B3LYP Method Research Articles

Isolation, NMR and Mass Characterization of Ducose - A Novel Tetrasaccharide from Goat Milk

Milk is an excellent source of all the necessary nutrients in the proper proportions. Besides the other regular constituents it has oligosaccharides in it which are indigestible by the infant yet are consumed by the microbial populations in the developing intestine. These oligosaccharides are believed to facilitate enrichment of a healthy infant gastrointestinal micro biota, often associated with bifidobacteria. Goat milk is a rich source of oligosaccharides that have enormous biological activities such as anti-bacterial, immunological, anti-inflammatory, hypoallergenic and therapeutic properties. It is used against tuberculosis in folk medicine and also helps in the enhancement of platelet count during dengue fever. Goat milk oligosaccharides have anti-inflammatory properties and are involved in the repairing process after a dextran sodium sulphate-induced colitis. Keeping in mind the biological importance of goat milk and the role of oligosaccharides, in the present studies, goat milk was analyzed for its oligosaccharide content which led to the isolation of a novel tetrasaccharide, ducose, C28H48O21N2. The structure of the isolated oligosaccharide was elucidated by chemical transformation, chemical degradation, 1H, 13C, 2D-NMR (COSY, TOCSY, HMBC and HSQC) and mass spectrometry as under. The geometry of compound ducose was optimized by B3LYP method and 6-31 G (d,p) basis set.

Raman, ATRIR and NMR spectra, conformational stability, vibrational assignments, normal coordinates analysis and DFT calculations of hydrochlorothiazide drug

The Raman (4000-50 cm−1), attenuated total reflectance (ATR) infrared (4000-400 cm−1) spectra of Hydrochlorothiazide (C7H8ClN3O4S2; HCTZ) have been recorded in the solid state in addition to LCMS in the dimer and trimer ranges. The 1H, 13C and 15N NMR spectra were also recorded in addition to DEPT (45, 90 and 135) of HCTZ sample dissolved DMSO‑d6. Initially, three conformers resulting from the rotation of -SO2NH2 moiety around C9-S11 were proposed, namely gauche, trans and cis conformers. And then Density Functional Theory (DFT) calculations for an isolated molecule were carried out employing both B3LYP and P3PW91 methods at 6-31G(d), 6-311+G(d), 6–311++G(d,p) basis set. The cis isomer is a transition state owing to the prediction of an imaginary wavenumber, while the gauche being more stable than trans by ∼438–538 cm−1 (∼1.25–1.54 kcal) employing the afore-mentioned computations. Moreover, we carried out a potential surface scan for the gauche to determine SO2NH2 barriers to internal rotations and to ensure the optimal gauche is the most stable conformer. Aided by normal coordinate analysis (NCA) in addition to the atomic displacements in Cartesian coordinates (ADCC), confident vibrational assignment of the observed infrared and Raman bands are proposed for all fundamentals of the gauche rotamer. Nevertheless, force constants (FCs) in internal coordinates were also estimated using the above-mentioned methods and basis sets as well. The 1H, 13C and 15N chemical shifts were also correlated to their corresponding atoms. The results are reported herein and compared with HCTZ and its cocrystals whenever appropriate.

Theoretical investigation of the conformational preference and spectroscopic analysis of cinnamoyl chloride and cinnamide

The rotational isomers of cinnamoyl chloride and cinnamide have been computed using the B3LYP method and the 6-311++G (d, p) basis set to calculate their molecular structure, conformational stability, and spectroscopic properties. Computations revealed that the s-cis rotamers of both compounds are the most stable rotamers in both the gas phase and in the solution. The s-trans rotational barrier is 8.76 kcal/mol and 5.63 kcal/mol for cinnamoyl chloride and cinnamide, respectively. Replacing the Cl group of the cinnamoyl chloride with the NH2 group in the cinnamide has reduced the highest occupied molecular orbital – lowest unoccupied molecular orbital (HOMO-LUMO) gap. The solvation effects on the conformational stability of rotamers have been studied in nine solvents (heptane, chloroform, tetrahydrofuran, dichloroethane, acetone, ethanol, methanol, dimethyl sulfoxide, and water) using the integral equation formalism of the polarizable continuum model. The chemical shifts of 13C and 1H NMR spectra have been simulated in the gas phase, dimethyl sulfoxide (DMSO), and chloroform using the gauge-independent atomic orbital (GIAO) method. The UV absorption spectral analysis has been computed in different solvents (chloroform, methanol, and water), and atomic charges calculated. The examination of vibrational wave numbers and their corresponding assignments revealed excellent agreement between simulated and experimental infrared spectra for the studied molecules.

