HOMO-LUMO Gap Research Articles

Enhanced NLO response and switching self-focussing in benzodiazepine derivative with –NO2 and -Br substitution

Optoelectronic and the cubic nonlinear optical properties of 4-(4-Bromophenyl)-2-(4-nitrophenyl)-2, 3-dihydro-1H-1, 5-benzodiazepine have been studied. Z-scan technique was used for the third-order nonlinear optical measurements namely, nonlinear absorption, nonlinear refraction, and optical power limiting behaviour employing an Nd: YAG laser of 532 nm wavelength having 5 ns Gaussian pulses. B3LYP/6–311 ++ G (d, p) level of theory was employed for structural optimization, vibrational wavenumber, frontier molecular orbitals, natural bond orbital and population analysis. The MOLVIB programme was used to perform unambiguous vibrational assignments based on potential energy distribution values acquired from normal coordinate analysis. B3LYP and CAM-B3LYP hybrid functions have been employed at the DFT level to calculate the theoretical second-order hyperpolarizability. The substitution of –NO2 and -Br in this benzodiazepine compound enhances the second-order hyperpolarizability (γ) to the order of 10−34 esu and, switching of self-defocussing to self-focussing phenomenon. The HOMO-LUMO and optical band gap analysis illustrates that polarizing nature of the molecule vary with substituents. The obtained results indicate that this compound has potential applications in optoelectronics and photonics.

Isosterism in pyrrole via azaboroles substitution, a theoretical investigation for electronic structural, stability and aromaticity

This work uses ab-initio CBS-QB3 and density functional theory (B3LYP) to analyze the structure, stability, and aromaticity of all isosteric nitrogen-boron pyrroles. The mono-NB unit substituted group of the isosteric NB pyrrole has four isosteres, whereas the multi-NB unit substituted group has two isosteres. These two groups make up all isosteric NB pyrrole. For structural, energetic, magnetic, and electron delocalization criteria, the results highlight the predominance of the PN3B2 isostere and its greater stability over other conformers. In addition, the global reactivity indices, ESP, HOMO-LUMO, and NBO charges have all been estimated to forecast the active side's electron donation and acceptance. These isosteres are categorized as weak electrophiles and marginal nucleophiles. NB-isosteres have poorer stability, HOMO-LUMO gap, and aromaticity than the parent (pyrrole). In general, NB compounds with more ring sharing are less aromatic than NB molecules with less ring sharing. The current study is anticipated to help in understanding of the chemistry of NB substituted molecules and their experimental identification and characterization.

DFT study and docking of xanthone derivatives indicating their ability to inhibit aromatase, a crucial enzyme for the steroid biosynthesis pathway

Aromatase is a crucial enzyme in the aromatization process, which catalyzes the conversion of androgenic steroids to estrogens. Aromatase dysregulation, as well as elevated estrogen levels, have been linked to a variety of malignancies, including breast cancer. Herein, we present the results of the optimization of Xanthones employing density functional theory (DFT) using the B3LYP/6-311G+(d, p) basis set to determine their frontier molecular orbitals, Mulliken charges, and chemical reactivity descriptors. According to the DFT results, Erythrommone has the smallest HOMO-LUMO gap (3.85 Kcal/mol), as well as the greatest electrophilicity index (5.19) and basicity (4.47). Xanthones and their derivatives were docked into the active site cavity of CYP450 to examine their structure-based inhibitory effect. The docking simulation studies predicted that Erythrommone has the lowest binding energy (-7.43 Kcal/mol), which is consistent with the DFT calculations and may function as a powerful CYP450 inhibitor equivalent to its known inhibitor, Exemestane, which has a binding affinity of −8.13 Kcal/mol. The high binding affinity of Xanthones was linked to the existence of hydrogen bonds as well as various hydrophobic interactions between the ligand and the receptor's essential amino acid residues. The findings demonstrated that Xanthones are more powerful inhibitors of the Aromatase enzyme than the recognized inhibitor Exemestane.

