P-glycoprotein 1 (Pgp), also called multidrug resistance protein 1 (MDR1), is one of the most widely dispersed and effective transporters found in cancer resistances. This research works sought to use computational methods to understand structure and functional relationship using the binding energies and structural similarity of the lowest binding molecules. A series of 479 molecules including alkaloids, flavinoids, cyclic imides, lactams, lactones, NSAIDS, sulfanilamides, and known Pgp binders were bound to 3 Pgp crystal structures (35GU, 3G60, 3G61) . Computational results matched that of experimental result with a group of current pharmaceuticals which include Digoxin, Etoposide, Tacrolimus, and Paclitaxel maintaining the lowest energy (averaged over the three proteins). Similarity searches of the lowest binding molecules were conducted to determine important structural motifs. This research allows a better understanding of drug interaction towards the blockade of the function of Pgp.

Drug resistances in Gram-negative bacteria arise through several mechanisms including that of an over-expression of the multidrug transporter AcrB and its homologues. This research works sought to use computational methods to understand structure and functional relationship using the binding energies and structural similarity of the lowest binding molecules. A series of 479 molecules including alkaloids, flavinoids, cyclic imides, lactams, lactones, NSAIDS, sulfanilamides, and known pharmaceuticals were bound to 10 AcrB crystal structures (1IWG, 1OY6, 1OY8, 1OY9, 1OYD, 2W1B, 2RDD, 2J8S, 2HRT, 2DRD). Computational results matched found a group of current pharmaceuticals maintaining the lowest energy overall. Similarity searches of the lowest binding molecules were conducted to determine important structural motifs. This research allows a better understanding of drug interaction towards the blockade of Gram-negative resistances.

Dye pollutants produced from the textile industries are becoming a major source of environmental contamination. Traditional methods such as flocculation, carbon adsorption, reverse osmosis and activated sludge process have difficulties in the complete destruction of dye pollutants for the treatment of dye-containing. In the past decades, scientists and engineers are all interested in developing the semiconductor photocatalytic reactions. TiO₂ has widely been investigated for photocatalyzed degradation of organic dyes because of its strong photoactive ability, stability, non-toxic and low cost. TiO₂ photocatalyst is well known to generate various active oxygen species such as hydroxyl radicals, hydrogen peroxide, superoxide radical anions, etc. by redox reactions under UV irradiation. Anatase-type of TiO₂ has highly photocatalytic activity for decomposition of various environmental pollutants in both gas and liquid phases. However, TiO₂ can only utilize a small part (less than 5%) of the solar light energy for photocatalytic oxidation and the artificial UV light sources are unstable and expensive. In order to achieve photooxidation of pollutants with efficient utilization by titania particles under visible light irradiation, i.e., the band gaps must be smaller than 3.2 eV, the development of photocatalysts with high activity under visible light irradiation has been required. In attempt to devise the photocatalysts that can be operated at lower energies, the methods of modified TiO₂ are ion implantation using Cr or V ions, various synthesis techniques and substitutional doping of non-metals such as N. In this study, Cr-doped TiO₂ powder was prepared by sol–gel method with the aim of extending the light absorption spectrum toward the visible light region. The photocatalytic activity under visible light irradiation was evaluated using rhodamine B as a model organic compound and was carried out in a recycle fluidized bed reactor. The effects of initial acid dye concentration, particle size and loading amounts of photocatalyst were investigated.

