Design, synthesis, spectral characterization and molecular docking studies of novel pyranoquinolinyl dihydropyridine carboxylates as potential antibacterial agents including Vibrio cholerae with minimal cytotoxity towards fibroblast cell line (L-929)

Novel pyranoquinolinyl dihydropyridine carboxylate (PDC) derivatives were designed by incorporating the multi-drug resistance modulating effects of 1,4 dihydropyridines along with potential antibacterial activity of quinolines in the molecular design. The designed PDC derivatives were synthesized by multi-step synthesis involving Michael addition, reduction followed by inverse electro demand Diels-Alder reaction to produce pyranoquinolinyl dihydropyridine carboxylates in good yields. All the PDC derivatives were characterized by ¹H NMR, ¹³C NMR, FT-IR, Mass spectral and CHN analysis. The Quinolinyl dihydropyridine carboxylate derivatives were evaluated for in vitro antibacterial activity by agar well diffusion method. Molecular docking studies revealed that the exo diethyl 4-(4aR,5S,10bR)-5-(4-chlorophenyl)-3,4,4a,5,6,10b-hexahydro-2H-pyrano[3,2-c]quinolin-8-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate diastereomer (5c) forms four hydrogen bonds with the cell wall protein of vibrio cholerae in comparison to the endo diethyl 4-((4aR,5R,10bR)-5-(4-chlorophenyl)-3,4,4a,5,6,10b-hexahydro-2H-pyrano[3,2-c]quinolin-8-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate diastereomer (4c) which forms two hydrogen bonds with the cell wall protein of vibrio cholerae and hence leading to better anchorage, enhanced gold score and relatively good antibacterial activity for the exo PDC derivatives. Minimum inhibitory concentration (MIC) of the active compounds was evaluated by macro dilution method. The mechanism of antibacterial action of the PDC derivatives was investigated by SEM studies. The cytotoxicity of PDC derivatives were evaluated against fibroblast cells (L-929).

A nanocrystalline CdS thin film as a heterogeneous, recyclable catalyst for effective synthesis of dihydropyrimidinones and a new class of carbazolyl dihydropyrimidinones via an improved Biginelli protocol

An improved Biginelli protocol for the efficient synthesis of a new class of carbazolyl dihydropyrimidinones mediated by CdS thin film nanoparticles deposited on the inner walls of a glass reactor as a recyclable, heterogeneous catalyst.

Sn(ii)-Mediated facile approach for the synthesis of 2-aryl-2H-indazole-3-phosphonates and their anticancer activities

The efficient synthesis of 2-aryl-2H-indazole-3-phosphonates has been achieved successfully via a SnCl₂·2H₂O mediated one-pot method.

5-Benzoyl-2-(5-bromo-1H-indol-3-yl)-4-(4-methoxyphenyl)-1H-pyrrole-3-carbonitrile

In the title compound, C27H18BrN3O, the indole and central pyrrole ring systems are inclined to one another by 13.15 (15)°. The carbonitrile group is almost coplanar with its attached pyrrole ring, the C[triple-bond]N bond making a dihedral angle of 1.9 (2)° with the ring plane. The 4-methoxybenzene ring and the benzoyl ring are inclined to the central pyrrole ring by 55.1 (2) and 51.5 (2)°, respectively. The dihedral angle between these two benzene rings is 37.68 (17)°. In the crystal, molecules are linked by pairs of N—H...N hydrogen bonds, forming inversion dimers with anR22(16) ring motif. The dimers are linked by offset π–π interactions [intercentroid distance = 3.614 (2) Å], which leads to the formation of chains propagating in the [010] direction.

5-Benzoyl-2-(1H-indol-3-yl)-4-(naphthalen-2-yl)-1H-pyrrole-3-carbonitrile

In the title compound, C30H19N3O, the indole and the naphthalene ring systems are inclined to the central pyrrole ring (r.m.s. deviation = 0.012 Å) by 29.09 (9) and 49.92 (9)°, respectively. The naphthalene ring system and the indole ring are inclined to one another by 73.57 (6) and by 42.58 (10) and 74.12 (10)°, respectively, to the benzoyl ring. In the crystal, molecules are linked by pairs of Np—H...O (p = pyrrole) hydrogen bonds, forming inversion dimers withR22(10) loops. These dimers are linkedviapairs of Ni—H...Nc(i = indole and c = carbonitrile) hydrogen bonds, enclosingR22(16) loops, which leads to the formation of chains propagating in [101]. The chains are linked by C—H...π interactions, forming slabs lying parallel to (10-1).

