Publications by authors named "Julian Cruz Borbolla"

The hydrodesulfurization (HDS) process is widely used in the industry to eliminate sulfur compounds from fuels. However, removing dibenzothiophene (DBT) and its derivatives is a challenge. Here, the key aspects that affect the efficiency of catalysts in the HDS of DBT were investigated using machine learning (ML) algorithms.

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Context: Several descriptors from conceptual density functional theory (cDFT) and the quantum theory of atoms in molecules (QTAIM) were utilized in Random Forest (RF), LASSO, Ridge, Elastic Net (EN), and Support Vector Machines (SVM) methods to predict the toxicity (LD) of sixty-two organothiophosphate compounds. The A-RF-G1 and A-RF-G2 models were obtained using the RF method, yielding statistically significant parameters with good performance, as indicated by R values for the training set (R) and R values for the test set (R), around 0.90.

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Thermal processing of certain foods implies the formation of acrylamide, which has been proven to provoke adverse effects on human health. Thus, several strategies to mitigate it have been developed. One of them could be the application of organosulfur compounds obtained from natural sources to react with the acrylamide, forming non-toxic adducts.

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Compounds containing carbamate moieties and their derivatives can generate serious public health threats and environmental problems due their high potential toxicity. In this study, a quantitative structure-toxicity relationship (QSTR) model has been developed by using one hundred seventy-eight carbamate derivatives whose toxicities in rats (oral administration) have been evaluated. The QSRT model was rigorously validated by using either tested or untested compounds falling within the applicability domain of the model.

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The relationship between structure and corrosion inhibition of a series of twenty-eight quinoline and pyridine derivatives has been established through the investigation of quantum descriptors calculated with PBE/6-311 +  + G** method. A quantitative structure-property relationship (QSPR) model was obtained by examining these descriptors using a genetic algorithm approximation method based on a multiple linear regression analysis. The results indicate that the efficiency of corrosion inhibitors is strongly associated with hardness (η), minimal electrostatic potential (ESP), and volume (V) descriptors.

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  • - This study examines how to optimize the shape and total spin of small iron clusters (Fe) using Simulated Annealing (SA) and DFTB theory, focusing on clusters ranging from 3 to 40 atoms.
  • - The researchers allowed for a flexible total spin by adjusting the occupancy of spin densities during the SA process, leading to varied spin states throughout the simulations.
  • - Their results showed that the optimized cluster structures closely matched previously reported geometries and magnetic moments, and they also computed binding energies to further validate their findings, noting few discrepancies likely due to competing magnetic states at high temperatures.
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The structural and electronic properties were calculated for seventy organic compounds used as dye sensitizers in solar cells, applying the B3LYP exchange-correlation energy functional with the 6-311G∗∗ basis set. Moreover, the present study proposes two new quantitative structure-property relationship (QSPR) models that enable the prediction of the power conversion efficiency (PCE) and maximum absorption wavelength (λ) of these systems, the two QSPR models were validated using the coefficient of determination (R) of 0.62 for both models with the leave-one-out cross-validation correlation coefficient (Q) of 0.

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The use of corrosion inhibitors is an important method to retard the process of metallic attack by corrosion. The construction of mathematical models from theoretical-computational and experimental data obtained for different molecules is one of the most attractive alternatives in the analysis of corrosion prevention, whose objective is to define those molecular characteristics that are common in high-performance corrosion inhibitors. This review includes data of corrosion inhibitors evaluated in different media, the most commonly studied molecular descriptors, and some examples of mathematical models generated by different researchers.

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Since the high incidence of aflatoxin M1 (AFM1) in milk and dairy products poses a serious risk to human health, this work aimed to investigate the complex formation between bovine α-lactalbumin (α-La) and AFM1 using different spectroscopic methods coupled with molecular docking studies. Fluorescence spectroscopy measurements demonstrated the AFM1 addition considerably reduced the α-La fluorescence intensity through a static quenching mechanism. The results indicated on the endothermic character of the reaction, and the hydrophobic interaction played a major role in the binding between AFM1 and α-La.

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The possible interactions between α-zein and Ca in nixtamalization process were analyzed from a multidisciplinary approach, considering the effect of these interactions on the thermal properties of the nixtamalized flour. SDS-PAGE under reducing and non-reducing conditions did not reveal differences between patterns of zeins from nixtamalized and control samples. However, analysis from affinity capillary electrophoresis indicated an increment in protein volume when calcium is added to zein extracted from nixtamalized flour.

