Cancer has been cursed for human beings for long time. Millions people lost their lives due to cancer. Despite of the several anticancer drugs available, cancer cannot be cured; especially at the ...late stages without showing any side effect. Heterocyclic compounds exhibit exciting medicinal properties including anticancer. Some market selling heterocyclic anticancer drugs include 5-flourouracil, methortrexate, doxorubicin, daunorubicin, etc. Besides, some natural products such as vinblastine and vincristine are also used as anticancer drugs. Overall, heterocyclic moeities have always been core parts in the expansion of anticancer drugs. This article describes the importance of heterocyclic nuclei in the development of anticancer drugs. Besides, the attempts have been made to discuss both naturally occurring and synthetic heterocyclic compounds as anticancer agents. In addition, some market selling anticancer heterocyclic compounds have been described. Moreover, the efforts have been made to discuss the mechanisms of actions and recent advances in heterocyclic compounds as anticancer agents. The current challenges and future prospectives of heterocyclic compounds have also been discussed. Finally, the suggestions for syntheses of effective, selective, fast and human friendly anticancer agents are discussed into the different sections.
A new graphene-based tetraethoxysilane-methyltrimethoxysilane sol-gel hybrid magnetic nanocomposite (Fe3O4@G-TEOS-MTMOS) was synthesised, characterized and successfully applied in magnetic ...solid-phase extraction (MSPE) for simultaneous analysis of polar and non-polar organophosphorus pesticides from several water samples. The Fe3O4@G-TEOS-MTMOS nanocomposite was characterized using Fourier transform-infrared spectroscopy, energy-dispersive X-ray spectroscopy, field emission scanning electron microscopy and X-ray diffraction. Separation, determination and quantification were achieved using gas chromatography coupled with micro electron capture detector. Adsorption capacity of the sorbent was calculated using Langmuir equation. MSPE was linear in the range 100–1000 pg mL−1 for phosphamidon and dimethoate, and 10–100 pg mL−1 for chlorpyrifos and diazinon, with limit of detection (S/N = 3) of 19.8, 23.7, 1.4 and 2.9 pg mL−1 for phosphamidon, dimethoate, diazinon and chlorpyrifos, respectively. The LODs obtained is well below the maximum residual level (100 pg mL−1) as set by European Union for pesticides in drinking water. Acceptable precision (%RSD) was achieved for intra-day (1.3–8.7%, n = 3) and inter-day (7.6–17.8%, n = 15) analyses. Fe3O4@G-TEOS-MTMOS showed high adsorption capacity (54.4–76.3 mg g−1) for the selected OPPs. No pesticide residues were detected in the water samples analysed. Excellent extraction recoveries (83–105%) were obtained for the spiked OPPs from tap, river, lake and sea water samples. The newly synthesised Fe3O4@G-TEOS-MTMOS showed high potential as adsorbent for OPPs analysis.
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•New sol-gel hybrid magnetic adsorbent synthesised for organophosphorus pesticides (OPPs).•Fe3O4 modified with graphene (G) and inorganic–organic sol-gel hybrid (TEOS-MTMOS).•Fe3O4@G-TEOS-MTMOS used as new adsorbent for simultaneous preconcentration of OPPs.•High extraction recovery (>80%) and high enrichment (>109) with Fe3O4@G-TEOS-MTMOS.•71 × lower LOD (than EU) with the new Fe3O4@G-TEOS-MTMOS for OPPs in water samples.
NACE is an alternative technique to aqueous CE in the chiral separations of partially soluble racemates. Besides, partially water‐soluble or insoluble chiral selectors may be exploited in the ...enantiomeric resolution in NACE. The high reproducibility due to low Joule heat generation and no change in BGE concentration may make NACE a routine analytical technique. These facts attracted scientists to use NACE for the chiral resolution. The present review describes the advances in the chiral separations by NACE and its application in pharmaceutical and biomedical analysis. The emphasis has been given to discuss the selection of the chiral selectors and organic solvents, applications of NACE, comparison between NACE and aqueous CE, and chiral recognition mechanism. Besides, efforts have also been made to predict the future perspectives of NACE.
Ionic Liquids in HPLC and CE: A Hope for Future Ali, Imran; Suhail, Mohd; Sanagi, Mohd. Marsin ...
Critical reviews in analytical chemistry,
07/2017, Letnik:
47, Številka:
4
Journal Article
Recenzirano
The ionic liquids (ILs) are salts with melting points below 100°C. These are called as ionic fluids, ionic melts, liquid electrolytes, fused salts, liquid salts, ionic glasses, designer solvents, ...green solvents and solvents of the future. These have a wide range of applications, including medical, pharmaceutical and chemical sciences. Nowadays, their use is increasing greatly in separation science, especially in chromatography and capillary electrophoresis due to their remarkable properties. The present article describes the importance of ILs in high-performance liquid chromatography and capillary electrophoresis. Efforts were also made to highlight the future expectations of ILs.
