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A Novel class of 1,4-disubstituted 1,2,3-triazoles have been synthesized in good to excellent yields via Cu(I) accelerated azide-alkyne click chemistry reaction strategy. The newly synthesized compounds were assessed for their in vitro antimicrobial activity against five Gram-positive, seven Gram-negative bacteria and three fungi. Most of the synthesized compounds displayed significant activity against the tested Gram-positive and Gram-negative bacteria. Molecular docking study revealed that all docked compounds are bound efficiently with the active site of Topoisomerase IV (4EMV) receptor with the observed the free energy of binding from −7.79 to −9.44 kcal/mol. Interestingly, compound 13a forms four hydrogen bonds and displayed high binding energy (−9.44 kcal/mol) with the Topoisomerase IV (4EMV) receptor which correlated with their in vitro antimicrobial assays.

Rhodium-catalysed decarbonylative annulation of isatoic anhydrides with alkynes through C-H activation for the synthesis of aminoisocoumarins was developed. This enables the gram-scale transformation to iodoisocoumarin which is a vital building block in transition-metal-catalysed cross couplings. These compounds exhibit blue-emitting luminescence properties.

A facile ruthenium(II)-catalyzed regiospecific C–H/O–H oxidative annulation methodology was developed to construct isochromeno[8,1-ab]phenazines. This methodology delivers various advantages, such as scope for diverse substrates, tolerance to a range of functional groups, stability under air, and yields regioselective products. This methodology was successfully applied to synthesize far red (FR) fluorescent probes for live cancer cell imaging. The synthesized compounds displayed notable fluorescence properties in solution and thin-film. Their application in live cancer cell imaging was investigated using various cancer cell lines. The synthesized compound showed prominent FR fluorescence, with high quantum yield, and exhibited better cell-imaging properties, with excellent biocompatibility.

In our earlier studies, we have shown that the introduction of amino moieties at carboxylic acid of 4,5-diarylthiophene-2-carboxylic acid significantly improved the anti-inflammatory activity of the compound against the standard drug diclofenac sodium. In the present study, we have synthesized new derivatives of 4,5-diarylthiophene-2-carboxylic acid by modifying the hydroxyl group of the phenyl ring and carboxylic acid group of the thiophene ring. A series of novel 4,5-diarylthiophene-2-carboxylic acid derivatives containing bis-allyloxy and hydroxypropoxy with methyl or ethyl ester moieties were synthesized, characterized and subsequently evaluated for anti-inflammatory and antioxidant property. Among the novel compounds, the inhibition of bovine serum albumin denaturation assay revealed that the compound 4,5-bis(4-(3-hydroxypropoxy)phenyl)thiophene-2-carboxylic acid (15) and ethyl ester (13) having anti-inflammatory activity better than the standard drug diclofenac sodium. The antioxidant screening showing 4,5-bis(4-(allyloxy)phenyl)thiophene-2-carboxylic acid (10), 4,5-bis(4-(3-hydroxypropoxy)phenyl)thiophene-2-carboxylic acid methyl ester (11) and 4,5-bis(4-(3-hydroxypropoxy)phenyl)thiophene-2-carboxylic acid ethyl ester (13) exhibited a slightly moderate antioxidant activity than standard ascorbic acid. Molecular docking analysis was performed for the synthesized compounds with the cyclooxygenase-2 (COX-2) receptor (PDB 1D: 1PXX). Docking studies revealed that all the synthesised compounds exhibit greater binding affinity than the standard drug. Particularly, the compound ethyl 4,5-bis(4-(allyloxy)phenyl)thiophene-2-carboxylate (8) and allyl 4,5-bis(4-(allyloxy)phenyl)thiophene-2-carboxylate (9) having high free energy binding of −10.40 and −10.48 Kcal/mol, respectively. Synopsis: A new series of bis-allyloxy and hydroxypropoxy substituted 4,5-diarylthiophene-2-carboxylic acid derivatives were synthesized, characterized, evaluated their in vitro anti-inflammatory and anti-oxidant activity, and performed molecular docking study.

