Efficient, one-pot synthesis of 14-aryl-14Hdibenzo[a, j]xanthenes in aqueous medium catalyzed by bis-piperidinium compounds

A novel procedure for the synthesis of 14-aryl-14Hdibenzo[a,j]xanthenes through one-pot condensation of b-naphthol with aryl halides in aqueous media catalyzed by bis-piperidinium compounds is described. The method resulted in good to excellent yields in short reaction times

Synthesis and antioxidant potential of some biscoumarin derivatives

Purpose: To synthesize and screen some 3-substituted-bis-2H-chromen-2t-ones in a search for possible new antioxidants for use in food and pharmaceuticals industries.Methods: 2-Hydroxycoumarin was allowed to react with various substituted aromatic aldehydes in the presence of base as a catalyst to obtain to obtain 3-substituted-bis-2H-chromen-2t-ones. The chemical structures of the synthesized compounds were confirmed by Fourier transform infra-red (FT-IR) spectroscopy, proton nuclear magnetic resonance (1H NMR), mass spectrometry (MS) and elemental analysis. The synthesized biscoumarin derivatives were screened by three parallel antioxidant assays, namely, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, reducing power, and linoleic acid lipid peroxidation. Further, the half minimal inhibitory concentration (IC50) of the compounds was also determined. Butylatedhydroxy toluene (BHT) was used as a standard reference in the antioxidant assay.Results: A library of ten biscoumarin analogues (3a-3j) were synthesized and evaluated for their antioxidant potential. The highest DPPH activity was shown by 3,3'-(3-hydroxy-4- methoxyphenylmethylene)-bis-4-hydroxy-2H-chromen-2-one (3g) and 3,3'-(4-methoxyphenylmethylene)- bis-4-hydroxy-2H-chromen-2-one (3h) with IC50 values of 53.33 ± 6.12 and 68.44 ± 2.67 μg/mL, respectively, compared to the standard compound BHT (butylatedhydroxy toluene) with IC50 of 71.00 ± 0.82 μg/mL. The strongest inhibition of linoleic acid peroxidation was by 3,3'-(3-hydroxy-4- methoxyphenylmethylene)-bis-4-hydroxy-2H-chromen-2-one (3g) and 3'-(4-hydroxy-3-methoxyphenylmethylene)- bis-4-hydroxy-2H-chromen-2-one (3d) with inhibition values of 70.34 and 69.87 %, respectively. Compound 3g demonstrated the highest reducing power with an absorbance of 0.49 at 10 mg/mL concentration (p < 0.001). It was observed that the change in substitution greatly affected the antioxidant potential of the compounds, with the presence of the methoxy group at position-4 of aryl moiety along with 2-hydroxycoumarin being critical for antioxidant activity.Conclusion: The synthesized biscoumarin derivatives, 3g and 3h, are superior antioxidants to standard (BHT) and are suitable lead molecules for further development.Keywords: Antioxidant, Biscoumarins, DPPH, Ferric reducing assay, linoleic acid lipid peroxidation assa

Recent advancements in oxadiazole-based anticancer agents

Oxadiazole ring system occupies a significant position among heterocyclic templates for medicinal compounds due to its wide spectrum of biological activities. This article entails an in-depth review of the ability of oxadiazole derivatives to induce apoptosis of cancer cells. FDA has approved a number of drugs for the treatment of different types of cancer. There is, however, a continuing need for the development of new anticancer agents due to increasing cases of drug resistance. Moreover, medicinal chemists are continuously struggling to invent selective cytotoxic agents with minimum side effects. This work reviews the significance of oxadiazole ring system and its potential to act as a template for novel anticancer agents.Keywords: Oxadiazole ring system, Anticancer activity, Antitumor activity,  Cytotoxicity, Apoptosi

Recent advances in the synthesis of triazole derivatives

Triazole ring system has attracted a continuously growing interest of synthetic organic chemists and those dealing with the medicinal compounds due to its versatile potential to interact with biological systems. The triazole compounds possess a wide range of biological activities and are especially focused for antifungal behavior. In thisreview article, we have summarized the recent developmentsin the synthetic methodologies of this ring system. The main focus was on the methodologies which deal with the facile and convenient synthesis

Chemoradiation and the role of adjuvant chemotherapy in lymph nodal-metastatic cervical cancer

Purpose: To report the long-term outcome in lymph nodal-metastatic cervical squamous cell cancer after chemoradiation followed by adjuvant chemotherapy.Patients and Methods: Between 2010 and 2013, five patients were diagnosed with advanced cervical cancer with clinically involved para-aortic lymph nodes (ie, International Federation of Gynecology and Obstetrics stage IVB). These patients were treated with concurrent chemoradiation therapy followed by adjuvant chemotherapy. Concurrent chemoradiation consisted of cisplatin given once per week concomitantly with extended-field radiation therapy followed by high-dose-rate brachytherapy. Adjuvant chemotherapy comprised four courses of carboplatin and paclitaxel given every three weeks. The primary outcomes were local and distant failures.Results: None of the patients had local recurrence or distal failure after a minimum follow-up time of 3 years.Conclusion: Adjuvant chemotherapy after chemoradiation has a probable role in the management of lymph nodal-metastatic cervical cancer

Antioxidant, antimicrobial and antiproliferative activities of peel and pulp extracts of red and white varieties of Ipomoea batatas (L) Lam

