Ph.D. Program in Chemistry
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- ItemDesign, Synthesis, Antimicrobial and Cytotoxicity of Curcumin Based Benzodiazepines, Diazepines, Diazoles and Amines(An-Najah National University, 2021-02-17) الكرم, رولا سلطان محمودIn this study novel sets of curcumin-based benzodiazepine, diazepine, diazoles and amines were prepared using simple and convenient condensation reaction; by reacting curcumin with various types of 1,2-diamino and hydrazine compounds. The prepared compounds were characterized using FT-IR, 1H NMR, and 13C NMR. Several simple and convenient synthetic methods were employed in order to prepare the desired products. In the first method, curcumin-based benzodiazepine, diazepine, diazoles, and amines were prepared by condensation reaction of curcumin with various 1,2 diamino and hydrazine compounds in either ethanol which was used as a solvent and H2SO4 as a catalyst. Another new set of curcumin-based benzodiazepine, diazepine, diazoles and amines were prepared using Knoevenagel Condensation that involves two-fold mechanism; The first step includes the formation of α,β-unsaturated intermediate 20 A using Knoevenagel condensation; by mixing curcumin with benzaldehyde in ethanol solvent, in the presence of catalytic amount of diisopropylamine (DIPA) base. Meanwhile, acid-catalyzed condensation cyclization reactions of the curcumin carbonyl groups of the synthesized intermediate with various 1,2-diamino or hydrazine compounds were involved in the second step to produce the desired products. The Knoevenagel condensation was employed in this work to prevent keto-enol tautomerization, which expected to enhance the yield. H-Curcumin-based amine was prepared by condensation reaction of H-curcumin with ammonium acetate in two steps; the first step involved heating the resulting mixture at 60 °C until complete solvent evaporation. Followed by heating the resulted compound again at 60 °C for an hour. Then a selected set of the prepared curcumin-based compounds was functionalized with methoxy group. Where; the phenolic groups of the selected compounds were alkylated by reacting with iodomethane in the presence of sodium hydroxide. Functionalization of the prepared curcumin-based compounds with alkyl groups was employed in this work in order to determine the effect of the hydroxyl group on the antimicrobial activity. Antibacterial activities of selected set of the prepared curcumin-based heterocycles were evaluated against four types of bacteria strains: S. aureus, MRSA, E. coli and K. pneumoniae. The antimicrobial activity occurred by inhibition of growth of the tested strains with MIC values ranging between 1.56-200 μg/mL. In general, the potency against S. aureus and Klebsiella is greater than that against MRSA and E. coli. However, the highest activity was shown by compound 9 as it showed MIC of (1.56, 1.56, 50 μg/ mL) against S. aureus, MRSA, and Klebsiella respectively. And it is the only compound that showed activity against MRSA with MIC of (1.56 μg/ mL). Moreover, the prepared curcumin-based heterocycle diazepines (compounds 2, 4, 10, 35) showed synergistic effects with ampicillin antibiotics. Furthermore, the Genotoxicity test was performed on compound 8. Results showed that compound 8 did not interact with the DNA molecule in E. coli strains. Thus, it is considered as a non-mutagenic or non-genotoxic agent. This study revealed that, the prepared curcumin-based diazepine could be a promising design for a potentially active antibacterial synergized agent with conventional antibiotics.
- ItemModification of Biologically Active Compounds from selected Medicinal Plants in Palestine(2009) Ahmed Ibrahim Ahmed Hussein; Prof.Mohammed Saleem Ishtayeh; Dr.Wahid Al Jundi; Dr.Nidal Za'tarSix plants used in traditional medicine in Palestine were tested for their biological activity. They were collected from Nablus region. These plants include four families namely Araceae (Arum palaestinum), Urticaceae (Urtica pilulifera), Labiatae (Coridothymus capitatus, Majorana syriaca) and Lamiaceae (Teucrium creticum, Teucrium polium). The ethanolic extracts of those plants were tested for their antioxidant activity through DPPH assay and β-Carotene-linoleic acid assay. The concentrations of Phenolic compounds and Flavonoids were determined as µg/mg equivalent of quercetin and pyrocatechol. The extracts of the plants were tested also for their antifungal activity against four pathogenic fungi: Trichophyton tonsurans, Microsporum canis, Trichophyton rubrum and Trichophyton violaceum, compared with the activity of econazole. The extracts were also tested for their anticancer activity against prostate PC3 human carcinoma. All of the extracts showed different potential biological activities in all tests. Phytochemical screening indicated the presence of Flavonoids and phenolics in all extracts. T. creticum and C. capitatus were the most efficient antioxidants in DPPH assay, while U. pilulifera and C. capitatus were the most efficient as antioxidants in β-Carotene-linoleic acid assay. C. capitatus and M. syriaca were the active against fungi between the six plants. U. pilulifera and A. palaestinum showed the highest potent antiproliferative activity. Some constituents were detected from plants extracts using GC-MS spectrophotometer and separated by flash chromatography. These constituents were tested for their biological activity. Many reactions were done to modify the activity of these constituents. Four phenolic acid esters were synthesized and tested for their biological activity in the same methodology used in testing the extracts. All of the synthesized compounds showed significant biological activity in all tests.
