The Fifth Palestinian International Chemistry Conference

In this study, the adsorption of gemifloxacin mesylate (antibiotic) using selected pharmaceutical adsorbents such as activated charcoal and kaolin was investigated spectrophotometrically in terms of initial pH, residence time, initial concentration of drug (adsorbate), weight of adsorbent and temperature. For equilibrium studies, data for adsorption of gemifloxacin mesylate (GEMX) on charcoal were shown to fit Langmuir isotherm whereas, Freundlich isotherm fitted the data very well for the adsorption on kaolin. The maximum adsorption capacity of GEMX were 137mg/g on charcoal compared to 0.04 mg/g on kaolin. This is due to high surface area of charcoal compared to kaolin. The amount adsorbed at equilibrium decreases as adsorbate's concentration increases and increases as the weight of adsorbent increases. pH played a role in the adsorption of GEMX on charcoal which was more in acidic than in basic medium. The maximum adsorption was at pH 6 and at neutral pH for kaolin. Thermodynamics parameters showed that adsorption process was exothermic and spontaneous as ΔHo and ΔGo had negative values. The positive value of ΔSo showed an increase in freedom of molecules with increasing temperature. This study suggests activated charcoal as an effective antidote for cases of GEMX overdose or poisoning. Keywords: adsorption; Gemifloxacin mesylate; Thermodynamics parameters; poisoning.

Recently, nanoparticles biological and medical applications is gaining a great interest becauseof their great positive influence in finding novel innovations and solving escalating medicalproblems like the multi drug resistance in infectious microorganisms that threaten the worldof not finding a curing drug. Nanoparticles of different physical and chemical properties are ofprimary concern to find a compound with antibacterial activity. Moreover, the ability tosynthesis nanoparticles in different shells; ranging from pure chemical to natural materialsopen new era of investigating the antipacterial activity and finding the magical antibacterialdrug. In this study, different forms of metallic nanoparticles synthesized in different shellswill be investigated for their antibacterial activities.Size selective synthesis of ZnO nanoparticles is being prepared by electrochemical and/orreduction methods. Two forms of stabilization; with alkyl quaternary ammonium compoundssurfactants and with quaternary surfactant in combination with antibiotics are in progress toinvestigate their antibacterial activity. Primarily, antibacterial activity presented by theminimum inhibitory concentration of the different forms of the prepared nanoparticles isbeing evaluated spectrophotometrically or visually. The reference materials and theindividual nanoparticles possess a relative antibacterial activity. A more detailed analysis ofthe nanoparticles prepared with tetra-alkyl ammonium salt as stabilizing matrix and tetraalkylammonium salt with amoxicillin is now in progress.

Ethanolic extracts of six plants (Arum palaestinum, Urtica pilulifera, Coridothymus capitatus, Majorana syriaca, Teucrium creticum, Teucrium polium), used in traditional medicine in Palestine were tested for their antioxidant and anticancer activities. They showed different ranges of antioxidant activity due to DPPH and β-Carotene-linoleic acid assays. The extracts were also tested for their ability to inhibit the proliferation of breast cancer cells (MCF-7) using the MTT reduction assay. The extract of U. pilulifera revealed the highest antioxidant due to β-Carotene-linoleic acid assay and showed the highest cytotoxicity against breast cancer.

The self-assembly behavior of Benzotriazoles in aqueous solutions below its solubility limit has been investigated using light scattering techniques. Various light scattering techniques were used to study the aqueous behavior of benzotriazole-1-methanol (BTAOH) and other family members. These studies have revealed the self-assembly of these molecules in water. Results show that Benzotriazoles molecules tend to aggregate in water to form nanoparticles with radius in the range of 25 nm and more. However, a range of sizes was always present in BTAOH solutions even with lower concentrations. Variable temperature DLS studies show that large particles are mainly formed due to the aggregation of smaller ones.