Computational analysis of substituent effects on proton affinity and gas-phase basicity of TEMPO derivatives and their hydrogen bonding interactions with water molecules

The study investigates the molecular structure of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and its derivatives in the gas phase using B3LYP and M06-2X functional methods. Intermolecular interactions are analyzed using natural bond orbital (NBO) and atoms in molecules (AIM) techniques. NO2-substituted TEMPO displays high reactivity, less stability, and softer properties. The study reveals that the stability of TEMPO derivatives is mainly influenced by LP(e) → σ∗ electronic delocalization effects, with the highest stabilization observed on the oxygen atom of the nitroxide moiety. This work also considers electron density, atomic charges, and energetic and thermodynamic properties of the studied NO radicals, and their relative stability. The proton affinity and gas-phase basicity of the studied compounds were computed at T = 298 K for O-protonation and N-protonation, respectively. The studied DFT method calculations show that O-protonation is more stable than N-protonation, with an energy difference of 16.64–20.77 kcal/mol (22.80–25.68 kcal/mol) at the B3LYP (M06-2X) method. The AIM analysis reveals that the N–O…H interaction in H2O complexes has the most favorable hydrogen bond energy computed at bond critical points (3, − 1), and the planar configurations of TEMPO derivatives exhibit the highest EHB values. This indicates stronger hydrogen bonding interactions between the N–O group and water molecules.

Computational insight into the spectroscopic and molecular docking analysis of estrogen receptor with ligand 2,3-dimethyl-N[2-(hydroxy)benzylidene] aniline

A comprehensive approach encompassing a blend of spectral techniques and Density Functional Theory (DFT) was employed to elucidate the electronic, vibrational, structural, and nonlinear optical properties of 2,3-dimethyl-N[2-(Hydroxy)benzylidene] aniline (DNHBA). The investigation of this chemical compound involved a meticulous examination using spectroscopic techniques (FTIR, FT-Raman). The DFT calculations utilized the B3LYP method in conjunction with 6-311G (d, p) basis sets. The findings were substantiated by comparing the estimated vibrational frequencies and molecule geometry with experimental data. Using the Time Dependent −Density Functional Theory (TD-DFT) method to calculate the energy band gap of the compound at different solvents. We looked into frontier molecular orbitals (FMO) Molecular electrostatic potential (MEP) and natural bond analysis (NBO) to determine the compound’s kinetic stability and chemical reactivity. Hirshfeld surface (HS) analysis calculated the O–H..O, H-H and intermolecular interaction energy of the compound. The electron density distribution, interactions, and excitation within the title molecule are illustrated by performing topological analyses (RDG, ELF and LOL) using the Multiwfn software. In addition to these assessments, molecular dynamics provides an understanding of the system's dynamic development over a predefined duration during which atoms and molecules are permitted to interact. Utilizing the molecular docking approach allows us to energize the atomic-level interplay between small molecules and proteins within the binding sites of target proteins. This approach enhances our comprehension of vital biochemical processes associated with the behavior of small molecule. The intricacy and hazards associated with drug discovery and development processes have increased dramatically, leading to higher drug research costs.

