Ultrasound-assisted chiral derivatization of etodolac with (1R)-(-)-menthyl chloroformate for the determination of etodolac enantiomers

Jin, Y.,Zhao, J.,Rhyman, L.,Ramasami, P.,Shin, Y.,Jeong, K.M.,Lee, J. Elsevier ; King Saud University 2016 Arabian journal of chemistry Vol.9 No.suppl2

<P>This study presents the first report of an ultrasound-assisted derivatization reaction between a carboxylic acid of etodolac (ETO) and a chiral derivatization reagent, (1R)-(-)-menthyl chloroformate (R-MCF). Fifty mu L of deproteinated mouse serum containing ETO enantiomers was derivatized with 125 mu L of 200 mM R-MCF and 17 mu L of pyridine (a catalyst), with the reaction facilitated by ultrasonic radiation for 13 min, which were the optimal conditions as determined by response surface methodology. After quenching the reaction by adding an aqueous L-proline solution, the mixture was subjected to salting-out assisted liquid-liquid extraction (SA-LLE), which provided phase separation for sample concentration as well as cleanup. The ETO diastereomers were separated on a Phenomenex Gemini C-18 column (150 x 4.6 mm, 5 mu m) under a simple gradient elution of a mobile phase containing a mixture of methanol: acetonitrile (10: 1, V/V) and 10 mM acetic acid at a flow rate of 1.0 mL min(-1), followed by fluorescence detection with excitation and fluorescence emission wavelengths of 235 nm and 345 nm, respectively. The developed method was validated for specificity, sensitivity, linearity, accuracy, precision, stability, and matrix effect. A good linearity in the range of 0.5-50.0 mu g mL(-1) for each ETO enantiomer with r(2) > 0.998 and acceptable values for the intra-day and inter-day accuracy and precision as well as negligible matrix effects supported the suitability and reliability of the method. Finally, this method was used to analyze real samples taken from mice treated with (+/-)-ETO. (C) 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University.</P>

Synthesis, characterization and application of 1-butyl-3-methylimidazolium tetrafluoroborate for extractive desulfurization of liquid fuel

Dharaskar, S.A.,Wasewar, K.L.,Varma, M.N.,Shende, D.Z.,Yoo, C. Elsevier ; King Saud University 2016 Arabian journal of chemistry Vol.9 No.4

<P>In the present paper the experimental data of extractive desulfurization of liquid fuel using 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM]BF4 have been presented. The data of FTIR, 1 H NMR and C-13 NMR have been discussed for the molecular confirmation of synthesized [BMIM]BF4. Further, the thermal properties, conductivity, solubility, and viscosity analysis of the [BMIM]BF4 were carried out. The effects of reaction time, reaction temperature, sulfur compounds, and recycling of ionic liquid without regeneration on dibenzothiophene removal of liquid fuel were presented. In extractive desulfurization process, the removal of dibenzothiophene in n-dodecane was 73.02% for mass ratio of 1: 1 in 30 min at 30 degrees C under the mild reaction conditions. The ionic liquids could be reused four times without a significant decrease in activity. Also, the desulfurizations of real fuels, multistage extraction were presented. The data and results provided in the present paper explore the significant insights of imidazoled ILs for extractive desulfurization of liquid fuels. (C) 2013 Production and hosting by Elsevier B.V. on behalf of King Saud University.</P>

X-ray diffraction and X-ray absorption spectroscopic analyses for intercalative nanohybrids with low crystallinity

Park, D.H.,Yang, J.H.,Vinu, A.,Elzatahry, A.,Choy, J.H. Elsevier ; King Saud University 2016 Arabian journal of chemistry Vol.9 No.2

<P>Intercalation reactions can be achieved through ion-exchange, pillaring, and exfoliation-reassembling reactions to explore new intercalation compounds with desired electronic, electrochemical, and optical functions. Such intercalative nanohybrids with lamellar or porous structure have received much attention due to their potential applications such as catalysts, electrodes, selective adsorbents, stabilizing agents, and even drug delivery systems. In this review, we briefly introduce and highlight X-ray diffraction and X-ray absorption spectroscopy studies on the intercalative nanohybrids to understand their intracrystalline and electronic structures along with physicochemical functions. (C) 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University.</P>