5-(2-Hydroxybenzoyl)-1-methyl-3-nitropyridin-2(1H)-one

In the title compound, C13H10N2O5, the dihedral angle between the pyridine and phenyl ring is 50.47 (2)°. The hydroxyl H and ketone O atoms form an intramolecular O—H...O hydrogen bond with the hydroxyl group almost coplanar with the phenyl ring. In the crystal, molecules are linked by two C—H...O hydrogen bonds, forming dimers. The dimers are linked by further C—H...O hydrogen bonds, forming a three-dimensional architecture.

5-(2-Hydroxybenzoyl)-2-(1H-indol-3-yl)pyridine-3-carbonitrile

In the title compound, C21H13N3O2, the indole and pyridine rings are planar. The pyridine ring is in an antiperiplanar (−ap) orientation with the indole ring system and an antiperiplanar (+ap) orientation with the hydroxyphenyl ring. An intramolecular O—H...O hydrogen bond stabilizes the molecular structure. In the crystal, N—H...N hydrogen bonds involving the indole NH group and the cyanide nitrogen atom lead to the formation of a two-dimensional supramolecular network lying parallel to (011).

5,6-Dipropylphthalazino[2,3-a]cinnoline-8,13-dione

In the title compound, C22H22N2O2, the two central fused pyridazine rings have screw-boat conformations and the dihedral angle between their mean planes is 36.22 (8)°. The mean plane of the cinnoline ring system makes a dihedral angle of 46.56 (5)° with the mean plane of the phthalazine ring to which it is fused. In the crystal, molecules are linkedviaC—H...O hydrogen bonds, forming chains along thebaxis. The chains are reinforced by C—H...π interactions.

In vitro antiproliferative activity of 2,3-dihydroxy-9,10-anthraquinone induced apoptosis against COLO320 cells through cytochrome c release caspase mediated pathway with PI3K/AKT and COX-2 inhibition

The present study investigated the anticancer activity of 2,3-dihydroxy-9,10-anthraquinone against different cancer cells such as MCF-7, COLO320, HepG-2, Skov-3, MOLM-14, NB-4, CEM, K562, Jurkat, HL-60, U937, IM-9 and Vero. 2,3-dihydroxy-9,10-anthraquinone showed good antiproliferative activity against COLO320 cells when compared to other tested cells. The cytotoxicity results showed 79.8% activity at the dose of 2.07 μM with IC50 value of 0.13 μM at 24 h in COLO320 cells. So we chose COLO320 cells for further anticancer studies. mRNA expression was confirmed by qPCR analysis using SYBR green method. Treatment with 2,3-dihydroxy-9,10-anthraquinone was found to trigger intrinsic apoptotic pathway as indicated by down regulation of Bcl-2, Bcl-xl; up regulation of Bim, Bax, Bad; release of cytochrome c and pro-caspases cleaving to caspases. Furthermore, 2,3-dihydroxy-9,10-anthraquinone stopped at G0/G1 phase with modulation in protein levels of cyclins. On the other hand PI3K/AKT signaling plays an important role in cell metabolism. We found that 2,3-dihydroxy-9,10-anthraquinone inhibits PI3K/AKT activity after treatment. Also, COX-2 enzyme plays a major role in colorectal cancer. Our results showed that the treatment significantly reduced COX-2 enzyme in COLO320 cells. These results indicated antiproliferative activity of 2,3-dihydroxy-9,10-anthraquinone involving apoptotic pathways, mitochondrial functions, cell cycle checkpoint and controlling the over expression genes during the colorectal cancer. Molecular docking studies showed that the compound bound stably to the active sites of Bcl-2, COX-2, PI3K and AKT. This is the first report of anticancer mechanism involving 2,3-dihydroxy-9,10-anthraquinone in COLO320 cells. The present results might provide helpful suggestions for the design of antitumor drugs toward colorectal cancer treatment.