Purpose: To investigate the antioxidant, antibacterial and anticancer potentials of methanol and ethanol extracts of the peel and pulp of red and white species of Ipomoea batatas (L.) fruit.Methods: Total phenolic contents and flavonoids were determined using chemical assays. Antioxidant studies were carried out using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, inhibition of linoleic acid peroxidation assay and reducing power assay. Antibacterial and antiproliferative activities of extracts were determined using disc diffusion and MDBK cancer cell line inhibition methods, respectively.Results: The extract of peels of red specie (PERS) showed total phenolic contents (TPC) 8.9 mg gallic acid equivalent (GAE)/g dry extract and flavonoids 6.5 mg catechin equivalent (CE)/g dry extract. The extract of PERS also showed promising DPPH free radical scavenging activity, inhibition of linoleic acid peroxidation and reducing power activity. However, mild antibacterial and anti-proliferative activities were noted except that the extract showed significant inhibition of Bacillus subtilis growth.Conclusion: The results indicate that the peel and the pulp of red sweet potato (SP) specie are rich in antioxidants and can potentually be processed as antioxidant food supplements.Keywords: Ipomoea batatas (L.) Lam, Sweet potato, Phenolic content, Antioxidants, Antibacterial activity, Antiproliferative activit

Synthesis and consecutive reactions of a-azido ketones: a review

This review paper covers the major synthetic approaches attempted towards the synthesis of α-azido ketones, as well as the synthetic applications/consecutive reactions of α-azido ketones

Impact of peer review in the radiation treatment planning process: Experience of a tertiary care university hospital in Pakistan

Purpose: To evaluate and report the frequency of changes in radiation therapy treatment plans after peer review in a simulation review meeting once a week.Materials and Methods: Between July 1 and August 31, 2016, the radiation plans of 116 patients were discussed in departmental simulation review meetings. All plans were finalized by the primary radiation oncologist before presenting them in the meeting. A team of radiation oncologists reviewed each plan, and their suggestions were documented as no change, major change, minor change, or missing contour. Changes were further classified as changes in clinical target volume, treatment field, or dose. All recommendations were stratified on the basis of treatment intent, site, and technique. Data were analyzed by Statistical Package for the Social Sciences and are presented descriptively.Results: Out of 116 plans, 26 (22.4%) were recommended for changes. Minor changes were suggested in 15 treatment plans (12.9%) and a major change in 10 (8.6%), and only one plan was suggested for missing contour. The frequency of change recommendations was greater in radical radiation plans than in palliative plans (92.3% v 7.7%). The head and neck was the most common treatment site recommended for any changes (42.3%). Most of the changes were recommended in the technique planned with three-dimensional conformal radiation therapy (50%). Clinical target volume (73.1%) was identified as the most frequent parameter suggested for any change, followed by treatment field (19.2%) and dose (0.08%).Conclusion: Peer review is an important tool that can be used to overcome deficiencies in radiation treatment plans, with a goal of improved and individualized patient care. Our study reports changes in up to a quarter of radiotherapy plans

Synthesis of Nickel Spinel Ferrites Nanoparticles Coated with Thermally Reduced Graphene Oxide for EMI Shielding in the Microwave, UV, and NIR Regions

The co-precipitation and in situ modified Hummers’ method was used to synthesize Nickel Spinal Ferrites (NiFe) nanoparticles and NiFe coated with Thermally Reduced Graphene Oxide (TRGO) (NiFe-TRGO) nanoparticles, respectively. By using polyvinyl chloride (PVC), tetrahydrofuran (THF), and NiFe-TRGO, the nanocomposite film was synthesized using the solution casting technique with a thickness of 0.12–0.13 mm. Improved electromagnetic interference shielding efficiency was obtained in the 0.1–20 GHz frequency range. The initial assessment was done through XRD for the confirmation of the successful fabrication of nanoparticles and DC conductivity. The microstructure was analyzed with scanning electron microscopy. The EMI shielding was observed by incorporating a filler amount varying from 5 wt.% to 40 wt.% in three different frequency regions: microwave region (0.1 to 20 GHz), near-infrared (NIR) (700–2500 nm), and ultraviolet (UV) (200–400 nm). A maximum attenuation of 65 dB was observed with a 40% concentration of NiFe-TRGO in nanocomposite film

DFT Study for the Spectroscopic and Structural Analysis of p-Dimethylaminoazobenzene

The study under consideration represents the computational calculations of Azo-based direct dye named p-(dimethylamino)azobenzene (DMAB) under the effect of solvents with different relative permittivities. A density functional theory (DFT) method at the B3LYP level with 6-311G++ was applied for the spectroscopic and structural analysis of the title compound. Calculations of geometric parameters (bond orders, bond lengths, and dihedral angles), electron densities, thermodynamic parameters, and orbital energies were performed for the title compound. Mulliken population analysis (MPA) as well as natural population analysis (NPA) was also performed at the B3LYP level with different solvents for finding solvent effects. In order to predict the reactivity of DMAB, molecular electrostatic potential (MESP) calculations were carried out for it. For vibrational analysis, the infrared (IR) spectra were computed for the title compound at the B3LYP/6-311G++ level in the gas phase and in different solvents with good agreement to the experimental FT-IR spectrum. The different modes of vibrations were assigned using potential energy distribution (PED). The computed Raman spectra also showed appreciable agreement with the experimental recorded Raman spectrum. The electronic absorption spectra of the title compound have been computed employing DFT/B3LYP with the 6-311G++ basis set in the gas phase and in four different solvents, that is, DMSO, ethanol, acetonitrile, and water which were compared with the experimental spectra with appreciable agreement. NBO analysis was carried out for understanding the intramolecular and intermolecular bonding of the compound and the density transfer from completely filled to unfilled orbital was found. The HOMO-LUMO energies were determined for analyzing the mechanism of intramolecular charge transfer