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Wyszukujesz frazę "molecular orbital" wg kryterium: Temat


Tytuł:
Application of Fragment Molecular Orbital Method to investigate dopamine receptors
Autorzy:
Preikša, Jokūbas
Śliwa, Paweł
Tematy:
Fragment Molecular Orbital
molecular dynamic
dopamine receptor
Fragment Molecular Orbital (FMO)
dynamika molekularna
receptor dopaminowy
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Wydawca:
Państwowa Wyższa Szkoła Zawodowa w Tarnowie
Powiązania:
https://bibliotekanauki.pl/articles/93092.pdf  Link otwiera się w nowym oknie
Opis:
GPCRs are a vast family of seven-domain transmembrane proteins. This family includes dopamine receptors (D1, D2, D3, D4, and D5), which mediate the variety of dopamine-controlled physiological functions in the brain and periphery. Ligands of dopamine receptors are used for managing several neuropsychiatric disorders, including bipolar disorder, schizophrenia, anxiety, and Parkinson’s disease. Recent studies have revealed that dopamine receptors could be part of multiple signaling cascades, rather than of a single signaling pathway. For these targets, a variety of experimental and computational drug design techniques are utilized. In this work, dopamine receptors D2, D3, and D4 were investigated using molecular dynamic method as well as computational ab initio Fragment Molecular Orbital method (FMO), which can reveal atomistic details about ligand binding. The results provided useful insights into the significances of amino acid residues in ligand binding sites. Moreover, similarities and differences between active-sites of three studied types of receptors were examined.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Photophysical and biological studies on structurally modified chlorophenyl-substituted pyrazolone derivatives
Autorzy:
Naglah, Ahmed M.
Almehizia, Abdulrahman A.
Maniyar, A.K.
Marrakkur, Vidyagayatri
Naik, Lohit
Tematy:
Chlorophenyl-substituted pyrazolone
biological activity
HOMO
Highest Occupied Molecular Orbital
LUMO
Lowest Unoccupied Molecular Orbital
Mulkin plot
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Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Powiązania:
https://bibliotekanauki.pl/articles/59124247.pdf  Link otwiera się w nowym oknie
Opis:
In this study, chlorophenyl-substituted pyrazolone derivatives (5a–5c) were synthesized via the Baylis-Hillman acetate reaction. Comprehensive physicochemical characterization was conducted using 1H-NMR, FT-IR, and mass spectroscopy. Density Functional Theory (DFT) calculations at the B3LYP/6-31(G) level was employed to optimize molecular geometries and investigate electronic properties, revealing predominantly planar structures, with notable deviations in the pyrazole group. The HOMO and LUMO analyses showed π-delocalization across the entire molecule, with charge-transfer transitions dominating the excited states. Global Chemical Reactivity Descriptors (GCRD), including chemical potential, hardness, and electrophilicity index, were used to assess molecular stability and reactivity, indicating the molecules’ resistance to electron cloud deformation. Biological evaluations revealed exceptional antimicrobial and antifungal activities of the derivatives, with compound 5a demonstrating the highest efficacy against S. aureus, E. coli, A. niger and C. albicans. Furthermore, antiproliferative studies against HepG2 liver carcinoma cells showed that compound 5a exhibited superior anticancer activity (IC50 = 6 μg/mL), attributed to its structural features, such as chlorophenyl groups and a piperidin-4-one moiety. These moieties enhance the compound’s lipophilicity, facilitating cell membrane penetration and ROS generation, which contribute to apoptosis and inhibition of cancer cell growth. The findings suggest that chlorophenyl-pyrazolone derivatives, particularly 5a, hold promise as potent candidates for antimicrobial and anticancer therapies, paving the way for further pharmaceutical development.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Optical and Electrochemical Properties of Solvent-Dependent Natural Dye Extracted from Rivina humilis L
Autorzy:
Aliah, Hasniah
Iman, Ryan N.
Sriwidati, Sriwidati
Sawitri, Asti
Setiawan, Andhy
Putri, Assa P. D.
Kurniawati, Fera
Tematy:
natural dye
betalains
Rivina humilis L.
DSSC
dye-sensitized solar cell
HOMO
higher occupied molecular orbital
LUMO
lower unoccupied molecular orbital
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Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Powiązania:
https://bibliotekanauki.pl/articles/59113763.pdf  Link otwiera się w nowym oknie
Opis:
This work aimed to study the natural dye extracted from Indonesian wild plants (Rivina humilis L.) using different solvents. The natural dye was extracted using the maceration method. Three different solvents, namely, aquades, acetone, and ethanol 96%, were used to extract natural dye from Rivina humilis L fruit. The absorbance spectra of the extracted dye were recorded using Ultraviolet-Visible (UV-Vis) spectroscopy. The different spectra of betalain pigment revealed the dye extract’s dependence on the solvent. The functional groups of the extracted dye were analyzed using Fourier transform infrared (FTIR) spectroscopy. The adherence of carbonyl and hydroxyl groups from FTIR spectra indicated that this dye could anchor to a semiconducting material, e.g., TiO2, which was commonly used in dye-sensitized solar cells (DSSC). The electrochemical properties of the extracted pigments were studied through higher occupied molecular orbital (HOMO) and lower unoccupied molecular orbital (LUMO) energy levels. Based on the results, the best performance to construct DSSC was achieved by natural dye adsorption with aquades solvent.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular orbital estimation of reduced partition function ratios of lithium ions in ion exchanger phase of aqueous ion exchange systems
Autorzy:
Yanase, S.
Oi, T.
Tematy:
ion exchange
lithium
lithium isotopes
molecular orbital calculations
ONIOM calculations
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Wydawca:
Instytut Chemii i Techniki Jądrowej
Powiązania:
https://bibliotekanauki.pl/articles/147007.pdf  Link otwiera się w nowym oknie
Opis:
Structures of Li+(H2O)5SO3 --R with -R representing the methyl and other groups modeling the lithium ion in the ion exchanger phase of aqueous ion exchange systems were optimized based on the molecular orbital theory and the reduced partition function ratios (RPFRs) for the 6Li/7Li isotope substitutions were estimated. The structure around the lithium ion was nearly unchanged by the substitutions of the methyl group by the other groups. Correspondingly, the RPFR value did not vary substantially, either; the maximum decrease of 0.0008 was observed for -R = -C(C2H5)3 from that of -CH3. It was indicated that the equilibrium constant of the lithium isotope exchange reaction between the ion exchanger and the external solution phases could change by ca. 0.001 without any substantial structural change around the lithium ion in the ion exchanger phase. It was also indicated the ONIOM calculation is effective when treating isotope effects of large molecules.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On quadratic bond-order decomposition within molecular orbital space
Autorzy:
Mrozek, Janusz
Szczepanik, Dariusz
Opis:
A simple method of analysing and localization of canonical molecular orbitals for particular chemical bond using the MO-resolved bond-order decompo- sition scheme is presented. An alternative definition of classical bond order orbitals is provided and links to communication theory of the chemical bond are outlined and briefly discussed. The introduced procedure of decomposition of quadratic bond orders allows one to analyse two- as well as three- center chemical bonds within the framework of the same theory.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
Tytuł:
Synthesis and multifaceted exploration of 4-phenylpiperidin-4-ol substituted pyrazole: photophysical insights with biological activity
Autorzy:
Al-Hazmi, Ghaferah H.
Marrakkur, Vidyagayatri
Naik, Lohit
Refat, Moamen S.