Crystal structures of methyl (E)-3-(2-chloro-phen-yl)-2-({2-[(E)-2-nitro-vin-yl]phen-oxy}meth-yl)acrylate and methyl (E)-2-({4-chloro-2-[(E)-2-nitro-vin-yl]phen-oxy}meth-yl)-3-(2-chloro-phen-yl)acrylate

In the title compounds, (I) and (II), both of which crystallize in the monoclinic space group P2₁/n, the methyl acrylate and nitro­vinyl units are relatively planar with an E conformation about the C=C bonds. The two aromatic rings are inclined to one another by 74.87 (9) and 75.65 (2)° for compounds (I) and (II), respectively. In the crystal of (I), chains along the b axis are formed via C—H⋯O hydrogen bonds. In the crystal of (II), mol­ecules are linked by C—H⋯O hydrogen bonds, forming sheets parallel to the ac plane.

The title compounds, C₁₉H₁₆ClNO₅, (I), and C₁₉H₁₅Cl₂NO₅, (II), both crystallize in the monoclinic space group P2₁/n. They differ essentially in the orientation of the methyl acetate group, with the C=O bond directed towards the NO₂ group in (I) but away from it in (II). In compound (I), the mean plane of the methyl acrylate unit is planar, with a maximum deviation of 0.0044 (2) Å for the methyl C atom, while in (II) this deviation is 0.0147 Å. The inter­planar angles between the two aromatic rings are 74.87 (9) and 75.65 (2)° for compounds (I) and (II), respectively. In both compounds, the methyl acrylate and nitro­vinyl groups each adopt an E conformation about the C=C bond. In the crystal of (I), mol­ecules are linked by C—H⋯O hydrogen bonds forming chains along the b axis. The chains are linked via C—H⋯Cl hydrogen bonds, forming sheets parallel to the ab plane. The sheets are linked via C—H⋯π inter­actions, forming a three-dimensional structure. In the crystal of (II), mol­ecules are linked by pairs of C—H⋯O hydrogen bonds, forming inversion dimers with an R₂²(30) ring motif. The dimers are linked via C—H⋯O hydrogen bonds, forming sheets parallel to the ac plane and enclosing R₄⁴(28) ring motifs. The sheets are linked via parallel slipped π–π inter­actions (inter­centroid distances are both ca 3.86 Å), forming a three-dimensional structure.

Synthetic investigation on chirally pure Mannich derivatives of pseudophenylpropanolamine and their anticancer properties against HepG-2 cells with inhibition of JAK2/STAT3

In vitro and in vivo anticancer activity of compound 3a was proved as a novel blocker of JAK2/STAT3 signaling pathway and exerts both anti-proliferative and apoptotic activities in HepG-2 cells with xenograft mice model.

Crystal structure of 5-(5-chloro-2-hydroxy-benzo-yl)-2-(2-methyl-1H-indol-3-yl)nicotino-nitrile

In the title compound, C₂₂H₁₄ClN₃O₂, the indole unit is essentially coplanar, with a maximum deviation of 0.035 Å for the C atom bearing the methyl group. The central pyridine ring is inclined to the indole ring system by 43.7 (1)°. The dihedral angle between the phenyl ring and the indole ring system is 15.7 (2)°, while that between the phenyl ring and the central pyridine ring is 46.3 (1)°. The mol­ecular structure is stabilized by an intra­molecular O—H⋯O hydrogen bonding, forming an S(6) ring motif. In the crystal, mol­ecules are linked via pairs of N—H⋯N hydrogen bonds, forming inversion dimers with an R₂²(16) ring motif. The crystal structure also features C—H⋯π and π–π inter­actions [centroid–centroid separation = 3.688 (1) Å].

