Displaying publications 3821 - 3840 of 10390 in total

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  1. Fulltext Pharmaceutical quality of nine generic orlistat products compared with Xenical(r)
    Taylor PW, Arnet I, Fischer A, Simpson IN
    Obes Facts, 2010 Aug;3(4):231-7.
    PMID: 20823686 DOI: 10.1159/000319450
    OBJECTIVE: To compare the pharmaceutical quality of Xenical (chemically produced orlistat) with nine generic products, each produced by fermentation processes.

    METHODS: Xenical 120 mg capsules (Roche, Basel, Switzerland) were used as reference material. Generic products were from India, Malaysia, Argentina, Philippines, Uruguay, and Taiwan. Colour, melting temperature, crystalline form, particle size, capsule fill mass, active pharmaceutical ingredient content, amount of impurities, and dissolution were compared. Standard physical and chemical laboratory tests were those developed by Roche for Xenical.

    RESULTS: All nine generic products failed the Xenical specifications in four or more tests, and two generic products failed in seven tests. A failure common to all generic products was the amount of impurities present, mostly due to different by-products, including side-chain homologues not present in Xenical. Some impurities were unidentified. Two generic products tested failed the dissolution test, one product formed a capsule-shaped agglomerate on storage and resulted in poor (=15%) dissolution. Six generic products were powder formulations.

    CONCLUSIONS: All tested generic orlistat products were pharmaceutically inferior to Xenical. The high levels of impurities in generic orlistat products are a major safety and tolerability concern.

    Matched MeSH terms: Lactones/chemistry; Drugs, Generic/chemistry; Anti-Obesity Agents/chemistry
  2. Trends in the use of Fenton, electro-Fenton and photo-Fenton for the treatment of landfill leachate
    Umar M, Aziz HA, Yusoff MS
    Waste Manag, 2010 Nov;30(11):2113-21.
    PMID: 20675113 DOI: 10.1016/j.wasman.2010.07.003
    Advanced oxidation processes (AOPs) such as Fenton, electro-Fenton and photo-Fenton have been applied effectively to remove refractory organics from landfill leachate. The Fenton reaction is based on the addition of hydrogen peroxide to the wastewater or leachate in the presence of ferrous salt as a catalyst. The use of this technique has proved to be one of the best compromises for landfill leachate treatment because of its environmental and economical advantages. Fenton process has been used successfully to mineralize wide range of organic constituents present in landfill leachate particularly those recalcitrant to biological degradation. The present study reviews the use of Fenton and related processes in terms of their increased application to landfill leachate. The effects of various operating parameters and their optimum ranges for maximum COD and color removal are reviewed with the conclusion that the Fenton and related processes are effective and competitive with other technologies for degradation of both raw and pre-treated landfill leachate.
    Matched MeSH terms: Electrochemistry/methods; Hydrogen Peroxide/chemistry*; Iron/chemistry*; Oxygen/chemistry
  3. Ex-situ bioremediation of crude oil in soil, a comparative kinetic analysis
    Mohajeri L, Aziz HA, Isa MH, Zahed MA, Mohajeri S
    Bull Environ Contam Toxicol, 2010 Jul;85(1):54-8.
    PMID: 20577869 DOI: 10.1007/s00128-010-0058-1
    Weathered crude oil (WCO) removals in shoreline sediment samples were monitored for 60 days in bioremediation experimentation. Experimental modeling was carried out using statistical design of experiments. At optimum conditions maximum of 83.13, 78.06 and 69.92% WCO removals were observed for 2, 16 and 30 g/kg initial oil concentrations, respectively. Significant variations in the crude oil degradation pattern were observed with respect to oil, nutrient and microorganism contents. Crude oil bioremediation were successfully described by a first-order kinetic model. The study indicated that the rate of hydrocarbon biodegradation increased with decrease of crude oil concentrations.
    Matched MeSH terms: Hydrocarbons/chemistry; Soil Pollutants/chemistry; Geologic Sediments/chemistry
  4. Optimisation of reactive dye removal by sequential electrocoagulation-flocculation method: comparing ANN and RSM prediction
    Nourouzi MM, Chuah TG, Choong TS
    Water Sci Technol, 2011;63(5):984-94.