Since the discovery of carbon nanotubes in 1991 by Sumio Iijima, carbon nanotubes are becoming rapidly prominent in research and innovative new technologies. This paper explores the fundamentals behind the unique structure of carbon nanotubes and the concepts in synthesizing them. Furthermore, this report provides a brief overview of their properties and various applications

Certain cyanobacteria change the tetrapyrrole pigments attached to phycoerythrin inresponse to the color of light available. These tetrapyrrole pigments consist ofphycoerythrobilin (PEB) and phycourobilin (PUB) which are structural isomers PEB andPUB differ in the position of one double bond and are therefore isobaric but have differentUV-absorbance spectra. Each phycobiliprotein may have several bilin pigments attached tovarious cysteine residues. Researchers purify microgram amounts of protein to performHPLC-UV-VIS experiments to identify the pigments utilized by the organism. The pigmentsattached to phycoerythrins produced in green vs blue light in Synechococcus RS 9916 havenot been determined. This work utilizes the CID fragmentation patterns of differentbilipeptides in conjunction with UV-absorbance to facilitate pigment attachment siteidentifications.

Clarithromycin is a semi-synthetic broad spectrum macrolide antibiotic widely used for theeradication of respiratory tract infections including atypical pneumonias and soft tissueinfections. It is an important substitute for patients exhibiting penicillin sensitivity andallergy.The methods reported previously for the detection of clarithromycin have mainly used lengthysample preparation procedures involving liquid–liquid extraction or solid-phase extractionprior to chromatographic analysis and most of these methods suffer from long run times andrequire large sample volumes. Although these methods offer selective detection ofclarithromycin but they are much more complex than the conventional ultraviolet (UV)detection. Clarithromycin has weak UV absorbance because it lacks a suitable chromophorewhich makes difficult to develop a specific, selective and sensitive method usingspectrophotometry without complexation and derivatization. As a impact of such laboratorypractice, large amounts of waste chemical are produced every day in industrial laboratorieswhich is of great concern throughout the world since long. So it becomes necessary to developalternative strategy which can substitute such traditional methods with clean andenvironmental friendly analytical means involving minimum consumption or replacement oftoxic reagents with the reagents having no or less polluting effects.A rapid, sensitive and environmental friendly analytical method for the direct determinationof clarithromycin in tablet formulations through transmission Fourier Transform Infrared(FT-IR) spectroscopy has been successfully developed for routine quality control analysis. Thismethod avoids any sample pretreatment except grinding or use of any solvent as extraction isno more required. Standards and samples were used in the form of KBr for recording FT-IRspectra. In the final step, chemometric method was used to filter out unmatched spectralfeatures and the converted and filtered spectra were used to build a calibration model basedon partial least square (PLS) using the FT-IR carbonyl region (C=O) from 2965-1662 cm−1.The excellent correlation coefficient (R2) was achieved (0.9999). This method gives maximumAnalytical Chemistry(IYC-2011) 79recovery of 102% and is fully validated. This also fulfills the ever increasing demand ofpharmaceutical industries for developing sensitive, economical, time consuming andenvironmental friendly analytical methods for the quantification of Active PharmaceuticalIngredients (API) while monitoring quality of finished product with total analysis time of lessthan three minutes.

Chiral bimetallic palladium (II) complex B was used in a catalytic air oxidation process to convert ketones directly into optically active α-hydroxyketones. The reaction was carried out in an aqueous solution of THF or dioxane, and in the presence of a catalytic amount of an acid. The enantiomeric excess (e.e.) of produced

A disposable single-use optical sensor to determine potassium based on an ion-exchange mechanism is described. The test strip is formed by a circular sensing film zone 6 mm in diameter and 4.7 |im in thickness that contains all the reagents necessary to produce a selective response to potassium on a polyester sheet. The sensing zone is formed by a plasticised PVC that incorporates the cation-selective neutral ionophore dibenzo-18-crown-6, lipophilised Nile Blue, and a lipophilic salt. At pH 9.0, the absorbance response of the test strip at 660 nm shows a good correlation with the theoretical behavior. All experimental variables that influence response, especially in terms of selectivity and response time, have been studied. The sensor responded linearly in activities in the range of 0.0125 and 76.8 mM. The detection limit is 0.0125 mM, the reproducibility intermembrane, at a medium level of the range, is 3.4%, as R.S.D. of log aK+ and the intramembrane, 3.0%. The procedure was applied to the determination of potassium in different human plasma samples, pharmaceutical compounds and seawater samples, validating results against a reference procedure.

