Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Isothiocyanates”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 883 records · Page 49Linked to original sources
PubMed1992

Different sensitivity of the sarcoplasmic reticulum Ca(2+)-ATPase enzyme to fluorescein-isothiocyanate in rabbit and carp muscles.

1. Carp and rabbit sarcoplasmatic reticulum Ca(2+)-ATPase enzymes were compared with respect to their sensitivity to FITC labelling. 2. The carp enzyme showed much lower sensitivity to FITC in the Ca(2+)-Mg2+ activated ATPase activity. Fifty percent inhibition was observed at 20 microM labelling FITC concentration; in rabbit enzyme this inhibition was already achieved at 2 microM FITC. 3. The tryptic cleavage products of the carp enzyme identified with immunoblot analysis as well as with FITC fluorescence, suggest multiple cleavage, yielding different fragments from the ones well known in rabbit and in rat enzyme. 4. The present results indicates major structural differences with respect to the FITC binding, and tryptic cleavage between the SR Ca(2+)-ATPase enzymes from carp and rabbit, despite the cross-reactivity with polyclonal antibodies.

Animals↗
PubMed1993

Systematic approach to the development of plasma amino acid analysis by high-performance liquid chromatography with ultraviolet detection with precolumn derivatization using phenyl isothiocyanate.

A reversed-phase liquid chromatographic method for the separation of 26 phenylthiocarbamyl derivatives of amino acids in human plasma in ca. 35 min. is described. The method used a C18 column (150 x 4.6 mm I.D., 3 micron) thermostatted at 41 degrees C, and a simple multistep linear gradient of two solvents. Solvent A was 0.05 M sodium acetate (pH 5.1)-acetonitrile (98:2, v/v), and solvent B was water-acetonitrile (40:60, v/v). A simple and successful approach to the optimization of the conditions for the separation of the 26 amino acid derivatives was realized. In the initial phase of development, the composition of the gradient, its timings, the column temperature, the flow-rate and the mobile phase compositions were optimized. At the end the influence of pH was studied, and this approach led to a clear resolution of the 26 amino acids. The method was validated by accuracy, precision, and recovery studies, by analyzing patient samples, and by comparing the quality control sample results with the classical ion-exchange method.

Amino Acids↗
PubMed2006

Gene expression profiles induced by cancer chemopreventive isothiocyanate sulforaphane in the liver of C57BL/6J mice and C57BL/6J/Nrf2 (-/-) mice.

Sulforaphane (SFN) is a potent and promising naturally occurring dietary cancer chemopreventive compound that exerts its cancer protective effects by the induction of genes including cellular defensive genes such as phase II detoxifying and antioxidant enzymes. This gene induction primarily occurs via the transcription factor Nrf2 acting on the antioxidant response element (ARE) located at the 5'-flanking region of these genes. In the present study, transcriptional expression profiles of the livers obtained from the nrf2 wild-type mice and the nrf2 knockout (-/-) mice after treatments with vehicle or SFN at 3 and 12h were generated using the Affymetrix 39K oligonucleotide microarray. The Nrf2-dependent, SFN-inducible genes were identified which include detoxification phase I, II drug metabolizing enzymes and phase III transporters. Unexpected clusters of genes include genes for heat shock proteins (HSP), ubiquitin/26S proteasome subunits, and lipid metabolism genes. Collectively, SFN increases the expression of genes through the Nrf2 signaling pathway that directly detoxify exogenous toxins/carcinogens or endogenous reactive oxygen species, and genes involved in the recognition and repair/removal of damaged proteins, which could provide secondary protection against DNA or protein damage that enhance cell survival.

Animals↗
PubMed2006

Immunomodulatory activity of Sulforaphane, a naturally occurring isothiocyanate from broccoli (Brassica oleracea).

The effect of Sulforaphane on the immune system was studied using BALB/c mice. Intraperitoneal administration of five doses of Sulforaphane (500 microg/dose/animal/day) was found to enhance the total WBC count (12,950 cells/mm3) on 9th day. Bone marrow cellularity (23 x 10(6) cells/femur) and number of alpha-esterase positive cells (1346.66/4000 cells) were also increased by the administration of Sulforaphane. Treatment with Sulforaphane along with the antigen, sheep red blood cells (SRBC), produced an enhancement in the circulating antibody titre and the number of plaque forming cells (PFC) in the spleen. Maximum number of PFC (315.83 PFC/10(6) spleen cells) was obtained on the 6th day. Administration of Sulforaphane also showed an enhancement in the phagocytic activity of peritoneal macrophages. Moreover administration of Sulforaphane significantly reduced the elevated level of TNF-alpha production by LPS stimulated macrophages. These results indicate the immunomodulatory activity of Sulforaphane.