    PMID: 21411950 DOI: 10.2166/wst.2011.280
    The removal of Reactive Black 5 dye in an aqueous solution by electrocoagulation (EC) as well as addition of flocculant was investigated. The effect of operational parameters, i.e. current density, treatment time, solution conductivity and polymer dosage, was investigated. Two models, namely the artificial neural network (ANN) and the response surface method (RSM), were used to model the effect of independent variables on percentage of dye removal. The findings of this work showed that current density, treatment time and dosage of polymer had the most significant effect on percentage of dye removal (p<0.001). In addition, interaction between time and current density, time and dosage of polymer, current density and dosage of polymer also significantly affected the percentage of dye removal (p=0.034, 0.003 and 0.024, respectively). It was shown that both the ANN and RSM models were able to predict well the experimental results (R(2)>0.8).
    Matched MeSH terms: Coloring Agents/chemistry*; Naphthalenesulfonates/chemistry*; Water Pollutants, Chemical/chemistry*
  5. Study on the removal of pesticide in agricultural run off by granular activated carbon
    Jusoh A, Hartini WJ, Ali N, Endut A
    Bioresour Technol, 2011 May;102(9):5312-8.
    PMID: 21232934 DOI: 10.1016/j.biortech.2010.12.074
    In this batch study, the adsorption of malathion by using granular activated carbon with different parameters due to the particle size, dosage of carbons, as well as the initial concentration of malathion was investigated. Batch tests were carried out to determine the potential and the effectiveness of granular activated carbon (GAC) in removal of pesticide in agricultural run off. The granular activated carbon; coconut shell and palm shells were used and analyzed as the adsorbent material. The Langmuir and Freundlich adsorption isotherms models were applied to describe the characteristics of adsorption behavior. Equilibrium data fitted well with the Langmuir model and Freundlich model with maximum adsorption capacity of 909.1mg/g. The results indicate that the GAC could be used to effectively adsorb pesticide (malathion) from agricultural runoff.
    Matched MeSH terms: Charcoal/chemistry*; Cocos/chemistry; Arecaceae/chemistry
  6. Rearranged diterpenoids from the biotransformation of ent-trachyloban-18-oic acid by Rhizopus arrhizus
    Leverrier A, Martin MT, Servy C, Ouazzani J, Retailleau P, Awang K, et al.
    J Nat Prod, 2010 Jun 25;73(6):1121-5.
    PMID: 20481544 DOI: 10.1021/np100145n
    In our search for inhibitors of the antiapoptotic protein Bcl-xL, investigation of Xylopia caudata afforded a new diterpenoid, ent-trachyloban-4beta-ol (2), and five known ent-trachylobane or ent-atisane compounds. Only ent-trachyloban-18-oic acid (1) exhibited weak binding activity to Bcl-xL. These compounds exhibited cytotoxicity against KB and HCT-116 cell lines with IC(50) values between 10 and 30 microM. Bioconversion of compound 1 by Rhizopus arrhizus afforded new hydroxylated metabolites (3-7) of the ent-trachylobane and ent-kaurene type and compound 8, with a rearranged pentacyclic carbon framework that was named rhizopene. Compounds 3-8 were noncytotoxic to the two cancer cell lines, and compounds 3 and 5 exhibited only weak binding affinity for Bcl-xL.
    Matched MeSH terms: Diterpenes/chemistry*; Plant Bark/chemistry; Xylopia/chemistry*
  7. Treatment of p-nitrophenol in an adsorbent-supplemented sequencing batch reactor
    Loo YM, Lim PE, Seng CE
    Environ Technol, 2010 Apr 14;31(5):479-87.
