Novel pyrrole derivatives bearing sulfonamide groups: Synthesis in vitro cytotoxicity evaluation, molecular docking and DFT study

Exploring the Impact of Structural Modifications of Phenothiazine-Based Novel Compounds for Organic Solar Cells: DFT Investigations

This paper explores a novel group of D-π-A configurations that has been specifically created for organic solar cell applications. In these material compounds, the phenothiazine, the furan, and two derivatives of the thienyl-fused IC group act as the donor, the π-conjugated spacer, and the end-group acceptors, respectively. We assess the impact of substituents by introducing bromine atoms at two potential substitution sites on each end-group acceptor (EG1 and EG2). With the donor and π-bridge held constant, we have employed density functional theory and time-dependent DFT simulations to explore the photophysical and optoelectronic properties of tailored compounds (M1-M6). We have demonstrated how structural modifications influence the optoelectronic properties of materials for organic solar cells. Moreover, all proposed compounds exhibit a greater Voc exceeding 1.5 V, a suitable HOMO-LUMO energy gap (2.14-2.30 eV), and higher dipole moments (9.23-10.90 D). Various decisive key factors that are crucial for exploring the properties of tailored compounds-frontier molecular orbitals, transition density matrix, electrostatic potential, open-circuit voltage, maximum absorption, reduced density gradient, and charge transfer length (Dindex)-were also explored. Our analysis delivers profound insights into the design principles of optimizing the performance of organic solar cell applications based on halogenated material compounds.

Synthesis, Cytotoxicity and Antiproliferative Effect of New Pyrrole Hydrazones

Novel pyrrole-based carbohydrazide (1) and hydrazones (1A-D) were synthesized, characterized, and subjected to spectroscopic studies. The hydrazones were obtained by reacting a pyrrole hydrazide with substituted pyrrole aldehydes. The initial carbohydrazide was prepared by selective hydrazinolysis of the obtained N-pyrrolylcarboxylic acid ethyl ester. The biological activity of the newly synthesized compounds was investigated in vitro on a panel of tumor and non-tumor cell lines. Mouse embryonic fibroblasts BALB 3T3 clone A31 were used in the safety test (BALB 3T3 NRU-assay). Antiproliferative activity was determined on keratinocytes (HaCaT) and melanoma (SH-4) cells by MTT dye reduction assay. The safety test of the compounds showed low cytotoxicity and absence of phototoxic potential. Among our novel pyrrole hydrazones, 1C was the most selective (SI = 3.83) in human melanoma cells and exhibited very good antiproliferative activity (IC50 = 44.63 ± 3.51 μM). The cytotoxic effect of 1C correlates with its ability to induce apoptosis and to cause cell cycle arrest in the S phase. In addition, the results show that hydrazones obtained by condensation with β-aldehydes are more bioactive than those obtained by condensation with α-aldehydes.

Optimizing non-fullerene acceptor molecules constituting fluorene core for enhanced performance in organic solar cells: a theoretical methodology

CONTEXT

Looking for novel outstanding performance materials suitable for organic solar cells, we constructed a range of non-fullerene acceptors (NFAs) evolved from the recently synthesized acceptor molecule identified as DICTIF, structured around fluorene core where 2-(2,3-dihydro-3-oxo-1H-inden-1-ylidene) propanedinitrile presented the terminals end-groups. Employing density functional theory (DFT) and time dependent-DFT (TD-DFT) simulations, we have simulated the impact of altering the end groups of DICTIF molecule by five assorted acceptors molecules, for the purpose of exploring their opto-electronic properties and their performance in organic solar cell (OSC) applications. We proved that the designed non-fullerene acceptors provide enhanced efficiency compared to the synthesized molecule, such as planar geometries and narrower energy gap ranging from 1.51 to 1.95 eV. A red shift in absorption was observed for all tailored molecules (λmax = 583.5-711.4 nm) as compared to the reference molecule (λmax = 578 nm).Various decisive factors such as frontier molecular orbitals (FMOs), exciton binding energy (EB), absorption maximum (λmax), open circuit voltage (VOC), reorganization energies (RE), transition density matrix (TDM), reduced density gradient (RDG), and electron-hole overlap have also been computed for analyzing the performance of NFAs. Low reorganizational energy values facilitate charge mobility which improves the conductivity of all the designed molecules. This study showed that our novel tailored molecules might be suitable candidates for the fabrication of highly efficient photovoltaic materials.

METHODS

After testing various hybrid functionals, optimized geometries were assigned using DFT HSEH1PBE/6-31G(d) level of theory. Electronic excitations and absorption spectra were investigated using the TD-DFT MPW1PW91/6-31G(d) level of theory. We ascertained that HSEH1PBE/6-31G(d) level of theory yield the closest calculated highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the DICTIF to the corresponding experimental ones and that TD-MPW1PW91//6-31G(d) was the most suitable level of theory for exploring electronic excitations and finding the maximum of absorption (λmax).

