Displaying publications 1 - 20 of 46 in total

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  1. New macroporous β-cyclodextrin functionalized ionic liquid polymer as an adsorbent for solid phase extraction with phenols
    Raoov M, Mohamad S, bin Abas MR, Surikumaran H
    Talanta, 2014 Dec;130:155-63.
    PMID: 25159393 DOI: 10.1016/j.talanta.2014.06.067
    Cyclodextrin-ionic liquid polymer (βCD-BIMOTs-TDI) is a new class of macroporous material and has great potential to be used as an SPE adsorbent material for extraction of phenols in river water samples. Six phenols, as model analytes, were extracted on a βCD-BIMOTs-TDI SPE cartridge, and then, eluted with 2 mL of methanol containing 1% acetic acid. The optimum experimental condition was 15 mL of sample volume (sample at pH 6) and 2 mL of methanol containing 1% acetic acid as an eluent solvent. The eluent concentration was determined by using Gas Chromatography-Flame Ionization Detector (GC-FID). Under optimized condition, high sensitivity (detection limits 0.23-0.35 µg/L) and good recoveries (87-116%) were achieved with satisfactory relative standard deviation (RSD) (0.1-1.7%). The developed βCD-BIMOTs-TDI-SPE was then compared with other adsorbents, and the obtained results showed that the βCD-BIMOTs-TDI exhibited higher extraction recovery due to the unique structure and properties. Finally, the βCD-BIMOTs-TDI was applied as a solid phase extraction sorbent for phenols determination under optimized condition, in river and tap waters, prior to the GC-FID separation.
    Matched MeSH terms: beta-Cyclodextrins/chemistry*
  2. Fulltext Efficiency of newly formulated camptothecin with β-cyclodextrin-EDTA-Fe3O4 nanoparticle-conjugated nanocarriers as an anti-colon cancer (HT29) drug
    Krishnan P, Rajan M, Kumari S, Sakinah S, Priya SP, Amira F, et al.
    Sci Rep, 2017 09 08;7(1):10962.
    PMID: 28887536 DOI: 10.1038/s41598-017-09140-1
    Camptothecin (CPT) is an anti-cancer drug that effectively treats various cancers, including colon cancer. However, poor solubility and other drawbacks have restricted its chemotherapeutic potential. To overcome these restrictions, CPT was encapsulated in CEF (cyclodextrin-EDTA-FE3O4), a composite nanoparticle of magnetic iron oxide (Fe3O4), and β-cyclodextrin was cross-linked with ethylenediaminetetraacetic acid (EDTA). This formulation improved CPT's solubility and bioavailability for cancer cells. The use of magnetically responsive anti-cancer formulation is highly advantageous in cancer chemotherapy. The chemical characterisation of CPT-CEF was studied here. The ability of this nano-compound to induce apoptosis in HT29 colon cancer cells and A549 lung cancer cells was evaluated. The dose-dependent cytotoxicity of CPT-CEF was shown using MTT. Propidium iodide and Annexin V staining, mitochondrial membrane depolarisation (JC-1 dye), and caspase-3 activity were assayed to detect apoptosis in CPT-CEF-treated cancer cells. Cell cycle analysis also showed G1 phase arrest, which indicated possible synergistic effects of the nano-carrier. These study results show that CPT-CEF causes a dose-dependent cell viability reduction in HT29 and A549 cells and induces apoptosis in colon cancer cells via caspase-3 activation. These data strongly suggest that CPT could be used as a major nanocarrier for CPT to effectively treat colon cancer.
    Matched MeSH terms: beta-Cyclodextrins/chemistry
  3. Immobilization of horseradish peroxidase on β-cyclodextrin-capped silver nanoparticles: Its future aspects in biosensor application
    Karim Z, Khan MJ, Maskat MY, Adnan R
    Prep Biochem Biotechnol, 2016 May 18;46(4):321-7.