In vitro anticancer activity of methyl caffeate isolated from Solanum torvum Swartz. fruit

The present study was undertaken to investigate the anticancer activity of methyl caffeate isolated from Solanum torvum Swartz. fruit and to explore the molecular mechanisms of action in MCF-7 cells. Cytotoxic properties of hexane, ethyl acetate and methanol extracts were carried out against MCF-7 cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Ethyl acetate extract showed good cytototoxic activities compared to hexane and methanol extracts. Methyl caffeate was isolated from the ethyl acetate extract using column chromatography. Cytotoxic properties of methyl caffeate was investigated against MCF-7, A549, COLO320, HepG-2 and Vero cells. The compound showed potent cytotoxic properties against MCF-7 cells compared to A549, COLO320 and HepG-2 cells. Methyl caffeate significantly reduced cell proliferation and increased formation of fragmented DNA and apoptotic body in MCF-7 cells. Bcl-2, Bax, Bid, p53, caspase-3, PARP and cytochrome c release were detected by western blot analysis. The activities of caspases-3 and PARP gradually increased after the addition of isolated compound. Bcl-2 protein was down regulated; Bid and Bax were up regulated after the treatment with methyl caffeate. Molecular docking studies showed that the compound bound stably to the active sites of poly (ADP-ribose) polymerase-1 (PARP1), B cell CLL/lymphoma-2 (BCL-2), E3 ubiquitin-protein ligase (MDM2) and tubulin. The results strongly suggested that methyl caffeate induced apoptosis in MCF-7 cells via caspase activation through cytochrome c release from mitochondria.

Synthesis of BF₃ catalyzed Mannich derivatives with excellent ee from phenylpropanolamine, study of their antimicrobial activity and molecular docking

Antimicrobial agents 4a-g and 5a-g with very good potency were synthesized with 100% ee from phenylpropanolamine (norephedrine) by BF3 catalyzed three components one pot Mannich reaction in good yields. Obtained compounds were characterized using spectral techniques. Antimicrobial study of these compounds revealed a good to very high potential activity against tested microbes when compared to standard antimicrobial drugs streptomycin and ketoconazole. These synthesized compounds exhibited significant minimum inhibitory concentration (MIC) values against Gram positive and Gram negative bacteria. Amongst compound 4b, 4c, 4d, 4e, 5a, and 5e exhibited very high potent MIC values against tested twelve bacteria and three fungi when compared to control. When subjected to molecular docking, in silico studies revealed significant binding energies ranging from -7.06 to -8.90 kcal/mol for all obtained compounds towards target receptor DNA topoisomerase IV and amongst compounds 4b and 4d have shown maximum binding energies 8.70 and 8.90 kcal/mol, respectively.

Crystal structure of 1'-(prop-2-yn-1-yl)-1,4-di-hydro-spiro-[benzo[d][1,3]oxazine-2,3'-indolin]-2'-one

In the title compound, C₁₈H₁₄N₂O₂, the six-membered oxazine ring adopts a half-chair conformation and its mean plane makes a dihedral angle of 83.23 (7)° with the pyrrolidine ring of the indoline ring system. In the crystal, mol­ecules are linked via N—H⋯O hydrogen bonds, forming chains along [100]. The chains are linked by C—H⋯π inter­actions, forming slabs parallel to (001).

Synthesis of novel 1,4-disubstituted 1,2,3-triazolo-bosentan derivatives – evaluation of antimicrobial and anticancer activities and molecular docking

One pot synthesis with good yields. Good antimicrobial activity against 4EMV receptor. Prominent anticancer activity against A549 and SKOV-3 cell lines. Significantin vitrocytotoxicity at 7.81 μg mL⁻¹. Docking mode of1hwith 2XP2 receptor.

Cu(OTf)2 catalyzed three component strategy for the synthesis of thienopyridine containing spirooxindoles and their cytotoxic evaluation

Compound 5v docked in caspase-3 (−10.5 kcal mol⁻¹).

An expedient route to highly diversified [1,2,3]triazolo[1,5-a][1,4]benzodiazepines and their evaluation for antimicrobial, antiproliferative and in silico studies

A simple and facile synthesis of a series of diversified [1,2,3]triazolo[1,5-a][1,4]benzodiazepines has been achieved successfully via a one-pot method under milder conditions and evaluated for their biological activity.