DFT study on adsorption of small gas molecules on Pt-capped armchair and zigzag single-walled carbon nanotubes

The adsorption of small gas molecules (CO, O2 and N2) on Pt-capped armchair and zigzag single-walled carbon nanotubes (SWCNT) has been investigated by density functional theory (DFT) method to determine the potential for gas sensor detection. Results indicated that O2 and N2 molecules with lower adsorption energies (1.66 eV and 1.00 eV) exhibited weak chemical adsorption on SWCNT(4,4)-Pt. However, CO demonstrates strong chemical adsorption with a high adsorption energy of 2.23 eV on SWCNT(4,4)-Pt. The adsorption energy of CO on SWCNT(7,0)-Pt shows the chemical adsorption between CO and SWCNT(7,0)-Pt. In addition, these findings also implied Pt-capped SWCNT could act as small gas molecule sensors to detect CO toxic gas at room temperature. In this system, CO is the electron donor and SWCNT-Pt is the electron receptor. The interaction of Pt and carbon nanotube backbone delocalized π electrons could not only increases the conductivity of SWCNT-Pt, but also enhances the conductivity of SWCNT-Pt-CO. The HOMO-LUMO gap (Δε) of Pt-capped SWCNT(7,0) reduced from 0.43 eV to 0.39 eV after CO adsorption, and the Δε value of Pt-capped SWCNT(4,4) decreased by 0.08 eV. The electrical conductivity of Pt-capped armchair and zigzag SWCNT has increased after the adsorption of CO molecule. The results may be helpful for designing a promising Pt-capped SWCNT-based CO sensors.

Double-chain conjugated carbonyl polymer cathode for rechargeable magnesium batteries: Constructing active sites for reversible storage of bivalent magnesium cations

Rechargeable Mg batteries are advantageous substitutes for lithium-ion batteries in large-scale energy storage with low cost and high safety, but the lack of cathode materials is blocking the development. Organic polymers are promising Mg-storage materials, and the construction of suitable Mg-storage active sites is of great significance for the performance. In the present study, a double-chain conjugated carbonyl polymer is designed and investigated as cathode material of rechargeable Mg batteries. The double-chain structure builds favorable active sites for reversible storage of bivalent Mg2+ cation by means of immobilization of the two adjacent carbonyls. This double-chain polymer shows a higher Mg-storage capacity (194 mAg–1) than the corresponding single-chain polymer (116 mAg–1). The Mg-storage capacity of this double-chain polymer also exceeds the Li-storage capacity (106 mAg–1) significantly. A mechanism study demonstrates the reversible carbonyl enolization in Mg-storage reactions. A theoretical computation demonstrates the magnesiation structure has a higher HOMO and a lower LUMO energy level, as well as a smaller HOMO–LUMO gap. This is favorable for the Mg-storage reaction reversibility and stability of the magnesiation structure, thus improving the capacities and cycling stabilities. The principle revealed in the present study provides an important insight to design organic conjugated polymers with favorable Mg-storage active sites, which would assist the development of high-performance Mg-storage materials.

Investigating the properties of nano crystalline beta metal-free phthalocyanine films: From molecules to optoelectronic applications

A study was conducted to investigate the structural and optical properties of nanocrystalline beta metal-free phthalocyanine (β-H2Pc) thin films using computational and experimental methods. DFT calculations using the B3LYP basis set 6–311G were performed to predict the HOMO-LUMO gap of the β-H2Pc (2.13 eV). The crystalline structural properties of the β-H2Pc were examined through XRD analysis, which revealed that the powder β-H2Pc had a monoclinic polycrystalline structure, while the β-H2Pc thin film was amorphous. Various methods were used to determine and compare the average crystallite size and microstrain, with the size-strain plot method yielding an average crystallite size and microstrain size of 73.15 nm and 0.0051, respectively. Using SEM to analyze the film's surface topography, the mean grain size was found to be 0.85 µm due to agglomeration. Linear and nonlinear spectrophotometric measurements were employed to examine the optical properties of the β-H2Pc thin film. The film exhibited indirectly permitted inter-band transitions, with the onset and fundamental band gaps of 1.51 eV and 2.74 eV, respectively. Furthermore, several absorption and dispersion characteristics for thin films were identified. The properties exhibited by Au/β-H2Pc/p-Si/Al heterojunction indicate its potential suitability for photosensor applications.

Solution stage fluorescence and anticancer properties of azomethine compounds from sulpha drugs: Synthesis, experimental and theoretical insights