    PMID: 20480823 DOI: 10.1080/09593330903514482
    The objective of this research was to evaluate the treatment ofp-nitrophenol (PNP) as a sole organic carbon source using a sequencing batch reactor (SBR) with the addition of adsorbent. Two types of adsorbents, namely powdered activated carbon (PAC) and pyrolysed rice husk (PRH) were used in this study. Two identical SBRs, each with a working volume of 10 L, were operated with fill, react, settle, draw and idle periods in the ratio of 2:8:1:0.75:0.25 for a cycle time of 12 h. The results showed that, without the addition of adsorbent, increasing the influent PNP concentration to 200 mg/L resulted in the deterioration of chemical oxygen demand (COD) removal efficiency and PNP removal efficiency in the SBRs. Improvement in the performance of the SBR was observed with the addition of PAC. When the dosage of 1.0 g PAC/cycle was applied, COD removal of 95% and almost complete removal of PNP were achieved at the influent PNP concentration of 300 mg/L. The kinetic study showed that the rates of COD and PNP removal can be described by the first-order kinetics. The enhancement of performance in the PAC-supplemented SBR was postulated to be due to the initial adsorption of PNP by the freshly added and the bioregenerated PAC, thus reducing the inhibition on the microorganisms. The PRH was found to be ineffective because of its relatively low adsorption capacity for PNP, compared with that of PAC.
    Matched MeSH terms: Carbon/chemistry; Nitrophenols/chemistry; Oxygen/chemistry
  8. Synthesis, crystal structure and luminescent properties of some Zn(II) Schiff base complexes: experimental and computational study
    Eltayeb NE, Teoh SG, Adnan R, Teh JB, Fun HK
    J Fluoresc, 2011 Jul;21(4):1393-400.
    PMID: 21222144 DOI: 10.1007/s10895-010-0822-y
    A series of Zn(II)-Schiff bases I, II and III complexes were synthesized by reaction of o-phenylenediamine with 3-methylsalicylaldehyde, 4-methylsalicylaldehyde and 5-methylsalicylaldehyde. These complexes were characterized using FT-IR, UV-Vis, Diffuse reflectance UV-Vis, elemental analysis and conductivity. Complex III was characterized by XRD single crystal, which crystallizes in the triclinic system, space group P-1, with lattice parameters a=9.5444(2) Å, b=11.9407(2) Å, c=21.1732(3) Å, V=2390.24(7) Å(3), D ( c )=1.408 Mg m(-3), Z=4, F(000)=1050, GOF=0.981, R1=0.0502, wR2=0.1205. Luminescence property of these complexes was investigated in DMF solution and in the solid state. Computational study of the electronic properties of complex III showed good agreement with the experimental data.
    Matched MeSH terms: Organometallic Compounds/chemistry*; Schiff Bases/chemistry*; Zinc/chemistry*
  9. Determination of partition coefficient and analysis of nitrophenols by three-phase liquid-phase microextraction coupled with capillary electrophoresis
    Sanagi MM, Miskam M, Wan Ibrahim WA, Hermawan D, Aboul-Enein HY
    J Sep Sci, 2010 Jul;33(14):2131-9.
    PMID: 20549667 DOI: 10.1002/jssc.201000172
    A three-phase hollow fiber liquid-phase microextraction method coupled with CE was developed and used for the determination of partition coefficients and analysis of selected nitrophenols in water samples. The selected nitrophenols were extracted from 14 mL of aqueous solution (donor solution) with the pH adjusted to pH 3 into an organic phase (1-octanol) immobilized in the pores of the hollow fiber and finally backextracted into 40.0 microL of the acceptor phase (NaOH) at pH 12.0 located inside the lumen of the hollow fiber. The extractions were carried out under the following optimum conditions: donor solution, 0.05 M H(3)PO(4), pH 3.0; organic solvent, 1-octanol; acceptor solution, 40 microL of 0.1 M NaOH, pH 12.0; agitation rate, 1050 rpm; extraction time, 15 min. Under optimized conditions, the calibration curves for the analytes were linear in the range of 0.05-0.30 mg/L with r(2)>0.9900 and LODs were in the range of 0.01-0.04 mg/L with RSDs of 1.25-2.32%. Excellent enrichment factors of up to 398-folds were obtained. It was found that the partition coefficient (K(a/d)) values were high for 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol and 2,6-dinitrophenol and that the individual partition coefficients (K(org/d) and K(a/org)) promoted efficient simultaneous extraction from the donor through the organic phase and further into the acceptor phase. The developed method was successfully applied for the analysis of water samples.