Tematy:
pyrazolones
in-vitro biological activity
in-silico biological activity
HOMO-LUMO
Highest Occupied Molecular Orbital
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Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Powiązania:
https://bibliotekanauki.pl/articles/59124230.pdf  Link otwiera się w nowym oknie
Opis:
In this study, we successfully synthesized a pyrazole derivative, specifi cally 4-phenylpiperidin-4-ol substituted pyrazole (CHP), through the reaction of Grignard reagents in combination with pyrazole. This newly synthesized molecule was subjected to a comprehensive evaluation for both its photophysical and biological applications. Notably, CHP exhibited promising invitro antifungal and antibacterial activities, primarily attributed to the presence of the 4-phenylpiperidin-4-ol moiety and resulting component contributed to an enhanced absorption rate of lipids, thereby improving the pharmacological activity of CHP. This correlation between structure and function was further supported by the outcomes of structure-activity relationship studies. Additionally, we conducted in silico studies to examine the molecular interactions of the synthesized molecule with key proteins, including DNA Gyrase, Lanosterol 14 α-demethylase, and KEAP1-NRF2. The results unveiled robust binding interactions at specific sites within these proteins, indicating potential therapeutic relevance. Furthermore, the photophysical properties of the synthesized compounds were thoroughly investigated using the ab-initio technique. This involved the determination of ground state optimization and HOMO-LUMO energy levels, all calculated with the DFT-B3LYP-6-31G(d) basis set. The assessment of the theoretically estimated HOMO-LUMO value provided insights into the global chemical reactivity descriptors, revealing that the synthesized molecule boasts a highly electronegative and electrophilic index. Taken together, our findings suggest that pyrazole derivatives with 4-phenylpiperidin-4-ol substitutions exhibit promising applications in both photophysical and biological contexts.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ag+/S2O8 2– system for the degradation of aqueous flutriafol
Autorzy:
Yang, H.
Zhou, W.
Yang, L.
Deng, J.
Hu, Q.
Wei, H.
Au, C.
Yi, B.
Tematy:
chemical analysis
degradation
free radicals
metal ions
molecular orbital
transition metals
analiza chemiczna
degradacja
wolne rodniki
jony metali
orbital molekularny
metale przejściowe
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Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/207760.pdf  Link otwiera się w nowym oknie
Opis:
The degradation of flutriafol in aqueous persulfate (S2O82–) system in the presence of selected transition metal ions was investigated. In the presence of Ag+ or Fe2+, flutriafol degradation occurs, whereas in the presence of Mn2+, Co2+, Ni2+, Cu2+, Zn2+ and Bi3+ ions, the degradation is less than 15%. The Ag+/ S2O82– aqueous system being the most effective was adopted for experimental and theoretical investigations. It was confirmed that pH of 3.0 is the most suitable, and that both · SO4and ·OH– radicals are the main active species to afford flutriafol degradation, with the former contributes more than the latter. To elucidate degradation mechanism, molecular orbital calculations were performed and reaction intermediates identified by GC/MS and HPLC/MS/MS analyses. Three degradation pathways are proposed that involve the cleavage of C–N and C–C bonds as a result of ·SO4 attack, as well as the formation of hydroxylated products due to · OH radicals.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical study of kinetic isotope effects on hydrogen abstraction reactions
Autorzy:
Kurosaki, Y.
Tematy:
ab initio molecular orbital method
hyrogen abstraction reaction
potential energy surface
secondary isotope effect
transition state theory
tunneling
Pokaż więcej
Wydawca:
Instytut Chemii i Techniki Jądrowej
Powiązania:
https://bibliotekanauki.pl/articles/147000.pdf  Link otwiera się w nowym oknie
Opis:
Effects of isotopic substitutions of "spectator" hydrogens on rate constants have been theoretically examined for the CH3 + H2 ' CH4 + H (I) and C2H + H2 ' C2H2 + H (II) reactions using variational transition state theory with the multidimensional semiclassical tunneling correction. A small but significant secondary isotope effect was found for reaction (I) but almost no isotope effect was found for reaction (II). This is because the potential energy surface for reaction (II) has an "early" character.
Dostawca treści:
Biblioteka Nauki
Artykuł

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