- ItemDye-Modified Nano-Crystalline TiO2 Surfaces in Light-Driven Water Purification from Organic Contaminants(2005) Lamees Zuhair Abdul Razeq Majjad; Prof. Hikmat Hilal; Dr. Nidal ZatarPhenol and benzoic acid are examples of water contaminants that are difficult to degrade by conventional chemical and/or biological methods in water. Photo-electrochemical methods have been examined to degrade phenol and benzoic acid, in this work. Naked, and/or modified TiO2 (anatase) surfaces have been examined for such purposes. There are many researches in this field, but for the first time TiO2, modified with metalloporphyrins (MnP) and triphenylpyrilium hydrogen sulfate (TPPHS) have been prepared and used, and also for the first time the modified TiO2 systems were supported onto activated carbon (AC) and used in degradation experiments. UV light was needed for degradation of phenol and benzoic acid, giving CO2 and H2O as final products. Visible light was successfully used to degrade Tamaron insecticide using TiO2/TPPHS and AC/TiO2/TPPHS catalytic systems, which are prepared for the first time in this research.Supported and unsupported TiO2/MnP was also catalytically active in visible light degradation of Tamaron, which are also prepared for the first time in this research. All photo-degradation processes demanded oxygen but not in high concentrations. It was noticed that the degradation was also temperature, speed of stirring, catalyst concentration, and initial concentration of contaminants independent. Recovered AC/TiO2/TPPHS catalyst samples showed lower activity than fresh ones. The activity loss is attributed not to TPPHS degradation but to TiO2/TPPHS burial inside AC bulk. The results indicate the importance of TPPHS or MnP dyes in activating TiO2 in degradation processes, by behaving either as sensitizers, when using visible light, or as charge transfer catalysts, when using ultra violet light. Considering that, we propose charge transfer catalyst model for the first time.
- ItemNanoparticle CdS-Sensitized TiO2 Catalyst for Photo-Degradation of Water Organic Contaminants: Feasibility Assessment and Natural-Dye Alternatives(2009) Ahed Husni Abdel-Razaq Zyoud; Prof. Dr. Hikmat Hilal; Dr. Nidal ZatarThe photocatalytic degradation of organic contaminants (like dyes, insecticide, pesticide, … etc) in water, using TiO2 under UV are commonly used procedures. Modifying TiO2 with CdS also a common technique used for water purification under visible light. In this work both commercially and prepared TiO2 were used for photo-degradation of both contaminates models ( Methyl Orange MO and Phenazpyridine PhPy), TiCl3 was used as a starting rote for preparation of rutile structure TiO2 by hydrolysis. In order to sensitization of TiO2 to photoexcited under visible light, A chemical path deposition method (CBD) was used to precipitate a nonsocial particles of CdS on TiO2 particles surface. Sand was used as a supporting surface for the prepared catalyst. UV-visible scanning, photoluminescence measurements, XRD characterization, and SEM imaging were run for the prepared catalyst systems. The particles size of prepared CdS particle was found to be 20 nm. The influence of the catalyst concentration, initial contaminant concentration and pH on photo-degradation rate were studied. Turnover number and Quantum yield were also calculated for comparison study. There is no observable increases in photo-degradation rate with increasing contaminants and catalyst concentration, but a decrease in the rate was observed, no effect to the temperature on the rate, also a higher photo-degradation rate for (MO & PhPy) was observed at higher pH degrees. Voltametric analysis shows almost complete CdS decomposition during the photo-degradation process. Due to hazardous and toxicity of decomposed Cd2+ in the treated water, an alternative of natural nontoxic dyes (Anthocyanin) was used for the first time as a sensitizer for the rutile TiO2. AC was also used as a supporting substrate. Electronic absorption spectra, FT-IR spectra, and TGA analysis were applied on the prepared TiO2/Anthocyanine catalyst systems.A screen study was done to test the efficiency of the prepared sensitized catalyst, the catalyst was applied to photodegradate MO and PhPY. An observable efficiency was noted specially when using AC/TiO2/Anthocyanin at low pH in photo-degradation of MO.
- ItemThe Influence Of Surfactants On The Adsorption Of Heavy Metal Ions Using Inorganic Legands In Selected Contaminated Soil Samples In Palestine(2010) Ahmad A.Abu-Obaid; Prof. Radi Dauood; Dr. Shdeh JoudehHeavy metals are persistent pollutants in the environment. Problems associated with the cleanup of sites contaminated by metals have demonstrated the need to develop remediation technologies that are feasible, quick, and effective in a wide range of physical settings. Experiments were conducted to investigate the efficiency of surfactants and ligands on cleaning artificially contaminated red, sandy and white chalk soil samples with heavy metals e.g. (Cd (II), Cu (II), Pb (II) and Zn (II)). Before contamination, soils were characterized to determine particle size, pH, organic matter content and heavy metal contents. The results of experimental sorption data fitted very well the Freundlich isotherm model and first order kinetics model.In this study we have investigated the adsorption of Cd (II), Cu (II), Pb (II) and Zn (II) onto each soil in single and multi-element systems as a function of soil and heavy metal concentrations. The best pH for adsorption of Cu2+ on red soil was found to be 4.0.Adsorption of metals on soil increased in the order Cu > Pb > Zn Cd.This trend might be related to the increase in the electronegativity of the metalion. Surfactants are efficient soil remediation agents for heavy metals.Various concentrations of four different surfactants Triton; X-100, SDS, Tergitol and Tween 80 were used as washing solution for remediation of contaminated soils. Triton X-100 (0.1 M) was the best surfactant to desorb copper from red soil. Tween 80 was the best surfactant to desorb copper from sandy and white chalk soils. Recently, ligands were enhancing surfactants to desorb heavy metals from contaminated soils. Surfactants in combination with ligands were tested as washing agents for contaminated soils. Different concentrations of three different ligands (I- , SCN- and EDTA) along with nonionic surfactant, Triton X-100 were applied as soil washing agents to desorb copper from artificially contaminated soils. Triton X-100 with 0.1 M EDTA showed a higher capacity to desorb copper than did with 0.4 M SCN‑ or 0.4 M I-.The increase of ligand concentration was a critical factor for increasing leaching capacity. Without the presence of a ligand, the surfactant alone was not able to desorb copper effectively from soil.