The study includes the preparation, characterisation, and application of a new adsorbent, 3-aminopropyltriethoxysilane modified chrysin (CHY-APTES), to extract Pb(II), Cr(III), and Cd(II) from ...stingless bee honey samples using dispersive micro-solid phase extraction (d-µ-SPE) and detected by graphite furnace atomic absorption spectrometer. Characterisation techniques of CHY-APTES including Brunauer-Emmett-Teller surface area analysis, Fourier transform infrared spectroscopy, scanning electron microscopy-energy dispersive x-ray imaging and point of zero charge determination. Several parameters were studied and optimised, such as a desorption time of 15 min, an adsorption time of 3 min, the use of nitric acid solution as the desorption solvent, 120 mg of adsorbent mass, solution pH adjusted to pH 5, and ethanol employed as the dispersive solvent. The results demonstrated good relative recoveries for Pb(II), Cr(III) and Cd(II) in the range of 74.76–116.34 %, 83.59–115.83 % and 89.03–117.66 %, respectively, with good precision at a relative standard deviation≤11.46%. For method sensitivity, the method showed acceptable detection limits (3 S/N) for Pb(II), Cr(III) and Cd(II) extracted from stingless bee honey samples at 43.6, 348.9 and 56.7 µg/kg, respectively. The preconcentration factors calculated for Pb(II), Cr(III), and Cd(II) were 111, 9.5, and 49, respectively. The newly developed CHY-APTES was successfully applied in d-µ-SPE for the first time. It was adequate in terms of analytical performance and simple in preparing stingless bee honey samples via dilution.
•A new 3-aminopropyltriethoxysilane-modified chrysin was developed as DSPE sorbent.•Interaction mechanisms between heavy metal ion and CHY-APTES were illustrated.•The biobased sorbent was applied to extract and enrich heavy metals in honey.•The developed sorbent achieved extraction recoveries of > 74.7 %.
A novel sol–gel hybrid methyltrimethoxysilane–tetraethoxysilane (MTMOS–TEOS) was produced and applied as sorbent for solid phase extraction (SPE). Five selected organophosphorus pesticides (OPPs) ...were employed as model compounds to evaluate the extraction performance of the synthesized sol–gel organic–inorganic hybrid MTMOS–TEOS. Analysis was performed using gas chromatography–mass spectrometry. Several important SPE parameters were optimized. Under the optimum extraction conditions, the method using the sol–gel organic–inorganic hybrid MTMOS–TEOS as SPE sorbent showed good linearity in the range of 0.001–1μgL−1, good repeatability (RSD 2.1–3.1%, n=5), low limits of detection at S/N=3 (0.5–0.9pgmL−1) and limit of quantification (1–3pgmL−1, S/N=10). The performance of the MTMOS–TEOS SPE was compared to commercial C18 Supelclean SPE since C18 SPE is widely used for OPPs. The MTMOS–TEOS SPE method LOD was 500–600× lower than the LOD of commercial C18 SPE. The LOD achieved with the sol–gel organic–inorganic hybrid MTMOS–TEOS SPE sorbent allowed the detection of these OPPs in drinking water well below the level set by European Union (EU) at 0.1μgL−1 of each pesticides. The developed MTMOS–TEOS SPE method was successfully applied to real sample analysis of the selected OPPs from several water samples and its application extended to the analysis of several fruits samples. Excellent recoveries and RSDs of the OPPs were obtained from the various water samples (recoveries: 97–111%, RSDs 0.4–2.8%, n=3) and fruit samples (recoveries: 96–111%), RSDs 1–4%, n=5) using the sol–gel organic–inorganic hybrid MTMOS–TEOS SPE sorbent. Recoveries and RSDs of OPPs from river water samples and fruit samples using C18 Supelclean SPE sorbent were 91–97%, RSD 0.9–2.6, n=3 and 86–96%, RSD 3–8%, n=5, respectively). The novel sol–gel hybrid MTMOS–TEOS SPE sorbent demonstrate the potential as an alternative inexpensive extraction sorbent for OPPs with higher sensitivity for the OPPs.
A new sol–gel hybrid coating, polydimethylsiloxane–2-hydroxymethyl-18-crown-6 (PDMS–2OHMe18C6) was prepared in-house for use in solid phase microextraction (SPME). The three compositions produced ...were assessed for its extraction efficiency towards three selected organophosphorus pesticides (OPPs) based on peak area extracted obtained from gas chromatography with electron capture detection. All three compositions showed superior extraction efficiencies compared to commercial 100
μm PDMS fiber. The composition showing best extraction performance was used to obtain optimized SPME conditions: 75
°C extraction temperature, 10
min extraction time, 120
rpm stirring rate, desorption time 5
min, desorption temperature 250
°C and 1.5% (w/v) of NaCl salt addition. The method detection limits (S/N
=
3) of the OPPs with the new sol–gel hybrid material ranged from 4.5 to 4.8
ng
g
−1, which is well below the maximum residue limit set by Codex Alimentarius Commission and European Commission. Percentage recovery of OPPs from strawberry, green apple and grape samples with the new hybrid sol–gel SPME material ranged from 65 to 125% with good precision of the method (%RSD) ranging from 0.3 to 7.4%.