In Silico Coformer Screening for Mefenamic Acid Cocrystallization

Cocrystallization is a widely used approach to enhance the solubility and dissolution characteristics of poorly soluble drugs. A pharmaceutical cocrystal is a multicomponent system composed of a solid active pharmaceutical ingredient (API) and a coformer, governed by non-covalent interactions. Screening for suitable coformers is essential to obtain an optimal cocrystal for specific drugs. This study aims to determine the drug-coformer interactions to select the most suitable coformer for cocrystal formation using the molecular docking method. Mefenamic acid, classified as a class II drug in the biopharmaceutical classification system (BCS), was used as the model drug. Two-dimensional structures of mefenamic acid (PubChem CID: 4044) and potential coformers were sourced from PubChem. Geometric optimization of all compounds was performed using GaussView 5.0.8 and Gaussian09 with the 3-21G basis set and Density Functional Theory (DFT) B3LYP method. The optimized compounds were prepared by adding hydrogen atoms and calculating Kollman partial charges using AutoDock 4.2. A grid box of size 40 Å × 40 Å × 40 Å was generated, with a maximum radius of 0.375 Å set as the surface distance in each simulation. A hundred conformations were run using the Lamarckian Genetic Algorithm. Interaction types and binding energies were analyzed using VMD 1.9.2 and BIOVIA Discovery Studio 2020 to compare interactions between mefenamic acid and each coformer. The results revealed that most coformer compounds formed interactions with mefenamic acid via hydrogen bonding and π–interactions. Saccharin demonstrated the most optimal interaction with mefenamic acid, with a binding free energy of –3.1 kcal/mol. Saccharin was identified as the most suitable coformer for mefenamic acid cocrystal formation based on the molecular docking study. Further experimental validation of saccharin is recommended to confirm its effectiveness in cocrystallization with mefenamic acid.

Synthesis, Spectroscopic, Computational, and Biological Evaluation of Pyrazole mono azo dyes

In the present work, a series of new dispersed mono azo dyes (3) were synthesized through conventional diazo-coupling reaction between 4-hydroxy-phenylacetamide with pyrazole derivatives at low temperature. All the synthesized mono azo compounds were characterized by various spectroscopic methods like IR, NMR, electronic spectral, LC-MS, and fluorescence spectral studies. The experimental IR data was compared with that of the theoretical data and it has been observed that, the experimental IR spectral values are found to be lower than that of the theoretical values. The quantum chemical calculations were also carried out to understand the chemical reactivity of the compounds by using B3LYP method in conjugation with 6-311++G (d, p) basis set. The compounds were screened for anti-tuberculosis properties against M. tuberculosis and the compound 7 was found to exhibit a significant inhibitory effect with MIC value of 12.5μg/mL. The anti-microbial studies were carried for synthesized mono azo compounds. Further, the in silico molecular docking study was carried out to know the significant interaction of the synthesized compounds against VEGFR2 target protein.

Synthesis, crystal structure, DFT, vibrational properties, Hirshfeld surface and antitumor activity studies of a new compound 2-(2-chloro-6-(m-tolyl)imidazo[1,2-a]pyridin-3-yl)-N,N-diethylacetamide

Imidazo[1,2-a]pyridine derivatives are a kind of fused heterocyclic substances, which play an important role in the chemical field and have been proved to be the core fragments of various drug molecules. In this study, a new title compound was finally synthesized by cyclization, substitution, Suzuki coupling, hydrolysis and condensation. And the crystal of the title compound was obtained by single crystal culture. The structure of 2-(2-chloro-6-(m-tolyl)imidazo[1,2-a]pyridin-3-yl)-N,N-diethylacetamide was confirmed by 1H NMR, 13C NMR, FT-IR and single crystal X-ray diffraction. In addition, the title compound was theoretically calculated at the level of 6–311+G (2d, p) based on density functional method B3LYP, and the molecular structure optimized by DFT was consistent with the results obtained by X-ray diffraction. By calculating the Hirschfield surfaces and 2D fingerprints of molecules, the interactions between molecules can be visually revealed based on the size and color of the spots near the atoms. In addition, according to the characteristic vibration absorption band, the vibration of the title compound is reliably attributed. Furthermore, MEP, RDG, and ELF analyses were conducted to characterize the reaction sites susceptible to electrophilic and nucleophilic attacks. FMOs was used to evaluate the stability of the molecular structure. Finally, the results of the determination of biological activity showed that the compound exhibited significant inhibitory activity against HCT116 cancer cell.