Animals↗
PubMed2000

A chromatographic study of the reaction sequence and effect of ligand on the reaction of human hemoglobin with negatively charged isothiocyanates: characterization of an intermediate modified only on the amino termini of the alpha chains.

A HPLC investigation of the reaction of 4-isothiocyanatobenzoic acid and 4-isothiocyanatobenzenesulfonic acid with oxy- and deoxyhemoglobin was carried out. The initial reaction of aromatic isothiocyanato sulfonates and benzoates with either oxy- or deoxyhemoglobin is with the amino termini of the alpha chains followed by a much slower reaction with the amino termini of the beta chains. Both reactions are much faster with deoxyhemoglobin than with oxyhemoglobin. An intermediate reacted only at the termini of the alpha chains with 4-isothiocyanatobenzoic acid was isolated and purified and its functional properties determined. The intermediate showed a reduced oxygen affinity over a wide pH range and a reduced alkaline Bohr effect in the absence of chloride. The oxygen affinity of the intermediate showed a reduced but still significant response to chloride.

Benzenesulfonates↗
PubMed2001

Histochemical characterization of primary capillary endothelial cells from porcine brains using monoclonal antibodies and fluorescein isothiocyanate-labelled lectins: implications for drug delivery.

Primary endothelial cells isolated from cerebral microvessels by combined mechanical and enzymatic treatment from porcine brains were characterized with regard to identity, purity and membrane surface characteristics. Cells were grown in culture to adherent monolayers and characterized morphologically and histochemically by their binding for fluorescently-labelled lectins and monoclonal antibodies detected by indirect immunofluorescence. The binding patterns of the cells were compared with the affinity of frozen tissue sections of porcine brain cortex for the markers. Endothelial cells in culture were characterized by the binding of von Willebrand factor, vimentin and fibronectin antibodies. They failed to react with anti-glial fibrillary acid protein, anti-galactocerebroside C and anti-neurofilament 160 antibodies characteristic for astrocytes, oligodendrocytes and neurons, respectively. Cell cultures were stained by the lectins, wheat germ agglutinin, horse gram agglutinin and soybean agglutinin, demonstrating the presence of N-acetylglucosamine and N-acetylgalactosamine residues on membrane surface. Binding sites for concanavalin A and peanut agglutinin characteristic for mannose and galactose could not be detected. Cell age and differentiation had no effect on lectin and antibody staining. Cell cultures gave staining results similar to those of microvessels in frozen tissue sections. The results of morphology, antibody and lectin staining pattern indicate that our in vitro endothelial cell culture model retained many histological characteristics observed for capillary microvessels in vivo and appears to be suitable for studying uptake and targeting properties of drug carrier systems with regard to the blood-brain barrier.

Animals↗
PubMed2006

Cell-free bioassay for measurement of dioxins based on fluorescence enhancement of fluorescein isothiocyanate-labeled DNA probe.

This study aims to develop a rapid and sensitive cell-free bioassay of dioxins. It is known that dioxin ligand can bind heterodimeric aryl hydrocarbon receptor (AhR) and triggers the formation of the complex of dioxin-AhR, AhR nuclear translocator (ARNT), and dioxin-responsive element (DRE) region of the DNA. The hypothesis of the proposed method is that if FITC were labeled at the DRE sequence, its fluorescence intensity would be enhanced when the complex forms because the interaction interface of the binding components (AhR, ARNT, and DRE) creates a rather hydrophobic condition that is in favor of FITC emission. Effects of modification site of FITC on the DNA probes on binding efficiency between the complex components and fluorescence emission enhancement were evaluated by surface plasmon resonance and fluorescence analysis, respectively. Results showed that the labeling site at the second base at the 5' end apart from the core region (5'-TNGCGTG-3') of DRE did not obviously interfere with the binding between the DNA probe and dioxin-AhR/ARNT hybrid but presented significant fluorescence emission enhancement. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) was used as the typical toxin in this study. The method had a linear range of 1-100 pM, with detection limit of 0.1 pM (0.64 fg/assay) and coefficient of variation of 5.6% (n = 10, 50 pM TCDD in transformed cytosol). The whole detection cycle was approximately 4 h. The method was also used to estimate the toxic equivalents (TEQ) of 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD) and 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin (HxCDD). Measurement of TEQs of the mixture of TCDD, PeCDD, and HxCDD were highly consistent with the predicted data. The average recovery using fly ash extract was approximately 93%.