    Matched MeSH terms: Solvents/chemistry; Water/chemistry; 1-Octanol/chemistry
  10. QSAR study of substituted 1,3,4-oxadiazole naphthyridines as HIV-1 integrase inhibitors
    Ravichandran V, Shalini S, Sundram K, Sokkalingam AD
    Eur J Med Chem, 2010 Jul;45(7):2791-7.
    PMID: 20347187 DOI: 10.1016/j.ejmech.2010.02.062
    A linear quantitative structure activity relationship (QSAR) model is presented for modeling and predicting the inhibition of HIV-1 integrase. The model was produced by using the stepwise multiple linear regression technique on a database that consists of 67 recently discovered 1,3,4-oxadiazole substituted naphthyridine derivatives. The developed QSAR model was evaluated for statistical significance and predictive power. The key conclusion of this study is that valence connectivity index order 1, lowest unoccupied molecular orbital and dielectric energy significantly affect the inhibition of HIV-1 integrase activity by 1,3,4-oxadiazole substituted naphthyridine derivatives. The selected physicochemical descriptors serve as a first guideline for the design of novel and potent antagonists of HIV-1 integrase.
    Matched MeSH terms: Naphthyridines/chemistry*; Oxadiazoles/chemistry*; HIV Integrase Inhibitors/chemistry*
  11. Optimization of enzymatic synthesis of palm-based kojic acid ester using response surface methodology
    Ashari SE, Mohamad R, Ariff A, Basri M, Salleh AB
    J Oleo Sci, 2009;58(10):503-10.
    PMID: 19745577
    Kojic acid monooleate is a fatty acid derivative of kojic acid which can be widely used as a skin whitening agent in a cosmetic applications. In avoiding any possible harmful effects from chemically synthesized product, the enzymatic synthesis appears to be the best way to satisfy the consumer demand nowadays. The ability of immobilized lipase from Rhizomucor meihei (lipozyme RMIM) to catalyze the direct esterification of kojic acid and oleic acid was investigated. Response Surface Methodology (RSM) and 5-level-4-factor central composite rotatable were employed to evaluate the effects of synthesis parameters such as enzyme amount (0.1-0.4 g), temperature (30-60 degrees C), substrate molar ratio (1-4 mmol, kojic acid:oleic acid) and reaction time (24-48 h) on percentage molar conversion to kojic acid monooleate. Analysis of the product using TLC, GC and FTIR showed the presence of kojic acid monooleate. The optimal conditions for the enzymatic reaction were obtained after analysis with backward elimination using 0.17 g of enzyme and 4 mmol of substrate at 52.50 degrees C for 42 h. Under these conditions the esterification percentage was 37.21%. The results demonstrated that response surface methodology can be applied effectively to optimize the lipase-catalysed synthesis of kojic acid monooleate. The optimum conditions can be used to scale up the process.
    Matched MeSH terms: Esters/chemistry; Pyrones/chemistry; Oleic Acid/chemistry
  12. Fulltext Performance evaluation of the Arkray Adams HA-8160 HbA1c analyser
    Thevarajah TM, Nani N, Chew YY
    Malays J Pathol, 2008 Dec;30(2):81-6.
    PMID: 19291916 MyJurnal
    HbA1c measurement is currently routinely used to predict long term outcome of diabetes, thus playing a fundamental role in the management of diabetes. The relationship between HbA1c value and long term diabetic complications has been established by a randomised control Diabetes Control and Complications Trial (DCCT) which used high performance liquid chromatography (HPLC) as a reference method for HbA1c assay. To ensure that HbA1c results from a variety HbA1c assay methods are similar to the DCCT values, the American Diabetes Association (ADA) recommended that all laboratories should use methods certified by the National Glycohemoglobin Standardization Programme (NGSP) with interassay coefficient variation (CV) of < 5% (ideally < 3%). The International Federation of Clinical Chemistry (IFCC) working group on HbA1c standardisation has set a CV < 2.5% as a criteria for its reference laboratories.