    PMID: 25830286 DOI: 10.1080/10826068.2015.1031389
    This study aimed to work out a simple and high-yield procedure for the immobilization of horseradish peroxidase on silver nanoparticle. Ultraviolet-visible (UV-vis) and Fourier-transform infrared spectroscopy and transmission electron microscopy were used to characterize silver nanoparticles. Horseradish peroxidase was immobilized on β-cyclodextrin-capped silver nanoparticles via glutaraldehyde cross-linking. Single-cell gel electrophoresis (Comet assay) was also performed to confirm the genotoxicity of silver nanoparticles. To decrease toxicity, silver nanoparticles were capped with β-cyclodextrin. A comparative stability study of soluble and immobilized enzyme preparations was investigated against pH, temperature, and chaotropic agent, urea. The results showed that the cross-linked peroxidase was significantly more stable as compared to the soluble counterpart. The immobilized enzyme exhibited stable enzyme activities after repeated uses.
    Matched MeSH terms: beta-Cyclodextrins/chemistry*
  4. Cytotoxicity evaluation of vancomycin and its complex with beta-cyclodextrin on human glial cell line
    Sofian ZM, Abdullah JM, Rahim AA, Shafee SS, Mustafa Z, Razak SA
    Pak J Pharm Sci, 2012 Oct;25(4):831-7.
    PMID: 23010001
    The possible cytotoxic effects of vancomycin and its complex with beta-cyclodextrin (β-CD) on human glial cell line (CRL 8621) were studied accordingly by means of MTS assay. The cultured cells were incubated with various concentrations of vancomycin, β-CD as well as β-CD/vancomycin complex ranging from 4.69 to 300 ug/ml. A linear dose-dependency cytotoxicity followed by hermetic-like biphasic dose-dependence was observed after incubation period of 72 hours. In general, significant increase (p<0.001) of cell proliferation was observed at lower concentrations: <18.75 μg/ml for cells treated with β-CD and their complex while < 9.38 μg/ml for cells treated with vancomycin. In contrary, regardless of the treatments given, significant (p<0.001) reduce in cell survival was found at higher concentrations >150 μg/ml. In particular, 50 % inhibitory in vitro was achieved at the concentrations of 115.95 μg/ml (for β-CD), 116.48 μg/ml (for vancomycin) and 115.44 μg/ml (for β-CD/vancomycin complex).
    Matched MeSH terms: beta-Cyclodextrins/chemistry
  5. Fulltext Nanoparticle-Encapsulated Camptothecin: Epigenetic Modulation in DNA Repair Mechanisms in Colon Cancer Cells
    Farhana A, Koh AE, Tong JB, Alsrhani A, Kumar Subbiah S, Mok PL
    Molecules, 2021 Sep 06;26(17).
    PMID: 34500845 DOI: 10.3390/molecules26175414
    Molecular crosstalk between the cellular epigenome and genome converge as a synergistic driver of oncogenic transformations. Besides other pathways, epigenetic regulatory circuits exert their effect towards cancer progression through the induction of DNA repair deficiencies. We explored this mechanism using a camptothecin encapsulated in β-cyclodextrin-EDTA-Fe3O4 nanoparticles (CPT-CEF)-treated HT29 cells model. We previously demonstrated that CPT-CEF treatment of HT29 cells effectively induces apoptosis and cell cycle arrest, stalling cancer progression. A comparative transcriptome analysis of CPT-CEF-treated versus untreated HT29 cells indicated that genes controlling mismatch repair, base excision repair, and homologues recombination were downregulated in these cancer cells. Our study demonstrated that treatment with CPT-CEF alleviated this repression. We observed that CPT-CEF exerts its effect by possibly affecting the DNA repair mechanism through epigenetic modulation involving genes of HMGB1, APEX1, and POLE3. Hence, we propose that CPT-CEF could be a DNA repair modulator that harnesses the cell's epigenomic plasticity to amend DNA repair deficiencies in cancer cells.
    Matched MeSH terms: Cyclodextrins/chemistry
  6. Fulltext Conjugated β-Cyclodextrin Enhances the Affinity of Folic Acid towards FRα: Molecular Dynamics Study
    Al-Thiabat MG, Gazzali AM, Mohtar N, Murugaiyah V, Kamarulzaman EE, Yap BK, et al.