Biological Assay↗
PubMedDate not supplied

Conjugation of phenyl isothiocyanate derivatives of carborane to antitumor antibody and in vivo localization of conjugates in nude mice.

A systematic study of the conjugation of 1-(p-isothiocyanatophenyl)-1,2-dicarba-closo-[2-3H]dodeca borane(12), 3H-1, and 7-(p-isothiocyanatophenyl)dodecahydro-7,8-dicarba-nido -[8-3H] undecaborate(1-)ion, 3H-2, to the murine monoclonal anti-CSAp antibody, Mu-9, was carried out to compare charged and uncharged boron cages in their effect upon antibody loading. Approximately one neutral cage and four of the anionic cages were successfully linked to antibody in two separate conjugates which were subsequently radioiodinated and evaluated in vivo. No significant loss of the antibody or its immunoreactivity was observed in either case. In nude mice bearing GW-39 tumor xenografts the conjugate containing the anionic carborane derivative showed a reduced tumor uptake although the tumor:non-tumor ratio was similar to that of the native antibody. The carborane cage in 2 was radiolabeled with 125I followed by attempts to purify and conjugate product 4 to a model goat IgG protein. This exploratory conjugation study was undertaken as a prelude to linking new conjugation reagents, which contain multiple anionic boron cages, to antitumor antibodies. The latter conjugates are required to maximize boron loading for the purpose of neutron-capture therapy.

Animals↗
PubMed1991

Temperature dependence of the rates of conformational changes reported by fluorescein 5'-isothiocyanate modification of H+,K(+)- and Na+,K(+)-ATPases.

Stopped-flow fluorometry has been used to measure the forward and reverse rates of the conformational change from E1 to E2 in the fluorescein-modified proton and sodium pumps (1) as a function of Na+ and K+ concentrations to verify the proposed mechanism of ion interaction with the enzymes and (2) as a function of temperature to gain insight into the nature of the conformational transition. (1) The fluorescence changes caused by Na+ and K+ are consistent with rapid competitive binding of the two ions to the E1 conformations of the enzymes followed by rate-limiting transitions between E1K and E2K. (2) Reaction coordinate diagrams for the E1K to E2K transitions in the H,K-ATPase and Na,K-ATPase are qualitatively similar. Enthalpy barriers to reaction are partially compensated by increased entropy in the transition states. However, there are striking quantitative differences between the two enzymes. The E2K to E1K reaction of the H,K-ATPase is more than 2 orders of magnitude faster (tau 1/2 = 6 ms at 22 degrees C) than the reverse rate of the Na,K-ATPase transition (tau 1/2 = 1.6 s), explaining repeated failure to detect a K(+)-"occluded" form of the H,K-enzyme. The E2K conformer of the Na,K-ATPase is 3 orders of magnitude more stable than E1K, while the E1K and E2K conformations of the H,K-ATPase are nearly equivalent energetically.

Adenosine Triphosphatases↗
PubMed2003

Ontogenic variations of ascorbic acid and phenethyl isothiocyanate concentrations in watercress (Nasturtium officinale R.Br.) leaves.

Watercress (Nasturtium officinale R.Br.) is the richest source of glucosinolate nasturtiin, which on hydrolysis produces phenethyl isothiocyante (PEITC). Interest in growing watercress is stimulated since demonstration of the role of PEITC in protection against cancers associated with tobacco specific carcinogens. Twenty-one days old watercress seedlings were transplanted into growth chambers (16-h days/8-h nights of 25/22 degrees C and photosynthetic photon flux (PPF) of approximately 265 micromol m(-2) s(-)(1)). The study was replicated three times. Leaves were analyzed for PEITC and ascorbic acid concentrations at transplant, and harvested at 10-days intervals until 60 days after transplant. The PEITC and ascorbic acid concentrations were the highest in leaves harvested at 40 days and the lowest at transplant. Leaves harvested at 40 days produced about 150% higher PEITC concentrations compared to the leaves at transplant. Both PEITC and ascorbic acid concentrations of leaves increased linearly with age until 40 days after transplant after which there was no significant increase. Seedlings at transplant had the lowest dry mass and leaf area, while plants harvested at 60 days had the highest dry mass and leaf area.

Ascorbic Acid↗