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Four new pyrazolo[3,4-d]pyrimidines (P1–P4) were successfully synthesized in good relative yields by reacting 3-methyl-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-ol with various alkylating agents (methyl iodide, propargyl bromide, and phenacyl bromide) at room temperature in DMF solvent, employing liquid–solid phase transfer catalysis. The P1–P4 structures were elucidated using NMR spectroscopy and X-ray diffraction. Intermolecular interactions in P1–P4 were analyzed via Hirshfeld surface analysis and 2D fingerprint plots. Geometrical parameters were accurately modeled by DFT calculations using the B3LYP hybrid functional combined with a 6–311++G(d,p) basis set. The antiproliferative activity of P1–P4 towards colorectal carcinoma (HCT 116), human hepatocellular carcinoma (HepG2), and human breast cancer (MCF-7) cell lines, along with one normal cell line (WI38) was investigated using the MTT assay and sunitinib as a reference. Compounds P1 and P2 exhibited antiproliferative activities comparable to the reference drug towards all tested cells, with an IC50 range of 22.7–40.75 µM. Both compounds also showed high selectivity indices and minimal cytotoxic effects on the normal cell line. Molecular docking revealed that the significant antiproliferative activity may attributed to the number and type of intermolecular hydrogen bonding established between pyrazolo[3,4-d]pyrimidines and DNA topoisomerase, a common target for various anticancer agents. [ABSTRACT FROM AUTHOR]

Dibenzocycloheptene antidepressants are tricyclic antidepressants (TCAs) that contain the dibenzocycloheptene moiety in their chemical structures. They are used to treat major depressive disorder, anxiety disorders, chronic pain, and addiction. Herein, we report the synthesis of a pure tricyclic antidepressant containing dibenzocycloheptene moiety named N-(5H-dibenzo[a,d][7]annulen-5-ylidene)-2-methylpropane-2-sulfinamide (3) in high chemical yield through condensing (R)-tert-butanesulfinamide with a dibenzosuberon ketone. Its structure is elucidated by employing the X-ray technique, NMR spectroscopy characterization, and DFT calculations at the B3LYP/6-31++G(d,p) level of theory. The geometrical parameters are relatively well reproduced, and the optimized and X-ray geometries are relatively well superimposed. The interconnects in the crystalline form of 3 were identified through the analysis of its Hirshfeld surface (HS) and fingerprint plots. The highest interatomic contacts were found between H...H of 58.2% and C.H of 30.6%. Further, the ADMET (absorption, distribution, metabolism, excretion, and toxicity) pharmacokinetics, and physicochemical properties of 3 were determined, which showed that 3 may act as a carbonic Anhydrase I inhibitor. The binding affinity of 3 into the binding site of carbonic Anhydrase I is investigated using a molecular docking study. It forms a stable complex into the binding site of CA I with a binding energy of −7.12 kcal/mol. [ABSTRACT FROM AUTHOR]

In this work, theoretical and experimental studies of a new Indazole derivative named 2-(5-nitro-1-H-indazol-1-yl) acetic acid (3), including the synthesis and characterization by 1H and 13C-NMR, FT-IR, UV spectroscopies are reported together with its X-ray crystal structure. The compound crystallizes in the monoclinic crystal system of P21/c space group and unit cell constants: a = 7.8541(10) Å, b = 7.9274(11) Å, c = 15.877(2) Å, β = 101.149(5)°. In the crystal, O–H···N and C–H···O hydrogen bonds form a 3-D network structure containing small channels running parallel to the b-axis. B3LYP/6-311++G** calculations in the gas phase and ethanol solution suggest the existence of C1 and C2 conformers where the structure of C1 in both media is in agreement with that observed by X-ray diffraction. Probably, the high values observed in the dipole moments of C1 justify its presence in gas and solution phases. The stabilities of both forms were justified by NBO and AIM calculations where C1 is more stable than C2. C1 shows a higher solvation energy, dipole moment, and higher hydration than C2 while the frontier orbitals suggest a higher reactivity of C1 over C2. Force fields and complete vibrational assignments were performed for the C1 conformer because it was detected in the solid phase. Scaled force constants for both forms are also reported. Calculated chemical shifts for (3) are consistent with the experimental 1H and 13C-NMR spectra in the DMSO-d6 solution. The anti-COVID activity of 3 is investigated by its molecular docking into the binding site of SARS CoV-2 3CLpro (3 C-like protease). It shows a moderate binding affinity into the binding site of 3 C-like protease with a maximum binding energy of −5.57 kcal mol−1. [ABSTRACT FROM AUTHOR]

