Sub 1 nm Poly(acrylic acid)-Capped Copper Nanoparticles for the Synthesis of 1,2,3-Triazole Compounds.

The stable, water-soluble, and fluorescent sub 1 nm sized poly(acrylic acid)-capped copper nanoparticles (PAACC NPs) were synthesized using a high-intensity ultrasound sonication (30 KHz) method. The reduction of copper NPs from copper(II) salt by mild reducing agent l-ascorbic acid in an aqueous medium was achieved in the presence of poly(acrylic acid). The PAACC NPs were characterized by DRS UV-visible, XPS, PL, FESEM, and HRTEM techniques. The resulting PAACC NPs show orange fluorescence with a peaking center at 560 nm. The PAACC NPs serve as effective catalysts for the synthesis of 1,2,3-triazoles via click reaction in good yields under mild reaction conditions.

Regio- and stereoselective synthesis of spiropyrrolidine-oxindole and bis-spiropyrrolizidine-oxindole grafted macrocycles through [3 + 2] cycloaddition of azomethine ylides.

A convenient and efficient method for the regioselective macrocyclization of triazole bridged spiropyrrolidine-oxindole, and bis-spiropyrrolizidine-oxindole derivatives was accomplished through intra and self-intermolecular [3 + 2] cycloaddition of azomethine ylides. The chalcone isatin precursors 9a-i required for the click reaction were obtained from the reaction of N-alkylazidoisatin 4 and propargyloxy chalcone 8a-i which in turn were obtained by the aldol condensation of propargyloxy salicylaldehyde 6 and substituted methyl ketones 7a-i. The regio- and stereochemical outcome of the cycloadducts were assigned based on 2D NMR and confirmed by single crystal XRD analysis. High efficiency, mild reaction conditions, high regio- and stereoselectivity, atom economy and operational simplicity are the exemplary advantages of the employed macrocyclization procedure.

Synthesis and DSSC application of BODIPY decorated triazole bridged and benzene nucleus cored conjugated dendrimers.

Conjugated dendrimers decorated with 5,5-difluoro-10-(4-(prop-2-ynyloxy)phenyl)-5H-dipyrrolo[1,2-c:1',2'-f][1,3,2]diazaborinin-4-ium-5-uide, usually known as boron dipyrromethene (BODIPY), have been synthesized and their application as photosensitizer in dye sensitized solar cells (DSSCs) has been evaluated. Third generation triazole bridged BODIPY dendrimers show higher light energy harvesting efficiency of 2.5% better than the first and second generation dendrimers, when used as a dye material in solar cells. The current intensity increases with an increase in the generation of the dendrimer as revealed by cyclic voltammetry. Fluorescence decay analysis shows that the relaxation times τ 1 and τ 2 increase as the dendrimer generation increases, however τ 2 for the third generation dendrimer decreases because of fluorescence quenching due to molecular crowding.

Discovery of new potential triplet acting inhibitor for Alzheimer's disease via X-ray crystallography, molecular docking and molecular dynamics.

The most common brain disorder of late life is Alzheimer's disease (AD), which is highly complicating dementia. There are several drug targets which are reported to control the severe level of AD; notably, acetylcholinesterase, ß-Secretase and glycogen synthase kinase enzymes are approached as a good drug targets for AD. Hence, the present study mainly focused to discover newly synthesized molecule (7-propyl-6H-pyrano[3,2-c:5,6-c']dichromene-6,8(7H)-dione) as a potential triplet acting drug for above said enzymes through the analysis of X-ray crystallography, molecular docking, molecular dynamics and quantum chemical calculation. The target drug molecule was crystallized in the monoclinic crystal structure with P21/n space group. The structure was solved by SHELXS and refined by SHELXL. The crystal packing is stabilized by C - H···O type of interactions. Further, the induced fit docking shows that the molecule has high docking score, glide energy, favorable hydrogen bonding and hydrophobic interactions on the protein targets. The molecular dynamics simulation was performed to understand the stability of the molecule in the presence of active site environment. Finally, quantum chemical calculation has been carried out for the molecule in gas phase and for the corresponding molecule lifted from the active site region. The structural comparison between gas phase and active site helps to understand the conformational modification of the molecule in the active site. Communicated by Ramaswamy H. Sarma.