A series of novel 4,5-diarylthiophene-2-carboxamide containing alkyl, cycloalkyl, aryl, aryl alkyl and heterocyclic alkyl moieties were synthesized, characterized and subsequently evaluated for anti-inflammatory property. Among the novel compounds, the inhibition of bovine serum albumin denaturation assay revealed that the aryl and aryl alkyl derivatives of 4,5-diarylthiophene-2-carboxamide showed anti-inflammatory activity comparable to the standard drug diclofenac sodium whereas alkyl and cycloalkyl amide derivatives showed less activity. Docking studies with these compounds against cyclooxygenase-2 receptor (PDB 1D: 1PXX) indicated that they exhibit specific interactions with key residues located in the site of the COX2 structure, which corroborates the hypothesis that these molecules are potential ligands of COX2. The analysis of the docking results, which takes into account the hydrophilic and hydrophobic interactions between the ligands and the target, identified N-(4-bromophenyl)-4,5-bis(4-hydroxyphenyl)thiophene-2-carboxamide (6k) having high binding free energy of −11.67 kcal /mole (comparable with standard diclofenac sodium) and the best docking score, indicating effective binding of the compound 6k at the active site.

A hybrid pharmacophore approach for the synthesis of isomeric pyranoindolones was achieved by employing gold(III) chloride-catalyzed cycloisomerization of alkyne-tethered indole carboxylic acids in good to excellent yield. All the synthesized compounds were evaluated for their tumor cell growth inhibitory activity against human cervix adenocarcinoma (HeLa) which revealed that three compounds exhibited activity comparable with the standard cis-platin (IC50 = 0.08 μM). Molecular docking of all the compounds in Vaccinia H1-Related (VHR) Phosphatase receptor also supported that compound 7d as the most active with a free energy of binding as −8.27 kcal/mol.

A novel series of Mannich derivatives of 3a–g and 3a′–g′ were designed and synthesized from pseudophenylpropanolamine (Ψ-PPA). The stereo chemical aspects of the synthesized compounds were studied and all compounds were well characterized with respect to spectral techniques. All Mannich derivatives, 3a–g and 3a′–g′ were evaluated for their anti-proliferative activity against A549 and HepG-2 cells. Among the tested compounds, 3a showed significant anti-proliferative activity against HepG-2 cells at 25 μM when compared to other compounds. The treatment of 3a exhibited morphological changes, nuclear condensation, colony formatting ability, apoptosis and cell cycle arrest at G2/M phase in HepG-2 cells. Besides, 3a triggered mitochondrial mediated apoptotic pathway as indicated by down regulation of Bcl-2, up-regulation of Bax, and release of cytochrome c and caspases-3. Furthermore, 3a effectively suppressed the cell proliferation and cell growth via JAK2/STAT3 signaling pathway in a time and dose dependent manner. In vivo administration of 3a inhibited tumor growth without significant change in body weight in HepG-2 xenograft mice model. Molecular docking studies revealed that good binding energies of compound 3a against JAK2 (−6.10 kcal mol−1) and Bcl-2 (−6.04 kcal mol−1) receptors. Taken together, 3a possessed potent antitumor activity; it could be a promising lead candidate for the potential treatment of human hepatocellular carcinoma.

The synthesis of substituted isoxazoles and pyrazoles through a general cycloisomerization methodology has been reported. The capability of gold(III) chloride to promote cycloisomerization of both α, β-acetylenic oximes and α, β-acetylenic hydrazones is the centrepiece of the strategy. A range of acetylenic precursors were investigated to afford 28 examples of the products with good to excellent chemical yields. Selected compounds were screened for their cytotoxic potential towards COLO320 cancer cell lines. The IC50 values of the tested compounds were in the micromolar range, with the best compound, 5-(6-Methoxy-naphthalen-2-yl)-3-phenyl-isoxazole (3h) displaying an IC50 of 38.9 μM. For this compound, the crystal structure in complex with Aurora-A kinase was obtained which revealed details of its binding mode within the active site with a free energy of binding -9.54 kcal/mol.