A group of compounds containing pyran, pyrazole, and pyranopyrazole were synthesized (2–4) using a facile and convenient protocol. The structure of the synthesized compounds was elucidated by spectroscopic and elemental analysis. In vitro antimicrobial evaluation was also performed for all synthesized derivatives against human pathogenic bacterial strains such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis using chloramphenicol as a reference. It was depicted that compounds 3d, 4b displayed a high degree of inhibition against Bacillus subtilis and Staphylococcus aureus. Compounds 2d, 4f and 2d, 4e, 4f, and 4e had high inhibition effects against Escherichia coli and Pseudomonas aeruginosa, respectively. The molecular docking study was performed against S. aureus bacteria to rationalize the binding affinities and the feasible modes of interaction with the active site of tyrosyl-tRNA synthetase. It was found that the synthesized compounds were well fit into the binding site of tyrosyl-tRNA synthetase. The obtained results were in good accordance with the experimental data. The data obtained were promising candidates for further development of novel heterocyclic scaffolds as therapeutics with high efficacy biomedical precursors.

AbstractIn the present work, five pyrazole-hydrazone biomolecule ligands (L1–L5) were synthesized by condensation between 1H-pyrazole-3-carbohydrazide (2) and aromatic benzaldehydes. Their corresponding structures were elucidated employing NMR and FT-IR spectra and ESI-MS data. Li-Cu(II) complexes (i = 1–5) were evaluated for catecholase activity in situ at standard conditions. The findings disclose that the catecholase oxidation rate varies with the substituted functional groups in ligand and the anion type in the copper (II) salt. Catecholase activity results showed that the L(i = 1–5) -Cu(II)SO4 complexes exhibited efficient catalytic activity, and a maximum activity of 105 ± 42 µM.min−1 is obtained with L5-Cu(II)SO4. DFT and NBO calculations have been carried out to identify the global reactivity and the strength of interaction bonds between the donors and acceptors in L1–L5. The optimized structure of L1–L3 and L5 were found planar, while that of L4 is out of the molecular plan and forms a torsion angle of 18 degrees due to the presence of methoxy and hydroxyl group at meta and para. In L4, the 5-methyl-1H-pyrazole moiety. NBO findings show that the strongest interactions in L1–L5 are those involved in the electronic transition from π-bonding → π*-antibonding and LP → π*- antibonding molecular orbitals. Further, the anti-SARS-CoV-2 of L1–L5 are investigated by estimating their binding affinities into its binding. The docking results reveal that L1–L5 may act as SARS-CoV-2 main protease inhibitors with estimated binding energies in the −6.00 to −8.0 kcal.mol−1 range. [ABSTRACT FROM AUTHOR]

Previously, a series of pyridotriazolopyrimidines (1–6) were synthesized and fully described. The target compounds (1–6) were evaluated for their cytotoxicity against MCF-7, HepG2, WRL 68, and A549 (breast adenocarcinoma, hepatocellular carcinoma, embryonic liver, and pulmonary adenocarcinoma, respectively) cell lines using MTT assay. The tested compounds demonstrated cytotoxicity, but no significant activity. To elucidate the structure–cytotoxicity relation of the prepared pyridotriazolopyrimidines, several chemical descriptors were determined, including electronic, steric, and hydrophobic descriptors. These chemical descriptors were calculated in the polarizable continuum model (water as solvent) using density functional theory calculations at B3LYP/6-31+G(d,p). By employing simple linear regression (SLR) and multiple linear regression (MLR) analyses, the impact of the selected descriptors was assessed statistically. The obtained results clearly reveal that the cytotoxicity of pyridotriazolopyrimidines depends on their (i) basic skeleton and (ii) the type of the tested cell. Interestingly, SLR and MLR analyses show that the impact of the selected descriptors is strongly related to the tested cells and basic skeleton of the tested compounds. For instance, the cytotoxicity of subclasses 2a and 2c–2f against A459 shows strong correlation with ionization potential, hardness (η), and hydrophobicity (log P) with a correlation coefficient of 99.86% and a standard deviation of 0.53.