Taibi Ben Hadda

Metal based biologically active compounds: Design, synthesis, and antibacterial/antifungal/cytotoxic properties of triazole-derived Schiff bases and their oxovanadium(IV) complexes

A new series of oxovanadium(IV) complexes have been designed and synthesized with a new class of triazole Schiff bases derived from the reaction of 3,5-diamino-1,2,4-triazole with 2-hydroxy-1-naphthaldehyde, pyrrole-2-carboxaldehyde, pyridine-2-carboxaldehyde and acetyl pyridine-2-carboxaldehyde, respectively. Physical (magnetic susceptibility, molar conductance), spectral (IR, (1)H NMR, (13)C NMR, mass and electronic) and analytical data have established the structures of these synthesized Schiff bases and their oxovanadium(IV) complexes. The Schiff bases, predominantly act as bidentate and coordinate with the vanadium(IV) metal to give a stoichiometric ratio of 1:2 [M:L], forming a general formulae, [M(L-H)(2)] and [M(L)(2)]SO(4) where L = (L(1))-(L(4)) and M = VO(IV) of these complexes in a square-pyramidal geometry. In order to evaluate the biological activity of Schiff bases and to assess the role of vanadium(IV) metal on biological activity, the triazole Schiff bases and their oxovanadium(IV) complexes have been studied for in vitro antibacterial activity against four Gram-negative (Escherichia coli, Shigella flexenari, Pseudomonas aeruginosa, Salmonella typhi) and two Gram-positive (Staphylococcus aureus, Bacillus subtilis) bacterial strains, in vitro antifungal activity against Trichophyton longifucus, Candida albican, Aspergillus flavus, Microscopum canis, Fusarium solani and Candida glaberata. The simple Schiff bases showed weaker to significant activity against one or more bacterial and fungal strains. In most of the cases higher activity was exhibited upon coordination with vanadium(IV) metal. Brine shrimp bioassay was also carried out for in vitro cytotoxic properties against Artemia salina.

Identification of antibacterial and antifungal pharmacophore sites for potent bacteria and fungi inhibition: indolenyl sulfonamide derivatives.

Synthesis of seven new indolenyl sulfonamides, have been prepared by the condensation reaction of indole-3-carboxaldehyde with different sulfonamides such as, sulphanilamide, sulfaguanidine, sulfathiazole, sulfamethoxazole, sulfisoxazole, sulfadiazine and sulfamethazine. These synthesized compounds have been used as potential ligands for complexation with some selective divalent transition metal ions (cobalt, copper, nickel & zinc). Structure of the synthesized ligands has been deduced from their physical, analytical (elemental analyses) and spectral (IR, (1)H NMR and (13)C NMR & UV-vis) data. All the compounds have also been assayed for their in vitro antibacterial and antifungal activities examining six species of pathogenic bacteria (Escherichia coli, Shigella flexneri, Pseudomonas aeruginosa, Salmonella typhi, Staphylococcus aureus and Bacillus subtilis) and six of fungi (Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium soloni and Candida glabrata). Antibacterial and antifungal results showed that all the compounds showed significant antibacterial activity whereas most of the compounds displayed good antifungal activity. Brine shrimp bioassay was also carried out for in vitro cytotoxic properties against Artemia salina.

Pharmacophores modeling in terms of prediction of theoretical physico-chemical properties and verification by experimental correlations of novel coumarin derivatives produced via Betti’s protocol

A general, simple and straight forward approach to new substituted coumarin derivatives via Bettis condensation reaction of aromatic aldehydes, coumarin and ammonia precursors has been demonstrated successfully under mild reaction conditions. All the synthesized molecules were characterized on the basis of IR, (1)H NMR, (13)C NMR, Mass spectrometry and Elemental data. We have reported the design and calculated molecular properties of some coumarin derivatives on the basis of hypothetical antibacterial pharmacophores, structures which were designed to interact with both of gram positive and gram negative bacteria. A correlation of structure and activities relationship of these compounds with respect to molecular modeling, Lipinski rule of five, drug likeness, toxicity profiles and other physico-chemical properties of drugs are described and verified experimentally.

