Can lines of C−2 be observed in carbon stars?

A²Π_u-X¹²Σ⁺_g lines of C^?₂ should be observable in the infrared spectra of carbon stars. A positive identification awaits laboratory spectroscopic data on this ion.     

Ultrasonic absorption studies in the cholesteric and isotropic phases of cholesteryl valerate

Ultrasonic absorption has been measured in the cholesteric and isotropic phases of cholesteryl valerate as a function of both temperature and frequency. The anomalous absorption observed in the cholesteric phase has been interpreted by considering the coupling of the sound wave to the director fluctuations. In the isotropic phase coupling of the sound wave to the tensor order parameter is considered to analyse the absorption results.     

Spectroscopic studies on Co(II), Ni(II), Cu(II) and Zn(II) complexes with a N4-macrocylic ligands

Complexes of cobalt(II), nickel(II), copper(II) and zinc(II) with a new tetraaza macrocyclic ligand have been synthesized and characterized by microanalyses, molar conductance, magnetic susceptibility, mass, thermogravimetric (TGA), IR, 1H and 13C NMR, electronic and ESR spectral studies. All the complexes are found to have the formula [MLX2]x nH2O and are six-coordinated with distorted octahedral geometry.     

Two quinazolinones: a ring conformational study

The molecules of (±)‐2‐(4‐methoxyphenyl)‐1‐phenethyl‐2,3‐dihydroquinazolin‐4(1H)‐one, C₂₃H₂₂N₂O₂, (I), and (±)‐2‐(1,3‐benzodioxol‐5‐yl)‐1‐phenethyl‐2,3‐dihydroquinazolin‐4(1H)‐one, C₂₃H₂₀N₂O₃, (II), have T‐shaped forms in the crystal structure. The tetrahydropyrimidine ring in both structures adopts a sofa conformation. Both molecules are linked by N—H...O and C—H...O hydrogen bonds to form sheets built from alternating R₂²(8) and R₄⁴(26) [R₄⁴(24) in (II)] edge‐fused rings. Additionally, the structures are stabilized by extensive C—H...π interactions.     

N,N′-(hexane-1,6-diyl)bis(N-((1-aryl/alkyl-1H-1,2,3-triazol-4-yl)methyl)-4-methyl benzenesulfonamide): Synthesis,antibacterial, antioxidant,and DNA-cleavage activities

Thirteen novel bis-1,2,3-triazole derivatives were synthesized under copper (I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition of N,N′-(hexane-1,6-diyl)bis(4-methyl-N-(prop-2-yn-1-yl)benzenesulfonamide) with different aryl azides and evaluated their biological activity. All the newly synthesized compounds were confirmed by ¹H-NMR, infrared, and elemental analysis and mass spectral studies. The synthesized bis-1,2,3-triazoles were evaluated for their antioxidant activity, and some of them were found to exhibit good to excellent antioxidant activity (IC₅₀: 11.13 ± 1.5 to 98.98 ± 1.7 μM) in comparison with standard references, Trolox (11.73 ± 1.5 μM) and ascorbic acid (3.34 ± 1.8 μM). The bistriazoles also exhibited excellent-to-moderate anti-bacterial activity (MIC: 2.253 to 75 µg mL^?1 against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa when compared with streptomycin. N,N′-(hexane-1,6-diyl)bis(N-((1-(3,5-dimethylphenyl)-1H-1,2,3-triazol-4-yl)methyl)-4-methyl benzenesulfonamide) has completely cleaved the DNA at a concentration of 100 mg mL^?1, and the remaining compounds have partially cleaved the DNA.     

Phosphorus-based allenes as scaffolds in cycloaddition and cyclization reactions

ABSTRACT

In this article, we describe some of our results on the reactions of allenylphosphonates/allenyl phosphine oxides and allenyl diazaphosphole oxides, primarily cycloaddition and cyclization reactions. Depending on the substituents, both the α,β and β,γ -cycloaddition products have been observed. A novel cyclization reaction of a functionalized allenylphosphine oxide with diethylamine leading to 3-diethylamino-4-diphenylphosphinoyl-1-naphthol is reported. Representative compounds have been characterized by X-ray crystallography.     

Synthesis,crystal structure and molecular docking studies of novel 2-(4-(4-substitutedphenylsulfonyl)piperazin-1-yl)quinolone-3-carbaldehyde derivatives

The present work reports the synthesis of novel 2-(4-(4-substitutedphenylsulfonyl) piperazin-1-yl) quinolone-3-carbaldehyde derivatives, namely, 2-(4-tosylpiperazin-1-yl)quinoline-3-carbaldehyde (4a), 2-(4-(4-nitrophenylsulfonyl)piperazin-1-yl)quinoline-3-carbaldehyde (4b) and 2-(4-(4-tert-butylphenylsulfonyl) piperazin-1-yl)quinoline-3-carbaldehyde (4c). These compounds have been characterized by FT-IR, ¹H-NMR, ¹³C-NMR and LCMS. Further, the structures of compounds 4b and 4c have been elucidated by single crystal X-ray diffraction studies. The asymmetric unit of 4b contains two molecules (A and B) and that of 4c contains one. The piperazine ring in both the molecules 4b and 4c has chair conformation and the aldehyde group is twisted with respect to the quinoline group, respectively, by 13.3 (3)°, 18.2 (3)° and 11.2 (3)° in Molecule A & B of 4b and 4c due to the bulky piperazinyl group present in the ortho position. The crystal structures of both features interactions of the type C-H…O, C-H…π_aryl and π_aryl… π_aryl, leading to a three-dimensional (3D) supramolecular architecture in 4b and a one-dimensional (1D) architecture in 4c. The various intermolecular interactions exhibited in 4b and 4c are well supported by Hirshfeld surface and fingerprint plots analysis. Further, the three compounds were evaluated for their in-silico antimicrobial activity. In-silico molecular docking studies were carried out in order to know the binding modes of the synthesized compounds with DNA Gyrase A and N-myristoyltranferase as target proteins for antibacterial and antifungal docking studies, respectively.     

Activation of p300 histone acetyltransferase by small molecules altering enzyme structure: probed by surface-enhanced Raman spectroscopy

Reversible acetylation of nucleosomal histones and nonhistone proteins play pivotal roles in the regulation of all the DNA templated phenomenon. Dysfunction of the enzymes involved in the acetylation/deacetylation leads to several diseases. Therefore, these enzymes are the targets for new generation therapeutics. Here, we report the synthesis of trifluoromethyl phenyl benzamides and their effect on histone acetyltransferase (HAT) activity of p300. One of these benzamides, CTPB (N-(4-chloro-3-trifluoromethyl-phenyl)-2-ethoxy-6-pentadecyl-benzamide), was discovered as a potent activator of the p300 HAT activity. We have found that pentadecyl hydrocarbon chain of CTPB is required to activate the HAT only under certain context. Furthermore, our results show that the relative position of -CF3 and -Cl in CTB (N-(4-chloro-3-trifluoromethyl-phenyl)-2-ethoxy-benzamide) is also very critical for the activation. Surface-enhanced Raman spectroscopy (SERS) of p300 and the HAT activator complexes evidently suggest that the activation of HAT activity is achieved by the alteration of p300 structure. Therefore, apart from elucidating the chemical basis for small molecule mediated activation of p300, this report also describes, for the first time, Raman spectroscopic analysis of the complexes of histone-modifying enzymes and their modulators, which may be highly useful for therapeutic applications.