Synthesis of new class of spirocarbocycle derivatives by multicomponent domino reaction and their evaluation for antimicrobial, anticancer activity and molecular docking studies

A series of 25 new spirocarbocycles were synthesized by a three component reaction that involves few cyclic nucleophiles, vinyl malononitriles and aldehydes with variable substitution patterns. All the synthesized compounds were evaluated for their antimicrobial activity and the compounds showed significant activity. Synthesized compounds 4c, 4i and 6i showed good anticancer activity against A549 cancer cell line. Molecular docking studies indicated that compound 4i had the greatest affinity for DNA gyrase receptor than others and compound 6i had the greatest affinity for anaplastic lymphoma kinase (ALK) receptor. These compounds can be better therapeutic agents for microbial and cancer cell lines.

Synthesis, antimicrobial and molecular docking studies of enantiomerically pure N-alkylated β-amino alcohols from phenylpropanolamines

Enantiomerically pure N-alkylated β-amino alcohols 1a, 1a', 1c, 1c', 1d, 1d', 1e and 1e', with ee 100% have been synthesized from phenylpropanolamines 2. Effect of the neighboring chiral environment on the newly formed chiral center has been studied experimentally and concluded that the newly formed chiral center's absolute configuration is opposite to the adjacent (α- or β-) chiral environment. The antimicrobial activity of the synthesized β-amino alcohols were screened using in vitro disc diffusion method and variable antimicrobial activities were shown for 1a, 1a', 1c, 1c', 1d, 1d', 1e &1e' and amongst them 1d &1d' exhibited significant activity against bacteria and fungi. In silico studies revealed all the synthesized β-amino alcohols 1a-e and 1a'-e' have shown good binding energies ranging from -7.38 to -6.09 kJ/mol towards the target receptor DNA topoisomerase IV and 1d' has shown maximum binding energy -7.38 kJ/mol.

Methyl 4-(4-bromo-anilino)-2',5-dioxo-5H-spiro-[furan-2,3'-indoline]-3-carboxyl-ate

In the title compound, C₁₉H₁₃BrN₂O₅, the spiro furan ring is almost planar with a maximum deviation of 0.034 (2) Å. The indole unit and the furan ring are normal to each other, making a dihedral angle of 87.82 (8) °. The mol­ecular structure is stabilized by an intra­molecular N—H⋯O hydrogen bond, which generates an S(6) ring motif. In the crystal, mol­ecules are linked via pairs of N—H⋯O hydrogen bonds, forming inversion dimers enclosing R²₂(8) ring motifs.

DNA binding, molecular docking and apoptotic inducing activity of nickel(ii), copper(ii) and zinc(ii) complexes of pyridine-based tetrazolo[1,5-a]pyrimidine ligands

The biological activity of metal(ii) complexes of tetrazolo[1,5-a]pyrimidine ligands show that the copper(ii) complexes may act as promising anticancer agents.

Methyl 4-anilino-2',5-dioxo-1',2'-di-hydro-5H-spiro-[furan-2,3'-indole]-3-carboxyl-ate

In the title compound, C₁₉H₁₄N₂O₅, the spiro junction links an oxindole moeity and a furan ring, which subtend a dihedral angle of 83.49 (6)°. The mol­ecular structure features an N—H⋯O hydrogen bond, which generates an S(6) ring motif. The crystal packing is governed by two N—H⋯O inter­actions, one of which generates a centrosymmetric R₂²(14) dimer. The other N—H⋯O inter­action along with a C—H⋯O hydrogen bond contributes to the formation of a C₂²[R₂²(9)] dimeric chain running along the b-axis direction.

5-(3-Meth-oxy-phen-yl)-3-phenyl-1,2-oxazole

In the title compound, C16H13NO2, the isoxazole ring makes dihedral angles of 17.1 (1)° with the 3-meth-oxy-phenyl ring and 15.2 (1)° with the phenyl group. Centrosymmetric dimers that are realised by pairs of C-H⋯π inter-actions are observed in the crystal structure.

