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1.
Environ Sci Technol ; 50(7): 3754-61, 2016 Apr 05.
Article in English | MEDLINE | ID: mdl-26937944

ABSTRACT

A sensitive, competitive enzyme-linked immunosorbent assay (ELISA) for the detection of the antimicrobial triclosan (TCS; 2,4,4'-trichloro-2'-hydroxydiphenyl ether) was developed. Novel immunizing haptens were synthesized by derivatizing at the 4-Cl position of the TCS molecule. Compounds derived from substitutions at 4'-Cl and that replaced the 2'-OH with a Cl atom were designed as unique coating antigen haptens. Polyclonal rabbit antisera were screened against the coating antigen library to identify combinations of immunoreagents resulting in the most sensitive assays. The most sensitive assay identified was one utilizing antiserum no. 1155 and a heterologous competitive hapten, where the 2'-OH group was substituted with a Cl atom. An IC50 value and the detection range for TCS in assay buffer were 1.19 and 0.21-6.71 µg/L, respectively. The assay was selective for TCS, providing low cross-reactivity (<5%) to the major metabolites of TCS and to brominated diphenyl ether-47. A second assay utilizing a competitive hapten containing Br instead of Cl substitutions was broadly selective for both brominated and chlorinated diphenylethers. Using the most sensitive assay combination, we measured TCS concentrations in water samples following dilution. Biosolid samples were analyzed following the dilution of a simple solvent extract. The immunoassay results were similar to those determined by LC-MS/MS. This immunoassay can be used as a rapid and convenient tool to screen for human and environmental exposure.


Subject(s)
Anti-Infective Agents/analysis , Enzyme-Linked Immunosorbent Assay/methods , Triclosan/analysis , Water Pollutants, Chemical/analysis , Animals , Anti-Infective Agents/chemistry , Cross Reactions , Female , Halogenated Diphenyl Ethers/analysis , Halogenated Diphenyl Ethers/immunology , Haptens/chemistry , Haptens/immunology , Immune Sera/immunology , Rabbits , Reproducibility of Results , Tandem Mass Spectrometry , Triclosan/chemistry , Triclosan/immunology , Water Pollutants, Chemical/chemistry
2.
Anal Bioanal Chem ; 407(24): 7263-73, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26255293

ABSTRACT

Triclosan-O-glucuronide (TCSG) is one of the primary urinary metabolites of the antibacterial compound triclosan or TCS that is found in many personal care products and consumer goods. We have developed a competitive, indirect heterologous ELISA for the detection of the target TCSG in urine. Such an ELISA for TCSG could be developed as a useful tool to measure this important biomarker of human exposure to TCS. Immunogens were prepared by conjugating TCSG to thyroglobulin, via heterobifunctional cross-linkers AEDP or 3-[(2-aminoethyl)dithio] propionic acid•hydrochloride and TFCS or N-[ε-trifluoroacetylcaproyloxy]succinimide ester. The coating antigen was prepared by the direct conjugation of TCSG to bovine serum albumin. Antibodies raised in rabbits 2619, 2621 (immunogen TCSG-AEDP-Thy), and 2623 (immunogen TCSG-TFCS-Thy), and the coating antigen were screened and characterized to determine their optimal concentrations. The optimized ELISA, developed with antibody 2621, gave an IC50 value of 2.85 ng/mL, with the linear range (IC20-IC80) determined to be 2.6-24.8 ng/mL. Selectivity of the assay was assessed by measuring cross-reactivity of antibody 2621 to related congeners such as the aglycone TCS, triclosan-O-sulfate, triclocarban, a polybrominated diphenyl ether derivative, and 3-phenoxybenzyl alcohol glucuronide. There was virtually no recognition by antibody 2621 to any of these cross-reactants. Graphical Abstract Urinary biomarker analysis of triclosan glucuronide.


Subject(s)
Anti-Bacterial Agents/urine , Glucuronides/urine , Immunoassay/methods , Triclosan/urine , Animals , Anti-Bacterial Agents/metabolism , Glucuronides/metabolism , Humans , Hydrogen-Ion Concentration , Immune Sera , Osmolar Concentration , Rabbits , Triclosan/metabolism
3.
J Agric Food Chem ; 61(28): 6964-70, 2013 Jul 17.
Article in English | MEDLINE | ID: mdl-23767873