    Matched MeSH terms: Chemistry, Clinical/instrumentation*; Chemistry, Clinical/methods; Chemistry, Clinical/standards*
  13. Effect of prenylated flavonoids and chalcones isolated from Artocarpus species on platelet aggregation in human whole blood
    Jantan I, Mohd Yasin YH, Jamil S, Sirat H, Basar N
    J Nat Med, 2010 Jul;64(3):365-9.
    PMID: 20349149 DOI: 10.1007/s11418-010-0410-0
    Five prenylflavonoids and two prenylchalcones from Artocarpus lowii King, A. scortechinii King and A. teysmanii Miq., and acetylated derivatives of cycloheterophyllin and artonin E were investigated for their ability to inhibit arachidonic acid (AA), collagen and adenosine diphosphate (ADP)-induced platelet aggregation in human whole blood by using an electrical impedance method. Among the tested compounds, only cycloheterophyllin inhibited AA-induced platelet aggregation with an IC(50) value of 100.9 microM. It also showed strong inhibition against ADP-induced aggregation, with an IC(50) value of 57.1 microM. Isobavachalcone, 2',4'-dihydroxy-4-methoxy-3'-prenyldihydrochalcone, cycloartobiloxanthone, artonin E and artonin E triacetate showed selective inhibition against ADP-induced aggregation, with IC(50) values ranging from 55.3 to 192.0 microM, but did not show such effect against other inducers.
    Matched MeSH terms: Flavonoids/chemistry; Artocarpus/chemistry*; Chalcones/chemistry
  14. Degradation and mineralization kinetics of acephate in humid tropic soils of Malaysia
    Chai LK, Wong MH, Mohd-Tahir N, Hansen HC
    Chemosphere, 2010 Apr;79(4):434-40.
    PMID: 20189217 DOI: 10.1016/j.chemosphere.2010.01.046
    Acephate is poorly sorbed to soil, thus the risk of leaching to the aquatic environment is high if it is not quickly degraded. The effect of soil moisture, temperature, microbial activity and application rate on acephate degradation has been studied in three Malaysian soils to examine and identify critical variables determining its degradation and mineralization kinetics. First-order kinetics could be used to describe degradation in all cases (r(2)>0.91). Acephate degraded faster in air-dry (t((1/2)) 9-11 d) and field capacity (t((1/2)) 10-16d) soils than in the wet soils (t((1/2)) 32-77 d). The activation energy of degradation was in the range 17-28 kJ mol(-1) and significantly higher for the soil with higher pH and lower clay and iron oxide contents. Soil sterilization caused a 3- to 10-fold decrease in degradation rates compared to non-sterile soils (t((1/2)) 53-116 d) demonstrating that acephate degradation is mainly governed by microbial processes. At 5-fold increase in application rates (25 microg g(-1)), half-life increased slightly (t((1/2)) 13-19 d) or was unaffected. Half-life from acephate mineralization was similar to those from degradation but much longer at the 5-fold increase in acephate application rates (t((1/2)) 41-96 d) demonstrating that degradation of metabolites is rate limiting. Thus, application of acephate should be restricted or avoided during wet seasons with heavy rainfall and flooded soil as in paddy cultivation. Sandy soils with low microbial activity are more prone to acephate leaching than clay soils rich in humic matter.
    Matched MeSH terms: Insecticides/chemistry; Organothiophosphorus Compounds/chemistry; Soil Pollutants/chemistry
  15. Isolation and characterization of an acrylamide-degrading Antarctic bacterium
    Shukor MY, Gusmanizar N, Ramli J, Shamaan NA, MacCormack WP, Syed MA
    J Environ Biol, 2009 Jan;30(1):107-12.