Triethylammonium acetate ionic liquid assisted one-pot synthesis of dihydropyrimidinones and evaluation of their antioxidant and antibacterial activities

Attri, P.,Bhatia, R.,Gaur, J.,Arora, B.,Gupta, A.,Kumar, N.,Choi, E.H. Elsevier ; King Saud University 2017 Arabian journal of chemistry Vol.10 No.2

<P>A mild and efficient catalytic method has been developed to synthesize 3,4-dihydropyrimidinones in high yield by one-pot three component Biginelli condensation in the presence of triethylammonium acetate (TEAA) which acts as catalyst/reaction medium. Further, we have studied the antioxidant and antibacterial activities of these synthesized 3,4-dihydropyrimidinones. All the synthesized compounds reveal the significant antioxidant properties, these properties have been studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and cupric reducing antioxidant capacity (CUPRAC) assays. In addition, to this, these compounds also show the good antibacterial activity against four human pathogenic bacteria. (C) 2014 King Saud University. Production and hosting by Elsevier B.V.</P>

Green synthesis: In-vitro anticancer activity of copper oxide nanoparticles against human cervical carcinoma cells

Nagajyothi, P.C.,Muthuraman, P.,Sreekanth, T.V.M.,Kim, D.H.,Shim, J. Elsevier ; King Saud University 2017 Arabian journal of chemistry Vol.10 No.2

<P>Copper oxide nanoparticles (CuO NPs) were synthesized by a green route using an aqueous black bean extract and characterized by XRD, FT-IR, XPS, Raman spectroscopy, DLS, TEM, SAED, SEM, and EDX. The synthesized CuO NPs were spherical in shape, and the XRD results show the average size of the NPs was similar to 26.6 nm. The cytotoxic effect of the CuO NPs was determined by sulforhodamine-B assay. Mitochondria-derived reactive oxygen species (ROS) were increased and initiated lipid peroxidation of the liposomal membrane, which regulates several signaling pathways and influences the cytokinetic movements of cells. Mitochondrial fragmentation disruption assay confirmed the alteration in the mitochondrial structure after incubation with nanoparticles. In addition, clonogenic assay confirmed the inability of NPs incubated cancer cells to proliferate well. Our experimental results show that the CuO NPs can induce apoptosis and suppress the proliferation of HeLa cells. (C) 2016 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University.</P>

High-performance liquid chromatography method development for the quality control of Ginkgonis Semen

Le, V.N.H.,Lee, W.,Kim, Y.H.,Chae, G.H.,Chin, Y.W.,Kim, K.T.,Kang, J.S. Elsevier ; King Saud University 2017 Arabian Journal of Chemistry Vol.10 No.6

<P>Ginkgonis Semen (GS) is the seed of Ginkgo biloba Linne and a valuable material for herbal medicines and functional foods in China, Japan and Korea. The main bio-compounds of GS are GA, GB and GC like the leaves. There are many studies for the analysis of ginkgolides in the leaves or leaves extract of G. biloba because the leaves extract is a valuable material in pharmaceutical industries. However, there is no efficient analytical method for the quality control of GS based on the quantitation of ginkgolides because of matrix effect induced by different chemical composition. So, there are no content criteria of GS in Pharmacopoeia of Korea, Japan and China until now. This study aimed to develop HPLC method using ginkgolides based on the quantitation of GA, GB and GC for the quality control of GS with the optimization of sample preparation to enhance the analytical sensitivity and reproducibility. At first, defatting process using petroleum ether and liquid-liquid extraction were applied for sample preparation to remove matrix effect. The HPLC-ELSD method was developed with the mobile phase of a 0.5% aqueous acetic acid and methanol-acetonitrile solution (1: 1 ratio) under gradient conditions. GA, GB and GC contents in GS were different between Korea and China. The mean quantity of Korean samples was 4.85 +/- 2.33 lg/g GA, 48.38 +/- 5.10 lg/g GB, and 37.83 +/- 7.64 lg/g GC. Those contents of Chinese samples were higher than Korean samples as 9.39 +/- 2.51 lg/g GA, 123.59 +/- 26.24 lg/g GB and 53.39 +/- 4.97 lg/g GC. It indicated that the discrimination of GS between Korea and China could be achieved by marker compound contents. Furthermore, the geographical discrimination of GS between Korea and China was confirmed by PCA using the quantitative data of marker compounds. By statistical analysis, the calculated content criteria of GS by regression method were 2.35 lg/g of GA, 29.20 lg/g of GB, and 27.75 lg/g of GC, based on dry weight. Thus, our HPLC method shows potential toward the development of a universal quality control methodology to quantify GS quality and origin. (C) 2016 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University.</P>