Diethyl [(2-chloroanilino)(1,3-diphenyl-1H-pyrazol-4-yl)methyl]phosphonate

In the title compound, C₂₆H₂₇ClN₃O₃P, the mean plane of the central pyrazole ring forms a dihedral angle of 71.37 (14)° with the chloro­phenyl ring. In the crystal, mol­ecules are linked by pairs of N—H⋯O hydrogen bonds, forming inversion dimers with R²₂(10) ring motifs. The 3-phenyl ring is disordered with four C atoms occupying two sets of sites with an occupancy ratio of 0.748 (4):0.252 (4).

1′-Butyl-2-methyl-1′,2,2′,3,4,9-hexahydrospiro[benzo[f]isoindole-1,3′-indole]-2′,4,9-trione

In the title compound, C₂₄H₂₂N₂O₃, the indoline and pyrrole-fused naphtho­quinone units are both essentially planar [r.m.s. deviations = 0.042 (3) and 0.133 (3) Å, respectively]. The pyrrole ring adopts a C-envelope conformation. The dihedral angle between the mean planes of the two five-membered rings is 89.94 (9)°. The O atoms deviate from the mean planes of the pyrrolidine and naphthalene rings by 0.0311 (2), 0.2570 (2) and 0.1669 (2) Å. In the crystal, C—H⋯O inter­actions generate dimers with R₂²(16) and R₂²(18) graph-set motifs. The carbonyl O atom is involved in bifurcated hydrogen bonding. C—H⋯π inter­actions also occur.

3-(1,2-Di-p-tolylvinyl)-2-methyl-1H-indole

In the title compound, C25H23N, the indole unit makes a dihedral angles of 79.03 (5) and 61.82 (4)° with the benzene rings. No classical hydrogen bonds are found in the crystal structure.

Diethyl [(2-bromoanilino)(1,3-diphenyl-1H-pyrazol-4-yl)methyl]phosphonate

In the title compound, C₂₆H₂₇BrN₃O₃P, the central pyrazole ring forms a dihedral angle of 71.7 (2)° with the bromo­phenyl ring. In the crystal, mol­ecules are linked by pairs of N—H⋯O hydrogen bonds, forming inversion dimers with R₂²(10) ring motifs. Four C atoms of the 3-phenyl ring are disordered over two sets of sites [site occupancies = 0.745 (6) and 0.225 (6)].

(E)-3-Phenyl-2-(1-tosyl-1H-indol-3-ylcarbonyl)acrylonitrile

In the title compound, C₂₅H₁₈N₂O₃S, the indole moiety is planar and makes a dihedral angle of 89.95 (09)° with the phenyl ring of the sulfonyl substituent. The mol­ecular conformation features a weak C—H⋯N short contact and the crystal packing reveals a weak C—H⋯O hydrogen bond.

2-Iodo-3-(4-meth-oxy-anilino)-5,5-dimethyl-cyclo-hex-2-en-1-one

The cyclo­hexene ring in the title compound, C₁₅H₁₈INO₂, adopts a sofa conformation. The dihedral angle between the cyclo­hexene (through all ring atoms) and benzene rings is 63.3 (1)°. The mol­ecular conformation features an N—H⋯I short contact and the crystal packing features C—H⋯O hydrogen bonds.

Ethyl 2-benzyl-3-[3-(4-chloro-phen-yl)-1-phenyl-1H-pyrazol-4-yl]-4,6-dioxo-5-phenyl-octa-hydro-pyrrolo-[3,4-c]pyrrole-1-carboxyl-ate

The title compound, C(37)H(31)ClN(4)O(4), crystallizes with two mol-ecules (A and B) in the asymmetric unit. The pyrrole rings in both mol-ecules are connected via cis fusion, whereas one ring has a twisted conformation and the other assumes a half-chair conformation. In the crystal, the A mol-ecules form inversion dimers via a pair of C-H⋯Cl inter-actions, while the B mol-ecules form chains propagating in [1[Formula: see text]0], via C-H⋯O inter-actions. In the crystal, there are also a number of C-H⋯π inter-actions present.