Neurotoxicity, Neuroprotection, In Vitro MAOA/MAOB Inhibitory Activity Assessment, Molecular Docking, and Permeability Assay Studies of Newly Synthesized Hydrazones Containing a Pyrrole Ring

Neurodegenerative diseases such as Parkinson's and Alzheimer's continue to be some of the most significant challenges in modern medicine. Recent research related to the molecular mechanisms of parkinsonism has opened up new approaches to antiparkinsonian therapy. In response to this, we present the evaluation of the potential neuroprotective and MAOA/MAOB inhibitory effects of newly synthesized hydrazones, containing a pyrrole moiety in the carboxyl fragment of the structure. The substances were studied on different brain subcellular fractions, including rat brain synaptosomes, mitochondria, and microsomes. The single application of 50 µM of each compound to the subcellular fractions showed that all substances exhibit a weak neurotoxic effect, with 7b, 7d, and 8d being the least neurotoxic representatives. The corresponding neuroprotective and antioxidant effects were also evaluated in different injury models on subcellular fractions, single out 7b, 7d, and 8d as the most prominent derivatives. A 1 µM concentration of each molecule from the series was also studied for potential hMAOA/hMAOB inhibitory effects. The results revealed a lack of hMAOA activity for all evaluated structures and the appearance of hMAOB effects, with compounds 7b, 7d, and 8d showing effects similar to those of selegiline. The best hMAOB selectivity index (>204) was determined for 7d and 8d, distinguishing these two representatives as the most promising molecules for further studies as potential selective MAOB inhibitors. The performed molecular docking simulations defined the appearance of selective MAOB inhibitory effects based on the interaction of the tested molecules with Tyr398, which is one of the components of the aromatic cage of MAOB and participated in π-π stabilization with the aromatic pyrrole ring. The preliminary PAMPA testing indicated that in relation to the blood-brain barrier (BBB) permeability, the tested pyrrole-based hydrazones may be considered as high permeable, except for 8a and 8e, which were established to be permeable in the medium range with -logP of 5.268 and 5.714, respectively, compared to the applied references.

Coupled internal rotations and 14N quadrupole hyperfine structure of 2,4-dimethylpyrrole investigated by microwave spectroscopy and quantum chemistry

The microwave spectrum of 2,4-dimethylpyrrole was investigated using a Fourier-transform microwave spectrometer in a supersonic expansion. Torsional splittings arising from two inequivalent methyl internal rotors in combination with hyperfine splittings due to the nuclear quadrupole coupling of the 14N nucleus were observed. The experiments were accompanied by quantum chemical calculations. A total of 1561 rotational lines were assigned and fitted in global fits using the programs XIAM and BELGI-Cs-2Tops-hyperfine, both achieved the measurement accuracy of 4 kHz. Local separate fits were also performed to verify the correctness of the assignment. Accurate experimental molecular and internal rotation parameters could be deduced and compared to the calculated ones. The barrier to internal rotation of the 2-methyl rotor was determined to be 277.830(26) cm-1, essentially the same as the value of about 280 cm-1 found for 2-methylpyrrole but lower than the value of 317 cm-1 found for 2,5-dimethylpyrrole. The torsional barrier value of the 4-methyl rotor is 262.210(27) cm-1, slightly higher than the value of 246 cm-1 found for 3-methylpyrrole. Benchmarking the rotational constants for 2,4- and 2,5-dimethylpyrrole revealed that the MP2/6-31G(d,p) level could be helpful to guide the assignment of microwave spectra of pyrrole derivatives.

Endoplasmic Reticulum Stress-Induced Apoptotic Effects of Novel 1-Pyrroline (3,4-Dihydro-2H-pyrrole) Derivatives on Breast Cancer Cells

Heterocyclic compounds have emerged as promising and appealing scaffolds for developing effective antitumor agents. Here, the effects of synthesized 24 different 1-pyrroline derivatives (PDs) containing substituted aryl sulfide moiety were investigated on human breast cancer cell lines. The viability of cells was assessed via MTT assay. Reactive oxygen species (ROS) generation was analyzed via fluorescent dye CM-H2DCFDA. Apoptotic cells were determined via flow cytometry. Endoplasmic reticulum (ER) stress-associated protein levels were analyzed via western blot analysis. Four of the PDs (PD-12, -14, -16 and -17) had great cytotoxic selectivity against breast cancer cells. Apoptotic cell death was induced by PDs via the generation of ROS. PDs significantly increased the GRP78, p-PEAK, p-eIF2α, and CHOP protein levels indicating ER stress in breast cancer cells. These results imply that newly synthesized PDs may be potential anticancer agents as they selectively inhibit breast cancer cells.