In this comprehensive scientific study, we present the synthesis, characterization, and detailed analysis of two Schiff base compounds, (E)-4-((4-bromobenzylidene)amino)-N-(thiazole-2-yl)benzenesulfonamide (4BRTH) and (E)-4-((1-phenylethylidene)amino)-N-(thiazole-2-yl)benzenesulfonamide (APTH). These Schiff bases were synthesized from sulfathiazole, 4-bromobenzaldehyde, and acetophenone, employing acid-catalyzed reactions. The compounds were characterized using spectroscopic techniques, including UV, IR, and NMR. Notably, the UV spectra revealed absorption peaks at 295, 328, and 345 nm for 4BRTH and 270, 295, and 325 nm for APTH, with calculated oscillator strengths of 0.497, 0.3637, and 0.4138 for 4BRTH and 0.4841, 0.0005, and 0.1247 for APTH. Furthermore, fluorescence studies indicated unique emission peaks at 401 and 706 nm for 4BRTH and 412 and 725 nm for APTH, with excitation wavelengths at 297 nm for 4BRTH and 289 nm for APTH. The compounds displayed fluorescence characteristics, further showcasing their potential as fluorescent probes. Computational simulations were performed using various theoretical levels, including DFT calculations with the B3LYP functional and cc-pVDZ basis sets. The HOMO-LUMO gap was found to be 1.83 eV for 4BRTH and 2.04 eV for APTH, suggesting their reactivity towards other molecules. Theoretical binding energies from molecular docking studies against the breast cancer-related protein 6NLV revealed binding affinities of -18.63 kcal/mol for 4BRTH and -19.84 kcal/mol for APTH, providing insights into their potential anti-cancer activity. Moreover, in vitro anti-cancer assays conducted on MCF7 breast cancer cells demonstrated that both compounds exhibited anti-cancer activity with IC50 values. Importantly, the IC50 values were within the range of the standard anti-cancer drug cisplatin, which had an IC50 value of 62.5 μg/mL. These findings underscore the potential of 4BRTH and APTH as candidates for further anti-cancer drug development.

Structural evolution and stability of plutonium oxide clusters

ABSTRACT Plutonium oxide clusters have attracted great interest as potential complex for the separation or storage of radioactive plutonium elements. However, the structural stability, chemical bonding mechanism and maximum oxygen adsorption capacity for plutonium oxygen clusters are not well understood due to the difference between the radial distribution function and orbital energy of the plutonium atom. Here, we systematically study the structural evolution and electronic properties of plutonium oxygen clusters with cluster sizes n from 2 to 15 by using the CALYPSO cluster structural prediction method in combination with density functional theory (DFT) calculations. The low-lying isomers searched by the CALYPSO method are re-optimised at the theoretical level of B3LYP/ECP60MWB(Pu)/aug-cc-pVTZ(O). Relative stability results indicate that the PuO8 cluster with CS symmetry is the most stable cluster due to the large HOMO–LUMO gap (of 4.84 eV). The high stability of PuO8 cluster is predominantly attributed to the strong interactions between Pu-5f orbitals and O-2p orbitals. The Pu atom can chemically adsorb up to eight O atoms, and the corresponding adsorption energy is −3.84 eV. The present findings shed light on the complex chemical bonding and structural evolution mechanisms of plutonium oxide clusters, which may facilitate the rational design and the synthesis of other actinide-oxygen clusters. Plutonium chemically adsorbs eight oxygen atoms, and its high stability is attributed to the interactions between Pu-5f and O-2p orbitals.

The effect of dopant P[dbnd]O functional group and OH, O, H2O adsorption on the structural, electronic, and optical properties of triangular g-C3N4 quantum dots by first-principles study

The effect of dopant PO functional group and OH, O, H2O adsorption on the structural, electronic, and optical properties of triangular g-C3N4 QDs has been studied by first-principle calculations. Negative formation energies indicate that the formation processes of these systems are exothermic. PO doping can enhance the stability of C3N4–H QD and weaken the stability of C3N4–F QD. O–C3N4–H QD presents a chemisorption process, whereas the adsorption of OH group or H2O molecule on the C3N4–H QD is proposed to be a physisorption process. The substitutional PO group significantly deforms the geometric structure of the tri-s-triazine unit and induces charge redistribution in the PO-C3N4–H and PO-C3N4–F QDs. For C3N4–H QD, PO-C3N4–H QD, C3N4–F QD, and PO-C3N4–F QD, the calculated HOMO-LUMO gaps are 3.248, 1.583, 2.821 and 1.478 eV, respectively. The charge transfer between the O radical and the C3N4–H QD is +0.522 e, indicating a strong chemical bonding interaction. The tiny charge transfers of +0.107 e and +0.003 e indicate weak interaction between OH or H2O and C3N4–H QD. The study will provide an effective theoretical foundation for the development of new g-C3N4 QDs sensors or catalysis systems.