ABSTRACT

Hesperetin dihydrochalcone 4'-glucoside, 1, and phloretin 4'-glucoside, 2, belong to a family of dihydrochalcone glycosides that exhibit flavorant properties. In this study was developed a competitive, indirect homologous ELISA for the detection of targets 1 and 2 in fermentation media. Immunogen and coating antigen were prepared by conjugating hapten, 4-(3-oxo-3-(2,6-dihydroxy-4-glucoside phenyl)propyl) benzoic acid, to thyroglobulin and bovine serum albumin, respectively. Antibodies raised in rabbits M6122, M6123, and M6124 and the coating antigen were screened and characterized to determine their optimum concentrations. The optimized ELISA, developed with antibody M6122, gave IC50 values of 27.8 and 21.8 ng/mL for 1 and 2, respectively. Selectivity of the assay was assessed by measuring cross-reactivity of antibody M6122 to related congeners such as aglycones and the 2'-glycosides of hesperetin dihydrochalcone, 5 and phloretin, 6. Antibody M6122 showed very low recognition of 5 and virtually no recognition of the aglycones and 6.


Subject(s)
Enzyme-Linked Immunosorbent Assay/methods , Flavanones/analysis , Glucosides/analysis , Phloretin/analogs & derivatives , Animals , Antibodies/immunology , Antibody Specificity , Female , Fermentation , Flavanones/immunology , Glucosides/immunology , Haptens/chemistry , Haptens/immunology , Immune Sera/biosynthesis , Immunization , Phloretin/analysis , Phloretin/immunology , Rabbits , Serum Albumin, Bovine/immunology , Taste
4.
Aquat Toxicol ; 105(3-4): 448-54, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21872556

ABSTRACT

The antimicrobial triclocarban (TCC) is frequently found in personal care products and commonly observed in surface waters and sediments. Due to its long environmental persistence TCC accumulates in sewage sludge. It also shows a high unintended biological activity as a potent inhibitor of the soluble epoxide hydrolase (sEH) and may be an endocrine disruptor. In this study, we investigated bioconcentration, metabolism and elimination of TCC in fish using medaka (Oryzias latipes) as a model. Medaka larvae (7 ± 1 days post hatching) were exposed to 63 nM (20 µg/L) TCC water for 24h. The LC-MS/MS analysis of water and tissues provided bioconcentration of TCC and its metabolites in fish body and rapid excretion into culture water. Results from tissue samples showed a tissue concentration of 34 µmol/kg and a log bioconcentration factor (BCF) of 2.86. These results are slightly lower than previous findings in snails and algae. A significant portion of the absorbed TCC was oxidatively metabolized by the fish to hydroxylated products. These metabolites underwent extensive phase II metabolism to yield sulfate and glucuronic acid conjugates. The most abundant metabolite in fish tissue was the glucuronide of 2'-OH-TCC. Elimination of TCC after transferring the fish to fresh water was rapid, with a half-life of 1h. This study shows that larval medaka metabolize TCC similarly to mammals. The rapid rate of metabolism results in a lower bioconcentration than calculated from the octanol-water coefficient of TCC.


Subject(s)
Carbanilides/pharmacokinetics , Oryzias/metabolism , Water Pollutants, Chemical/pharmacokinetics , Animals , Body Burden , Chromatography, Liquid , Female , Half-Life , Inactivation, Metabolic , Larva/metabolism , Male , Metabolic Detoxication, Phase II , Solid Phase Extraction , Tandem Mass Spectrometry
5.
Chem Commun (Camb) ; (35): 3637-9, 2007 Sep 21.
Article in English | MEDLINE | ID: mdl-17728878

ABSTRACT

A large, symmetrically substituted triazine-based molecule, synthesized by a copper-free Sonogashira coupling procedure self-assembles to form a novel 1D channel structure that hosts chlorobenzene molecules as guests.

6.
Chem Commun (Camb) ; (27): 2878-80, 2006 Jul 21.
Article in English | MEDLINE | ID: mdl-17007403

ABSTRACT

The ionic character of a set of two redox linkages and strong, directional halogen bonding at the organic-inorganic interface compromise to produce two materials sharing a common two-dimensional net, eventually extended in a third dimension, although two of the six symmetrical halogen bond acceptors ultimately remain uninvolved as a result of charge densification.

7.
Chemistry ; 11(8): 2433-9, 2005 Apr 08.
Article in English | MEDLINE | ID: mdl-15696584

ABSTRACT

Crystallisation of trithiocyanuric acid (TTCA) from various organic solvents that have hydrogen bonding capability (acetone, 2-butanone, dimethylformamide, dimethyl sulfoxide, methanol and acetonitrile) leads to the formation of co-crystals in which the solvent molecules are incorporated together with TTCA in the crystal structure. Structure determination by single-crystal X-ray diffraction reveals that these co-crystals can be classified into different groups depending upon the topological arrangement of the TTCA molecules in the crystal structure. Thus, three different types of single-tape arrangements of TTCA molecules and one type of double-tape arrangement of TTCA molecules are identified. In all co-crystals, hydrogen-bonding interactions are formed through the involvement of N-H bonds of TTCA molecules in these tapes and the other molecule in the co-crystal. Detailed rationalisation of the structural properties of these co-crystals is presented.