Spectroscopic and quantum chemical insights on supramolecular interaction between N-methylfulleropyrrolidine and designed porphyrins in solution

Present letter describes self-assembly of N-methylfulleropyrrolidine (A) with a designed free-base (H2Pr) and zinc porphyrin (ZnPr) in toluene. The binding constants (K) of A-H2Pr and A-ZnPr systems are estimated to be 5.92 × 103 dm3.mol–1 and 10.05 × 103 dm3⋅mol−1, respectively. DFT calculations by B3LYP (and MO6) method(s) extend very good support in favour of the K values of the A-H2Pr and A-ZnPr systems in terms of the heat of formation, i.e., 7.40 kcal⋅mol−1 (and 6.46 kcal⋅mol−1) and −128.25 kcal⋅mol−1 (and −125.05 kcal⋅mol−1), respectively. Present investigations envisage that A may be suitably employed as fulleropyrrolidine based photochromic devices in near future.

Naphthalene-based symmetrical liquid crystalline dimers: Synthesis, characterization, mesomorphic behaviour and DFT studies

The reactions of different α,ω-dibromo alkanes with (E)-4-(naphthalen-2-yldiazenyl)phenol and (E)-4-(naphthalen-2-ylimino)methyl)phenol, respectively, led to the synthesis of two new homologous series of liquid crystalline symmetrical dimers with azobenzene or azomethine central linkage and containing the naphthalene moiety as a rigid core. Spectroscopic techniques like FT-IR, 1H NMR, 13C NMR and elemental analysis confirmed their structure. These dimers exhibited mesomorphic phases, studied through POM and DSC. Their photophysical behaviour was explored using UV–visible spectroscopy. Remarkably, dimers with even spacer units (n = 2, 4, 6, 8, 10, 12) displayed excellent liquid crystalline properties as nematic phases, with extended mesophase lengths and thermal stability for both series. The study revealed the vital role of spacer length in determining liquid crystalline behaviour. The computational studies employed the B3LYP method and electron density method for optimization.

Quantum mechanical analysis of halogen-based ionic liquid crystal [C12MIM.X(where X = Cl, Br)] molecules

ABSTRACT The electrical and non-linear optical characteristics of 1-dodecyl 3-methyl-imidazolium chloride (C12MIM.Cl or DDMIM.Cl) and 1-dodecyl 3-methyl-imidazolium bromide (C12MIM.Br or DDMIM.Br) ionic liquid crystals for optoelectronic devices were investigated in this study utilising B3LYP method and 6-311++G(d,p) basis set with Gaussian09 software. The majority of ionic liquid crystal research to date has been experiment-driven, with very few theoretical studies on the material's optical characteristics. Additional understanding of the behaviour of ionic liquid crystals is revealed through molecular spectroscopic research. The electronic properties (molecular energy band gap, electrostatic potential map and HOMO–LUMO orbitals) and spectroscopic (IR, UV) characteristics were assessed with the aid of a theoretical/computational model at B3LYP/6-311++G(d,p), whereas a nonlinear optical (NLO) study was carried out using the B3LYP and M06-2X methods with 6-31G(d) and 6-311++G(d,p) basis sets. Results demonstrate reasonable nonlinear optical characteristics in these molecules.