An Ethnobotanical study of Medicinal Plants in high mountainous region of Chail valley (District Swat- Pakistan)

BackgroundThis paper represents the first ethnobotanical study in Chail valley of district Swat-Pakistan and provides significant information on medicinal plants use among the tribal people of the area. The aim of this study was to document the medicinal uses of local plants and to develop an ethnobotanical inventory of the species diversity.MethodsIn present study, semi-structured interviews with 142 inhabitants (age range between 31–75 years) were conducted. Ethnobotanical data was analyzed using relative frequency of citation (RFC) to determine the well-known and most useful species in the area.ResultsCurrent research work reports total of 50 plant species belonging to 48 genera of 35 families from Chail valley. Origanum vulgare, Geranium wallichianum and Skimmia laureola have the highest values of relative frequency of citation (RFC) and are widely known by the inhabitants of the valley. The majority of the documented plants were herbs (58%) followed by shrubs (28%), trees (12%) and then climbers (2%). The part of the plant most frequently used was the leaves (33%) followed by roots (17%), fruits (14%), whole plant (12%), rhizomes (9%), stems (6%), barks (5%) and seeds (4%). Decoction was the most common preparation method use in herbal recipes. The most frequently treated diseases in the valley were urinary disorders, skin infections, digestive disorders, asthma, jaundice, angina, chronic dysentery and diarrhea.ConclusionThis study contributes an ethnobotanical inventory of medicinal plants with their frequency of citations together with the part used, disease treated and methods of application among the tribal communities of Chail valley. The present survey has documented from this valley considerable indigenous knowledge about the local medicinal plants for treating number of common diseases that is ready to be further investigated for biological, pharmacological and toxicological screening. This study also provides some socio-economic aspects which are associated to the local tribal communities.

Protective effects of selenium against cadmium induced hematological disturbances, immunosuppressive, oxidative stress and hepatorenal damage in rats

Cadmium is a non-essential toxic metal used in industrial process, causes severe risk to human health. Selenium (Se) is an essential trace mineral of fundamental importance for human health. Selenium has antioxidant enzymes roles and is needed for the proper function of the immune system. In this study, the protective effects of selenium against cadmium intoxication in rats have been investigated by monitoring some selective cytokines (IL-1β, TNF α, IL-6, IL-10 and IFN-γ), antioxidant enzymes reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and lipid peroxidation malondialdehyde (MDA) as well as some selective biochemical markers of liver and kidney functions. Thirty-two rats were divided into four equal groups; the first group was used as a control. Groups 2-4 were treated with selenium (Se; 0.1mg/kg BW), cadmium (Cd; 40mg/L drinking water) and selenium plus cadmium, respectively. Rats were orally administered their relevant doses daily for 30 days. Blood samples were collected from heart puncture at the end of the experiment (30 days) for complete blood picture (CBC) and serum was separated to evaluate the different immunological parameters and biochemical parameters, as well as liver specimens for Cd and Se estimation. Rats in the Cd treated group have a significantly higher hepatic concentration of Cd than in other treated groups. Results revealed that cadmium significantly increased IL-1β, TNF α, IL-6 and IL-10, beside peripheral neutrophils count, while the IFN-γ and lymphocytes were decreased in rat sera. In addition, GSH level, CAT, SOD and GPx activities were significantly decreased while lipid peroxidation (MDA) was increased. Regarding, liver and renal markers, they were significantly increased in the activities of aminotransferases (AST, ALT), urea and creatinine, while total plasma proteins and albumin were significantly decreased. On the other hand, selenium treated group, showed significantly increased IFN-γ, GSH level, CAT, and GPx activities, as well as lymphocyte count while IL-10 was decreased. Selenium in combination with cadmium, significantly improved the elevation of serum IL-1β, IL-6, TNF α, IL-10 and malondialdehyde in addition to enhancing the antioxidant enzyme activities of GSH, CAT, GPx and SOD. Moreover, selenium has ameliorated the cadmium-induced liver and kidney damage by improving hepatic and renal markers. The results of this investigation demonstrated that selenium has the potential to countermeasure the immunosuppressive as well as hepatic and renal oxidative damage induced by cadmium in rats; selenium has shown promising effects against Cd toxicity.

Theoretical Calculations and Experimental Verification of the Antibacterial Potential of Some Monocyclic β-Lactams Containing Two Synergetic Buried Antibacterial Pharmacophore Sites