    Molecules, 2021 Aug 31;26(17).
    PMID: 34500740 DOI: 10.3390/molecules26175304
    Drug targeting is a progressive area of research with folate receptor alpha (FRα) receiving significant attention as a biological marker in cancer drug delivery. The binding affinity of folic acid (FA) to the FRα active site provides a basis for recognition of FRα. In this study, FA was conjugated to beta-cyclodextrin (βCD) and subjected to in silico analysis (molecular docking and molecular dynamics (MD) simulation (100 ns)) to investigate the affinity and stability for the conjugated system compared to unconjugated and apo systems (ligand free). Docking studies revealed that the conjugated FA bound into the active site of FRα with a docking score (free binding energy < -15 kcal/mol), with a similar binding pose to that of unconjugated FA. Subsequent analyses from molecular dynamics (MD) simulations, root mean square deviation (RMSD), root mean square fluctuation (RMSF), and radius of gyration (Rg) demonstrated that FA and FA-βCDs created more dynamically stable systems with FRα than the apo-FRα system. All systems reached equilibrium with stable RMSD values ranging from 1.9-2.4 Å and the average residual fluctuation values of the FRα backbone atoms for all residues (except for terminal residues ARG8, THR9, THR214, and LEU215) were less than 2.1 Å with a consistent Rg value of around 16.8 Å throughout the MD simulation time (0-100 ns). The conjugation with βCD improved the stability and decreased the mobility of all the residues (except residues 149-151) compared to FA-FRα and apo-FRα systems. Further analysis of H-bonds, binding free energy (MM-PBSA), and per residue decomposition energy revealed that besides APS81, residues HIS20, TRP102, HIS135, TRP138, TRP140, and TRP171 were shown to have more favourable energy contributions in the holo systems than in the apo-FRα system, and these residues might have a direct role in increasing the stability of holo systems.
    Matched MeSH terms: beta-Cyclodextrins/chemistry*
  7. Cyclodextrin-modified micellar electrokinetic chromatography for enantioseparations
    Ibrahim WA, Hermawan D, Sanagi MM
    Methods Mol Biol, 2013;970:349-61.
    PMID: 23283789 DOI: 10.1007/978-1-62703-263-6_22
    The separation of enantiomers is one of the important fields of modern analytical chemistry, especially for agrochemical and pharmaceutical products because the stereochemistry has a significant influence on the biological activities of compounds. Cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) has become an important capillary electrophoresis mode for enantioseparations. Here, we describe an example of a CD-MEKC method using hydroxypropyl-γ-cyclodextrin as chiral selector and sodium dodecyl sulfate as micellar solution for enantioseparation of triazole fungicides and the drug econazole.
    Matched MeSH terms: gamma-Cyclodextrins/chemistry*
  8. Enantioseparation of Selected Imidazole Drugs Using Dual Cyclodextrin-Modified Micellar Electrokinetic Chromatography
    Ibrahim WAW, Wahib SMA, Hermawan D, Sanagi MM
    Methods Mol Biol, 2019;1985:407-416.
    PMID: 31069749 DOI: 10.1007/978-1-4939-9438-0_24
    Particular attention has been paid to capillary electrophoresis as versatile and environmentally friendly approach for enantioseparations of a wide spectrum of compounds. Cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) is a method of choice to provide effective separation toward hydrophobic and uncharged stereoisomers. The chiral discrimination of the solutes relies upon the partitioning between a given CD in the aqueous phase and micelles formed from a surfactant. Synergistic combinations of chiral selectors, surfactant, and modifier contribute to successful enantioseparations of the enantiomers. In this chapter, an application of CD-MEKC for the enantioseparation of selected imidazole drugs employing a dual CDs system is described.