Study of six coordinated cobalt(III) oxophlorin with different axial ligands: Optimization of geometry and determining of energy and electronic configuration at various spin states by employing of B3LYP, BV86P and M06-2X methods

The six coordinated CoIIIoxophlorin have been studied with imidazole, pyridine and t-butylcyanide as axial ligands using B3LYP, BV86P and MO6-2X methods. Conversion between two isomers [(L)2CoIII(PO)][Formula: see text] and [(L)2CoIII(PO)][Formula: see text] can be occurred at various spin multiplicities, namely singlet, triplet and quintet states. L is employed to show axial ligand namely, imidazole or pyridine. London forces have a basic role in the stability of the mentioned complexes due to non-specific solvent effects. The latter fact has been obtained using the PCM model. Also, it is specified that minimum geometries have not been obtained for some parallel or perpendicular six-coordinated complexes with special axial ligands at a finite spin state. The B3LYP method indicates that one and three [Formula: see text]-electron can be found on the Co atom in every optimized complex at triplet and quintet spin states, respectively. Also, another [Formula: see text]-electron is placed on the ring of oxophlorin. This fact is obtained for different isomers of [(IM2(CoIII(PO)] and [(Py)2CoIII(PO)] at triplet and quintet spin states, while these complexes are optimized using B3LYP. Besides, results obtained from B3LYP show that the most stable state for six coordinated CoIIIoxophlorin with any axial ligand is the singlet state. Based on crystal field theory and molecular orbital theory, electron configuration and hybridization of cobalt in [(IM)2CoIII(PO)] at singlet state can be written as t2g6 eg0 and sp3d2, respectively. Former electronic configuration indicates a strong field with low spin for d orbitals of cobalt, and latter hybridization is expected for a metal with a coordination number of 6 in a complex with Oh symmetry. The results obtained are completely satisfied by NBO analysis.

2-(((2,4-Dichlorophenyl)imino)methyl)-3,4-difluorophenol: X-ray, DFT, MEP, HOMO-LUMO, NLO, Hirshfeld Surfaces, ADMET Profiling, Target Identification, Antipsychotic Activity Against Dopamine D2 and Serotonin 5-HT2A Receptors

Halogenated compounds, especially fluorine and chlorine, play a key role in drug development. They account for a large proportion of all approved drug molecules. The importance of these two halogens stems from their remarkable effects on biological activity and pharmacokinetic properties. The study presented here aims to give the results obtained by the DFT methods and in silico medicinal evaluations of a newly synthesized small molecule. The small molecule belongs to the Schiff base class of organic compounds and is substituted with halogen atoms. The tetrahalogenated compound (THSB) Schiff base, 2-(((2,4-dichlorophenyl)imino)methyl)-3,4-difluorophenol, was first synthesized via the classical condensation method and then characterized by spectroscopic techniques. The THSB optimized by the B3LYP method was evaluated in terms of geometrical parameters, surface area (MEP and Hirshfeld analysis) and secondary interaction analysis, NLO properties, and electronic properties (HOMO-LUMO and UV-Vis). Second, THSB was evaluated regarding medicinal chemistry, physicochemical and pharmacokinetic properties, and toxicity (ADMET). Then, we comprehensively investigated the potential biological targets of THSB. Using the results of the SwissSimilarity analysis, we investigated the antagonistic effects of THSB against serotonin 5-HT2A and dopamine D2 receptors. Docking results were compared with the known antipsychotics, clozapine and risperidone. THSB showed a higher antagonistic effect than clozapine for the D2 receptor. However, risperidone proved to be the most effective antagonist for both targets. The binding energies of THSB, risperidone, and clozapine were -8.30, -11.84, and -8.07 kcal/mol, respectively, for D2; those of THSB, risperidone, and clozapine were -6.94, -11.47, and -10.10 kcal/mol, respectively, for 5-HT2A.

Synthesis and Anti-Oxidant Properties of Some New Schiff Bases Containing Azole Moieties

Four new Schiff bases (L1-L4) were synthesized and characterized on the basis their spectra of 1H-NMR, 13C-NMR, Fourier transform infrared, and elemental analysis (CHN). The program Gaussian 09 software and DFT-based B3LYP method along using the 6-31G+(d,p) basis set were used for theoretical accounts. The antioxidant activity of the synthesized compounds was evaluated by DPPH scavenger and these compounds showed good antioxidant activity.. KEYWORDS :Antibacterial, Antioxidant, Azomethine, Schiff base.