Synthesis, optical, electrochemical properties and anticancer activity of (S)-BINOL cored triazole bridged dendrimers decorated with rhodamine B surface group.

(S)-BINOL cored dendrimers 1-3 with a rhodamine B surface group and triazole bridging unit were synthesized up to second generation in good yield by convergent synthesis through click chemistry. The chiro-optical property of the synthesized dendrimers reveals that the specific rotation increases as the order of dendrimer increases from the zeroth generation to the second generation dendrimer. The electrochemical properties of the dendrimers 1, 2 and 3 showed quasi-reversible behavior in cyclic voltammetry. The anticancer activity against human hepatocellular carcinoma cell for the second generation dendrimer 3 was found to be better than that for the lower generation dendrimers 1 and 2.

Crystal structures of three 1-[4-(4-bromo-but-oxy)-phen-yl] chalcone derivatives: (E)-1-[4-(4-bromo-but-oxy)-phen-yl]-3-phenyl-prop-2-en-1-one, (E)-1-[4-(4-bromo-but-oxy)-phen-yl]-3-(4-meth-oxy-phen-yl)prop-2-en-1-one and (E)-1-[4-(4-bromo-but-oxy)-phen-yl]-3-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one.

The crystal structures of three chalcones with a bromo-substituted but-oxy side chain, viz. (E)-1-[4-(4-bromo-but-oxy)-phen-yl]-3-phenyl-prop-2-en-1-one, C19H19BrO2, (I), (E)-1-[4-(4-bromo-but-oxy)-phen-yl]-3-(4-meth-oxy-phen-yl)prop-2-en-1-one, C20H21BrO3, (II), and (E)-1-[4-(4-bromo-but-oxy)-phen-yl]-3-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one, C21H23BrO4, (III), are reported. In all mol-ecules, the conformation of the keto group with respect to the olefinic bond is s-cis. Mol-ecules of (I) and (II) are nearly planar, while mol-ecule (III) is not planar. In the crystal of compounds (I) and (II), mol-ecules are linked into chains parallel to the c axis by C-H⋯π inter-actions. In the crystal of compound (III), mol-ecules are linked by a pairs of C-H⋯O hydrogen bonds, forming inversion dimers. Weak C-Br⋯π inter-actions are also observed in (III).

Synthesis and anticancer activity of bile acid dendrimers with triazole as bridging unit through click chemistry.

Triazole-based novel dendrimers with bile acid surface groups have been synthesized through click chemistry by divergent approach and characterized by spectral data. All the dendrimers exhibit excellent anticancer activity. Higher-generation dendrimers exhibit better anticancer activity than the lower-generation dendrimers.

Crystal structure of 2,2'-bis-[(2-chloro-benz-yl)-oxy]-1,1'-bi-naphthalene.

In the title binaphthyl compound, C34H24Cl2O2, the dihedral angle between the two naphthyl ring systems (r.m.s. deviations = 0.016 and 0.035 Å) is 76.33 (8)°. The chloro-phenyl rings make dihedral angles of 58.15 (12) and 76.21 (13)° with the naphthyl ring to which they are linked. The dihedral angle between the planes of the two chloro-phenyl rings is 27.66 (16)°. In the crystal, C-H⋯O hydrogen bonds link mol-ecules into chains propagating along [1-10]. The chains are linked by C-H⋯π inter-actions, forming a three-dimensional framework.

Crystal structure of bis-(prop-2-yn-1-yl) 5-nitro-isophthalate.