4-Propargyl-substituted 1H-pyrroles induce apoptosis and autophagy via extracellular signal-regulated signaling pathway in breast cancer

Novel pyrrole derivatives (PDs) with propargyl units (1-7) were investigated for their anticancer activity on breast cancer cells. The MTT assay was used to assess the cell viability. Morphological changes in human breast cancer cells were visualized under a phase-contrast microscope. Apoptosis and autophagy were detected using the DNA fragmentation assay and staining by autophagic vacuoles, respectively. The levels of apoptosis- and autophagy-related proteins such as cytochrome c, Bcl-2, LC3-I/II were investigated by Western blot analysis. The effect of PDs on the ERK1/2 signaling pathway was investigated using specific inhibitors. All the tested PDs were found to be active in the range of 36.7 ± 0.2 to 459.7 ± 4.2 µM. Compounds 3 and 4 showed cytotoxic activity in breast cancer cells, but were found to be safer with lower cytotoxicity on human nontumorigenic epithelial breast cells. Compound 4 induced apoptosis, whereas compound 3 induced autophagy. Both compounds inhibited the ERK signaling pathway in breast cancer cells. The present study revealed that both synthesized PDs induced different programmed cell death types by inhibiting the ERK signaling pathway in two genotypically different breast cancer cells. Therefore, novel PDs might be promising anticancer agents for breast cancer therapy and further structural modifications of PDs may yield promising anticancer agents.

Modulation of Differentiation of Embryonic Stem Cells by Polypyrrole: The Impact on Neurogenesis

The active role of biomaterials in the regeneration of tissues and their ability to modulate the behavior of stem cells in terms of their differentiation is highly advantageous. Here, polypyrrole, as a representantive of electro-conducting materials, is found to modulate the behavior of embryonic stem cells. Concretely, the aqueous extracts of polypyrrole induce neurogenesis within embryonic bodies formed from embryonic stem cells. This finding ledto an effort to determine the physiological cascade which is responsible for this effect. The polypyrrole modulates signaling pathways of Akt and ERK kinase through their phosphorylation. These effects are related to the presence of low-molecular-weight compounds present in aqueous polypyrrole extracts, determined by mass spectroscopy. The results show that consequences related to the modulation of stem cell differentiation must also be taken into account when polypyrrole is considered as a biomaterial.

New Palladium(II) and Platinum(II) Complexes Based on Pyrrole Schiff Bases: Synthesis, Characterization, X-ray Structure, and Anticancer Activity

New palladium (Pd)II and platinum (Pt)II complexes (C1-C5) from the Schiff base ligands, R-(phenyl)methanamine (L1), R-(pyridin-2-yl)methanamine (L2), and R-(furan-2-yl)methanamine (L3) (R-(E)-N-((1H-pyrrol-2-yl) methylene)) are herein reported. The complexes (C1-C5) were characterized by FTIR, 1H and 13C NMR, UV-vis, and microanalyses. Single-crystal X-ray crystallographic analysis was performed for the two ligands (L1-L2) and a Pt complex. Both L1 and L2 belong to P21/n monoclinic and P-1 triclinic space systems, respectively. The complex C5 belongs to the P21/c monoclinic space group. The investigated molar conductivity of the complexes in DMSO gave the range 4.0-8.8 μS/cm, suggesting neutrality, with log P values ≥ 1.2692 ± 0.004, suggesting lipophilicity. The anticancer activity and mechanism of the complexes were investigated against various human cancerous (Caco-2, HeLa, HepG2, MCF-7, and PC-3) and noncancerous (MCF-12A) cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Apopercentage assays, respectively. C5 demonstrated strong DNA-binding affinity for calf thymus DNA (CT-DNA) with a binding constant of 8.049 × 104 M-1. C3 reduced cell viability of all the six cell lines, which included five cancerous cell lines, by more than 80%. The C5 complex also demonstrated remarkably high selectivity with no cytotoxic activity toward the noncancerous breast cell line but reduced the viability of the five cancerous cell lines, which included one breast cancer cell line, by more than 60%. Further studies are required to evaluate the selective toxicity of these two complexes and to fully understand their mechanism of action.

