Publications by authors named "Pakawadee Sutthivaiyakit"

10 Publications

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Magnetic molecularly imprinted polymer prepared by microwave heating for confirmatory determination of chloramphenicol in chicken feed using high-performance liquid chromatography-tandem mass spectrometry.

J Environ Sci Health B 2018 17;53(11):738-745. Epub 2018 Jul 17.

d Department of Chemistry and Center of Excellence for Innovation in Chemistry , Faculty of Science, Ramkhamhaeng University , Bangkok , Thailand .

A magnetic molecularly imprinted polymer (MMIP) for chloramphenicol was prepared using a surface-imprinted and microwave-heating-induced polymerization method. The surfaces of the magnetic particles were first double-bond functionalized with 3-(trimethoxysilyl)propyl methacrylate (γ-MPS), followed by the copolymerization of 4-vinyl pyridine (4-VP) and trimethylolpropane trimethacrylate (TRIM) in the presence of chloramphenicol as a template and 1,1-azobis(cyclohexane-carbonitrile) (ABCN) as an initiator in a mixture of dimethyl sulfoxide and water with microwave heating at 80°C. The magnetic polymer possesses supraparamagnetic properties and was used to concentrate and cleanup chicken feed extract, followed by chromatographic separation using a Lichrospher®100 RP C8 column and detection with two multi-reaction monitoring transitions at m/z 321→ 152 and m/z 321→ 257. The mean recoveries obtained at two spiking levels were in the range of 94.6-100% The relative intra- and inter-day standard deviations were in the range of 1.4-2.6% and 5.1-5.7%, respectively. The detection limit of the method was 0.12 µg kg. This confirmatory method was successfully applied to determine chloramphenicol in chicken feed samples.
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http://dx.doi.org/10.1080/03601234.2018.1480161DOI Listing
April 2019

Degradation products of profenofos as identified by high-field FTICR mass spectrometry: Isotopic fine structure approach.

J Environ Sci Health B 2017 Jan 14;52(1):10-22. Epub 2016 Sep 14.

a Department of Chemistry and Center of Excellence for Innovation in Chemistry , Faculty of Science, Kasetsart University , Bangkok , Thailand.

This study was performed to identify the degradation products of profenofos "a phenyl organothiophosphate insecticide" in raw water (RW) collected from the entry point of Metropolitan Water Works Authority "Bangkaen, Thailand" and ultrapure water (UPW) with and without TiO under simulated sunlight irradiation. Degradation of profenofos was followed with ultrahigh performance liquid chromatography (UHPLC) and follows pseudo first-order kinetic. Accordingly, high-field FTICR mass spectrometry coupled to an electrospray ionization source was used to reveal the degradation routes of profenofos and the isotopic fine structures (IFS) elucidations to approve the chemical structures of its degradation products. More degradation products were detected in UPW as compared to RW. Consequently, two main degradation pathways namely (i) interactive replacements of bromine and hydrogen by hydroxyl functional groups and (ii) rupture of PO, PS, CBr and CCl bonds were observed. None interactive replacement of chlorine by hydroxyl functional group was detected. Accordingly, mechanistical pathways of the main degradation products were established.
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http://dx.doi.org/10.1080/03601234.2016.1224696DOI Listing
January 2017

Prenylfuranocoumarin-HMGA-flavonol glucoside conjugates and other constituents of the fruit peels of Citrus hystrix and their anticholinesterase activity.

Phytochemistry 2016 Jul 16;127:38-49. Epub 2016 Mar 16.

Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Hua Mark, Bangkapi, Bangkok 10240, Thailand. Electronic address:

Sixteen compounds including dihydroxy prenylfuranocoumarins/3-hydroxy-3-methylglutaric acid conjugates and dihydroxy prenylfuranocoumarins/3-hydroxy-3-methylglutaric acid/1-O-flavonyl-β-d-glucopyranoside conjugates, together with other dihydroxyprenylfuranocoumarins conjugates, were isolated from the ethyl acetate extract of the fruit peels of Citrus hystrix. Some of the isolates were evaluated for their cholinesterase inhibitory activity, but only one compound possessing a 3-O-β-d-glucopyranosyl-3,5,7,4'-tetrahydroxy-6,8,3'-trimethoxyflavonol nucleus in the prenylfuranocoumarin-HMGA conjugate showed strong activity.
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http://dx.doi.org/10.1016/j.phytochem.2016.03.009DOI Listing
July 2016

Microscale Ecotoxicity Testing of Moselle River Watershed (Lorraine Province, France) Sediments.

J Xenobiot 2015 Apr 9;5(1):5125. Epub 2015 Jun 9.

Environment Canada, Montréal, Québec, Canada.