8.
J Biol Chem ; 278(21): 19134-40, 2003 May 23.
Article in English | MEDLINE | ID: mdl-12624111

ABSTRACT

Histone acetyltransferases (HATs) are a group of enzymes that play a significant role in the regulation of gene expression. These enzymes covalently modify the N-terminal lysine residues of histones by the addition of acetyl groups from acetyl-CoA. Dysfunction of these enzymes is often associated with the manifestation of several diseases, predominantly cancer. Here we report that anacardic acid from cashew nut shell liquid is a potent inhibitor of p300 and p300/CBP-associated factor histone acetyltranferase activities. Although it does not affect DNA transcription, HAT-dependent transcription from a chromatin template was strongly inhibited by anacardic acid. Furthermore, we describe the design and synthesis of an amide derivative N-(4-chloro-3-trifluoromethyl-phenyl)-2-ethoxy-6-pentadecyl-benzamide (CTPB) using anacardic acid as a synthon, which remarkably activates p300 HAT activity but not that of p300/CBP-associated factor. Although CTPB does not affect DNA transcription, it enhances the p300 HAT-dependent transcriptional activation from in vitro assembled chromatin template. However, it has no effect on histone deacetylase activity. These compounds would be useful as biological switching molecules for probing into the role of p300 in transcriptional studies and may also be useful as new chemical entities for the development of anticancer drugs.


Subject(s)
Acetyltransferases/antagonists & inhibitors , Acetyltransferases/metabolism , Anacardic Acids , Cell Cycle Proteins/antagonists & inhibitors , Cell Cycle Proteins/metabolism , Enzyme Inhibitors/pharmacology , Salicylates/pharmacology , Acetylation , Acetyltransferases/pharmacology , Amino Acid Sequence , Anacardium/chemistry , Antineoplastic Agents , Benzamides/chemical synthesis , Benzamides/pharmacology , Cell Cycle Proteins/pharmacology , Chromatin/genetics , Electrophoresis, Polyacrylamide Gel , HeLa Cells , Histone Acetyltransferases , Histones/chemistry , Histones/metabolism , Humans , Models, Molecular , Molecular Sequence Data , Molecular Structure , Plant Extracts/chemistry , Recombinant Proteins , Salicylates/chemistry , Seeds/chemistry , Templates, Genetic , Transcription Factors , Transcription, Genetic/drug effects , p300-CBP Transcription Factors
9.
Inorg Chem ; 42(1): 187-97, 2003 Jan 13.
Article in English | MEDLINE | ID: mdl-12513094

ABSTRACT

A series of new dicationic dihydrogen complexes of ruthenium of the type cis-[(dppm)(2)Ru(eta(2)-H(2))(L)][BF(4)](2) (dppm = Ph(2)PCH(2)PPh(2); L = P(OMe)(3), P(OEt)(3), PF(O(i)Pr)(2)) have been prepared by protonating the precursor hydride complexes cis-[(dppm)(2)Ru(H)(L)][BF(4)] (L = P(OMe)(3), P(OEt)(3), P(O(i)Pr)(3)) using HBF(4).Et(2)O. The cis-[(dppm)(2)Ru(H)(L)][BF(4)] complexes were obtained from the trans hydrides via an isomerization reaction that is acid-accelerated. This isomerization reaction gives mixtures of cis and trans hydride complexes, the ratios of which depend on the cone angles of the phosphite ligands: the greater the cone angle, the greater is the amount of the cis isomer. The eta(2)-H(2) ligand in the dihydrogen complexes is labile, and the loss of H(2) was found to be reversible. The protonation reactions of the starting hydrides with trans PMe(3) or PMe(2)Ph yield mixtures of the cis and the trans hydride complexes; further addition of the acid, however, give trans-[(dppm)(2)Ru(BF(4))Cl]. The roles of the bite angles of the dppm ligand as well as the steric and the electronic properties of the monodentate phosphorus ligands in this series of complexes are discussed. X-ray crystal structures of trans-[(dppm)(2)Ru(H)(P(OMe)(3))][BF(4)], cis-[(dppm)(2)Ru(H)(P(OMe)(3))][BF(4)], and cis-[(dppm)(2)Ru(H)(P(O(i)Pr)(3))][BF(4)] complexes have been determined.

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