of 97-99-4.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Salnikova, Ksenia E.; Larichev, Yurii V.; Sulman, Esther M.; Bykov, Alexey V.; Sidorov, Alexander I.; Demidenko, Galina N.; Sulman, Mikhail G.; Bronstein, Lyudmila M.; Matveeva, Valentina G. published the artcile< Selective Hydrogenation of Biomass-Derived Furfural: Enhanced Catalytic Performance of Pd-Cu Alloy Nanoparticles in Porous Polymer>, Application of C5H10O2, the main research area is biomass derived furfural hydrogenation palladium copper nanoparticle polymer catalyst; Pd−Cu alloys; furfural; hydrogenation; hypercrosslinked polystyrene; nanostructures.

Here, the development of a new catalyst is reported for the selective furfural (FF) hydrogenation to furfuryl alc. (FA) based on about 7 nm sized Pd-Cu alloy nanoparticles (NPs) formed in inexpensive, com. available micro/mesoporous hypercrosslinked polystyrene (HPS). A comparison of the catalytic properties of as-synthesized and reduced (denoted “”r””) catalysts as well as Pd-Cu alloy and monometallic palladium NPs showed a considerable enhancement of the catalytic performance of Pd-Cu/HPS-r compared to other catalysts studied, resulting in about 100% FF conversion, 95.2% selectivity for FA and a TOF of 1209 h-1. This was attributed to the enrichment of the NP surface with copper atoms, disrupting the furan ring adsorption, and to the presence of both zerovalent and cationic palladium and copper species, resulting in optimal hydrogen and FF adsorption. These factors along with exceptional stability of the catalyst in ten consecutive catalytic cycles make it highly promising in practical applications.

ChemPlusChem published new progress about Adsorption. 97-99-4 belongs to class tetrahydrofurans, and the molecular formula is C5H10O2, Application of C5H10O2.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Nazarski, Ryszard; Skolimowski, Janusz; Skowronski, Romuald published the artcile< Sterically crowded five-membered heterocyclic systems. Part I. Synthesis of acetylene derivatives of azolidyne and oxolane>, Product Details of C8H14O2, the main research area is ethynylation Favorskii pyrrolidinone tetramethyl; alkynylation tetrahydrofuranone tetramethyl; alkynylpyrrolidinol tetramethyl; alkynylfuranol tetrahydrotetramethyl.

Alkynyl 5-membered heterocyclic compounds I (R = H, Ph; X = O, NH) were prepared by alkynylation of the heterocyclic ketones II by the Favorskii alkynylation (KOH, alkyne, THF) or Grignard-Iotsitch method (EtMgBr, alkyne). Favorskii ethynylation of II (X = NH) gave 44% I (R = H; X = NH), whereas Favorskii ethynylation of II (X = O) gave no ethynylation product which indicated that the amino group in II (X = NH) acts as a catalyst in the ethynylation.

Polish Journal of Chemistry published new progress about 5455-94-7. 5455-94-7 belongs to class tetrahydrofurans, and the molecular formula is C8H14O2, Product Details of C8H14O2.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Mineguchi, Yuri; Goto, Kyosuke; Sudo, Yuna; Hirayama, Kentaro; Kashiwagi, Hirotoshi; Sasagase, Izumi; Kitazawa, Haruki; Asakuma, Sadaki; Fukuda, Kenji; Urashima, Tadasu published the artcile< Characterisation of sugar nucleotides in colostrum of dairy domestic farms animals>, Recommanded Product: ((2R,3S,4R,5R)-5-(2,4-Dioxo-3,4-dihydropyrimidin-1(2H)-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl dihydrogen phosphate, the main research area is colostrum sugar nucleotide UMP UDP.

The biol. significance and heterogeneity of bovine, caprine and ovine colostrum sugar nucleotides is unclear. Colostrum sugar nucleotides and sugar monophosphates were purified and characterised with 1H-NMR spectroscopy. UDP-galactose (UDP-Gal) and UDP-glucose (UDP-Glc) were identified in colostrum of Holstein and Brown Swiss cows; UDP-Gal, UDP-Glc, UDP-N-acetylgalactosamine (UDP-GalNAc) and UDP-N-acetylglucosamine (UDP-GlcNAc) were found in Japanese Saanen goat colostrum. UDP-Gal, UDP-Glc, UDP-GalNAc and UDP-GlcNAc were found in Corriedale sheep but not in the Suffolk and Fraise Land breeds. The presence/absence of these sugar nucleotides in colostrum is heterogeneous among dairy domestic farm animals and the three sheep breeds. In addition, a nucleotide, uridine-ribose diphosphate (UDP) was identified in the colostra of Japanese Saanen goat, and Suffolk and Fraiseland sheep, while uridine-ribose monophosphate (UMP) was detected in the colostrum of Brown Swiss cow and the three breed sheep. N-acetylglucosamine-1-phosphate (GlcNAc-1-P) was also identified in the colostrum of the goat and two cow breeds.

International Dairy Journal published new progress about Bos taurus. 58-97-9 belongs to class tetrahydrofurans, and the molecular formula is C9H13N2O9P, Recommanded Product: ((2R,3S,4R,5R)-5-(2,4-Dioxo-3,4-dihydropyrimidin-1(2H)-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl dihydrogen phosphate.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Phanthuwongpakdee, Jakkapon; Harimoto, Toyohiro; Babel, Sandhya; Dwivedi, Sumant; Takada, Kenji; Kaneko, Tatsuo published the artcile< Flame retardant transparent films of thermostable biopolyimide metal hybrids>, Electric Literature of 4415-87-6, the main research area is flame retardant transparent film thermostable bio polyimide metal hybrid.

The development of flame retardant transparent films is important for elec. devices and building materials it but it is still a challenge. Herein, flame retardant films having high optical transparency were developed from the amino acid-based biopolyimide (BPI) salt with aluminum (BPI-COOAl) and copper ions (BPI-COOCu). The microscale combustion calorimetry anal. revealed that for BPI-COOAl, the total heat released (THR) and peak heat released rate were 4.5 W/g and 18.9 kJ/g, resp. These values were lower than those of its precursors and BPI-COOCu. BPI-COOAl was rated V-0 for the Underwriters Laboratories vertical burning standard test. The polymer also retained a high transparency of more than 80% transmittance at a wavelength of 450 nm. The tensile strength was also preserved at 63.7 MPa. For BPI-COOCu, 14.6 kJ/g THR and 47.1 MPa tensile strength were observed When a colorful ion such as Cu was used, BPI-COOCu became a flame retardant film that was a green filter. The char formation of Al2O3 and Cu2O in their resp. polymer complexes was deduced as the main flame suppression mechanism. The present films of biopolyimide salts are advantageous in showcasing the balance of different essential material properties such as flame retardancy, thermo-mech. stability, and transparency.

Polymer Degradation and Stability published new progress about Cation exchange. 4415-87-6 belongs to class tetrahydrofurans, and the molecular formula is C8H4O6, Electric Literature of 4415-87-6.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem