Article
Chemistry, Physical
Weslley G. D. P. Silva, Gabrielle Daudet, Sem Perez, Sven Thorwirth, Jennifer van Wijngaarden
Summary: By utilizing rotational spectroscopy and quantum chemical calculations, a rich conformational landscape with 42 energy minima was revealed for diallylamine (DAA). Experimental verification of four low energy conformers in the rotational spectrum showed their energy order. Computational studies indicated that the geometric preferences for the observed conformers are influenced by a combination of subtle attractive interactions and repulsive effects.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Physics, Fluids & Plasmas
Qiu-Shi Li, Yao-Gen Shu, Zhong-Can Ou-Yang, Ming Li
Summary: The high fidelity of DNA polymerase is crucial for accurate DNA replication. Various quantitative approaches are available to measure the fidelity of DNA polymerase, with biochemical kinetic methods being widely adopted. However, these methods can sometimes lead to inconsistent results when quantifying the proofreading efficiency of DNA polymerase.
Article
Chemistry, Physical
Ali Disli, Esin Eylem Yucesoy, Yusuf Erdogdu, Mehmet Tahir Gulluoglu, Ali Ozturk, Gulay Dilek
Summary: In this study, a novel compound was investigated using a combination of experimental and theoretical methods. The synthesized compounds showed good antimicrobial activity against various bacterial and fungal strains. Theoretical calculations successfully predicted the molecular properties and behavior of the compounds, which were consistent with the experimental results.
JOURNAL OF MOLECULAR STRUCTURE
(2021)
Article
Chemistry, Multidisciplinary
Firas F. Awwadi, Manal I. Alwahsh, Mark M. Turnbull, Christopher P. Landee
Summary: The impact of halogen bonding interactions on polymorphism in Cu(2I5YP)(2)X-2 was studied. It was found that there are two possible conformers for 2I5Y-X complexes: syn and anti. The stability of the conformers depends on the nature of the halogen atoms in the complex.
Article
Chemistry, Physical
Wenhong Yang, Erik Lotstedt, Kaoru Yamanouchi
Summary: We theoretically investigate the delay-dependent transient absorption of a femtosecond vacuum ultraviolet (VUV) pulse by a pi-conjugated system, trans-1,3-butadiene, exposed to a femtosecond near infrared (IR) intense laser pulse and find that the ultrafast dynamics of pi-electrons in the excited states of trans-1,3-butadiene are well reproduced by a three-level rotating-wave approximation. We identify the origin of the absorption features as the creation of a light-dressed (pi,pi*) state by the light-induced coupling with the near-IR laser pulse, resulting in the dynamical motion of the density of the pi-electrons driven by the near-IR pulse.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Biochemistry & Molecular Biology
Fernando Nainggolan
Summary: The molecular structure properties of the cis and trans form of azobenzene molecule from HMNA were investigated using the DFT method. The trans-HMNA has a molecular size of 9.0 t1 and exhibits a p → p* type electronic transition driven by an azo bond. The cis-HMNA has a molecular size of 6.6 t1 and exhibits an n → p* type electronic transition with respect to the non-bonding electrons of oxygen and nitrogen atoms. The study suggests that the mechanism pathway of HMNA from trans to cis form is feasible to undergo at the inversion pathway in the ground state.
JOURNAL OF MOLECULAR MODELING
(2023)
Article
Food Science & Technology
Yi Wu, Dong He, Minhua Zong, Hong Wu, Lin Li, Xia Zhang, Xinhui Xing, Bing Li
Summary: The study found that complexation of hydrolyzed wheat starch (HWS) with trans-resveratrol (RES) improves the stability of RES during storage and processing. The complexation with HWS enhances the UV and thermal stability of RES and improves its bioavailability and cellular antioxidant capacity. These findings have important implications for the storage and processing of polyphenolic compounds.
FOOD STRUCTURE-NETHERLANDS
(2022)
Article
Chemistry, Physical
H. A. Roy, M. T. Rodgers
Summary: Ionic liquids (ILs) have unique properties that can be tuned by varying cations and anions, affecting their feasibility for different applications. However, understanding of the microscopic cation-anion interactions within ILs is still limited.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Biochemistry & Molecular Biology
Vipin Bahadur Singh
Summary: This study investigates the conformation of dopamine in aqueous solution using different theoretical methods, revealing the higher energy level of the trans isomer in water. Additionally, the experimental Raman spectrum of dopamine was found to be significantly influenced by the solvent.
ACS CHEMICAL NEUROSCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Hualace Vinicius Emiliano, Raphaela Pereira Guaringue, Thiago de Castro Rozada, Barbara Celania Fiorin
Summary: This research presents the conformational analysis of three chalcone compounds using theoretical calculations and natural bond orbital analysis. The study found that s-cis conformers are more stable, and the population of s-trans conformers in o-Chal is influenced by the position of the nitro group.
ORBITAL-THE ELECTRONIC JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Nyancy Halder, Maheshwari Horalavadi Mahadavaiah, Dandamudi Usharani, Harapriya Rath
Summary: The study presents the first spectroscopic and theoretical report on distorted square planar Ni(II) organometallic complex and near square planar organometallic Cu(III) complex, synthesized by one inner CH activation and double inner CH activation, respectively. These highly stable nickel and copper organometallic complexes exhibit different oxidation states and conformational changes induced by M-C bond formations, as analyzed through various spectroscopic techniques and DFT level theoretical calculations.
JOURNAL OF PORPHYRINS AND PHTHALOCYANINES
(2021)
Article
Chemistry, Analytical
Luana Ferreira da Costa, Claudio Francisco Tormena, Marco Aurelio Zezzi Arruda
Summary: This study evaluated three generations of transgenic and non-transgenic soybean plants using multiomics, showing that some elements may share transport mechanisms and correlate with fatty acids, allowing for differentiation of generations and species.
MICROCHEMICAL JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Joao Vitor Soares, Guilherme Dal Poggetto, Renan V. Viesser, Uenifer R. Couto, Claudio F. Tormena
Summary: Long-range proton-fluorine coupling constants ((n)J(HF)) are important for the structure elucidation of fluorinated molecules. In this study, the transmission of (4)J(HF) was investigated using trans-4-tert-butyl-2-fluorocyclohexanone as the model compound. It was found that stereoelectronic interactions involving the pi system of the carbonyl group play a crucial role in the transmission pathway of (4)J(HF). Interactions where the pi system acts as an electron acceptor increase the value of (4)J(HF), while interactions where the pi system acts as an electron donor decrease it.
MAGNETIC RESONANCE IN CHEMISTRY
(2022)
Article
Biochemical Research Methods
Jose Roberto Aparecido dos Santos-Pinto, Franciele Grego Esteves, Claudio Francisco Tormena, Amilcar Perez-Riverol, Alexis Musacchio Lasa, Odair Correa Bueno, Mario Sergio Palma
Summary: The study investigated the fibroin-based silk fibers from weaver ants and provided a structural characterization of these fibers. It identified a glycoprotein with a molecular weight of around 40 kDa in the ant silk fibers and revealed a 3D structure predominantly composed of coiled-coil secondary units. The findings contribute to the development of new approaches for the production of silk-based polymers for biomedical applications.
JOURNAL OF PROTEOMICS
(2022)
Article
Chemistry, Multidisciplinary
Meire Y. Kawamura, Juan Alegre-Requena, Thais M. Barbosa, Claudio F. Tormena, Robert S. Paton, Marco A. B. Ferreira
Summary: [3+2] cycloadditions of nitroolefins are a selective and catalyst-free alternative for synthesizing 1,2,3-triazoles. Mechanistic studies reveal that the rate-limiting step is the cycloaddition, which shows high kinetic selectivity for the formation of 1,5-triazoles.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Shiwen Liu, Claudio F. Tormena, Gerald B. Hammond, Bo Xu
Summary: Alkynyltrifluoroborate nucleophiles can react with a wide range of sp(3)-carbon electrophiles to produce Sonogashira-type products, where an ion pair-organic complex may play a crucial role in the reaction.
Article
Biochemistry & Molecular Biology
Regina Westphal, Eclair Venturini Filho, Laiza Bruzadelle Loureiro, Claudio Francisco Tormena, Claudia Pessoa, Celina de Jesus Guimaraes, Mariana Palmeira Manso, Rodolfo Goetze Fiorot, Vinicius Rangel Campos, Jackson Antonio Lamounier Camargos Resende, Fabrizio Medici, Sandro Jose Greco
Summary: In this study, a microwave-assisted Knoevenagel/Michael/cyclization multicomponent domino methodology was developed for the synthesis of spiro compounds. Twelve spiro compounds were synthesized and one of them exhibited anti-cancer activity.
Article
Chemistry, Multidisciplinary
Lucas J. J. Karas, Said Jalife, Renan V. V. Viesser, Joao V. Soares, Michael M. M. Haley, Judy I. I. Wu
Summary: Whether tetra-tert-butyl-s-indacene is a symmetric D-2h structure or a bond-alternating C-2h structure is still uncertain. The close agreement between experimental and computed proton chemical shifts, using minima structures optimized at the M06-2X, ?B97X-D, and M11 levels, confirms the bond-localized C-2h symmetry which is consistent with the expected strong antiaromaticity of TtB-s-indacene.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Coral Mycroft, Guilherme Dal Poggetto, Thaiis M. Barbosa, Claiudio F. Tormena, Mathias Nilsson, Gareth A. Morris, Laura Castanar
Summary: The NMR analysis of fluorine-containing molecules is important in pharmaceuticals and biochemistry, but faces challenges due to severe peak overlap. This study introduces a new method, IPAP-FESTA, that simplifies measurements of proton-fluorine couplings. Its usefulness is demonstrated in the structural study of the drug fluticasone propionate and in assessing solvent effects on fluorohydrin conformational equilibrium in a mixture.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
Luiz Gustavo Bonato, Guilherme Dal Poggetto, Raphael Fernando Moral, Brener Rodrigo de Carvalho Vale, Jose Carlos Germino, Diogo Burigo Almeida, Patricia Santiago, Pablo Sebastian Fernandez, Claudio Francisco Tormena, Lazaro A. Padilha, Ana Flavia Nogueira
Summary: In this study, the influence of organic ligands on the photostability of CsPbBr3 perovskite nanocrystals was investigated. The results demonstrate that alkylphosphate ligands can improve the photostability of colloidal nanocrystals dispersions, which is important for applications requiring continuous excitation.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Polymer Science
Manami Kawakami, Karl H. G. Schulz, Anthony J. Varni, Claudio F. Tormena, Roberto R. Gil, Kevin J. T. Noonan
Summary: This study demonstrates the feasibility of homopolymerization and statistical copolymerization of 2-ethylhexyl thiophene-3-carboxylate and 2-ethylhexyl selenophene-3-carboxylate monomers via Suzuki-Miyaura cross-coupling. The use of a specific palladium catalyst allows for the preparation of regioregular conjugated polymers with high molecular weights and relatively narrow molecular weight distributions. Increasing the concentration of selenophene-3-carboxylate in the copolymer series can reduce the optical bandgap.
Article
Chemistry, Organic
Attilio Chiavegatti Neto, Kelly Cintra Soares, Maiara da Silva Santos, Tulio Jardini Aimola, Antonio Gilberto Ferreira, Guilherme A. M. Jardim, Claudio Francisco Tormena, Marcio Weber Paixao, Marco Antonio Barbosa Ferreira
Summary: Here, a fully detailed mechanistic study on the organocatalyzed metal-free click reactions for the synthesis of 1,2,3-triazoles is reported. The elementary steps, intermediates, and transition states of the reactions are investigated using DFT calculations and H-1 NMR monitoring experiments, providing detailed profiles for both reaction mechanisms. DIAS analysis is also employed to elucidate the regioselectivity in these reactions.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Gagan Sharma, Carolyne B. Braga, Kai-En Chen, Xinying Jia, Venkatraman Ramanujam, Brett M. Collins, Roberto Rittner, Mehdi Mobli
Summary: Chlorotoxin (ClTx) is a disulfide-rich peptide isolated from scorpion venom that selectively binds to brain tumors and has emerged as a potential target for the vascular endothelial growth factor receptor, neuropilin-1 (NRP1). This study characterized the binding details of ClTx to NRP1 through NMR spectroscopy, revealing a non-standard binding motif that provides a basis for future engineering of ClTx for improved applications.
CURRENT RESEARCH IN STRUCTURAL BIOLOGY
(2021)
Article
Chemistry, Physical
Renan V. Viesser, Claudio F. Tormena
Summary: The study reveals an inverse halogen dependence (IHD) in the anion series due to negative spin-orbit contribution rather than scalar paramagnetic effects. The presence of a carbon nonbonding orbital in anions allows for magnetic couplings that generate a deshielding effect on the nucleus, contradicting the classical association between delta C-13 and atomic charge.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