Isolation and characterization of bioactive compounds from Lepisorus thunbergianus (Kaulf.)

Yang, J.,Kwon, Y.S.,Kim, M.J. Elsevier ; King Saud University 2015 Arabian journal of chemistry Vol.8 No.3

Lepisorus thunbergianus (Kaulf.) (LET) is an evergreen fern found on rocks and tree trunks that is distributed in East and Southeast Asia. Our previous study showed that the methanol extract from LET had significant anti-oxidant activity, but the active components of LET are still unclear. In the present study, isovitexin, orientin, isoorientin and chlorogenic acid were isolated from LET under the guidance of antioxidant activity. In addition, the structure of isovitexin, orientin, isoorientin and chlorogenic acid was characterized using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and nuclear magnetic resonance spectroscopy (NMR). Orientin and isoorientin presented similar activities toward the DPPH, with half maximal inhibitory concentrations (IC<SUB>50</SUB>) of 15-17μmol, and inhibition of reactive oxygen species (ROS) production by 50% at 100μmol. Chlorogenic acid significantly inhibited intracellular ROS and nitric oxide (NO) production and had a strong effect toward DPPH. Furthermore, chlorogenic acid demonstrated decreased iNOS, COX-2, IFN-β and TNF-α gene expression. These findings demonstrate the potential anti-inflammatory effects of chlorogenic acid. Isoorientin, at a concentration of 100μmol, showed 50% inhibition of human liver cancer cells (Huh7 and HepG2). These results suggest that compounds isolated from LET have potential to prevent liver cancer cell lines.

Production of slow release crystal fertilizer from wastewaters through struvite crystallization - A review

Rahman, Md.M.,Salleh, M.A.Mohd.,Rashid, U.,Ahsan, A.,Hossain, M.M.,Ra, C.S. Elsevier ; King Saud University 2014 Arabian journal of chemistry Vol.7 No.1

Nitrogen and phosphorus in wastewaters are a burning environmental issue of the present world. This review covers the studies conducted on the removal and recovery of phosphorus and nitrogen from wastewaters through struvite crystallization. Wastewater which contains a high amount of phosphorus and nitrogen would be a good source of struvite. Struvite is a phosphate fertilizer, although it contains a significant amount of nitrogen and magnesium, and it is an effective alternative source of rock phosphate to maintain the agricultural production system. The present review deals with the principles and concept of struvite nucleation, crystal growth and the factors that affect on the struvite quality. Struvite precipitation occurs in an equimolecular concentration of Mg<SUP>2+</SUP>, NH<SUB>4</SUB><SUP>+</SUP> and PO<SUB>4</SUB><SUP>3-</SUP> at slightly alkaline conditions. Addition of a source of Mg is essential to maintain the favorable condition of PO<SUB>4</SUB> and Mg. Different factors such as Mg:PO<SUB>4</SUB> molar ratio, pH, aeration rate, reactor types, as well as P and N removal efficiencies were also discussed throughout this review. The slower nutrient leaching loss and its fertilizer quality make struvite an eco-friendly fertilizer. It is possible to overcome the acute shortage of rock phosphate if all the municipal and livestock wastewaters are connected with the wastewater treatment plants.