Gabapentin which is chemically known as 1-aminomethyl-1-cyclohexaneacetic acid and its structure is shown below is a very well known pharmaceutical drug useful for the treatment of epilepsy and other cerebral disorders. The medicine suffers form several disadvantages and low bioactivity. This presentation covers an overview about the drug synthesis, application and new ways of structure modification that could enhance the bioactivity of Gabapentin and reduces it side effects. The suggested chemical modification of Gabapentin is expected to increase its permeability to blood brain barrier.

Electrochromic films of NiO & NixTi1-xO(2-x) (with Ti concentrations 5, 10, 15, 20, 25 & 30%) have been prepared by the sol-gel route using dip coating technique onto fluorine-doped tin oxide-coated glass substrates (FTO/glass). Ethanolic sols from nickel acetate tetrahydrate (Ni(CH3COO)2 • 4H2O) and titanium isopropoxide precursors were used in the preparations. The nano-sized films were sintered in air between 250 and 300°C. Characteristics of different films were studied in a comparative manner. Photoluminescence spectra, electrochromic behavior, cyclic voltammetry, XRD, thickness and SEM have been investigated. Typically, as the TiO2 content was increased, film characteristics were enhanced. Mechanisms of coloration and morphology transformation of the layer during cycling in 0.05 M KOH electrolyte were discussed in terms of an activation and degradation period. Calculation of cathodic charge (QC ), anodic charge (Qa), Optical density & Coloration efficiency were made. Our results indicate that electrochromic and other characteristics of the NiO can be enhanced by addition of TiO2 at certain concentrations.

The reaction mechanism of the Stevens Rearrangement is very much controversial one. Theformation of the products in Stevens Rearrangement mainly explained by the “radical pairmechanism” and sometimes by the “ionic pair mechanism”. But the two mechanisms are stillvery much controversial. To explain the formation of normal and abnormal product of theStevens Rearrangement, I proposed a new mechanism scheme entitled the ERC (EliminationRecombination Coupling) mechanism. This mechanism will explain the formation ofabnormal as well as normal product and will also maintain parity between the “radical pairmechanism” and the “ionic pair mechanism”.

Nanomaterials are of enormous fundamental interest, both from the point of view of discovering new physical phenomena as well as for their exploitation in novel devices. It is for these reasons that new nanostructures are being synthesized, functionalized and examined with respect to their special optical and electronic properties. Carbon nanotubes have a broad spectrum of interesting properties, which are relevant for technological applications. They are used for field emission and gas storage and are discussed as basic elements for future electronic devices in nanoscience and technology. Because of their nanometric dimensions and their interesting electronic properties, single walled carbon nanotubes (SWNT), in particular, are considered attractive structures toreplace the semiconductor components essential in integrated circuits. The application of carbon nanotubes for producing transistors or saturable absorbers has been extensively studied; however for such applications isolated semiconducting tubes are needed. Conversely, isolated metallic nanotubes are desirable as nano-conductors. The direct synthesis of SWNT of a particular electronic form, and of a particular chirality is still lacking. Graphene is also a remarkable material with incredible electrical and mechanical properties which was isolated more recently. This has made graphene the “new rising star” in nano-carbon based materials due to its exciting properties at the nanoscale, e.g. high charge carrier mobility. In addition, when existing as narrow strips or ribbons (ca. 10 nm wide) a band gap opens making them excellent candidates for field effect transistors. Hence, apart from the exciting possibilities in discovering new physics from these 2D structures, they offer tantalizing opportunities for the development of high speed (and even flexible) molecular electronics. In order to integrate graphene in to electronics it needs to be fabricated in large areas or in highly defined ways (e.g. nanoribbons), better still, in a manner suited to current complimentary metal oxide semiconductor (CMOS) technology. Graphene synthesis routes which are directly compatible with current Si technology are limited. The more popular routes to synthesize carbon nanotubes and graphene are based on the use of catalysts and these are usually metallic catalysts. Despite the success of metal catalysts Plenary they have certain drawbacks; they can be toxic and cause problems in clean room environments. In addition, in the case of nanotubes, they can be quite difficult to remove and in the process of removing them, the nanostructures themselves are often damaged. Over the last few years the use of ceramics, in particular oxide catalyst systems have begun to emerge for carbon nanotube synthesis. These exciting new catalyst systems suggest some contemporary concepts regarding their growth need reevaluating. Moreover, many of the oxides used as catalysts are often implemented as supports in Supported catalytic growth of carbon nanotubes and raise the question as to whether such supports may actually participate in the growth of the carbon nanotubes? Recent studies suggest the oxides can play an active role in the catalytic decomposition of the hydrocarbon feedstock and in the formation of sp2 carbon. This latter point is particularly pertinent to graphene because it suggests the possibility of growing graphene directly on oxide surfaces. The CVD synthesis of grapheme directly on oxides dispenses the need to transfer graphene after synthesis, as is the case with metal catalysts. Early investigations have shown nanographene can be formed directly over oxide surfaces using simple CVD routes. Another emerging route is a catalyst “free” route in which no catalyst material is required. Some argue the carbon structures themselves fulfill the catalytic role.