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  • The study focuses on the synthesis of two oligophenyleneimine pentamers, DAFCHO and FDACHO, which contain terminal aldehydes, using mechanochemistry methods and various diamines.* -
  • The compounds were characterized using spectroscopy techniques (¹H and C-NMR, FT-IR, mass spectrometry) and displayed interesting photochromic properties in chloroform when exposed to sunlight, with notable energy band gap values measured.* -
  • Electrochemical studies revealed their potential as organic semiconductors, with HOMO and LUMO values indicating favorable electronic properties, and findings were further supported by Density Functional Theory (DFT) calculations.*
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  • A new electrokinetic chromatography method was created to detect and measure five antibiotics—ciprofloxacin, norfloxacin, sulfamethoxazole, tetracycline, and oxytetracycline—in animal feed samples.
  • The method uses a specially designed buffer solution that includes phosphate, a surfactant (Tween-80), and fullerene to enhance the separation of the antibiotics.
  • It can detect these substances at very low levels (0.7 to 1.5 µg/g) and completes the analysis in under 6 minutes, making it effective for monitoring antibiotic residues in animal feed.
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  • - The study used density functional theory to analyze the structural and electronic properties of 25 phosphonate derivatives, employing the PBEPBE functional with a 6-311++G
  • basis set to assess their chemical reactivity through quantum descriptors like HOMO, LUMO, and Hirshfeld charges.
  • - A multiple linear regression model was developed to predict the toxicity of phosphonates based on factors such as molecular volume, electronegative atom charge, and HOMO eigenvalue, showing strong internal validation results.
  • - The findings suggest that the oxygen atom in the O=P group significantly influences the interaction of phosphonates with the acetylcholinesterase enzyme, contributing to their inhibitory effect and potential toxicity.
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  • The study investigated how effective 2,6-bis[((2-pyridylmethyl)oxy)methyl)]pyridine (BPMMP) is at preventing corrosion of mild carbon steel in hydrochloric acid (HCl), revealing significant reductions in both cathodic and anodic currents during polarization studies.
  • Impedance analysis indicated that the effectiveness of BPMMP as a corrosion inhibitor was directly related to its concentration, and recurrence analysis showed changes in Shannon entropy that suggested a higher stability in the presence of the inhibitor.
  • The research also utilized density functional theory (DFT) to explore BPMMP's interactions with iron clusters, revealing insights into the structural and electronic behavior of BPMMP before and after forming complexes with iron
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  • - The study investigated how the chemical structure of 40 derivatives of 1,4-dihydropyridines (DHPs) relates to their biological activity using density functional theory (DFT) and multiple linear regression analysis.
  • - A new quantitative structure-activity relationship (QSAR) model was developed, incorporating factors like molecular orbital energy, volume, and non-covalent interactions to improve accuracy in predicting biological activity.
  • - The model showed strong validation metrics (R = 79.57, Q = 69.67) and can reliably estimate the biological activity of new DHP compounds, indicating a good correlation with the studied non-covalent interactions.
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  • The Ir(i) complexes [TpIr(η-1,4-diene)] 2b and 2c undergo thermal reactions with various aromatic aldehydes, resulting in the creation of metallabicyclic compounds 4e-k and Fischer-type carbenes 5a-b with moderate yields.
  • These reactions start with the formation of η-aldehyde adducts, leading to metallabicyclic compounds through decarboxylation and ortho metallation of the aromatic ring, while the synthesis of Fischer-type carbenes involves rearranged intermediates without decarboxylation.
  • The treatment of complex 2b with Lewis bases alters the diene ligand's binding mode, producing various Ir(
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  • - The study investigates the relationship between the structural properties of imidazol, benzimidazol, and pyridine derivatives and their effectiveness as corrosion inhibitors using quantum descriptors and a multiple linear regression analysis.
  • - Findings reveal that the efficiency of these corrosion inhibitors correlates with factors like aromaticity, electron donor ability, and molecular volume, leading to the development of a quantitative predictive model.
  • - Electrochemical impedance spectroscopy (EIS) results validate the model, showing a strong agreement with experimental corrosion inhibition values, and highlight the significance of aromaticity in the adsorption of these compounds on metal surfaces.
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  • A ruthenium complex with a specific ligand was created and its properties were explored through DFT analysis, focusing on oxidation states and reactive sites.
  • The complex demonstrates a preference for bonding based on metal oxidation states, with Ru(IV) interacting more readily with hard bases and Ru(II) with soft bases, influenced by the Jahn-Teller effect.
  • It effectively oxidizes phenol to benzoquinone using H2O2, with experiments identifying intermediates, while a potential mechanism and rate law for this reaction were also proposed.
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  • The reaction of the iridium complex [Tp(Me2)Ir(C2H4)2] with 2,4-pentanedione at 70 °C produces a main product, the Ir(iii) complex [Tp(Me2)Ir(acac)(C2H5)], along with two less abundant side complexes.
  • The proposed reaction mechanism involves the formation of an 18-electron intermediate that can lead to various complexes through processes such as hydrogen insertion or β-hydride elimination.
  • The resulting iridium compounds show stability in air and moisture, and their structures have been confirmed using techniques like NMR, IR, and X-ray diffraction.
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  • Two phenyleneimine oligomers, OIC1MS and OIC2MS, were synthesized using both traditional and mechanochemical methods.
  • These compounds were characterized using techniques like FT-IR and NMR, and their optical properties were examined with UV-visible spectroscopy, revealing that OIC2MS has notable photochromic characteristics.
  • Additionally, their structural and electronic properties were studied using TD-DFT, indicating that mechanosynthesis is a highly effective approach for creating these tetraimines.
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  • The study investigated how L-aminoglucosidic stereoisomers, specifically rhodostreptomycins A (Rho A) and B (Rho B), interact with cations like Mg(2+), Ca(2+), and H(+), using quantum mechanical methods and docking studies.
  • Both stereoisomers exhibit similar properties against the bacterium Helicobacter pylori, but Rho B has a stronger affinity for Mg(2+) ions, resulting in its hydration.
  • The results indicate that Rho B forms a more stable complex with hydrated Mg(2+) compared to Rho A, and docking suggests that both molecules bind to these cations through hydrogen bonding.
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  • * The resulting compounds are variously sized linear isomers, including dimers, trimers, tetramers, and a pentamer, as confirmed by their spectroscopic data.
  • * Computational chemistry methods, specifically density-functional theory calculations, helped clarify the chemical reactions involved, focusing on properties like dipole moments and electronic distributions of the molecules produced.
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