The use of pharmacologically inert derivatives as a means to overcome common drawbacks associated with the intake of drugs (i.e. low oral absorption, chemical instability or toxicity) has increased the interest in the development of efficient prodrugs [1]. Photoresponsive prodrugs have been proposed recently for the optimisation of drug delivery as the use of light as triggering agent allows spatial and temporal control of the release process [2]. In this communication we report the synthesis of ester conjugates of butyric acid, a short chain fatty acid involved in the regulatory mechanisms for gene expression known to promote markers of cell differentiation, apoptosis and cell growth control. Given our interest in the design of novel photolabile protecting groups based on oxygen heterocycles [3], the esters were prepared by reaction with several amino naphthopyranones, in order to evaluate the differences in the photolytic release of butyric acid from the heterocyclic cages. Photolysis studies were carried out under irradiation at different wavelengths (250, 300, 350 and 419 nm) in a Rayonet RPR-100 photochemical reactor in mixtures of organic solvent and HEPES buffer solution in a 80:20 proportion. [1] Dahan, A.; Khamis, M.; Agbaria, R.; Karaman, R. Expert Opin. Drug Del. 2012, 9, 1001-1013. [2] Fomina, N.; Sankaranarayanan, J.; Almutairi, A. Adv. Drug Deliver. Rev. 2012, 64, 1005-1020. [3] a) Piloto, A. M.; Soares, A. M. S.; Costa, S. P. G.; Gonçalves, M. S. T. Amino Acids, 2012, 42, 2275-2282. b) Piloto, A. M.; Soares, A. M. S.; Hungerford, G.; Costa, S. P. G.; Gonçalves, M. S. T. Eur. J. Org. Chem. 2011, 5447-5451.

There is a strong interest in the design of more efficient protecting groups that allow orthogonal cleavage/deprotection for application with biomolecules, by rapid and clean cleavage under irradiation at wavelengths that are not detrimental to biological systems, with spatial and temporal resolution.1 Coumarin derivatives are well established photolabile protecting groups that have been used in the caging of various functional groups (such as alcohols, amines, phosphates, aldehydes, ketones and carboxylic acids),2 whereas benzocoumarin derivatives were reported for the first time by us as carboxyl protecting groups cleavable by light and with sensitivity to two-photon excitation.3 In this communication, we present the synthesis of model amino acid conjugates, namely glycine, alanine, valine and phenylalanine, based on coumarin and benzocoumarin, with the aim of assessing the selectivity of photolytic removal. Photolysis studies were carried out under irradiation at different wavelengths (250, 300, 350 and 419 nm) in a Rayonet RPR-100 photochemical reactor in acetonitrile/HEPES buffer solution (80:20). It was found that, in some cases, the cleavage of the ester bond between the heterocycle and the model amino acids occurred in very different irradiation times at the same irradiation wavelength, enabling the selective removal of one heterocycle in the presence of the other heterocycle. These results opens up the possibility of considering coumarin and benzocoumarin as a protecting group pair for the protection of a bifunctional molecule through ester bonds. 1. Mayer, G.; Heckel, A. Angew. Chem. Int. Ed. 2006, 45, 4900-4921. 2. a) Givens, R. S.; Rubina, M.; Wirz, J. Photochem. Photobiol. Sci., 2012, 11, 472-488. b) Hagen, V.; Kilic, F.; Schaal, J.; Dekowski, B.; Schmidt, R.; Kotzur, N., J. Org. Chem. 2010, 75, 2790-2797. c) Furuta, T.; Noguchi, K., TRAC-Trend. Anal. Chem. 2004, 23, 511-519. 3. a) Piloto, A. M.; Soares, A. M. S.; Costa, S. P. G.; Gonçalves, M. S. T. Amino Acids, 2012, 42, 2275-2282. b) Piloto, A. M.; Soares, A. M. S.; Hungerford, G.; Costa, S. P. G.; Gonçalves, M. S. T., Eur. J. Org. Chem. 2011, 5447-5451. c) Hungerford, G.; Ryderfors, L.; Fernandes, M. J. G.; Gonçalves, M. S. T.; Costa, S. P. G. J. Photochem. Photobiol. A, 2010, 215, 214-222.