The whole mol-ecule of the title compound, C14H9NO6, is generated by twofold rotation symmetry; the twofold axis bis-ects the nitro group and the benzene ring. The nitro group is inclined to the benzene ring by 14.42 (9)°. The prop-2-yn-1-yl groups are inclined to the benzene ring by 13 (2)° and to each other by 24 (3)°; one directed above the plane of the benzene ring and the other below. In the crystal, mol-ecules are linked via pairs of C-H⋯O hydrogen bonds, forming inversion dimers with an R 2 (2)(18) ring motif. The dimers are linked by further C-H⋯O hydrogen bonds, forming sheets lying parallel to (100).

Investigation of Optical Spectroscopic and Computational Binding Mode of Bovine Serum Albumin with 1, 4-Bis ((4-((4-Heptylpiperazin-1-yl) Methyl)-1H-1, 2, 3-Triazol-1-yl) Methyl) Benzene.

A newly synthesized 1, 4-bis ((4-((4-heptylpiperazin-1-yl) methyl)-1H-1, 2, 3-triazol-1-yl) methyl) benzene from the family of piperazine derivative has good anticancer activity, antibacterial and low toxic nature; its binding characteristics are therefore of huge interest for understanding pharmacokinetic mechanism of the drug. The binding of piperazine derivative to bovine serum albumin (BSA) was investigated using fluorescence spectroscopy. The molecular distance r between the donor (BSA) and acceptor (piperazine derivative) was estimated according to Forster's theory of nonradiative energy transfer. The physicochemical properties of piperazine derivative, which induced structural changes in BSA, have been studied by circular dichroism and those chemical environmental changes were probed using Raman spectroscopic analysis. Further, the binding dynamics was expounded by synchronous fluorescence spectroscopy and molecular modeling studies explored the hydrophobic interaction and hydrogen bonding results, which stabilize the interaction.

Synthesis and photophysical, electrochemical, antibacterial, and DNA binding studies of triazinocalix[2]arenes.

Oxygen bridged highly functionalized novel calix[2]arene[2]triazine derivatives were synthesized from 2,6-pyridinedimethanol and cyanuric chloride. All the synthesized oxacalixarenes showed an absorbance band between 315-339 nm and two emission bands at 269-272 nm and 289-339 nm. All the oxacalixarenes exhibited quasireversible oxidation reduction signals in cyclic voltammetry. The binding properties of the oxacalixarenes towards calf thymus DNA (CT-DNA) were investigated by viscosity measurements, UV-VIS and circular dichorism studies and the oxacalixarenes possess comparable antibacterial activity against B. cereus, S. aureus and E. coli as supported by docking studies.

An amide cyclo-phane.

The title compound, 8,18-dithia-2,6-diaza-13(1,4)-piperidina-1(1,2),4(1,3),7(1,2)-tribenzenaoctadecaphane-10,15-diyne-3,6-dione, C32H30N4O2S2, is composed of a relatively planar bis-(2-mercaptophen-yl)isophthalamide unit linked to a bridging 1,4-di(but-2-yn-1-yl)piperazine unit, forming a macrocycle. The isophthalamide ring is inclined to the outer mercaptophenyl rings by 8.18 (11) and 5.59 (10)°, while these two rings are inclined to one another by 9.10 (12)°. The piperazine ring adopts a chair conformation. There are two intra-molecular N-H⋯S hydrogen bonds generating S(5) ring motifs. In the crystal, mol-ecules are linked via C-H⋯S and C-H⋯O hydrogen bonds, forming slabs lying parallel to (001). An O atom in the isophthalamide group is disordered over two positions with an occupancy ratio of 0.41 (6):0.59 (6).

Synthesis and cardio protective biological applications of glucodendrimers by H9C2 cell studies.

Novel glucodendrimers scaffolds containing α-d-glucopyranoside at the surface and triazole as bridging unit have been synthesized. Cardiomyocytes were exposed to normal and high glucose level in the presence and absence of glucodendrimers. Cytotoxicity studies were also carried out and the expression of metalloproteinases mainly MMP-2 and 9 was confirmed with gelatine zymography and RT-PCR gene expression studies. Cardio protective efficiency of the synthesized glucodendrimers against high glucose induced toxicity on mettalloproteinase-2 and 9 and also on H9C2 cell lines revealed that higher generation glucodendrimers 6 and 8 are more effective than the lower generation glucodendrimers.