Atomistic insights into the enhanced Na storage performance of CuP2 anchored on single vacancy graphene

CuP2 is considered as a promising anode material for sodium-ion batteries due to its considerable theoretical capacity (1280 mAh/g), but it suffers from rapid decline of capacity and its cyclic reversibility should be further improved. As far as possible, preventing reaction energy barrier from sudden change and holding back Cu diffusion at atomic level both are key strategies to solve these problems occurring on the electrochemical reaction between CuP2 and Na. Based on the surface anchoring effect and excellent electronic conductivity of single vacancy graphene (SVG), first principles calculations have been carried out to capture the key role of SVG in regulating the electrochemical properties of CuP2. Firstly, among various (CuP2)n (n = 1–6) clusters, haploid CuP2 cluster possesses the fairly stable structure due to its highest HOMO-LUMO gap (2.45 eV) and lowest vertical electronic affinity energy (0.64 eV). Most of all, CuP2/SVG composites exhibit much more stable reaction energy barrier than CuP2 during their Na storage. It is attributed to the strong C–P and Cu–C anchoring effect between CuP2 and SVG, slowing the break of Cu–P bond. This contributes to holding back volume mutations of CuP2/SVG during Na storage. Besides, after conversion reaction between CuP2/SVG and Na, Cu showsdiffusion energy barrier of 0.75 eV, exhibiting great difficulty for its migration in reaction products. Compared with CuP2, CuP2/SVG not only exhibits more stable voltage distribution, but also it has much higher theoretical capacity (1851 mAh/g vs.1280 mAh/g). That is to say. CuP2/SVG can be acted as anode materials for Na-ion batteries with high energy density. And our results also provide a new way to design long-life CuP2-based anode materials for Na-ion batteries.

Computational exploration of the structure-photophysical property relationship of 2,6-dicyanoaniline derivatives for optoelectronic applications

Design and development of 2,6-Dicyanoaniline based multifunctional organic molecules with an acceptor-donor-acceptor (A-D-A) framework is gaining momentum in recent years. However, identifying the suitable donor, acceptor and π-linkers remains challenging and necessitates a thorough understanding of the structure-property relationship. In this context, to enhance their properties, two experimentally reported dicyanoaniline (DCA) derivatives are subjected to structural modifications using four electron-releasing groups: OMe, NH2, NHMe, and NMe2, employing density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations. Our findings reveal that all the designed molecules exhibit higher reactivity compared to the reference molecules, with NMe2 showing the most promising attributes, including a lower HOMO-LUMO gap. Percentage contribution analysis reveals that the strength of electron releasing groups significantly alter the stabilization of HOMO. Absorption and emission spectra are obtained from TD-DFT calculations in dimethyl formamide solvent. Moreover, calculations are performed to explore the Nonlinear Optical (NLO) performance of the designed molecules, indicating that all the designed molecules outperform the reference molecules in terms of NLO properties. In summary, this study offers valuable guidance for the development of efficient 2,6-Dicyanoaniline derivatives with great potential for optoelectronic and NLO applications.

Ab Initio Approach to the Structure, Vibrational Properties, and Electron Binding Energies of H2S∙∙∙SO2.

The present study employs high-level ab initio calculations to investigate the structure, vibrational frequencies, and electronic properties of H2S∙∙∙SO2. The analysis of vibrational frequencies reveals an intramolecular vibrational energy transfer phenomenon, where energy from the stretching modes of H2S is transferred to the ν1s mode of SO2. At the CCSD(T)/aug-cc-pVQZ level, the interaction energy between H2S and SO2 is predicted to be 2.78 kcal/mol. Electron propagator theory calculations yield a HOMO-LUMO gap of 8.24 eV for H2S∙∙∙SO2. Furthermore, by utilizing ab initio results for the adiabatic ionization energy and electron affinity, the electrophilicity of H2S∙∙∙SO2 is estimated to be 2.01 eV. This value is similar to the electrophilicity of SO2, suggesting comparable reactivity and chemical behavior. The non-covalent interaction (NCI) analysis of the H2S∙∙∙SO2 complex emphasizes the significant contribution of non-covalent van der Waals interactions in its energetic stabilization.

