Green Preparation of Aluminum-based Metal-organic Framework (Al-MOF) from Waste Plastic Bottles and Waste Aluminum Scraps

The vast use of polyethylene terephthalate (PET) drinking water bottles has increased dramatically worldwide in recent decades, inflicting severe consequences on the environment. According to the latest survey, a million plastic bottles are bought around the globe every minute. The non-biodegradable nature of PET materials has led to a huge accumulation of plastic in waste landfills. Among the current recycling methods used to solve this environmental problem is chemical recycling. In this method, PET bottles are converted back cleanly into their starting materials: terephthalic acid and ethylene glycol. This paper unveils the exploitation of recycling products from PET bottles and aluminium scraps in order to prepare a metal-organic framework (MOF) material. The characterization of the prepared MOF substance was carried out using different techniques such as IR, XRD, SEM and elemental analysis.                 &nbsp

Convenient Synthesis of a Novel Flavonoid with Extended π-System: Active Agent for UVA Protection

Flavonoid derivative with extended cinnamic acid moiety was synthesized using Baker-Venkataraman reaction. The compound shows interesting UV absorption properties which make it a good UVA absorber. A bathochromic shift of 18 nm was observed when the size of cinnamic acid segment was increased by one styrylogous extension

Stereoselectivity of the Wittig reaction in two-phase system

370-374The Wittig reaction of benzyltriphenylphosphonium chloride with aliphatic and aromatic aldehydes has been investigated, respectively, in two-phase solvent system (dichloromethane / water) in the presence of sodium hydroxide. Both, the effect of the size of aliphatic aldehydes and the effect of substitution on benzaldehyde to the cis/trans ratios have been studied. It has been found that the use of aliphatic aldehydes in Wittig reaction gives higher ratio of trans alkene isomer. However, when aromatic aldehyde is used, the ratio of the cis alkene isomer is found to be higher than that of the trans isomer. In addition, the electronic nature of substituents (electron-donating group versus electron-withdrawing group) causes some changes in the cis/trans ratio of the product stilbene

Isolation of Aristolochic Acids from Aristolochia Bracteolata and Studies of their Antioxidant Activities

The isolation and structural elucidation of aristolochic acid-A and aristolochic acid-D from Omani Aristolochia bracteolata plant is reported. Antioxidant activities of these two natural products were evaluated for their capacity to reduce Mo(VI) to Mo(V).  The study revealed that aristolochic acid-D is more active than vitamin C while aristolochic acid-A has activity similar to vitamin C

Screening of Antioxidant and Radical Scavenging Activities of Some Omani Medicinal Plants

n-Butanol extracts of nine medicinal plants, Cressa cretica, Ziziphus spina-christ, Acacia tortilis, Tephrosia haussknechti, Aristolochiae bracteolata, Citrullus colocynthis, Teucrium mascatense, Rhazya stricta and Nerium oleander, found in Oman were screened for their antioxidant activity using phosphomolybdenum complex assays and their radical scavenging activity using DPPH assays. Ocimumi basilicum, a plant with well documented antioxidant activity, was used as a reference. A. tortilis, and T. haussknechti extracts possessed very high antioxidant activity (AOA) and high radical scavenging activity (RSA)

Research and Reviews: Journal of Chemistry UV Photocatalytic Degradation of Toluene and Tetradecane Using Anatase TiO2 Crystals

ABSTRACT Crystalline titanium oxide was obtained by simple and low cost method. X-ray diffraction (XRD) measurements confirmed that the prepared TiO2 catalyst has a single anatase structure with no indication of the presence of a secondary phase. Transmission electron microscopy (TEM) micrograph demonstrates that the anatse TiO2 has spherical homogenous crystals with average diameter of 1.10 nm. Toluene and tetradecane adsorbed on the surface of titanium oxide were easily degraded when exposed to UV light. The % removals of toluene and tetradecane at 120 minutes were 84.5 and 98.8 respectively

Development and Validation of an RP-HPLC-FLD Method for the Determination of Biogenic Amines after Pre-column Derivatization with a New Pyrazoline Based Reagent, 3- Naphthyl-1-(4-trifluoromethyl)-5-(4-carboxy phenyl)-2-pyrazoline

Application of 3-Naphthyl-1-(4-trifluoromethyl)-5-(4-carboxy phenyl)-2-pyrazoline (NFCP) as a novel fluorigenic label for the derivatization of biogenic amines (BAs) and separation by liquid chromatography (LC) was investigated. Optimum conditions for the pre-column derivatization and chromatographic separation were investigated. The resulting derivatives are fluorescent at λex/λem: 380/460 nm. For the sake of evaluating the efficacy of the proposed analysis of BAs of different nature, the formation of nine NFCP-BAs derivatives was tested individually. Simultaneous derivatization and separation of four BAs (histamine, tyramine, tryptamine, and phenylethylamine) were achieved under the isocratic elution mode. Furthermore, the derivatives were identified by the characteristic product ion obtained during LC-MS/MS analysis. The viability of the method was established by measuring levels of histamine in fresh and spoiled fish samples. Histamine concentrations were found to be 0.4 µgg-1 and 4.1 µgg-1 in fresh and spoiled tuna fish samples respectively. As a simple, reliable, and sensitive pre-column derivatization method, this work provides for future research to develop a novel HPLC method for the analysis of BAs from food samples such as fish and various other matrices by utilizing the new pyrazoline compound

Study on the Reactivity of Amino Acid Chemosensor, NPFNP, with Ethanol: Structural Elucidation through Single Crystal XRD and DFT Calculations

A novel ethoxy derivative of an amino acid chemosensor, 3-naphthyl-1-phenyl-5-(2ʹ-fluoro-5ʹ-nitrophenyl)-2-pyrazoline (NPFNP), has been synthesized and characterized by different spectroscopic methods.  A single crystal of the ethoxy derivative, 3-naphthyl-1-phenyl-5-(2ʹ-ethoxy-5ʹ-nitrophenyl)-2-pyrazoline NPENP, has been obtained and characterized.  The structure holds interest as it carries biologically active pyrazoline as a central ring attaching to electron donating and withdrawing substituents. The major motivation for this work was to gain detailed insight into the structural parameters of this compound for investigating the influence of crystal packing and geometrical dimensions on optical properties. Time-dependent DFT calculations have been employed for comparing the XRD data with theoretical parameters. The results show that the DFT method at B3LYP/6-31G level can well reproduce the structure of the title compound

Comparison of Chemical Composition and Antioxidant Activity of Four Essential Oils Extracted from Different Parts of Juniperus excelsa

The chemical contents and compositions of four essential oils extracted from leaves, branches, fruits and gum-resin of Juniperus excelsa from Jabal Al-Akhdhar in the Sultanate of Oman were studied using infra-red (IR) spectroscopy and gas chromatography-mass spectrometry (GC-MS). IR analysis revealed the presence of C-H, O-H, C=C and C=O functionality bonds with varied intensities. The GC-MS study showed the occurrence of 35 different monoterpenes of which 11 (31.43%) monoterpenes were shared by the four oils. α-Pinene was detected in branches and gum-resin oils as a major compound with different proportions (80.50% in     gum oil and 79.03% in branches oil).  The major component in leaf and fruit oils was the monoterpene limonene with proportions of 50.46% and 42.51%, respectively. Sesquiterpenes exist in leaf, branch and fruit essential oils but not in gum-resin oil. The essential oil of the leaves showed stronger antioxidant and radical scavenging activities than the other oils