Methyl 3,5-bis-[(3-chloro-pyrazin-2-yl)-oxy]benzoate.

In the title compound, C16H10Cl2N4O4, the pyrazine rings make dihedral angles of 67.82 (9) and 75.91 (9)° with the benzene ring, while the dihedral angle between the pyrazine rings is 44.69 (10)°. The meth-oxy-carbonyl group makes a dihedral angle of 16.82 (8)° with the benzene ring to which it is attached. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules, forming chains running along the ab plane.

8,15-Dioxa-10,13-di-aza-tetra-cyclo-[14.4.0.0(2,7).0(9,14)]icosa-1(16),2,4,6,9(14),10,12,17,19-nona-ene.

The asymmetric unit of the title compound, C16H10N2O2, contains one half-mol-ecule, the complete mol-ecule being generated by twofold rotation symmetry. The plane of the pyrazine ring forms a dihedral angle of 64.87 (6)° with that of the benzene ring, and the planes of the two benzene rings are inclined to one another by 54.20 (6)°. The O atom deviates from the plane of the benzene ring by 0.1549 (8) Å. There are no significant inter-molecular inter-actions in the crystal.

1,3-Bis[(3-chloro-pyrazin-2-yl)-oxy]benzene.

The asymmetric unit of the title compound, C14H8Cl2N4O2, contains one half-mol-ecule, the complete mol-ecule being generated by the operation of a twofold rotation axis. The Cl atom deviates significantly from the plane of the pyrazine ring [0.0215 (4) Å]. The central benzene ring makes a dihedral angle of 72.82 (7)° with the plane of the pyrazine ring.

1,4-Bis(3-chloro-pyrazin-2-yl-oxy)benzene.

In the title compound, C14H8Cl2N4O2, the pyrazine rings are orthogonal to the benzene ring, making dihedral angles of 88.42 (8) and 89.22 (8)°. The Cl atoms attached to the pyrazine rings deviate by -0.0597 (5) and 0.0009 (5) Šfrom the ring plane. The crystal structure features C-H⋯N hydrogen bonds.

(E)-1-(5-Iodo-thio-phen-2-yl)-3-(3,4,5-trimeth-oxy-phen-yl)prop-2-en-1-one.

In the title compound, C(16)H(15)IO(4)S, the dihedral angle between the thio-phene and benzene rings is 11.50 (2)°. The methoxy O atoms deviate by 0.0060 (2), -0.1319 (2) and 0.0426 (2) Šfrom the phenyl ring plane. The crystal packing features C-H⋯O hydrogen bonds, which link the molecules into C(11) chains propagating in [100xxx].

Synthesis, study on anti-arthritic, anti-inflammatory activity and toxicity of some novel bis-oxy cyclophane diamides.

A series of bis-oxy cyclophane diamides with bis(aminomethyl)m-terphenyl as spacer have been synthesized and characterized from spectral and analytical data. All the cyclophane diamides exhibit better anti-arthritic activity than the reference drug viz. diclofenac sodium. Some of the cyclophane diamides exhibit good anti-inflammatory activity. The cyclophane amide 4 and 5 do not show any evidence of mutagenicity and cytotoxicity.

Synthesis and in-vitro anti-inflammatory activity of novel glycodendrimers with benzene 1,3,5 carboxamide core and triazole as branching unit.

Novel glycodendrimers scaffolds containing twelve and eighteen α-D-glycopyranoside at the periphery and triazole as branching unit have been synthesized using click chemistry. Higher generation dendrimers exhibit better anti-inflammatory activity than the lower generation due to the presence of more triazole branching units and multivalent glycopyranoside units.