DFT modeling of new composite based on PANI/PVK functionalized With single-walled carbon nanotubes for optoelectronic applications

We present a comparative experimental and theoretical study of the vibrational, optical, and electronic properties of polyaniline at both emeraladine leuco-emeraldine forms and PVK. Our objective is first to select the appropriate form of PANI to be linked with PVK to form a hybrid polymer matrix. Then, on the basis of quantum chemical calculations, we present a theoretical study of a hybrid composite PANI/PVK functionalized with lower radius (5, 5) chiral single-walled carbon nanotubes (SWCNTs). The relationship structure-properties of the resulting nano-composite are proved based on the conformational and optical study made from Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) using B3LYP method with 6-31-G(d) basis set. First, it has been demonstrated that the resulting interaction between PANI and PVK leads to more advantageous properties, such as good optical absorption compatibility with the solar emission spectrum. It has also been found that after the incorporation of SWCNTs into the matrix of PANI/PVK hybrid polymer, a good organization of SWCNTs via π-staking interaction is imposed by polyaniline sequences. However, PVK moieties are grafted on the sidewalls of SWCNTs. Finally, the electronic structure of the resulting hybrid nano-composite PANI/PVK/SWCNTs was carried out with the use of different electrodes on both sides.

Geometrical Electronic parameters, Vibrational Assignment docking studies, Antioxidant and Anticancer Activities of (1- benzyl)-2-(-2-Methoxyphenylamino thiazol-4yl)benzimidaole

The compound(1- benzyl)-2-(-2-Methoxyphenylamino thiazol-4yl)benzimidazole was characterized by IR spectral data The optimized .molecular geometry ,bond lengths, bond angle and dihedral angle of the titled compound have been investigated by Density Functional Theory (DFT) method, using B3LYP method with 3-21G basic set available in Gaussian 09 package. The IR spectra were obtained and assigned by vibrational analysis and found to be reliable compared with the literature observation. The Mulliken population analysis on atomic charges has been computed using DFT calculation. The calculated HOMO and LUMO energy gaps also confirm that charge transfer occurs within the molecule. The compound has highest activity against Hep-C cell line. The antioxidant study also evaluated excellent IC50 value. It shows the best inhibitory concentration against breast cancer. The (1- benzyl)-2-(-2-Methoxyphenylamino thiazol-4yl)benzimidazole compound was highly active on the MDA-MB-231 breast cancer cell line.

Analyzing the structure of the metal complexes of biologically active azo dye ligand

A novel azo dye ligand was created by diazotizing 4‐aminoantipyrine and then coupling it with 2‐aminophenol as part of a methodical investigation of physiologically active compounds, 4‐aminoantipyrine. The novel complexes containing Cr(III), Fe(III), Mn(II), Co(II), Ni(II), Zn(II), Cu(II), and Cd(II) were created from the target ligand (L). The structures of the ligand and metal complexes were verified by elemental analyses, thermogravimetric analysis–difference thermogravimetry (TGA‐DTG), conductivity measurements, infrared (IR), UV–Vis, 1H‐nuclear magnetic resonance (NMR), X‐ray diffraction (XRD), and mass spectrometry. Using the Gaussian 09 tool, the density functional theory (DFT)/B3LYP method was utilized to compute the energy gaps and other important theoretical features. Also, the newly synthesized azo dye ligand, in comparison with metal complexes, was screened for its antimicrobial activity. The crystal structures of Staphylococcus aureus and Bacillus subtilis as gram‐positive bacteria, Salmonella sp. and Escherichia coli as gram‐negative bacteria, and fungal (Aspergillus fumigatus and Candida albicans) species were compared with the produced azo dye and its metal complexes via molecular docking. Most of the complexes exhibited greater antimicrobial activities against these organisms than did the original azo dye ligand.

A computational study of H-bonded networks in cyclic water clusters, (H2O)n (n = 3-12).