A new series of N-thiazole, 3-phenyl, 4-substituted phenyl azetidine-2-ones 4(a–h) have been synthesized in good yields starting from 2-aminothiazole 1. In the first step, then Schiffs bases 3(a–h) are prepared by the condensation of 2-aminothiazole 1 with different aryl aldehydes 2(a–h). Finally, monocyclic β-lactams, i.e. substituted azetidinones 4(a–h), were the products formed using three different methods by the dehydrative cyclocondensation of 3(a–h) with phenyl acetyl chloride in dioxane, phenyl acetic acid–thionyl chloride in dichloromethane and phenyl acetic acid–phosphorus oxychloride in dichloromethane in the presence of triethylamine. We found that latter method is the best as compared with the former two methods. The synthesized molecules 4(a–h) were screened for their antibacterial activity against four microorganisms: Staphylococcus aureus (Gram positive), Pseudomonas vulgaris (Gram positive), Pseudomonas aeruginosa (Gram negative), and Escherichia coli (Gram negative). Their antibacterial activities are reported, and on the basis of the screening data available, attempt is also made to elucidate the structure–activity relationship. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

Some new biologically active metal-based sulfonamide

A new series of sulfonamide derived Schiff bases has been synthesized by a condensation reaction of various sulfonamides with aromatic aldehydes. The so obtained sulfonamide were further investigated for their chelation and biological properties with first row d-transition metal ions [cobalt(II), copper(II), nickel(II) and zinc(II)]. The nature of bonding and structure of all the synthesized compounds have been inferred from magnetic susceptibility and conductivity measurements, IR, (1)H and (13)C NMR, electronic spectral, mass spectrometry and CHN analysis data. The structure of ligand, 4-{[(E)-(5-bromo-2-hydroxy phenyl)methylidene]amino}-N-(4,6-dimethylpyrimidin-2-yl)benzenesulfonamide has also been determined by X-ray diffraction method. An octahedral geometry has been suggested for all the complexes. The ligands and their metal complexes have been screened for in vitro antibacterial, antifungal and cytotoxic properties. The result of these studies have revealed that all compounds showed moderate to significant antibacterial activity against one or more bacterial strains and good antifungal activity against various fungal strains.

One Step Synthesis of NiO Nanoparticles via Solid-State Thermal Decomposition at Low-Temperature of Novel Aqua(2,9-dimethyl-1,10-phenanthroline)NiCl2 Complex

[NiCl2(C14H12N2)(H2O)] complex has been synthesized from nickel chloride hexahydrate (NiCl2·6H2O) and 2,9-dimethyl-1,10-phenanthroline (dmphen) as N,N-bidentate ligand. The synthesized complex was characterized by elemental analysis, infrared (IR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy and differential thermal/thermogravimetric analysis (TG/DTA). The complex was further confirmed by single crystal X-ray diffraction (XRD) as triclinic with space group P-1. The desired complex, subjected to thermal decomposition at low temperature of 400 ºC in an open atmosphere, revealed a novel and facile synthesis of pure NiO nanoparticles with uniform spherical particle; the structure of the NiO nanoparticles product was elucidated on the basis of Fourier transform infrared (FT-IR), UV-vis spectroscopy, TG/DTA, XRD, scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDXS) and transmission electron microscopy (TEM).

Design and synthesis of triazole Schiff bases and their oxovanadium(IV) complexes as antimicrobial agents

A new class of triazole Schiff bases have been prepared by the reaction of 3,5-diamino-1,2,4-triazole with methyl-, chloro-, and nitro-substituted furan-2-carboxaldehydes in an equimolar ratio (1 : 1). The bidentate ligands were characterized by IR, 1H-, and 13C-NMR, microanalysis, and mass spectrometry. The Schiff bases were complexed with vanadyl(IV) sulfate in a molar ratio (M : L) 1 : 2, [M(L)2]SO4 (where L = L1–L5 and M = VIVO) in a square-pyramidal geometry. In vitro antibacterial activity was determined by screening the compounds against four Gram-negative (Escherichia coli, Shigella flexenari, Pseudomonas aeruginosa, and Salmonella typhi) and two Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacterial strains and in-vitro antifungal activity was carried out on Trichophyton longifucus, Candida albican, Aspergillus flavus, Microscopum canis, Fusarium solani, and Candida glaberata strains.

Quinazoline-tyrphostin as a new class of antitumor agents, molecular properties prediction, synthesis and biological testing

A new series of substituted quinazolin-4-(3H)-one-tyrphostin derivatives was prepared and screened for their cytotoxic activity against three tumor cell lines, namely human breast cancer cell line (MCF-7), human cervical cancer cell line (HeLa) and human hepatocellular liver carcinoma cell line (HepG2) using the colorimetric MTT assay. Among the current series, 10 compounds exhibited remarkable in vitro antiproliferative activity against the three tested cell lines with the IC(50) values ranging from 0.009 to 0.015 mM. All the compounds showed suitable drug like characteristics according to Lipinskis rule.