Displaying all 10 publications

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  1. Adnani A, Basri M, Chaibakhsh N, Ahangar HA, Salleh AB, Rahman RN, et al.
    Carbohydr Res, 2011 Mar 1;346(4):472-9.
    PMID: 21276966 DOI: 10.1016/j.carres.2010.12.023
    Immobilized Candida antarctica lipase B-catalyzed esterification of xylitol and two fatty acids (capric and caproic acid) were studied in a solvent-free system. The Taguchi orthogonal array method based on three-level-four-variables with nine experiments was applied for the analysis and optimization of the reaction parameters including time, substrate molar ratio, amount of enzyme, and amount of molecular sieve. The obtained conversion was higher in the esterification of xylitol and capric acid with longer chain length. The optimum conditions derived via the Taguchi approach for the synthesis of xylitol caprate and xylitol caproate were reaction time, 29 and 18h; substrate molar ratio, 0.3 and 1.0; enzyme amount, 0.20 and 0.05g, and molecular sieve amount of 0.03g, respectively. The good correlation between the predicted conversions (74.18% and 61.23%) and the actual values (74.05% and 60.5%) shows that the model derived from the Taguchi orthogonal array can be used for optimization and better understanding of the effect of reaction parameters on the enzymatic synthesis of xylitol esters in a solvent-free system.
    Matched MeSH terms: Surface-Active Agents/chemical synthesis*
  2. Masoumi HR, Kassim A, Basri M, Abdullah DK
    Molecules, 2011 Jun 03;16(6):4672-80.
    PMID: 21642941 DOI: 10.3390/molecules16064672
    A Taguchi robust design method with an L₉ orthogonal array was implemented to optimize experimental conditions for the biosynthesis of triethanolamine (TEA)-based esterquat cationic surfactants using an enzymatic reaction method. The esterification reaction conversion% was considered as the response. Enzyme amount, reaction time, reaction temperature and molar ratio of substrates, [oleic acid: triethanolamine (OA:TEA)] were chosen as main parameters. As a result of the Taguchi analysis in this study, the molar ratio of substrates was found to be the most influential parameter on the esterification reaction conversion%. The amount of enzyme in the reaction had also a significant effect on reaction conversion%.
    Matched MeSH terms: Surface-Active Agents/chemical synthesis*
  3. Wan Nawawi WM, Jamal P, Alam MZ
    Bioresour Technol, 2010 Dec;101(23):9241-7.
    PMID: 20674345 DOI: 10.1016/j.biortech.2010.07.024
    This paper introduces sludge palm oil (SPO) as a novel substrate for biosurfactant production by liquid state fermentation. Potential strains of microorganism were isolated from various hydrocarbon-based sources at palm oil mill and screened for biosurfactant production with the help of drop collapse method and surface tension activity. Out of 22 isolates of microorganism, the strain S02 showed the highest bacterial growth with a surface tension of 36.2 mN/m and was therefore, selected as a potential biosurfactant producing microorganism. Plackett-Burman experimental design was employed to determine the important nutritional requirement for biosurfactant production by the selected strain under controlled conditions. Six out of 11 factors of the production medium were found to significantly affect the biosurfactant production. K(2)HPO(4) had a direct proportional correlation with the biosurfactant production while sucrose, glucose, FeSO(4), MgSO(4), and NaNO(3) showed inversely proportional relationship with biosurfactant production in the selected experimental range.
    Matched MeSH terms: Surface-Active Agents/chemical synthesis*
  4. Salman AA, Tabandeh M, Heidelberg T, Hussen RS, Ali HM
    Carbohydr Res, 2015 Aug 14;412:28-33.
    PMID: 26000863 DOI: 10.1016/j.carres.2015.04.022
    A series of surfactants combining carbohydrate and imidazolium head groups were prepared and investigated on their assembly behavior. The presence of the imidazolium group dominated the interactions of the surfactants, leading to high CMCs and large molecular surface areas, reflected in curved rather than lamellar surfactant assemblies. The carbohydrate, on the other hand, stabilized molecular assemblies slightly and reduced the surface tension of surfactant solutions considerably. A comparative emulsion study discourages the use of pure alkyl imidazolium glycosides owing to reduced assembly stabilities compared with APGs. However, the surfactants are believed to have potential as component in carbohydrate based surfactant mixtures.
    Matched MeSH terms: Surface-Active Agents/chemical synthesis
  5. Suhaida MG, Yahya IB, Darmawati MY
    Med J Malaysia, 2004 May;59 Suppl B:63-4.