    Matched MeSH terms: Cyclodextrins/chemistry*
  9. Cyclodextrin- and dendrimer-conjugated graphene oxide as a nanocarrier for the delivery of selected chemotherapeutic and photosensitizing agents
    Siriviriyanun A, Tsai YJ, Voon SH, Kiew SF, Imae T, Kiew LV, et al.
    Mater Sci Eng C Mater Biol Appl, 2018 Aug 01;89:307-315.
    PMID: 29752102 DOI: 10.1016/j.msec.2018.04.020
    In this study, nanohybrid materials consisting of graphene oxide (GO), β‑cyclodextrin (CD) and poly(amido amine) dendrimer (DEN) were successfully prepared by covalent bonding. GO-CD and GO-CD-DEN were found to be potential nanocarriers for anticancer drugs including chemotherapeutics (doxorubicin (DOX), camptothecin (CPT)) and photosensitizer (protoporphyrin IX (PpIX)). GO-CD possessed 1.2 times higher DOX-loading capacity than GO due to inclusion of additional DOX to the CD. The drug loading on GO-CD-DEN increased in the order: DOX 
    Matched MeSH terms: Cyclodextrins/chemistry*
  10. Cyclodextrin-modified MEKC for enantioseparation of hexaconazole, penconazole, and myclobutanil
    Wan Ibrahim WA, Hermawan D, Sanagi MM, Aboul-Enein HY
    J Sep Sci, 2009 Feb;32(3):466-71.
    PMID: 19142910 DOI: 10.1002/jssc.200800512
    A CD-modified micellar EKC (CD-MEKC) method with 2-hydroxypropyl-gamma-CD (HP-gamma-CD) as chiral selector for the enantioseparation of three chiral triazole fungicides, namely hexaconazole, penconazole, and myclobutanil, is reported for the first time. Simultaneous enantioseparation of the three triazole fungicides was successfully achieved using a CD-MEKC system containing 40 mM HP-gamma-CD and 50 mM SDS in 25 mM phosphate buffer (pH 3.0) solution with resolutions (R(s)) greater than 1.60, peak efficiencies (N) greater than 200,000 for all enantiomers and an analysis time within 15 min compared to 36 min as previously reported using sulfated-beta-CD.
    Matched MeSH terms: Cyclodextrins/chemistry*
  11. Chiral separation of econazole using micellar electrokinetic chromatography with hydroxypropyl-gamma-cyclodextrin
    Hermawan D, Wan Ibrahim WA, Sanagi MM, Aboul-Enein HY
    J Pharm Biomed Anal, 2010 Dec 15;53(5):1244-9.
    PMID: 20719457 DOI: 10.1016/j.jpba.2010.07.030
    A cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) method with hydroxypropyl-gamma-cyclodextrin (HP-gamma-CD) as chiral selector for the enantiomeric separation of econazole is reported. Enantioseparation of econazole was successfully achieved by the optimized CD-MEKC system containing 40mM HP-gamma-CD, 50mM SDS and 20mM phosphate buffer (pH 8) solution with an analysis time of less than 9min. Calibration curves were linear for the two stereoisomers of econazole (r(2)>0.998). Good repeatabilities in the migration time, peak area and peak height were obtained in terms of RSD% ranging from 0.30 to 7.67%. Combination of solid-phase extraction (SPE) procedure using diol column and the CD-MEKC method was successfully applied to the determination of econazole in a formulated cream sample.
    Matched MeSH terms: gamma-Cyclodextrins/chemistry
  12. Computational docking, molecular dynamics simulation and subsite structure analysis of a maltogenic amylase from Bacillus lehensis G1 provide insights into substrate and product specificity
    Manas NH, Bakar FD, Illias RM
    J Mol Graph Model, 2016 06;67:1-13.