The ecotoxic potential of seven Moselle river watershed sediments was assessed with a battery of bioassays comprised of rapid phototrophic [LuminoTox solid phase (L-SPA) and elutriate (L-ELU) assays] and bacterial [Microtox solid phase assay (M-SPA)] exposure tests, as well as with two micro-invertebrate solid phase tests conducted with (lethal and sublethal effects solid phase assay, H-SPA and H-SPA) and . Measured effects of sediments and their elutriates were varied and reflected responses that were ecotoxicity test-, endpoint- and site-dependent, suggesting some degree of risk toward benthic and water column organisms, respectively, at specific sites. Correlation analysis demonstrated that L-SPA and M-SPA ecotoxicity responses were significantly linked with the Hydra H-SPA assay, indicating their ability to predict ecotoxicity towards an invertebrate taxonomic group representing secondary consumers. While the L-SPA and M-SPA assays hold promise as rapid screens for sediment ecotoxicity, correlation analysis with grain size (L-SPA: r=-0.795, P=0.033; M-SPA: r=-0.73, P=0.07) points out that their responses can be influenced by the presence of fines (., sediment particles ≤0.063 mm in size) and that this information is essential to properly interpret ecotoxicity data generated with these assays. Finally, notable differences observed in trophic level sensitivities once again recall the importance of employing a test battery to adequately appraise the ecotoxicity of sediments.
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http://dx.doi.org/10.4081/xeno.2015.5125DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6324487PMC
April 2015

Photo-catalysis of bromacil under simulated solar light using Au/TiO₂: evaluation of main degradation products and toxicity implications.

Environ Sci Pollut Res Int 2015 Jan 28;22(2):1468-79. Epub 2014 Aug 28.

Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok, 10903, Thailand.

Bromacil (5-bromo-3-sec-butyl-6-methyluracil) is a substituted uracil herbicide used worldwide. It is not readily biodegradable and has the potential to contaminate different types of water bodies with possible impact on diverse non-target species. In this work, degradation of bromacil in aqueous Au/TiO2 suspension under simulated sunlight allowed fourteen degradation products to be identified. The photodegradation of bromacil followed (pseudo) first order kinetics in the presence of 0.2 g L(-1) of Au/TiO2 with a half-life of 25.66 ± 1.60 min and a rate constant of 0.0271 ± 0.0023 min(-1). Transformation routes of the photo-catalytic degradation of bromacil were then proposed. Complementary toxicity assessment of the treated bromacil solution revealed a marked decrease in toxicity, thereby confirming that by-products formed would be less harmful from an environmental point of view. Photo-catalytic degradation of bromacil thus appears to hold promise as a cost-effective treatment technology to diminish the presence of this herbicide in aquatic systems.
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http://dx.doi.org/10.1007/s11356-014-3425-3DOI Listing
January 2015

Eriosema chinense: a rich source of antimicrobial and antioxidant flavonoids.

Phytochemistry 2013 Dec 15;96:353-9. Epub 2013 Oct 15.

Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Hua Mark, Bangkapi, Bangkok 10240, Thailand.

Six prenylated flavonoids, (2R,3S)-3,5,4'-trihydroxy-6″-6″dimethylpyrano(2″,3″:7,6)-8-(3″', 3″'-dimethylallyl)flavanone, (2R,3S)-3,5,2'-trihydroxy-4'-methoxy-6″,6″-dimethylpyrano(2″,3″:7,6)-8-(3″',3″'-dimethylallyl)flavanone, (2R,3R)-3,5,2',4'-tetrahydroxy-6″,6″-dimethylpyrano(2″,3″:7,6)-8-(3″',3″'-dimethylallyl)flavanone, 3,5,2',4'-tetrahydroxy-6″,6″-dimethylpyrano(2″,3″:7,6)-8-(3″',3″'-dimethylallyl)flavone, (2R,3R,2″'R)-3,5,2″'-trihydroxy-4'-methoxy-6″,6″-dimethylpyrano(2″,3″:7,6)-8-(3″'-methylbut-3″'-enyl)flavanone, (2R,3R)-3,5-dihydroxy-4'-methoxy-6″,6″-dimethylpyrano(2″,3″:7,6)-8-(2″',3″'-epoxy-3″'-methyl butyl)flavanone, an isoflavone, 6,7-dimethoxy-5,2',4'-trihydroxyisoflavone, and octaeicosanyl-trans-p-coumarate together with 12 known compounds, were isolated from roots of Eriosema chinense. This structural elucidation was determined by spectroscopic methods. Several isolates and derivatives were evaluated for their antimicrobial and antioxidant activities. Results obtained provide additional evidence showing that the presence of both the free phenolic OH and the lipophilic prenyl groups are crucial for potent antimicrobial activity against yeast, gram positive and gram negative bacteria, whereas the presence of free phenolic OH group is required for strong radical scavenging property.
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http://dx.doi.org/10.1016/j.phytochem.2013.06.004DOI Listing
December 2013

Reactions of phenylurea compounds with aqueous chlorine: Implications for herbicide transformation during drinking water disinfection.

J Hazard Mater 2012 Mar 25;209-210:484-91. Epub 2012 Jan 25.

Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Kasetsart, Bangkok 10900, Thailand.

Phenylurea herbicides have been known to contaminate surface waters serving as potable supplies. To access the potential for transformation of these compounds during drinking water treatment, reactions of phenylurea compounds with aqueous chlorine at different pHs were investigated. The effect of substitution at the amino-N on the rate of transformation depends upon pH. Under acidic conditions, all of the phenylurea studied except 3,4-dichloro-3'-N-methylphenylurea (3,4-DCMPU) exhibited third-order kinetics, second order with respect to chlorine and first order with respect to phenylurea, while the reactions of 3,4-DCMPU were first order with respect to both chlorine and the organic compound. Under neutral and alkaline conditions, all compounds exhibited second-order kinetics that was first order with respect to chlorine and the organic compound. Apparent second-order rate constants at 25°C and pH 7 were 0.76 ± 0.16, 0.52 ± 0.11, 0.39 ± 0.02, 0.27 ± 0.04 and 0.23 ± 0.05 M(-1)s(-1) for phenylurea, 3, 4-dichlorophenylurea, 3, 4-DCMPU, metoxuron and monuron, respectively. Studies of the chlorination products, monitored by LC/MS/MS, under different pH values indicated the reaction to take place at both N atoms and also at ortho- and para- positions of the phenylurea aromatic group. The main chlorinating species were found to be different in different pH ranges. Under conditions typically encountered in drinking water treatment systems, transformation of these compounds by chlorine will be incomplete.
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http://dx.doi.org/10.1016/j.jhazmat.2012.01.063DOI Listing
March 2012

Citrusosides A-D and furanocoumarins with cholinesterase inhibitory activity from the fruit peels of Citrus hystrix.

J Nat Prod 2010 Nov 21;73(11):1879-83. Epub 2010 Oct 21.

Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Hua Mark, Bangkapi, Bangkok 10240, Thailand.

Four new compounds, citrusosides A-D (1-4), and 15 known compounds were isolated from the hexanes and CH(2)Cl(2) extracts of the peels of Citrus hystrix fruits. Compound 1 is a 1-O-isopropyl-6-O-β-D-glucopyranosyl ester of 5'',9''-dimethyl-2'',8''-decadienoic acid. Compounds 2-4 possess a 1-O-isopropyl-β-D-glucopyranosyl and a dihydroxyprenylfuranocoumarin moiety conjugated to the 3-hydroxy-3-methylglutaric acid as diesters. Several furanocoumarins were evaluated for their cholinesterase inhibitory activity. (R)-(+)-6'-Hydroxy-7'-methoxybergamottin, (R)-(+)-6',7'-dihydroxybergamottin, and (+)-isoimparatorin showed IC(50) values of 11.2 ± 0.1, 15.4 ± 0.3, and 23 ± 0.2 μM, respectively. Bioassay results indicated that the presence of a dioxygenated geranyl chain in the test compounds is crucial for the inhibitory activity.
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http://dx.doi.org/10.1021/np100531xDOI Listing
November 2010

New reagent for trace determination of protein-bound metabolites of nitrofurans in shrimp using liquid chromatography with diode array detector.

J Agric Food Chem 2009 Mar;57(5):1752-9

Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10903, Thailand.

The synthesis of derivatives of metabolites from furazolidone, furaltadone, nitrofurazone, and nitrofurantoin using a new derivatizing reagent, 2-naphthaldehyde (NTA), is described. The reaction product was used in liquid chromatography with diode array detector (LC-DAD) for determination of protein-bound metabolites of nitrofurans in shrimp followed by two steps of liquid-liquid extraction. Derivatives of nitrofuran metabolites are well separated from NTA remaining in the extract upon separation on a ChromSpher 5 Pesticide (250 x 4.6 mm, 5 microm) column at 40 degrees C with acetonitrile/5 mM ammonium acetate adjusted to pH 7.5 gradient as the mobile phase and DAD detection at 308 nm except for naphthyl derivative of 1-aminohydantoin at 310 nm. The high absorptivity of these derivatives makes simultaneous screening of these metabolites in shrimp at 1 microg/kg possible for the first time using LC-DAD. The method was validated using blank shrimp fortified with all four metabolites at 1, 1.5, and 2 microg/kg. Recoveries were >86% with relative standard deviations of <14% for all four metabolites. Comparison between LC-DAD and APCI-MS/MS shows very good agreement for shrimp samples.
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http://dx.doi.org/10.1021/jf803423rDOI Listing
March 2009

Constituents of the leaves of Macaranga tanarius.

J Nat Prod 2005 Jun;68(6):927-30

Department of Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok, Thailand.

From the leaves of Macaranga tanarius, three new constituents, tanarifuranonol (1), tanariflavanone C (2), and tanariflavanone D (3), together with seven known compounds, were isolated and identified. Substances obtained in this investigation were evaluated against a panel of bioassays.
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http://dx.doi.org/10.1021/np0500272DOI Listing
June 2005