    PMID: 15468820
    The aim of this study was to investigate the effect of the surfactant properties of polyvinyl alcohol (PVA) in enhancing the yield of small size microspheres. Naltrexone microspheres were prepared by solvent-solvent extraction evaporation process. PVA of various concentrations were added into the aqueous phase prior to the mixing process. The addition of PVA was expected to influence the shape, size distribution, drug loading and drug release profile. The results indicated that it is desirable to increase the weight fraction of the microspheres with size range below 106 mm for the highest possible yield.
    Matched MeSH terms: Surface-Active Agents/chemical synthesis*
  6. Salman AA, Tabandeh M, Heidelberg T, Duali Hussen RS
    Carbohydr Res, 2015 Apr 10;406:41-5.
    PMID: 25658065 DOI: 10.1016/j.carres.2014.12.015
    A series of glycolipid crown ether analogs was prepared by bis-propargylation of lauryl glycoside followed by subsequent click-coupling with ethylene glycol-based diazides. The triazole-linked macrocycles were obtained in remarkable high yields. While the surfactant assembly was affected by presence of sodium ions, suggesting the formation of complexes, no ion-selectivity was observed for the macrocylic ligands. Computational studies suggest a low but significant cation-binding activity of the macrocycle, involving coordination at both oxygen and nitrogen atoms.
    Matched MeSH terms: Surface-Active Agents/chemical synthesis
  7. Topkaya D, Ng SY, Bretonnière Y, Lafont D, Chung LY, Lee HB, et al.
    Photodiagnosis Photodyn Ther, 2016 Dec;16:12-14.
    PMID: 27475243 DOI: 10.1016/j.pdpdt.2016.07.008
    Matched MeSH terms: Surface-Active Agents/chemical synthesis
  8. Masoumi HR, Kassim A, Basri M, Abdullah DK, Haron MJ
    Molecules, 2011 Jun 29;16(7):5538-49.
    PMID: 21716175 DOI: 10.3390/molecules16075538
    An Artificial Neural Network (ANN) based on the Quick Propagation (QP) algorithm was used in conjunction with an experimental design to optimize the lipase-catalyzed reaction conditions for the preparation of a triethanolamine (TEA)-based esterquat cationic surfactant. Using the best performing ANN, the optimum conditions predicted were an enzyme amount of 4.77 w/w%, reaction time of 24 h, reaction temperature of 61.9 °C, substrate (oleic acid: triethanolamine) molar ratio of 1:1 mole and agitation speed of 480 r.p.m. The relative deviation percentage under these conditions was less than 4%. The optimized method was successfully applied to the synthesis of the TEA-based esterquat cationic surfactant at a 2,000 mL scale. This method represents a more flexible and convenient means for optimizing enzymatic reaction using ANN than has been previously reported by conventional methods.
    Matched MeSH terms: Surface-Active Agents/chemical synthesis*
  9. Hild F, Nguyen NT, Deng E, Katrib J, Dimitrakis G, Lau PL, et al.
    Macromol Rapid Commun, 2016 Aug;37(15):1295-9.
    PMID: 27315130 DOI: 10.1002/marc.201600149
    The use of dielectric property measurements to define specific trends in the molecular structures of poly(caprolactone) containing star polymers and/or the interbatch repeatability of the synthetic procedures used to generate them is demonstrated. The magnitude of the dielectric property value is shown to accurately reflect: (a) the number of functional groups within a series of materials with similar molecular size when no additional intermolecular order is present in the medium, (b) the polymer molecular size for a series of materials containing a fixed core material and so functional group number, and/or (c) the batch to batch repeatability of the synthesis method. The dielectric measurements are validated by comparison to spectroscopic/chromatographic data.
    Matched MeSH terms: Surface-Active Agents/chemical synthesis*
  10. Kumar PV, Lokesh BV
    Curr Drug Deliv, 2014;11(5):613-20.
    PMID: 25268676
    The present study aims to develop and explore the use of PEGylated rapamycin (RP-MPEG) micelles for the treatment of gastric cancer. RP-MPEG was synthesized and characterized by using IR, H(1) NMR and C(13) NMR. RP-MPEG was prepared in the form of micelles and characterized by using field emission scanning electron microscopy, dynamic light scattering, zeta sizer, chromatographic analyses and photostability studies. The cytotoxicity studies of RP-MPEG micelles were conducted on specific CRL 1739 human gastric adenocarcinoma and CRL 1658 NIH-3T3 mouse embryonic fibroblast cell lines. RP-MPEG micelles showed the particle size distribution of 125±0.26 nm with narrow size distribution (polydispersity index 0.127±0.01). The surface charge of RP-MPEG micelles was found to be -12.3 mV showing enhanced anticancer activity against the CRL 1739 human gastric adenocarcinoma cell lines with an IC50 value of 1 mcg/ml.
    Matched MeSH terms: Surface-Active Agents/chemical synthesis*
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