    PMID: 27155296 DOI: 10.1016/j.jmgm.2016.04.004
    Maltogenic amylase (MAG1) from Bacillus lehensis G1 displayed the highest hydrolysis activity on β-cyclodextrin (β-CD) to produce maltose as a main product and exhibited high transglycosylation activity on malto-oligosaccharides with polymerization degree of three and above. These substrate and product specificities of MAG1 were elucidated from structural point of view in this study. A three-dimensional structure of MAG1 was constructed using homology modeling. Docking of β-CD and malto-oligosaccharides was then performed in the MAG1 active site. An aromatic platform in the active site was identified which is responsible in substrate recognition especially in determining the enzyme's preference toward β-CD. Molecular dynamics (MD) simulation showed MAG1 structure is most stable when docked with β-CD and least stable when docked with maltose. The docking analysis and MD simulation showed that the main subsites for substrate stabilization in the active site are -2, -1, +1 and +2. A bulky residue, Trp359 at the +2 subsite was identified to cause steric interference to the bound linear malto-oligosaccharides thus prevented it to occupy subsite +3, which can only be reached by a highly bent glucose molecule such as β-CD. The resulted modes of binding from docking simulation show a good correlation with the experimentally determined hydrolysis pattern. The subsite structure generated from this study led to a possible mode of action that revealed how maltose was mainly produced during hydrolysis. Furthermore, maltose only occupies subsite +1 and +2, therefore could not be hydrolyzed or transglycosylated by the enzyme. This important knowledge has paved the way for a novel structure-based molecular design for modulation of its catalytic activities.
    Matched MeSH terms: beta-Cyclodextrins/chemistry
  13. Liquid chromatography-tandem mass spectroscopic method for the determination of zerumbone in human plasma and its application to pharmacokinetics
    Eid EE, Abdul AB, Rasedee A, Suliman FE, Sukari MA, Fatah SA
    J Mass Spectrom, 2011 Aug;46(8):772-81.
    PMID: 21834015 DOI: 10.1002/jms.1942
    A rapid, sensitive, specific and selective LC-MS/MS method for the determination of zerumbone (ZER) in human plasma using 2,4-diamino-6-(4-methoxyphenyl)-1,3,5-triazine (DMTZ) as an internal standard (IS) has been developed and validated. ZER was chromatographed on C8 column using a mobile phase of acetonitrile/water (80:20, v/v) at a flow rate of 0.25 ml min(-1) . Quantitation was achieved using ESI+ interface, employing multiple reaction monitoring (MRM) mode at m/z 219 > 81 and 218 > 134 for ZER and IS, respectively. The calibration standards were linear over a range of 5-3000 ng ml(-1) (r(2)=0.9994) with an LLOQ of 5 ng ml(-1) (RSD %; 11.4% and bias%; 9.5%). Intra- and inter-day precision of ZER assay ranged from 0.18 to 3.56% with accuracy (bias) that varied between -5.09 and 4.3%, demonstrating good precision and accuracy. Recoveries of ZER and the IS from human plasma were above 85%. The developed method was validated for the determination of ZER in rat plasma. Linearity, stability of ZER and the ME on rat plasma were discussed. The applicability of the developed method was demonstrated by measuring ZER in rat plasma samples following intravenous and intraperitoneal administration of ZER prepared in hydroxypropyl-β-cyclodextrin (HPβCD) and sodium carboxymethyl cellulose (CMC), respectively, in 20 mg kg(-1) and this study indicated a clear significant difference (p<0.05) in pharmacokinetic parameters of ZER in ZER/HPβCD complex compared with ZER in CMC preparation.
    Matched MeSH terms: beta-Cyclodextrins/chemistry
  14. Removal of 2,4-dichlorophenol using cyclodextrin-ionic liquid polymer as a macroporous material: characterization, adsorption isotherm, kinetic study, thermodynamics
    Raoov M, Mohamad S, Abas MR
    J Hazard Mater, 2013 Dec 15;263 Pt 2:501-16.