New type of heterogeneous nanocatalyst for deoximation based on Tungsten oxide supported
on mesoporous molecular sieve MCM-41 was developed. This new system representes
inexpensive and highly active heterogeneous nanocatalyst for deoximation under green and
mild reaction conditions.

A facile and short synthesis of a series of quinazolino[[3,2-a][1,4]benzodiazepine scaffold found in several biologically active naturally occurring alkaloids, including asperlicin C, circumdatin H and benzomalvin A is reported. Coupling of [1,4]benzodiazepine with 2- nitrobenzoyl chlorides, followed by a reductive N-heterocyclization afforded the quinazolino[[3,2-a][1,4]benzodiazepine ring system. Furthermore Lewis acid (MgCl2, ZnCl2) mediated cyclodehydration of a linear tripeptide comprised of three amino acid units provided the tricyclic quinazolino[3,2-d][1,4]benzodiazepine ring system found in few biologically active natural alkaloids. This methodology, implemented with a tripeptide encompassing the sequence of anthranilic-anthranilic-tryptophan methyl ester, furnish the first total synthesis of asperlicin D.

Pharmaceutical pollution is one of the most serious types of environmental pollution, that attracts increasing attention & lead research studies in recent years. Because of their great impact on aquatic life, soil & under ground water as emerging aquatic micro pollutants that have possibly been affecting the ecological system. It could have major implications on plants, wildlife and humans who may be directly & indirectly be responsible of this type of pollution. In this study two antibacterials were selected, oxytetracycline & doxycycline as examples of pharmaceuticals that are released into the environment, both are marketed in the Palestinian market either for human pharmaceutical industry or the veterinary one. In this research the adsorption behavior of both pharmaceuticals on soil, the effect of organic matter, the effect of magnesium chloride hepta hydrate addition on polluted soil, in addition their effect on characteristics of under ground water, all were studied using the UV-Vis spectrophotometry. The results showed that increasing organic matter increases the adsorption of oxytetracycline more than doxycycline, also showed that the composition of oxytetracycline complex with magnesium ion was more stable than doxycycline complex with magnesium. The study also revealed a higher concentration of doxycycline in leachate water from the soil than those of oxytetracycline, because doxycycline has higher solubility in water. It also showed a decrease of the concentrations for both substances over time in leachate water due to degradation. The degradation of both pharmaceuticals in soil & water would be produced by other substances may be harmful, as the threat of their presence in the soil and groundwater would increase the resistance of bacteria in the soil, in another words that would affect the natural properties of soil and groundwater as well.

The physical and chemical properties of low dimensional nanometer sized materials, such as nanocrystalline materials and clusters, are of particular interest because they are often size dependent and different to bulk properties [1,2]. With decreasing the size of the clusters to the nano-range the number of surface atom to volume is increased and their properties become size dependent. Metallic clusters are used intensively in catalysis reactions such as Hydrosilylation, isomerization and hydrogenation reactions. In the case of Palladium clusters and its alloys, hydrogen can be absorbed in internal sites of the clusters [2, 4]. The palladium-hydrogen system is thus in a special way is suited for the investigation of physical properties of binary alloy systems at the smallest scale. In this work the hydrogen solubility in different metallic clusters with discrete sizes have been investigated. Surfactant and polymer stabilized clusters, which are tension-free stabilized and have a narrow size distribution, have been prepared. Their crystallographic structure is a function of cluster size between the icosahedral and the cubic. The critical cluster size for the structural change was found to be about 4.8 nm for quasi-free stabilized Pd clusters. In this work the thermodynamic absorption behaviour of hydrogen in nanometerd- sized metallic clusters with different sized and different structure have been determined from gravimetric and volumetric solubility isotherms. The phase transition in these samples was monitored by in situ X-ray diffraction measurements during hydrogen loading. Preliminary studies have already shown that the phase boundaries and the hydrogen uptake ability in these samples depends strongly on the lattice structure which is affected by the type of metallic clusters and the stabilizer used in samples, and that the phase diagram of Pd-H system for small cluster is strongly different from that of the solid material [3,4,5]. In this paper comprehensive picture on the effect of the size and the structure on the activity and hence on the hydrogen absorption in the low dimension system will be presented.