Promotion of the catalytic polymerization of hydroquinone towards humic-like substances by graphitic carbon nitride

The utilization of graphitic carbon nitride (C3N4) to enhance the oxidative polymerization of hydroquinone (HQ) within manganese dioxide (MnO2) systems was investigated. C3N4, a Lewis base enriched with nitrogen, acted as a bridge through π − π interactions between metal oxides and polyphenols. These interactions increased the affinity of the reactants, resulting in an enhanced reaction rate of six-fold, accelerated browning, and improved complex stability of C3N4. HQ.MnO2 complex. As a result, a humic-like substance (HS) was rapidly formed with improved surface morphology and larger particle sizes. Electron transfer of HQ.MnO2 promoted by C3N4 played a crucial role in HQ oxidation, expanding atomic distance and composite morphology. Theoretical calculations supported the experimental results, indicating strong affinity and higher binding energies in the C3N4. HQ.MnO2 complex. The complex had a more stable structure with a narrower HOMO-LUMO gap, facilitating HS formation. 13C and 1H NMR spectra confirmed the experimental-theoretical agreement.

Azulene-Fused Linearly π-Extended Polycyclic Aromatic Compounds: Synthesis, Photophysical Properties, and OFETs Applications

Abstract By introducing azulene into linearly π-extended polycyclic aromatic hydrocarbons, we found that the HOMO–LUMO gap can be narrowed comparable to [n]acenes while affording high stability against air under visible light. The fabricated OFET devices with one of the derivatives exihibited typical p-type behavior under ambient conditions.

Reconsidering the Structures of C2 Al4 - and C2 Al5.

The study of C2 Al4 -/0 and C2 Al5 -/0 was conducted using anion photoelectron spectroscopy and quantum chemical computations. The present findings reveal that C2 Al4 - has a boat-like structure, with a single C2 unit surrounded by four aluminum atoms. In contrast, the neutral C2 Al4 species adopts a D2h planar structure with two planar tetracoordinate carbon (ptC) units, consistent with previous reports. Furthermore, the global minimum isomer of C2 Al5 - adopts a D3h symmetry, where the C2 unit interacts with five aluminum atoms. It was also found that a lower symmetry structure of C2 Al5 - , where all five aluminum atoms are located on the same side of the C2 unit, albeit slightly higher in energy compared to the D3h structure. These computations show that the D3h structure of C2 Al5 - is highly stable, exhibiting a large HOMO-LUMO gap.

A machine learning prediction model for quantitative analyzing the influence of non-radiative voltage loss on non-fullerene organic solar cells

The open-circuit voltage (Voc) in organic solar cells (OSCs) hardly exceeds 1.0 V because of the relatively high voltage loss caused by charge non-radiative recombination at the donor–acceptor interface. Herein, in this paper the machine learning (ML) prediction models are used to explore the relationship among the donor and acceptor structures, electronic properties, and the non-radiative voltage loss (△Vocnon-rad). Among the models, the prediction performance from the optimal random forest (RF) model has 13.48% enhancement compared with that of the support vector regression (SVR) model. A combination of correlation and importance is used to collaboratively screen out the key features of acceptor materials with low △Vocnon-rad in OSCs. The importance analysis indicates that the benzene-1,2-diamine, prop-2-en-1-imine and nitrogen sulfur bond are the important structures, which represents the electron-deficient unit (A') in the fused-ring core of non-fullerene acceptors (NFAs). It is worth mentioning that the selected key features also have good applicability in the small data with ternary OSCs, and its coefficient of determination (R2) is 0.704 in the testing set. In addition, the four new Y6 derivatives (Y6O, Y6B, Y18B, and Y18U) are designed by the screened key features. And quantum chemical calculations show that the introduction of benzene ring and branched side chain to the A' unit can make the HOMO and LUMO energy levels of the molecule tend to rise. More importantly, the HOMO-LUMO gap is 2.69 eV and the optical band gap is 1.80 eV in Y18B, which are smaller than those of Y6. Y18B also has the smallest electrostatic potential of 5.08 kcal/mol on the molecular surface. Significantly, it decreases the singlet–triplet energy gap and exciton binding energy of Y18B for effectively reducing the △Vocnon-rad in the device. This work provides an effective model to accelerate the exploration of new and highly efficient NFA-OSCs with the lower △Vocnon-rad.

Modeling of the photophysical and photovoltaic properties of an active layer based on the organic composite poly(2‐methoxy‐5‐(2‐ethyl‐hexyloxy)‐1,4‐phenylene‐vinylene) (MEH‐PPV)–poly(3‐hexylthiophene) (P3HT): (6,6)‐phenyl C61 butyric acid methyl ester (PCBM)

AbstractIn this work, two different composite architectures have been investigated. These materials are formed by the block and ramified MEHPPV‐P3HT copolymers mixing with the PCBM. Density Functional Theory (DFT) and Time‐Dependent Density Functional Theory (TD‐DFT) calculation methods have been used to simulate the properties of the photo‐physical and photovoltaic material. The results show that adding the PCBM decreases the HOMO–LUMO gap energy to approximately 1.4 eV compared to the basic copolymers. This reduction implies a higher charge transfer between the donor and acceptor materials. Therefore, these composites can be implemented as an active layer in bulk heterojunction organic solar cells. Furthermore, the coupling between the polymers MEH‐PPV and P3HT improves their performance order by 5.2%.