    PMID: 24231314 DOI: 10.1016/j.jhazmat.2013.10.003
    Cyclodextrin-ionic liquid polymer (βCD-BIMOTs-TDI) was firstly synthesized using functionalized β-Cyclodextrin (CD) with 1-benzylimidazole (BIM) to form monofunctionalized CD (βCD-BIMOTs) and was further polymerized using toluene diisocyanate (TDI) linker to form insoluble βCD-BIMOTs-TDI. SEM characterization result shows that βCD-BIMOTs-TDI exhibits macropore size while the BET result shows low surface area (1.254 m(2)g(-1)). The unique properties of the ILs allow us to produce materials with different morphologies. The adsorption isotherm and kinetics of 2,4-dichlorophenol (2,4-DCP) onto βCD-BIMOTs-TDI is studied. Freundlich isotherm and pseudo-second order kinetics are found to be the best to represent the data for 2,4-DCP adsorption on the βCD-BIMOTs-TDI. The presence of macropores decreases the mass transfer resistance and increases the adsorption process by reducing the diffusion distance. The change in entropy (ΔS°) and heat of adsorption (ΔH°) for 2,4-DCP on βCD-BIMOTs-TDI were estimated as -55.99 J/Kmol and -18.10 J/mol, respectively. The negative value of Gibbs free energy (ΔG°) indicates that the adsorption process is thermodynamically feasible, spontaneous and chemically controlled. Finally, the interactions between the cavity of βCD-BIMOTs and 2,4-DCP are investigated and the results shows that the inclusion of the complex formation and π-π interaction are the main processes involved in the adsorption process.
    Matched MeSH terms: Cyclodextrins/chemistry*
  15. Stability of Bioactive Compounds and Antioxidant Activities of Kenaf Seed Oil-in-Water Nanoemulsions under Different Storage Temperatures
    Cheong AM, Tan CP, Nyam KL
    J Food Sci, 2018 Oct;83(10):2457-2465.
    PMID: 30178877 DOI: 10.1111/1750-3841.14332
    Kenaf seed oil-in-water nanoemulsions (NANO) stabilized by sodium caseinate (SC), beta-cyclodextrin (β-CD), and Tween 20 (T20) have been optimized and shown to improve in vitro bioaccessibility and physicochemical stability in the previous study. The main objective of this study was to evaluate the stability of bioactive compounds and antioxidants in the NANO during storage at different temperatures (4 °C, 25 °C, and 40 °C). An evaluation of the antioxidant activities of each emulsifier showed that SC had good scavenging capability with 97.6% ABTS radical scavenging activity. Therefore, SC which was used as one of the main emulsifiers could further enhanced the antioxidant activity of NANO. At week 8 of storage, NANO that stored at 4 °C had maintained the best bioactive compounds stability and antioxidant activities with 90% retention of vitamin E and 65% retention of phytosterols. These results suggested that 4 °C would be the most suitable storage temperature for NANO containing naturally present vitamin E and phytosterols. From the accelerated storage results at 40 °C, NANO containing vitamin E and phytosterols had maintained half of its initial concentration until week 4 and week 2 of storage, which is equivalent to 16 weeks and 8 weeks of storage at room temperature, respectively.

    PRACTICAL APPLICATION: The results of this study provide a better understanding on the stability of bioactive compounds and antioxidant activities in oil-in-water nanoemulsions that stabilized by similar ternary emulsifiers during storage at different temperatures. In addition, this study could be used as a predictive model to estimate the shelf life of bioactive compounds encapsulated in the form of nanoemulsions.

    Matched MeSH terms: beta-Cyclodextrins/chemistry
  16. Capillary electrophoresis with capacitively coupled contactless conductivity detection for the determination of cis/trans isomers of octadec-9-enoic acid and other long chain fatty acids
    Wong YF, Saad B, Makahleh A
    J Chromatogr A, 2013 May 17;1290:82-90.