A series of N-substituted isatin thiosemicarbazone ligands (L1–L5) and their nickel(II) complexes [Ni(L)2] (1–5) were synthesized and characterized by elemental analyses and UV-Visible, FT-IR, 1H & 13C NMR, and mass spectroscopic techniques. The molecular structure of the ligands (L1 and L2) and complex 1 was confirmed by single crystal X-ray crystallography. The single crystal X-ray structure of 1 showed distorted octahedral geometry. The interaction of calf thymus (CT) DNA and bovine serum albumin (BSA) with the nickel(II) complexes was explored using absorption and emission spectral methods. A DNA cleavage study showed that the complexes cleaved DNA without any external agents. The alterations in the secondary structure of the protein by the nickel(II) complexes (1–5) were confirmed by synchronous and three dimensional fluorescence spectroscopic studies. The interaction of the complexes with DNA/protein also has been supported by molecular docking studies. An in vitro cytotoxicity study of the complexes found significant activity against human breast (MCF7) and lung (A549) cancer cell lines, with the best results for complexes 4 and 2 respectively, where the IC50 value is less than 0.1 μM concentration.

An efficient diversity oriented synthesis of [1,2,3]triazolo[1,5-a][1,4]benzodiazepines has been developed by sequential diazotization, azidation and cycloaddition reactions in a one-pot fashion. This strategy allows an easy accessibility of triazole fused [1,4]benzodiazepines in good yields. The main objective of this methodology is to introduce various substituents at all possible positions under mild reaction conditions. All the synthesized compounds were evaluated for their antimicrobial, anticancer and in silico activity. Among the tested compounds (2a–n), the derivatives 2a, 2b, 2d, 2k, 2g, 2j, 2m and 2l have displayed a broad spectrum of antibacterial activity. Anticancer activity results revealed that compounds 2a, 2g and 2m exhibited potent in vitro anticancer activity against A549 lung adenocarcinoma cancer cell line. Further, molecular docking studies of all the synthesized compounds were performed to gain a comprehensive understanding of the plausible binding modes and also to compare the theoretical and experimental results of these compounds.

Novel 1,4-disubstituted 1,2,3-triazolo bosentan derivatives 1a–n from bosentan 2 were synthesized in good yields by sequential chlorination, azidation followed by Cu(I) catalyzed 1,3-dipolar cycloaddition. All obtained compounds 1a–n were evaluated for their antimicrobial and in vitro anticancer activities and by in silico docking studies. Among all tested compounds 1e,f and 1h–j show better antimicrobial activities against the tested bacteria and fungi. When subjected to anticancer testing, compounds 1g–j and 1n show significant activities against both A549 and SKOV-3 cell lines with IC50 values at 7.81 μg mL−1 and among them compound 1i exhibited very potent activity. In addition, no toxicity was calculated up to 2 mg mL−1 in Vero cells. In silico studies were conducted to investigate the possible bonding modes of 1a–n with target receptors namely DNA topoisomerase IV (4 EMV) and anaplastic lymphoma kinase (2XP2). Among them, compounds 1e and 1h show maximum binding energies with 4EMV and 2XP2 receptors, respectively which also exhibited good antimicrobial and potent anticancer activities.

Six mononuclear copper(II), nickel(II) and zinc(II) complexes, [ML1Cl2] (1–3) and [M(L2)2Cl2] (4–6), of two biologically active tetrazolo[1,5-a]pyrimidine core ligands, ethyl 5-methyl-7-pyridine-2-yl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate (L1) and ethyl-5-methyl-7-pyridine-4-yl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate (L2), have been synthesized and characterized. The molecular structure of the ligands (L1&2) and complex 6 were determined by single crystal X-ray diffraction. The X-ray crystal structure of 6 confirms that it has a distorted tetrahedral structure with a ZnN2Cl2 coordination environment. All of the complexes exhibit an unusually strong luminescence at room temperature. Electroparamagnetic resonance spectra of copper(II) complexes (2 and 5) show four lines, characteristic of square planar geometry, with nuclear hyperfine spin 3/2. DNA binding studies of complexes with calf-thymus DNA suggest that complexes 2 and 5 bind in the grooves of the DNA. These results were further supported by molecular docking studies. In vitro cytotoxic activities of the ligands (L1&2) and complexes (1–6) against human cancer cell lines such as lung (A549), cervical (HeLa), colon (HCT-15) and a non-cancer human embryonic kidney cell line revealed that the complexes selectively inhibit the growth of cancer cells and are inactive against non-cancer cell lines, whereas the ligands were found to be inactive with both cancer and non-cancer cell lines. The IC50 values of the complexes revealed that the copper(II) complexes (2 and 5) exhibit high cytotoxic activity against colon (HCT-15) cells when compared to the standard drug cisplatin. Furthermore, the live cell and fluorescent imaging of cancer cells show that complexes 2 and 5 induce cell death through apoptosis.