The search for light-sensitive moieties which allow a controlled spatio-temporal triggering of chemical and biological relevant molecules within cellular systems represents an important challenge in chemical biology. Caging strategies make use of photochemically removable protecting groups to mask the activity of biologically relevant molecules and release the bioactive species upon irradiation with light of appropriate wavelength [1].The use of fluorescent caging groups allows the visualization, quantification, and the follow-up of spatial distribution, localization, and depletion of the active compound through the monitoring of its fluorescent caged precursor using fluorescent techniques. As a continuation of our research work concerning the synthesis of new fluorescent heterocyclic compounds, their application on the design of fluorescent conjugates of biologically relevant molecules and studies on their photorelease [2], the present study aims to give a contribution to the development of novel photoactivable groups based on azaheterocycles, namely carbazole and acridine. A model carboxylic acid was used for the preparation of novel ester conjugates of acridine and carbazole, in order to be compared with the corresponding 2-nitrobenzyl derivative (a widely known caging group). The resulting compounds were evaluated in a photochemical reactor under irradiation at 254, 300, 350 and 419 nm and the monitoring of the photocleavage process was carried out by HPLC and 1H NMR. [1] Furuta, T. in Dynamic Studies in Biology: Phototriggers, Photoswitches and Caged Biomolecules, M. Goeldner, R. S. Givens (Eds.), Wiley-VCH, New York, 2005. [2] a) Piloto A.M., Soares A.M.S., Hungerford G., Costa S.P.G.; Goncalves, M.S.T. Eur. J. Org. Chem. 2011, 5447-5451. b) Piloto A.M., Hungerford G., Costa S.P.G. Gonçalves M.S.T., Photochem. Photobiol. Sci. 2012, in press DOI:10.1039/C2PP25261A.

We report herein the synthesis and the characterization of the tetradentate thiosemicarbazone ligand bis(4-N-ethyl-thiosemicarbazone)-1,4-diacetylbencene. Its crystal structure has been analysed together with the possible coordination modes that could feature in its derived metal complexes.

Objective: To screen the antimicrobial activity of different extracts of leaves of Artemisia vulgaris. Materials and Methods: To detect the in vitro antibacterial activity, 10 bacterial strains were selected. These bacteria are both gram +ve and gram -ve. Leaves were extracted with a petroleum ether, chloroform, ethyl acetate, ethanol and aqueous . In the present work the antibacterial activity was done by cup plate method. The antibacterial activity was expressed as zone diameter in millimeters. Different extracts from leaves of the plant was compared with standards like benzyl penicillin for gram +ve bacteria and streptomycin for gram –ve bacteria using DMF as control. The readymade media for inoculum and culture was obtained from Himedia labs. For antifungal activity four fungal organisms were selected and Griseofulvin was used as standard. Results: Herbal extracts prepared from the leaves of the plant were screened against bacteria and fungal organisms at the concentration range between 50 µg and 300 µg/0.1ml. The results of antimicrobial activity revealed that the extract exhibited activity against both gram +ve, gram –ve and fungal organisms. Conclusion: The present investigation reveals that the aqueous, chloroform and ethyl acetate extracts and in some cases petroleum ether extract showed significant antimicrobial activity when compared with standard.

Abstract: Organic solar cells have been attracted much attention because of the good efficient, low-cost and easy fabrication in recent years. The performance of an organic dye in real devices depends sensitively on its structure and electronic/ optical properties, such as the binding stability, the band alignment, and the absorption maximum and intensity. These types of solar cell form a donor- acceptor system, which dyes are donor and semiconductors are acceptor. Design a suitable linker, which contain a bridge between dye and anchoring group, is an important factor to improve efficient of solar cells In this work, the (E)-2-(5-methacrylamido-2,3-bis (methylthio) phenyl) diazenesulfonate dye molecule were optimized by DFT/6-31G (d, p) method in gas phase and Ethanol solvent by using CPCM model. The UV-Vis spectra of dyes were computed by using the TD-DFT/6-31G (d, p) method in gas phase and Ethanol solvent. Reference: [1] S. Meng, E. Kaxiras, Md. K. Nazeeruddin, and M. Gr€atzel; "Design of Dye Acceptors for Photovoltaics from First-Principles Calculations"; J. Phys. Chem. C; 115, 9276–9282 [2] E. Galoppini; "Linkers for anchoring sensitizers to semiconductor nanoparticles"; Coordination Chemistry Reviews 248, 1283–1297, 2004

This article focuses on the synthesis of a new polymeric phosphors containing Tb+3 ions as a potential material for next generation optoelectronic devices. Here we are presented the results of the synthesis and luminescence properties of copolymers containing: 2-(9-carbazolyl)ethyl methacrylate (CEM) and p-methacryloyloxybenzoic acid (pMBA) complexed with Tb(III). All copolymers have been characterized by HNMR, GPC, FTIR and UV-Vis. Solutions of the copolymers in THF or CHCl3 have been examined for their photoluminescence properties. Finally, the possibility of using these materials in optoelectronics were compared to those already synthesized.