Synthesis, Molecular Docking, DFT Study of Novel N-Benzyl-2-(3-cyano-4-isobutoxyphenyl)- 4-methylthiazole-5-carboxamide Derivatives and their Antibacterial Activity

A series of febuxostat based new chemical entities was synthesized using microwave method and characterized by NMR, mass and FT-IR spectral studies. Molecular docking of febuxostat amide nucleus substitution compounds 8c (-7.91kcal/mol), 8g (-7.94 kcal/mol) exhibiting high binding energy against ALK receptors. Theoretical investigation of MEPs, HOMO, LUMO and energy gap of HOMO-LUMO were calculated by B3LYP/6-31G method. Among the tested compounds, methoxy substituted compound 8g showed highest antibacterial activity against S. aereus and B. subtilis.

Computational approach to study the synthesis of noscapine and potential of stereoisomers against nsP3 protease of CHIKV

Chikungunya fever is a major public health issue in India affecting millions of people and occurs due to Chikungunya. Chikungunya virus (CHIKV) is a single stranded RNA virus from the family of Togaviridae and genus alpha virus. It contain three structural proteins: glycosylated E1 and E2, embedded in the viral envelope, and a non-glycosylated nucleocapsid protein. Till date, researchers are working on inhibition of CHIKV but till now no cheap and effective medicine is available in the market. Therefore, the authors of this work thought of isoquinoline based noscapine to inhibit the nsP3 protease of CHIKV. The aim of the work is to understand the mechanism for the synthesis of noscapine theoretically using DFT. Further study the potential of all four isomers of noscapines {(13 (S,R), 14 (R,R), 15 (R,S) and 16 (S,S)} against nsP3 protease of CHIKV with the help of docking and MD simulation. The integrated e-pharmacophore binding affinity based virtual screening, docking and molecular dynamics simulation recognized four hits isomers as inhibition nsP3 protease of CHIKV. The docking energies of all the isomers of noscapine (13–16) with nsP3 protease CHIKV was found out to be more negative than baicalin (−8.06 kcal/mol) on selected sites. Amongst the isomers of noscapine, CMPD 13 possessed best binding affinity with four hydrogen bonding interactions. Further, ADME properties and blood-brain barrier permeability properties have been calculated. DFT studies of all the isomers of noscapine was investigated.

A model to study the inhibition of nsP2B-nsP3 protease of dengue virus with imidazole, oxazole, triazole thiadiazole, and thiazolidine based scaffolds

A theoretical model was developed to allosterically inhibit the biological activity of dengue virus (DENV) by targeting the non-structural protein ns2B-nsP3 protease based on the in silico studies. The imidazole, oxazole, triazole, thiadiazole, and thiazolidine based scaffolds were imported from the ZINC database, reported by various research group with different biological activity. They were found biologically active as they contain heterocyclic fragments. Generic evolutionary based molecular docking was performed to screen the highly potent molecule. The docking results show that the molecule having ZINC ID-633972 is best inhibitor. Further, the bioavailability and other physiochemical parameters were also calculated for the top four molecule. The highly potent molecule was further refined by the density functional theory and molecular dynamic (MD) simulation. The MD analysis coroborate the successful docking of the molecule in the binding cavity of nsP2B-nsP3 protease of DENV. The Molecular Mechanics Poisson-Boltzmann Surface Area approach was also applied and result coroborate the docking and MD result.

Pyrrole: An insight into recent pharmacological advances with structure activity relationship

Pyrrole is a heterocyclic ring template with multiple pharmacophores that provides a way for the generation of library of enormous lead molecules. Owing to its vast pharmacological profile, pyrrole and its analogues have drawn much attention of the researchers/chemists round the globe to be explored exhaustively for the benefit of mankind. This review focusses on recent advancements; pertaining to pyrrole scaffold, discussing various aspects of structure activity relationship and its bioactivities.

Flavonoids as potent allosteric inhibitors of protein tyrosine phosphatase 1B: molecular dynamics simulation and free energy calculation

Protein tyrosine phosphatase 1B (PTP1B) is a member of the PTP superfamily which is considered to be a negative regulator of insulin receptor (IR) signaling pathway. PTP1B is a promising drug target for the treatment of type 2 diabetes, obesity, and cancer. The existence of allosteric site in PTP1B has turned the researcher's attention to an alternate strategy for inhibition of this enzyme. Herein, the molecular interactions between the allosteric site of PTP1B with three non-competitive flavonoids, (MOR), (MOK), and (DPO) have been investigated. Three ligands were docked into allosteric site of the enzyme. The resulting protein-ligand complexes were used for molecular dynamics studies. Principal component and free-energy landscape (FEL) as well as cluster analyses were used to investigate the conformational and dynamical properties of the protein and identify representative enzyme substrates bounded to the inhibitors. Per residue energy decomposition analysis attributed dissimilar affinities of three inhibitors to the several hydrogen bonds and non-bonded interactions. In conclusion, our results exhibited an inhibitory pattern of the ligands against PTP1B.