Substituted thiosemicarbazido/semicarbazido quinolines as possible antimalarials

Several 2-aryl substituted thiosemicarbazido-4-methyl-6-methoxyquinolines and 2-aryl substituted semi-carbazido 4-methyl-6-methoxyquinolines were synthesized and evaluated for their antimalarial activity in mice infected with Plasmodium berghei. Two of these substituted quinolines were found to exhibit 50% clearance in a dose of 500 mg./kg. administered intraperitoneally for 5 days.     

Synthesis of 10-(substituted phenylhydrazonoacetyl)phenothiazines as possible anticonvulsants

Some 10-(substituted phenylhydrazonoacetyl)phenothiazines were synthesized as possible anticonvulsants. These compounds were investigated for their anticonvulsant activity and inhibitory effects on the oxidation of pyruvic acid by rat brain homogenates.     

Fourier transform 13C NMR analysis of benzodiazepines

The natural abundance carbon-13 nuclear magnetic resonance spectra of diazepam, clonazepam, flurazepam and chlordiazepoxide were recorded in suitable solvent using the Fourier transform technique on a JEOL FX-60 spectrometer. The relaxation time (T₁) of these compounds were also measured. The chemical shift of the various carbon resonances have been assigned on the basis of chemical shift theory, multiplicity generated in single-frequency off-resonance decoupled spectra, relaxation time and the chemical shifts of the model compounds.     

6‐Hydroxy‐2,2‐di­methyl‐3,4‐di­hydro‐2H‐benzo[b]pyran

The title compound, 2,2‐di­methyl­chroman‐6‐ol, C₁₁H₁₄O₂, has been identified as a side product from the condensation of hydro­quinone with 2‐methyl­but‐3‐en‐2‐ol. The pyran ring has a half‐chair conformation. The hydroxyl groups are involved in intermolecular hydrogen bonding which generates infinite spiral chains around the fourfold screw axes; the O?O hydrogen‐bonded distances are 2.661 (1) Å.     

Hetero‐oligophenylene‐Based AIEE Material as a Multiple Probe for Biomolecules and Metal Ions to Construct Logic Circuits: Application in Bioelectronics and Chemionics

New hetero‐oligophenylene derivative ( 2 ) was synthesized which exhibits aggregation‐induced emission enhancement (AIEE) in H₂O/THF (80:20). The aggregates serve as a biological probe for three different proteins, that is bovine serum albumin (BSA), cytochrome c, and lysozyme, and DNA in contrasting modes. Further, among 29 metal ions tested, the contrasting fluorescence behavior of aggregates of 2 is observed with only Pb²⁺ and Pd²⁺ ions. Multiple output logic circuits based upon the fluorescence behavior between BSA and cytochrome c and between Pb²⁺ and Pd²⁺ ions are constructed.     

Synthesis,Characterization, Covalent Binding,and Degree of Unwinding of Platinum(II) Bipyridine Complexes

The complexes [Pt(3′′‐clpbpy)Cl₂] ( 1 ) [3′′‐clpbpy = 4‐(3′′‐chlorophenyl)‐6‐phenyl‐2, 2′‐bipyridine], [Pt(4′′‐clpbpy)Cl₂] ( 2 ) [4′′‐clpbpy = 4‐(4′′‐chlorophenyl)‐6‐phenyl‐2, 2′‐bipyridine], [Pt(3′′‐brpbpy)Cl₂] ( 3 ) [3′′‐brpbpy = 4‐(3′′‐bromophenyl)‐6‐phenyl‐2, 2′‐bipyridine], and [Pt(4′′‐brpbpy)Cl₂] ( 4 ) [4′′‐brpbpy = 4‐(4′′‐bromophenyl)‐6‐phenyl‐2, 2′‐bipyridine] were synthesized and characterized. The binding of the complexes with herring sperm DNA (HS DNA) was investigated by absorption titration and viscosity measurements. It was found that the complexes have ability of interaction with DNA by covalent mode. The intrinsic binding constant K_b of the complexes with HS DNA is 8.76 × 10⁴ ( 1 ), 9.89 ×10⁴ ( 2 ), 1.52 × 10⁵ ( 3 ), and 2.31 × 10⁵ ( 4 ) M^–1. The slight depression in relative specific viscosity was observed, which also attributes to covalent binding of complexes with DNA bases. Gel electrophoresis assay demonstrated the ability of the complexes to unwind negatively supercoiled pUC19 plasmid by 14° ( 1 ), 13° ( 2 ), 13° ( 3 ), and 11° ( 4 ). The in vitro cytotoxic property of the synthesized metal complexes was also carried out against brine shrimp bioassay.     

Nuclease activity via self-activation and anticancer activity of a mononuclear copper(II) complex: novel role of the tertiary butyl group in the ligand frame

The copper complex [Cu((t)BuPhimp)(Cl)] (1) derived from tridentate ligand (t)BuPhimpH having N(2)O donors was synthesized, and its molecular structure was determined. A phenoxyl radical complex was generated in solution at room temperature using Ce(IV). The nuclease and anticancer activities of 1 were investigated. The roles of the tert-butyl group and singlet oxygen in the DNA cleavage activity were also discussed.     

Autoacetylation of Purified Calreticulin Transacetylase Utilizing Acetoxycoumarin as the Acetyl Group Donor

Our earlier reports documented that calreticulin, a multifunctional Ca²⁺-binding protein in endoplasmic reticulum lumen, possessed protein acetyltransferase function termed Calreticulin Transacetylase (CRTAase). The autoacetylation of purified human placental CRTAase concomitant with the acetylation of receptor proteins by a model acetoxycoumarin, 7,8-Diacetoxy-4-methylcoumarin, was observed. Here, we have examined the autoacetylation property of CRTAase by immunoblotting and mass spectrometry. Ca²⁺ was found to inhibit CRTAase activity. The inhibition of both autoacetylation of CRTAase as well as acetylation of the receptor protein was apparent when Ca²⁺ was included in the reaction mixture as visualized by interaction with anti-acetyl lysine antibody. The acetylation of lysines residues: −48, −62, −64, −153, and −159 in N-domain and −206, −207, −209, and −238 in P-domain of CRTAase were located by high-performance liquid chromatography-electronspray ionization tandem mass spectrometry. Further, computer assisted protein structure modeling studies were undertaken to probe the effect of autoacetylation of CRTAase. Accordingly, the predicted CRTAase 3D model showed that all the loop regions of both N- and P-domain bear the acetylated lysines. Energy minimization of the acetylated residues revealed charge neutralization of lysines due to the N-ε-acetylation which may facilitate the interaction of CRTAase with the protein substrate and the subsequent transacetylase action. An erratum to this article can be found at     

Can Polymer Solar Cells Open the Path to Sustainable and Efficient Photovoltaic Windows Fabrication?

Sunlight is among the most abundant energy sources available on our planet. Finding adequate solutions to properly and efficiently harvest it is of major importance to potentially solve the global energy crisis. Polymer solar cells have been introduced in the late 20^th century as low‐cost and easily processed alternative to the state‐of‐the‐art silicon photovoltaics. Their power conversion efficiencies, which were initially rather low, are constantly improving and now reach values close to 15 %. As their optical properties can be easily tuned, designing active layer which absorb homogeneously throughout the visible spectrum is relatively simple. These peculiar characteristics enable the possibility to fabricate visibly transparent solar cells with high color rendering indices which can be employed as photovoltaic windows. After reviewing some of the most successful examples of polymer solar cell‐based transparent photovoltaic window fabrication, I will discuss the possibility to produce these devices in a sustainable and/or eco‐friendly manner while maintaining their performances.