    PMID: 20112871
    The presence of acrylamide in the environment poses a threat due to its well known neurotoxic, carcinogenic and teratogenic properties. Human activities in various geographical areas are the main anthropogenic source of acrylamide pollution. In this work, an acrylamide-degrading bacterium was isolated from Antarctic soil. The physiological characteristics and optimum growth conditions of the acrylamide-degrading bacteria were investigated. The isolate was tentatively identified as Pseudomonas sp. strain DRYJ7 based on carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. The results showed that the best carbon sources for growth was glucose and sucrose with no significant difference in terms of cellular growth between the two carbon sources (p>0.05). This was followed by fructose and maltose with fructose giving significantly higher cellular growth compared to maltose (p<0.05). Lactose and citric acid did not support growth. The optimum acrylamide concentration as a nitrogen source for cellular growth was at 500 mgl(-1). At this concentration, bacterial growth showed a 2-day lag phase before degradation took place concomitant with an increase in cellular growth. The isolate exhibited optimum growth in between pH 7.5 and 8.5. The effect of incubation temperature on the growth of this isolate showed an optimum growth at 15 degrees C. The characteristics of this isolate suggest that it would be useful in the bioremediation of acrylamide.
    Matched MeSH terms: Environmental Pollutants/chemistry; RNA, Ribosomal, 16S/chemistry; Acrylamide/chemistry
  16. Reduction of Mo(VI) by the bacterium Serratia sp. strain DRY5
    Rahman MF, Shukor MY, Suhaili Z, Mustafa S, Shamaan NA, Syed MA
    J Environ Biol, 2009 Jan;30(1):65-72.
    PMID: 20112865
    The need to isolate efficient heavy metal reducers for cost effective bioremediation strategy have resulted in the isolation of a potent molybdenum-reducing bacterium. The isolate was tentatively identified as Serratia sp. strain DRY5 based on the Biolog GN carbon utilization profiles and partial 16S rDNA molecular phylogeny. Strain DRY5 produced 2.3 times the amount of Mo-blue than S. marcescens strain Dr.Y6, 23 times more than E. coli K12 and 7 times more than E. cloacae strain 48. Strain DRY5 required 37 degrees C and pH 7.0 for optimum molybdenum reduction. Carbon sources such as sucrose, maltose, glucose and glycerol, supported cellular growth and molybdate reduction after 24 hr of static incubation. The most optimum carbon source that supported reduction was sucrose at 1.0% (w/v). Ammonium sulphate, ammonium chloride, glutamic acid, cysteine, and valine supported growth and molybdate reduction with ammonium sulphate as the optimum nitrogen source at 0. 2% (w/v). Molybdate reduction was optimally supported by 30 mM molybdate. The optimum concentration of phosphate for molybdate reduction was 5 mM when molybdate concentration was fixed at 30 mM and molybdate reduction was totally inhibited at 100 mM phosphate. Mo-blue produced by this strain shows a unique characteristic absorption profile with a maximum peak at 865 nm and a shoulder at 700 nm, Dialysis tubing experiment showed that 95.42% of Mo-blue was found in the dialysis tubing suggesting that the molybdate reduction seen in this bacterium was catalyzed by enzyme(s). The characteristics of isolate DRY5 suggest that it would be useful in the bioremediation ofmolybdenum-containing waste.
    Matched MeSH terms: Carbon/chemistry; Molybdenum/chemistry; Phosphates/chemistry
  17. Development of an inhibitive enzyme assay for copper
    Shukor MY, Bakar NA, Othman AR, Yunus I, Shamaan NA, Syed MA
    J Environ Biol, 2009 Jan;30(1):39-44.
    PMID: 20112861
    In this work the development of an inhibitive assay for copper using the molybdenum-reducing enzyme assay is presented. The enzyme is assayed using 12-molybdophosphoric acid at pH 5.0 as an electron acceptor substrate and NADH as the electron donor substrate. The enzyme converts the yellowish solution into a deep blue solution. The assay is based on the ability of copper to inhibit the molybdenum-reducing enzyme from the molybdate-reducing Serratia sp. Strain DRY5. Other heavy metals tested did not inhibit the enzyme at 10 mg l(-1). The best model with high regression coefficient to measure copper inhibition is one-phase binding. The calculated IC50 (concentration causing 50% inhibition) is 0.099 mg l(-1) and the regression coefficient is 0.98. The comparative LC50, EC50 and IC50 data for copper in different toxicity tests show that the IC50 value for copper in this study is lower than those for immobilized urease, bromelain, Rainbow trout, R. meliloti, Baker's Yeast dehydrogenase activity Spirillum volutans, P. fluorescens, Aeromonas hydrophilia and synthetic activated sludge assays. However the IC50 value is higher than those for Ulva pertusa and papain assays, but within the reported range for Daphnia magna and Microtox assays.