We have performed a detailed MM and DFT investigation of neutral water clusters (H2O)n (n = 3-12). Our results show the trend of interaction energies in these clusters as a function of the size of the cluster. They show that the H-bond strength increases with cluster size and that the model of water is better described if two different partial charges are used on the hydrogen, depending on whether hydrogen is H-bonded or not. The average binding enthalpy change due to the formation of H-bonds between water molecules is found to be - 25.9kJmol-1 at B3LYP/aug-cc-pVDZ level of theory. We observe the formation of cyclic H-bonded networks through the analysis of frontier orbitals and IR vibrational frequencies spectra. For the water cluster with n = 11, we observe an unusual reduction of the bandgap indicative of a cyclic H-bonded network. Calculations were performed with the MMFF94 force field and the B3LYP method using various large basis sets. Molecular orbital diagrams and population analysis were done using standard tools in Gaussian.

Quantum chemical study on non-thermal plasma degradation tar in gasification syngas

The bond dissociation energies (BDEs) of benzene, toluene, and naphthalene which are the main components of tar in fluidized bed gasification syngas have been investigated by B3LYP method at 6-31G (d, p), 6-31G+ (d, p), 6-31G++ (d, p) and 6-311G++ (d, p) basis setsof density functional theory (DFT).The structures of benzene, toluene, naphthalene, and corresponding radicals were optimized, and their total energiesand zero-point energies (ZPE) were calculated.The frequency analysis was carried out, then, the transition state and the high order saddle were excluded, and the influence of zero point energy scaling factors was neglected.The results showed thatthe BDEs decreased with increasing computational basis sets. The calculated results obtained by B3LYP/6-31G (d, p) are much closer to the results of the documents than the other three basis sets. This indicates that the basis set of B3LYP/6-31G (d, p) is much more credible in reproducing the BDEs. The lowest electron energy values for the ring opening of benzene, toluene and naphthalene are 8.05 eV, 7.45 eV, and 7.35 eV, respectively, indicating that when the energy of high-energy electrons reaches 8.05 eV, the ring of aromatic hydrocarbon can be broken.

The Molecular Structural Analysis of Biologically Important Catechol Molecule: An Integrative Perspective from Experiments and Futuristic Tools

Background: Catechol is a phenolic molecule found naturally in plants. It is also known as pyrogallic acid or 1, 2-dihydroxybenzene. Catechol is currently produced commercially by decarboxylating gallic acid at high temperatures and pressures. Aims and Objectives: This research aimed to understand the biological importance of catechol and perform molecular structural analysis on catechol molecules. Methods: Catechol (1, 2, dihydroxy benzene) was studied via computational analysis by employing the use of DFT and B3LYP methods. Hirshfeld analysis was carried out to investigate crystal intermolecular interactions, and the NBO study was performed to study chemical donating and accepting interactions. Moreover, the computational study was performed using FTIR, HNMR and other instrumentation like AIM theory for circular dichroism data. Results: Furthermore, the surface iso-projection study and binding energy results did prove to run in alignment with experimentally obtained values from the computational studies. Fukui functional study and molecular electrostatic potential were utilized in the study to investigate interactions between anionic and cationic sites of catechol. In addition, molecular dynamic simulations revealed that biomolecular stability was also present. Thus, the antibiotic efficacy of catechol displayed chemical oxidative interactions that exhibited close chemical correlations with ascorbic acid, ellagic acid, and gallic acid. Conclusion: The catechol has been examined experimentally and theoretically. The results were compared with catechol spectra, including IR and UV-visible spectra generated through computer analysis. The experimentally observed spectra were found to be in parallel with theoretical data. According to drug-likeness investigations, the following compounds, gallic acid, ellagic acid, and ascorbic acid, were found to be closely related to catechol as an antibiotic. Hence, it can be concluded that catechol, whether in its entirety or in a portion, is a potent antibacterial, anti-inflammatory, and anti-malarial drug.