    PMID: 23578483 DOI: 10.1016/j.chroma.2013.03.014
    A capillary electrophoresis (CE)-capacitively coupled contactless conductivity detection (C(4)D) method for the simultaneous separation of eleven underivatized fatty acids (FAs), namely, lauric, myristic, tridecanoic (internal standard), pentadecanoic, palmitic, stearic, oleic, elaidic, linoleic, linolenic and arachidic acids is described. The separation was carried out in normal polarity mode at 20 °C, 30 kV and using hydrodynamic injection (50 mbar for 1 s). The separation was achieved in a bare fused-silica capillary (70 cm × 75 μm i.d.) using a background electrolyte of methyl-β-cyclodextrin (~6 mM) and heptakis-(2,3,6-tri-O-methyl)-β-cyclodextrin (~8 mM) dissolved in a mixture of Na2HPO4/KH2PO4 (5 mM, pH 7.4):ACN:MeOH:n-octanol (3:4:2.5:0.5, v/v/v/v). C(4)D parameters were set at fixed amplitude of 100 V and frequency of 1000 kHz. The developed method was validated. Calibration curves of the ten FAs were well correlated (r(2)>0.99) within the range of 5-250 μg mL(-1) for lauric acid, and 3-250 μg mL(-1) for the other FAs. The method was simple and sensitive with detection limits (S/N=3) of 0.9-1.9 μg mL(-1) and good relative standard deviations of intra- and inter-day for migration times and peak areas (≤9.7%) were achieved. The method was applied to the determination of FAs in margarine samples. The proposed method offers distinct advantages over the GC and HPLC methods, especially in terms of simplicity (without derivatization) and sensitivity.
    Matched MeSH terms: Cyclodextrins/chemistry
  17. On-line preconcentration and chiral separation of propiconazole by cyclodextrin-modified micellar electrokinetic chromatography
    Wan Ibrahim WA, Hermawan D, Sanagi MM
    J Chromatogr A, 2007 Nov 2;1170(1-2):107-13.
    PMID: 17915239
    A method for the chiral separation of propiconazole using cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) with hydroxypropyl-gamma-cyclodextrin (HP-gamma-CD) as chiral selector is reported. The use of a mixture of 30 mM HP-gamma-CD, 50mM SDS, methanol-acetonitrile 10%:5% (v/v) in 25 mM phosphate buffer solution was able to separate two enantiomeric pairs of propiconazole. Stacking- and sweeping-CD-MEKC under neutral pH (pH 7) and under acidic condition (pH 3.0) were used as two on-line preconcentration methods to increase detection sensitivity of propiconazole. Good repeatabilities in the migration time, peak area and peak height were obtained in terms of relative standard deviation (RSD). A sensitivity enhancement factor of 100-fold was achieved using sweeping-CD-MEKC at acidic pH. This is the first report on the separation of two pairs of propiconazole enantiomers and all the enantiomers of fenbuconazole and tebuconazole using sweeping-CD-MEKC. The limit of detection (S/N=3) for the three triazole fungicides ranged from 0.09 to 0.1 microg/mL, which is well below the maximum residue limits (MRL) set by Codex Alimentarius Commission (CAC). Combination of solid-phase extraction (SPE) pretreatment and sweeping-CD-MEKC procedure was applied to the determination of selected triazole fungicides in grapes samples spiked at concentration 10-40 times lower than the MRL established by the CAC. The average recoveries of the selected fungicides in spiked grapes samples were good, ranging from 73% to 109% with RSD of 9-12% (n=3).
    Matched MeSH terms: Cyclodextrins/chemistry*; gamma-Cyclodextrins/chemistry*
  18. Cyclodextrin based polymer sorbents for micro-solid phase extraction followed by liquid chromatography tandem mass spectrometry in determination of endogenous steroids
    Manaf NA, Saad B, Mohamed MH, Wilson LD, Latiff AA
    J Chromatogr A, 2018 Mar 30;1543:23-33.