Anion Photoelectron Spectroscopy and Theoretical Studies of Ge3n+1O (n = 1-3) Clusters with the C3v Symmetric Ge3 Structural Unit.

We investigate Ge3n+1O-/0 (n = 1-3) clusters using anion photoelectron spectroscopy and theoretical calculations. The results show that the lowest energy structure of Ge4O- is a bent Cs symmetric trigonal bipyramidal structure, while Ge4O has a C3v symmetric trigonal bipyramidal structure. Ge7O- has two coexisting low-lying isomers, the first one can be viewed as a Ge2O unit interacting with a Ge5 trigonal bipyramid, the second one can be regarded as an O atom interacting with a Ge7 pentagonal bipyramid; whereas Ge7O has a C3v symmetric structure with a Ge atom and an O atom capping a Ge6 trigonal antiprism from the bottom and top, respectively. The structures of Ge10O- and Ge10O can be obtained by adding an O atom to different binding sites of a C3v symmetric Ge10. Chemical bonding analyses of Ge3n+1O (n = 1-3) reveal that the O atom interacts with its neighboring three Ge atoms forming one 4c-2e σ bond and two 4c-2e π bonds in the top Ge3O trigonal pyramid, while the terminal Ge atom forms one 4c-2e σ bond in the bottom Ge4 trigonal pyramid. The large HOMO-LUMO gaps of Ge3n+1O (n = 1-3) indicate that they have good stabilities. Ab initio molecular dynamics simulations suggest that both Ge7O and Ge10O are dynamically stable in general at 300 and 500 K. The current work suggests that the C3v symmetric Ge3 units and the insertion growth pattern may be viable for constructing 1D germanium oxide nanostructures with the chemical formula of Ge3n+1O.

The Electrical Conductivity of Methylene-Methyliminomethyl Formamidine Molecular Nanowire via DFT and QTAIM Theory

The effect of metal electrodes on methylene-methyliminomethyl formamidine (MMF) molecule has been calculated by Density functional analysis using Gaussian09 program package. The various applied electric fields (0.00 – 0.26 VÅ-1) altered the geometrical parameters and the corresponding electrostatic and transport properties of the molecule has been analyzed. The variations in the atomic charges (MPA, NPA) of the molecule for the various applied electric fields have been compared. The HOMO-LUMO gap of the molecule for zero bias is 1.904 eV, as the field increases this gap decreases to 0.272 eV. The ESP shows the potential difference between charges accumulated of the molecule for various applied electric fields. The applied electric field polarizes the molecule, in consequence of that the dipole moment of the molecule decreases from 9.65 to 8.82 Debye. The small decrease of dipole moment shows that the molecule exhibits smaller conductivity.

Computational studies of Salvurmin A and Salvurmin B, two ursane triterpenoids of Salvia Urmiensis as anti-cancer agents: molecular docking, molecular dynamic simulation, and DFT and ADMET analysis

Salvurmin A and Salvurmin B are novel cytotoxic ursane triterpenoids isolated from Salvia urmiensis, an endemic plant species of Iran. The isolation, structure elucidation and in vitro anticancer properties of these two compounds were reported in our recent publications. For further studies, we assessed computational studies of Salvurmin A and Salvurmin B as anticancer agents. Molecular docking studies were performed to predict their affinity toward VEGFR-2 and Bcl-2 apoptosis regulator. Molecular dynamic simulation was also performed on the potent compound (Salvurmin B) to understand the virtual interaction in the active site of the enzyme (VEGFR-2). In addition, to obtain details of the structural properties of the compounds DFT analysis was performed. In order to better comprehend the reactivity of these molecules, the frontier orbitals were studied in detail, including HOMO–LUMO gap, molecular softness and hardness, electron affinity, chemical potential and electron surface potential studies. Taken together, Salvurmin B had desired chemical reactivity compared to Salvurmin A. In silico ADMET profiling calculations were also performed. Therefore, computational studies of the compounds in this study confirmed in vitro anticancer assessment in our recent report, and Salvurmin B can be considered as a potential candidate for further studies against human carcinoma cells.