In the title compound, C31H25N5O3·C2H6OS, the three indole/indoline units are all essentially planar with maximum deviations of 0.0172 (3), 0.053 (2) and 0.07 (2) Å. The pyrrolidine ring adopts an envelope conformation with the C atoms bearing the 1-ethyl-2-oxo-indole substituent (in which the five-membered ring adopts a twisted conformation) as the flap. The dimethyl sulfoxide solvent mol-ecule is disordered over two positions, with an occupancy factor ratio of 0.871 (4):0.129 (4). The solvent components are linked to the heterocyclic mol-ecule via C-H⋯O and C-H⋯S hydrogen bonds. In the crystal, the solvent components are linked to the heterocyclic molecule via C-H⋯O and C-H⋯S inter-actions, forming R 2 (2)(10) ring motifs. The mol-ecules are further connected into a chain along the a-axis direction via N-H⋯O hydrogen bonds.

The title compound, C24H29NO7, is asymmetric with a chiral centre located in the pyran ring and crystallizes as a racemate. The coumarin ring system and the fused pyran ring make a dihedral angle of 10.46 (8)°. A short intramolecular N—H...O hydrogen bond between the amino group and the vicinal carbonyl group generates an S(6) ring. Intermolecular C—H...O interactions contribute to the stability of the crystal structure.

The title compound, C20H21NO7, is asymmetric with a chiral centre located in the pyran ring and crystallizes as a racemate. The molecular framework is somewhat bent; the coumarin moiety and the pyran ring are inclined by 7.85 (5)°. The molecular structure is characterized by an intramolecular N—H...O hydrogen bond, which generates an S(6) ring motif, and the crystal packing is stabilized by intermolecular C—H...O hydrogen bonds. The 3-carboxylate O atom is involved in both of them, having a bifurcated character.

In the title compound, C26H20N4O2S, the central pyrrolidine ring adopts a twist conformation on the C-C bond involving the spiro C atom. Its mean plane makes dihedral angles of 78.83 (14), 65.91 (15) and 44.49 (18)° with the mean planes of the adjacent oxindole ring system, the indole system and the thio-phene ring, respectively. The indole and indoline units are essentially planar, with maximum deviations of 0.019 (3) and 0.090 (3) Å, respectively. In the oxindole fused-ring system, the pyrrole ring adopts an envelope conformation with the spiro C atom as the flap. In the crystal, pairs of N-H⋯O hydrogen bonds link the mol-ecules, forming inversion dimers with an R (2) 2(8) ring motif. The dimers are linked by further N-H⋯O hydrogen bonds, forming a two-dimensional network lying parallel to (100).

In the title compound, C25H20N6O2·0.15H2O, the dihedral angles between the least-squares planes of the indole and pyrrolidine rings and between the oxindole and imidazole rings are 77.66 (7) and 45.31 (7)°, respectively. The pyrrolidine ring and the fused five-membered pyrrolidine ring of the oxindole moiety exhibit twisted conformations. The amide N atom is involved in both intra- and inter-molecular hydrogen bonding, having a bifurcated character. The mol-ecular structure is characterized by an intra-molecular N-H⋯O hydrogen bond, which generates an S(7) ring motif while an inter-molecular N-H⋯O hydrogen bond links the organic and solvent water mol-ecules. In the crystal, N-H⋯N hydrogen bonds generate a zigzag chain running parallel to c-axis direction. The H atoms of the solvent water mol-ecule were not located.