    PMID: 29478831 DOI: 10.1016/j.chroma.2018.02.032
    Sorbents were prepared by cross-linking β-cyclodextrin (β-CD) using two different types of cross-linker units at variable reactant mole ratios. The resulting polymers containing β-CD were evaluated as sorbents in micro-solid phase extraction (μ-SPE) format for the extraction of the endogenous steroids testosterone (T), epitestosterone (E), androsterone (A), etiocholanolone (Etio), 5α-androstane-3α,17β-diol (5αAdiol) and 5β-androstane-3α,17β-diol (5βAdiol). The best sorbent (C1; cyclodextrin polymer) showed superior extraction characteristics compared with commercial sorbents (C18 and Bond Elut Plexa). Parameters influencing the extraction efficiency of the C1 sorbent such as extraction and desorption times, desorption solvent and volume of sample were investigated. The extracts were separated using a Hypersil Gold column (50 × 2.1 mm, 1.9 μm) under gradient elution coupled to a LC-MS/MS. The compounds were successfully separated within 8 min. The method offers good repeatability (RSD  0.995) were within the range of 1-200 ng mL-1 for T and E, 250-4000 ng mL-1 for A and Etio and 25-500 ng mL-1 for 5αAdiol and 5βAdiol, respectively. The method was applied for the determination of steroid profile of urine from volunteers.
    Matched MeSH terms: beta-Cyclodextrins/chemistry*
  19. Fulltext Exploiting β-cyclodextrin in molecular imprinting for achieving recognition of benzylparaben in aqueous media
    Asman S, Mohamad S, Sarih NM
    Int J Mol Sci, 2015;16(2):3656-76.
    PMID: 25667978 DOI: 10.3390/ijms16023656
    The molecularly imprinted polymer (MIP) based on methacrylic acid functionalized β-cyclodextrin (MAA-β-CD) monomer was synthesized for the purpose of selective recognition of benzylparaben (BzP). The MAA-β-CD monomer was produced by bridging a methacrylic acid (MAA) and β-cyclodextrin (β-CD) using toluene-2,4-diisocyanate (TDI) by reacting the -OH group of MAA and one of the primary -OH groups of β-CD. This monomer comprised of triple interactions that included an inclusion complex, π-π interaction, and hydrogen bonding. To demonstrate β-CD performance in MIPs, two MIPs were prepared; molecularly imprinted polymer-methacrylic acid functionalized β-cyclodextrin, MIP(MAA-β-CD), and molecularly imprinted polymer-methacrylic acid, MIP(MAA); both prepared by a reversible addition fragmentation chain transfer polymerization (RAFT) in the bulk polymerization process. Both MIPs were characterized using the Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and Brunauer-Emmett-Teller (BET). The presence of β-CD not only influenced the morphological structure, it also affected the specific surface area, average pore diameter, and total pore volume of the MIP. The rebinding of the imprinting effect was evaluated in binding experiments, which proved that the β-CD contributed significantly to the enhancement of the recognition affinity and selective adsorption of the MIP.
    Matched MeSH terms: beta-Cyclodextrins/chemistry*
  20. Fulltext Molecular imprinted polymer of methacrylic acid functionalised β-cyclodextrin for selective removal of 2,4-dichlorophenol
    Surikumaran H, Mohamad S, Sarih NM
    Int J Mol Sci, 2014;15(4):6111-36.
    PMID: 24727378 DOI: 10.3390/ijms15046111
    This work describes methacrylic acid functionalized β-cyclodextrin (MAA-βCD) as a novel functional monomer in the preparation of molecular imprinted polymer (MIP MAA-βCD) for the selective removal of 2,4-dichlorophenol (2,4-DCP). The polymer was characterized using Fourier Transform Infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) and Field Emission Scanning Electron Microscopy (FESEM) techniques. The influence of parameters such as solution pH, contact time, temperature and initial concentrations towards removal of 2,4-DCP using MIP MAA-βCD have been evaluated. The imprinted material shows fast kinetics and the optimum pH for removal of 2,4-DCP is pH 7. Compared with the corresponding non-imprinted polymer (NIP MAA-βCD), the MIP MAA-βCD exhibited higher adsorption capacity and outstanding selectivity towards 2,4-DCP. Freundlich isotherm best fitted the adsorption equilibrium data of MIP MAA-βCD and the kinetics followed a pseudo-second-order model. The calculated thermodynamic parameters showed that adsorption of 2,4-DCP was spontaneous and exothermic under the examined conditions.
    Matched MeSH terms: beta-Cyclodextrins/chemistry*
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