5-Methoxy-3-[(5-methoxy-1H-indol-3-yl)(phenyl)methyl]-1H-indole

In the title compound, C₂₅H₂₂N₂O₂, the indole rings are individually almost planar [with maximum deviations of 0.0116 (19) and 0.0113 (18) Å] and are almost orthogonal to each other, making a dihedral angle of 84.49 (6)°. The benzene ring is inclined at 72.83 (9) and 80.85 (9)° with respect to the indole rings. In the crystal, mol­ecules are linked by N—H⋯O inter­actions into chains running parallel to the c axis. The crystal structure is further stabilized by C—H⋯π inter­actions.

2-Methyl-3-{2-nitro-1-[2-(prop-2-yn-1-yl-oxy)phen-yl]eth-yl}-1H-indole

In the title compound, C₂₀H₁₈N₂O₃, the indole unit is essentially planar, with a maximum deviation of 0.0197 (18) Å for the N atom and forms a dihedral angle of 78.09 (9)° with the propyne-subsituted phenyl ring. The propyne group is almost linear, the C—C C angle being 176.5 (2)°, and is also in the flagpole position on the O atom. In the crystal, mol­ecules are linked via N—H⋯O and C—H⋯O inter­molecular hydrogen bonds involving the nitro-group O atoms as acceptors.

5-(3-Methyl-phen-yl)-3-phenyl-1,2-oxazole

In the title compound, C₁₆H₁₃NO, the isoxazole ring makes dihedral angles of 16.64 (7)° with 3-methyl­phenzyl ring and 17.60 (7)° with the unsubstituted phenyl ring.

cis-6-Bromo-4-(1-methyl-1H-indol-3-yl)-10,10a-dihydro-1H,4H-2,9-dioxa-3-aza-benz[f]azulene

In the title compound, C(20)H(17)BrN(2)O(2), the seven-membered oxepine ring adopts a chair conformation. The indole moiety is essentially planar with a maximum deviation of 0.031 (3)Å. The indole ring system forms a dihedral angle of 21.87 (8)° with the mean plane of the 10-membered heterobicycle. The crystal packing is stabilized by inter-molecular C-H⋯O and C-H⋯π inter-actions.

3-(1,2-Diphenylethenyl)-2-phenyl-1H-indole

In the title compound, C₂₈H₂₁N, the planar pyrrole ring makes dihedral angles of 1.5 (2), 42.4 (2), 65.4 (2) and 79.7 (1)°, with the least squares planes of the four phenyl rings. The mol­ecular structure and crystal packing are stabilized by weak inter- and intra­molecular C—H⋯π inter­actions.

5-Chloro-3-[(E)-1,2-diphenylethenyl]-1H-indole

In the title compound, C₂₂H₁₆ClN, the pyrrole system makes a dihedral angle of 68.9 (1)° with the plane of phenyl ring at the ethenyl 1-position. An intra­molecular C—H⋯π inter­action is observed. In the crystal, inter­molecular C—H⋯π inter­actions link the mol­ecules into infinite chains running along the b axis.

1-Benzyl-3-(1,2-diphenylethenyl)-1H-indole

In the title compound, C₂₉H₂₃N, the planar [maximum deviation from the least squares plane = 0.056 (1) Å] indole ring makes dihedral angles of 83.4 (4), 69.9 (1) and 59.9 (1)°, with the least-squares planes of three benzene rings. The mol­ecular packing is stabilized by weak inter­molecular C—H⋯π inter­actions.

Synthesis, antibacterial activity evaluation and QSAR studies of novel dispiropyrrolidines

A series of novel dispiropyrrolidines have been synthesized through 1,3-dipolar cycloaddition of an azomethine ylide generated from sarcosine and isatin with the dipolarophile 3-benzylidene-1-methyl-pyrrolidine-2,5-dione. Their antibacterial activity was evaluated against Bacillus subtilis NCIM 2718, Staphylococcus aureus NCIM5021, Salmonella typhi NCIM2501, Pseudomonas aeruginosa NCIM 5029 and Proteus vulgaris NCIM2813 by two fold dilution method. Compound 6e exhibits reasonably good activity and compound 6c exhibits poor activity against all the organisms. The QSAR's were developed for all antibacterial activities. The models had either one or two descriptors (r2 = 0.81-0.97, , q2 = 0.57-0.92, F-ratio = 12.73-162.76). Topology, shape, charge distribution and hydrophobic nature of the molecules had pronounced effect on their antibacterial activity.