•MIP-SPE method was developed for the determination of organophosphorus pesticides.•Crucial MIP-SPE parameters were optimized to select optimum conditions.•Fruit samples were analyzed by using the ...MIP-SPE coupled with GC–MS.•The MIP-SPE showed improved selectivity and recovery compared to C18-SPE.
A new selective material based on molecularly imprinted polymers (MIPs) was prepared and used as solid-phase extraction (SPE) sorbent for sample enrichment of organophosphorus pesticides (OPP) residues prior to high performance liquid chromatography (HPLC). Three OPPs widely used in agriculture (diazinon, quinalphos and chlorpyrifos) were selected as target analytes. Various parameters affecting the extraction efficiency of the imprinted polymers were evaluated to optimize the selective preconcentration of OPPs from water samples. Under the optimized conditions, the developed MIP-SPE method showed excellent linearity in the range of 4–200μgL−1 with coefficient of determination (r2)>0.997 and good OPP recoveries of >91% and limits of detection (LODs) ranging from 0.83μgL−1 to 2.8μgL−1,which is much lower than the maximum residue limits (MRLs) set by the Codex Alimentarius Commission and Japan Food Chemical Research Foundation. The developed method was successfully applied to the analysis of OPPs in selected fruit samples. MIP-SPE showed superior extraction efficiency towards the OPPs as compared to non-imprinted polymer solid-phase extraction (NIP-SPE) and commercial C18-SPE methods.
•Chitin was grafted with polystyrene using ammonium persulfate initiator.•The graft copolymer showed improved thermal stability compared to chitin itself.•Polystyrene was successfully cleaved by acid ...hydrolysis of the grafted copolymer.
Chitin was successfully grafted with polystyrene by free radical mechanism using ammonium persulfate (APS) initiator. The reaction was carried out in aqueous medium. The effect of pH, chitin:monomer weight ratio, APS, reaction time and reaction temperature were investigated. The results showed that the optimum conditions for grafting of polystyrene were found as follows: pH 7, chitin:monomer weight ratio of 1:3, 0.4g of APS, reaction temperature of 60°C and reaction time 2h. The graft copolymer was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA) and differential scanning electron microscopy (DSC). Gel permeation chromatography (GPC) analysis carried out on the hydrolyzed graft copolymer showed that the Mn and Mw were 6.3395×104g/mol and 1.69283×105g/mol, respectively, with polydispersity index of 2.7.
•Fe3O4-sporopollenin-cyanopropyltriethoxysilane (MS-CNPrTEOS) as D-μ-SPE sorbent.•First use of MS-CNPrTEOS in D-μ-SPE ofnon-steroidal anti-inflammatory drugs.•Simple surface modification of bio-based ...sporopollenin was demonstrated.•The developed MS-CNPrTEOS D-μ-SPE HPLC method achieved ppb level LOD.•The method provided highrecoveries in tap, river, lake and waste water samples.
A facile dispersive-micro-solid phase extraction (D-μ-SPE) method coupled with HPLC for the analysis of selected non-steroidal anti-inflammatory drugs (NSAIDs) in water samples was developed using a newly prepared magnetic sporopollenin-cyanopropyltriethoxysilane (MS-CNPrTEOS) sorbent. Sporopollenin homogenous microparticles of Lycopodium clavatum spores possessed accessible functional groups that facilitated surface modification. Simple modification was performed by functionalization with 3-cyanopropyltriethoxysilane (CNPrTEOS) and magnetite was introduced onto the biopolymer to simplify the extraction process. MS-CNPrTEOS was identified by infrared spectrometrywhile the morphology and the magnetic property were confirmed by scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM), respectively. To maximize the extraction performance of ketoprofen, ibuprofen, diclofenac and mefenamic acid using the proposed MS-CNPrTEOS, important D-μ-SPE parameters were comprehensively optimized. The optimum extraction conditions were sorbent amount, 40 mg; extraction time, 5 min; desorption time; 5 min; sample volume, 15 mL; sample pH 2.0; and salt addition, 2.5% (w/v). The feasibility of the developed method was evaluated using spiked tap water, lake water, river water and waste water samples. Results showed that ketoprofen and ibuprofen were linear in the range of 1.0–1000 μg L−1 whilst diclofenac and mefenamic acid were linear in the range 0.8–500 μg L−1. The results also showed good detection limits for the studied NSAIDs in the range of 0.21–0.51 μg L−1 and good recoveries for spiked water samples in the range of 85.1–106.4%. The MS-CNPrTEOS proved a promising dispersive sorbent and applicable to facile and rapid assay of NSAIDs in water samples.
