Article
Chemistry, Multidisciplinary
Hai-Feng Ji
Summary: In this letter, a general rule is proposed to predict the sign of optical rotation of chiral molecules with a RCHXY structure from their absolute configurations using the Hammett constant, sigma(p), based on the electron withdrawing/donating power of functional groups. The rule uses a priority list of functional groups based on their electron withdrawing powers, where a clockwise arrangement of the other three priorities from the most electron withdrawing to the least withdrawing (1-2-3) predicts dextrorotation, and a counterclockwise arrangement predicts levorotation.
Article
Chemistry, Physical
Nikolay O. Mchedlov-Petrossyan, Sergey V. Shekhovtsov, Elena G. Moskaeva, Iryna V. Omelchenko, Alexander D. Roshal, Andrey O. Doroshenko
Summary: The article investigates the behavior of nitro derivative fluorescein dyes in solution, revealing their unique properties and sensitivity to pH, as well as their strong acidity.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Engineering, Chemical
Iveth Romero, Fernando Montero, Sergey Kucheryavskiy, Reinhard Wimmer, Anders Andreasen, Marco Maschietti
Summary: A new kinetic model for the hydrogensulfide scavenging reactions using MEA-triazine (HET) is proposed, supported by experimental observations obtained by NMR spectroscopy. The model assumes the existence of 3,5-bis-(2-hydroxyethyl)-hexahydro-1,3,5-thiadiazine (TDZ) as a reaction intermediate. Experimental data were obtained using in situ Raman spectroscopy, and the optimal model parameters were determined through regression analysis. The rate constants and activation energies for the scavenging reactions were also estimated.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Analytical
Matthew Wallace, Nduchi Abiama, Miranda Chipembere
Summary: This paper presents a method to directly determine the acid dissociation constant (pK(a)) in aqueous-organic solvents using nuclear magnetic resonance (NMR). By measuring the chemical shift of an organic acid as a function of concentration and using it as a reference, the pK(a) values of less acidic molecules can be determined. The method was successfully applied to determine the pK(a) values of organic acids and bases in different aqueous-organic solvent mixtures, and the results were in good agreement with literature values.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Jessica L. Smith-Osorio, Henry Torres-Quezada, Andrea P. Sandoval-Rojas, Jesus A. . Agreda
Summary: This study proposes an alternative method for metrology by implementing the theoretical coulometric titration curve. The results show that the proposed method provides similar results to the traditional method, and the experimental data agrees with the literature. The theoretical coulometric titration curve method has a stronger chemical support compared to the traditional method.
Article
Food Science & Technology
Sukan Braspaiboon, Sukhuntha Osiriphun, Suthat Surawang, Wachira Jirarattanarangsri, Nattapong Kanha, Thunnop Laokuldilok
Summary: Ultrasound-assisted alkaline extraction (UAAE) was used to extract proteins from five types of algae (Arthrospira platensis, Cladophora glomerata, Porphyra tenera, Laminaria japonica and Undaria pinnatifida). The UAAE of A. platensis protein at 60% amplitude level and 30 min extraction time provided the highest protein yield and altered the surface of A. platensis. Most algal proteins were dominant in lysine and branched-chain amino acids (BCAAs). C. glomerata protein had the highest digestibility and protein digestibility-corrected amino acid scores for BCAAs. L. japonica protein was rich in aspartic and glutamic acids and had an umami taste. Algal proteins had low contents of carbohydrates and nucleic acids, while total phenolics were relatively high. They could be used as ingredients in vegan and vegetarian foods.
INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
(2022)
Article
Energy & Fuels
Morteza Aminnaji, Ross Anderson, Khosro Jarrahian, Bahman Tohidi
Summary: Low dosage kinetic hydrate inhibitors (KHIs) are an effective method for preventing solid gas hydrate plug formation in the oil and gas industry. Efforts have been made to develop environmentally friendly KHIs due to concerns around the non-biodegradability of traditional chemistries. Natural pectin has been identified as a potential green KHI with good hydrate inhibition properties. This study compared the performance of food grade apple pectin and the commercial biodegradable KHI polymer Luvicap Bio using crystal growth inhibition methods. Results show that Luvicap Bio offers significant inhibition to high subcoolings, while pectin only shows some anti-nucleation properties.