    Matched MeSH terms: Copper/chemistry; Enzyme Inhibitors/chemistry; Molybdenum/chemistry
  18. Leuconicines A-G and (-)-eburnamaline, biologically active strychnan and eburnan alkaloids from Leuconotis
    Gan CY, Low YY, Etoh T, Hayashi M, Komiyama K, Kam TS
    J Nat Prod, 2009 Dec;72(12):2098-103.
    PMID: 20035556 DOI: 10.1021/np900576b
    Seven new indole alkaloids of the Strychnos type, leuconicines A-G (1-7), and a new eburnan alkaloid, (-)-eburnamaline (8), were isolated from the stem-bark extract of two Malayan Leuconotis species. The structures of these alkaloids were established using NMR and MS analysis and in the case of 8 also by partial synthesis. Alkaloids 1-5 reversed multidrug resistance in vincristine-resistant KB cells.
    Matched MeSH terms: Plant Stems/chemistry; Plant Bark/chemistry; Indole Alkaloids/chemistry
  19. Bio-ethanol from lignocellulose: Status, perspectives and challenges in Malaysia
    Goh CS, Tan KT, Lee KT, Bhatia S
    Bioresour Technol, 2010 Jul;101(13):4834-41.
    PMID: 19762229 DOI: 10.1016/j.biortech.2009.08.080
    The present study reveals the perspective and challenges of bio-ethanol production from lignocellulosic materials in Malaysia. Malaysia has a large quantity of lignocellulosic biomass from agriculture waste, forest residues and municipal solid waste. In this work, the current status in Malaysia was laconically elucidated, including an estimation of biomass availability with a total amount of 47,402 dry kton/year. Total capacity and domestic demand of second-generation bio-ethanol production in Malaysia were computed to be 26,161 ton/day and 6677 ton/day, respectively. Hence, it was proven that the country's energy demand can be fulfilled with bio-ethanol if lignocellulosic biomass were fully converted into bio-ethanol and 19% of the total CO(2) emissions in Malaysia could be avoided. Apart from that, an integrated national supply network was proposed together with the collection, storage and transportation of raw materials and products. Finally, challenges and obstacles in legal context and policies implementation were elaborated, as well as infrastructures shortage and technology availabilities.
    Matched MeSH terms: Ethanol/chemistry*; Carbon Dioxide/chemistry; Lignin/chemistry*
  20. Study of evaluation of groundwater in Gadilam basin using hydrogeochemical and isotope data
    Prasanna MV, Chidambaram S, Shahul Hameed A, Srinivasamoorthy K
    Environ Monit Assess, 2010 Sep;168(1-4):63-90.
    PMID: 19609693 DOI: 10.1007/s10661-009-1092-5
    Gadilam river basin has gained its importance due to the presence of Neyveli Lignite open cast mines and other industrial complexes. It is also due to extensive depressurization of Cuddalore aquifer, and bore wells for New Veeranam Scheme are constructed downstream of the basin. Geochemical indicators of groundwater were used to identify the chemical processes that control hydrogeochemistry. Chemical parameters of groundwater such as pH, electrical conductivity, total dissolved solids, sodium (Na(+)), potassium (K(+)), calcium (Ca(+)), magnesium (Mg(+)), bicarbonate (HCO(-)(3)), sulfate (SO(-)(4)), phosphate (PO(-)(4)), and silica (H(4)SiO(4)) were determined. Interpretation of hydrogeochemical data suggests that leaching of ions followed by weathering and anthropogenic impact controls the chemistry of the groundwater. Isotopic study reveals that recharge from meteoric source in sedimentary terrain and rock-water interaction with significant evaporation prevails in hard rock region.
    Matched MeSH terms: Fresh Water/chemistry*; Metals/chemistry; Water Pollutants, Chemical/chemistry
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