tert-Butyl 3-(8-bromo-4H,10H-1,2-oxazolo[4,3-c][1]benzoxepin-10-yl)-2-methyl-1H-indole-1-carboxyl-ate

In the title compound, C₂₅H₂₃BrN₂O₄, the seven-membered ring adopts a twisted-boat conformation. The indole ring system is planar within 0.021 (2) Å and the ester group [–C(=O)—O—C–] is almost coplanar with it [dihedral angle = 3.0 (2)°]. The conformation of the ester group is influenced by intra­molecular C—H⋯O inter­actions. In the crystal structure, mol­ecules are linked into chains along the b axis by C—H⋯N hydrogen bonds.

Synthesis, antibacterial activity evaluation and QSAR studies of novel dispiropyrrolidines

A series of novel dispiropyrrolidines have been synthesized through 1,3-dipolar cycloaddition of an azomethine ylide generated from sarcosine and isatin with the dipolarophile 3-benzylidene-1-methyl-pyrrolidine-2,5-dione. Their antibacterial activity was evaluated against Bacillus subtilis NCIM 2718, Staphylococcus aureus NCIM5021, Salmonella typhi NCIM2501, Pseudomonas aeruginosa NCIM 5029 and Proteus vulgaris NCIM2813 by two fold dilution method. Compound 6e exhibits reasonably good activity and compound 6c exhibits poor activity against all the organisms. The QSAR's were developed for all antibacterial activities. The models had either one or two descriptors (r(2) = 0.81-0.97, r(adj)(2)=0.75-0.96, q(2) = 0.57-0.92, F-ratio = 12.73-162.76). Topology, shape, charge distribution and hydrophobic nature of the molecules had pronounced effect on their antibacterial activity.

Diethyl 2-oxo-3-(2-oxo-2,3-dihydro-1H-indol-3-yl-idene)butane-dioate

The title compound, C(16)H(15)NO(6), crystallizes with two symmetry-independent mol-ecules in the asymmetric unit. The crystal structure is stabilized by inter-molecular C-H⋯O and N-H⋯O hydrogen bonds, and intra-molecular C-H⋯O hydrogen bonds. In addition, the crystal structure exhibits two inter-molecular C-H⋯π inter-actions.

3-(6-Benz-yloxy-2,2-dimethyl-perhydro-furo[2,3-d][1,3]dioxolan-5-yl)-5-(4-chloro-phen-yl)-4-nitro-2-phenyl-2,3,4,5-tetra-hydro-isoxazole

In the title compound, C₂₉H₂₉ClN₂O₇, the isoxazole and dioxolane rings adopt envelope conformations, and the furan ring adopts a twisted conformation. The crystal structure is stabilized by inter­molecular C—H⋯π inter­actions between a benz­yloxy methyl­ene H atom and the 4-chloro­phenyl ring of an adjacent mol­ecule, and by weak non-classical inter­molecular C—H⋯O hydrogen bonds. In addition, the crystal structure exhibits a Cl⋯O halogen bond of 3.111 (3) Å, with a nearly linear C—Cl⋯O angle of 160.7 (1)°.

4'-(4-Methoxy-phen-yl)-1,1',1''-trimethyl-dispiro-[indoline-3,2'-pyrrolidine-3',3''-pyrrolidine]-2,2'',5''-trione

In the title compound, C(24)H(25)N(3)O(4), the pyrrolidine ring adopts an envelope conformation while the pyrrolidine-2'',5''-dione ring adopts a twist conformation. The indoline unit is planar [maximum deviation of -0.050 (9) Å] and forms a dihedral angle of 40.36 (4)° with the methoxy-phenyl ring. Intra-molecular C-H⋯O hydrogen bonds are observed. In the crystal, mol-ecules are linked into a two-dimensional network parallel to the ab plane by inter-molecular C-H⋯O hydrogen bonds and C-H⋯π inter-actions.