Single-walled carbon nanotubes (SWNT) are considered to be a potential material for next generation nano-electronics because of their physical and electrical properties. Their potential as key components for devices has already been proven in different applications including, field-effect transistors and logic circuits. For such applications, it’s essential to synthesis SWCNT with controlled spatial position, orientation, alignment, yield and electronic type. One promising synthesis technique used for synthesizing horizontally or vertically aligned SWCNT is chemical vapor deposition (CVD). Using this method, different approaches to grow and control oriented SWNTs horizontally aligned on substrates have been explored, including low gaseous fluxes, electric fields, and selectively cut single crystal substrates such as ST-cut and AT-cut quartz. An important goal behind many of these studies is to control the density of the grown SWNT. Thermal annealing of the substrates prior the CVD process is an often implemented step to improve yield. Nevertheless, the role of the annealing step has not been fully investigated. In this study we systematically investigate the effect of the annealing step on the morphology and smoothness of the used ST-cut quartz substrates, in order to provide excellent conditions for high nucleation yields and allow for unhindered growth leading to long tubes (> 100μm). In addition, the surface morphology is shown to affect the size distribution of the catalyst nanoparticles which in turn affects their propensity to nucleate SWNT. The ratio of the metals (Fe:Co) in the catalyst mix is shown to be a less important parameter for the high yield synthesis of horizontally aligned SWNT on ST-cut quartz. The successful transfer of the grown SWCNTs onto other surfaces without incurring damage is also demonstrated.

Two medicinal plants Rosmarinus officinalis and Salvia Fruticosa are used in traditional medicine in Palestine for the treatment of gastrointestinal tract, also as antiseptic, antispasmodic and wound healing. In previous studies we have demonstrated the inhibitory effect of different aqueous and organic extracts of the arial parts of these shrubs. In this study we have been able to isolate the main active ingredient of R. officinalis, which is called Verbenone. The isolated compound was identified by means of different techniques such as UV. GC, IR, HNMR and C 13 NMR, with respect to Salvia Fruticosa (triloba) grows widely on the hills of the West Bank, and has been used by the local population to relief intestinal pain . Intensive studies were conducted to determine the organic and aqueous extracts of Salvia Fruticosa on intestinal motility. In the current study, the aerial parts of Salvia Fruticosa were collected and identified and the powdered were extracted with n- Hexane , DCM and methanol. The n- Hexane crude extract was found to be the most active with anti-inflammatory activity by inhibiting 5- lipooxygenase and cyclooxygenase enzymes. The n- Hexane crude extract was subjected to VLC and the fractions were collected and identified by TLC, HPLC, GC- MS, HNMR and 13 C- NMR.

In Palestine many factors affect the soil, surface and ground water. The extensive use of pesticides, fertilizers in agriculture, as well as disposal of wastewater from Israeli settlements in the West Bank, are also cited as contaminating the soil and further reducing the water resources available for Palestinians. Hazards chemicals including their intermediate metabolites may reach ground water and contaminate it. In recent years, pesticides were used heavily in Palestine, which led to the contamination of soil and water and causing much disease. Many studies focused on the impact of pollutants such as pesticides and oil on soil and how does it affect on humans, animals, plants and the environment in general. There are many factors affecting leachates of glyphosate to ground water as properties of the pesticide; chemical content, persistence, adsorption, solubility, volatility, and properties of glyphosate. Properties of the soil; permeability, Soil Texture, soil structure, organic matter, soil moisture and site conditions including rainfall and depth to ground water and sinkholes and bedrock were studied. In this study, the effect of glyphosate and its movement and distribution in soil columns were studied. The results of physical and chemical properties of soil were studied. The kinetic studies showed that the adsorption of glyphosate was first order and followed the Freundlich isotherm pattern.