Article
Biochemistry & Molecular Biology
Gustavo Ravelo-Ortega, Jesus Salvador Lopez-Bucio, Leon Francisco Ruiz-Herrera, Ramon Pelagio-Flores, Juan Angel Ayala-Rodriguez, Homero Reyes de la Cruz, Angel Arturo Guevara-Garcia, Jose Lopez-Bucio
Summary: Amino acids act as important biostimulants for plants, with 15 of the 20 amino acids evaluated in Arabidopsis inhibiting primary root growth. Specifically, L-Leu, L-Lys, L-Trp, and L-Glu were found to repress cell division and elongation in the roots.
Article
Energy & Fuels
Liang Mu, Qiqi Tan, Xianlong Li, Ziqi Zhou, Huixing Zhao, Qingyan Cui
Summary: This study developed a novel type of kinetic hydrate promoters (CDA) to promote CH4/THF hydrate formation and alleviate the hydrate wall-climbing growth. Results showed that the hydrate formation rate enhanced, and the induction time decreased as the CDA concentration increased. The largest CH4 storage capacity achieved was 107.78 +/- 1.89 v/v at 283.15 K and at an initial pressure of 7.2 MPa, which was obtained at the CDA concentration of 0.2 wt %.
Article
Biotechnology & Applied Microbiology
Alba Galafat, Antonio Jesus Vizcaino, Maria Isabel Saez, Juan Luis Gomez-Pinchetti, Francisco Gabriel Acien, Tomas Francisco Martinez, Francisco Javier Alarcon
Summary: This study evaluated the potential dietary ingredients of different microalgae and cyanobacteria in aquafeeds. The results showed that all the evaluated microalgae and cyanobacteria had high protein content and a balanced amino acid profile.
JOURNAL OF APPLIED PHYCOLOGY
(2022)
Article
Chemistry, Physical
C. C. He, L. A. Hamlow, B. Kimutai, H. A. Roy, Zachary J. Devereaux, N. A. Cunningham, J. Martens, G. Berden, J. Oomens, C. S. Chow, M. T. Rodgers
Summary: Cisplatin and its analogue Argplatin are investigated for their different reactivity towards DNA and RNA, with Arginine found to bind to platinum in a bidentate manner in both forms. Sodium cationization and protonation of the side chain of Arginine were also found to affect the binding mode. This study demonstrates the preservation of the NO- binding mode of arginine to platinum under varying conditions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Shaoyuan Zhou, Bach T. Nguyen, John P. Richard, Ronald Kluger, Jiali Gao
Summary: This study reveals that the decarboxylation reactions of organic carboxylate compounds in aqueous and dimethylformamide solutions are influenced by solvent effects. A linear relationship was found between decarboxylation rates and Gibbs energies, suggesting diminishing recombination barriers in dimethylformamide. Protonation of carbanions by the solvent has large free energy barriers, allowing the competing exchange of isotope-labeled CO2 to be reversible in dimethylformamide. The intricate interplay of carbanion stability and solute-solvent interaction in decarboxylation and carboxylation could be beneficial in designing novel materials for CO2 capture.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Xin Yang, Xun Liu, Fujun Yao, Lingyuan Chen, Wenyuan Hu, Jiawen Li, Zheng Kang, Xiaohui Duan, Chonghua Pei
Summary: A chiral superstructure resembling the Turritella terebra shell can be easily formed in aragonite by the combined action of CTAB and Mg2+. The asymmetric adsorption of the CTAB head group on aragonite, known as adsorption chirality, is responsible for the chiral assembly.
CHEMICAL COMMUNICATIONS
(2023)
Article
Energy & Fuels
Cuiping Tang, Yanan Zhang, Deqing Liang
Summary: Adding hydrate inhibitors, such as Es-PVCap-OH, is an effective method to prevent gas hydrates from blocking pipelines and equipment. This study investigated the inhibitory performance of Es-PVCap-OH for methane hydrate formation and compared it with the kinetic inhibitor PVCap. The results showed that Es-PVCap-OH exhibited better inhibitory performance and changed the morphology of the hydrate structure.
Article
Nanoscience & Nanotechnology
Shyam P. Khanal, Rajendra P. Koirala, Esha Mishra, Narayan P. Adhikari
Summary: Transportation of amino acids in an aqueous medium is vital for supporting life processes. This study used classical molecular dynamics simulation to investigate the transportation properties of gamma-aminobutyric acid (GABA) in a water environment. Diffusion coefficients of GABA and water molecules, as well as their binary diffusion coefficient, were estimated at different temperatures. The study also examined the effect of system size on diffusion coefficients and viscosity coefficients of the solvent. Additionally, the temperature dependence of the diffusion coefficient and the hydrogen bonds between the solute and solvent were analyzed.
