Monohydrochloride Research Articles

Flame‐retardant epoxy resins with high glass‐transition temperatures. II. Using a novel hexafunctional curing agent: 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene 10‐yl‐tris(4‐aminophenyl) methane

AbstractWe synthesized a novel phosphorus‐containing triamine [9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene 10‐yl‐tris(4‐aminophenyl) methane (dopo‐ta)] from the nucleophilic addition of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene 10‐oxide and pararosaniline chloride, using triethylamine as an acid receiver. We confirmed the structure of dopo‐ta by IR, mass, and NMR spectra and elemental analysis. dopo‐ta served as a curing agent for diglycidyl ether of bisphenol A (DGEBA) and dicyclopentadiene epoxy (hp7200). Properties such as the glass‐transition temperature (Tg), thermal decomposition temperature, flame retardancy, moisture absorption, and dielectric properties of the cured epoxy resins were evaluated. The Tg's of cured DGEBA/dopo‐ta and hp7200/dopo‐ta were 171 and 190 °C, respectively. This high Tg phenomenon is rarely seen in the literature after the introduction of a flame‐retardant element. The flame retardancy increased with the phosphorus content, and a UL‐94 V‐0 grade was achieved with a phosphorus content of 1.80 wt % for DGEBA/dopo‐ta/diamino diphenylmethane (DDM) systems and 1.46 wt % for hp7200/dopo‐ta/DDM systems. The dielectric constants for DGEBA/dopo‐ta and hp7200/dopo‐ta were 2.91 and 2.82, respectively, implying that the dopo‐ta curing systems exhibited low dielectric properties. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5971–5986, 2005

Simple methods for rapid determination of sulfite in food products

Two simple methods for sulfite determination in food products were proposed. The modified para-rosaniline (PRA)-formaldehyde method showed a much broader linear range (0.05–5.0 mg l −1 as SO 2) than the commonly used procedure for the sulfur dioxide detection in the atmosphere (0.05–1.0 mg l −1 as SO 2). By using a standard reference color card, this method only needed 5 min to complete a test. The 5,5′-dithiobis(2-nitrobenzoic acid) (DTNB) method was another good alternative for rapid determination of sulfite since it only needed one main reagent and the method was robust and easy to operate with the linear range of 0.10–4.3 mg l −1 as SO 2. When applying to real food samples, the DTNB method had good recoveries for all the tested samples and the results agreed well with those obtained by the official iodometric titration. The modified PRA-formaldehyde method worked well with all the tested dried food products, though matrix effect of sulfite binding was observed for the beer samples. Thus, the modified PRA-formaldehyde method has advantages of sensitivity and rapidity, but the DTNB method offers a wider range of applications. Both methods provided practical ways for in situ determination of sulfite by non-professional operators with the modified PRA-formaldehyde method suited for food samples with less sulfite binding problems.

Generation of Charge-control Ability of Pararosaniline Due to Protonation and its Protonation Mechanism

Generation of Charge-control Ability of Pararosaniline Due to Protonation and its Protonation Mechanism

Changes in Composition of Ballpoint Pen Inks on Aging in Darkness

A method for comparison of the relative age of ink entries written by the same ballpoint pen on documents stored in darkness is presented. Inks were extracted from the document and analyzed by HPLC (high performance liquid chromatography). On aging, changes in the chemical composition of the inks were noted. These changes were similar to those observed when inks were exposed to light or heat. The aging was followed by using ternary diagrams constructed for dyes generally present in blue-colored inks--Crystal Violet, Methyl Violet, and Tetramethyl Para Rosaniline. The procedure is applicable for relative dating of ink entries in diaries, notebooks, etc., where often several ink entries are written by the same ink. However, a prolonged exposure of the document to daylight and/or artificial light (light from fluorescent tubes) as well as to extensive heat will render the whole procedure inapplicable. An example of the use of the proposed method in casework is given.

HPLC Analysis of Ballpoint Pen Inks Stored at Different Light Conditions

A method for comparison of ink entries on documents stored in different light conditions is presented. Various blue inks were exposed to light, both daylight and artificial light from fluorescent tubes. Inks were then extracted from the document and analyzed by HPLC (high performance liquid chromatography). Significant changes in composition were noted on exposure to light. These changes were followed by using ternary diagrams constructed for dyes generally present in blue-colored inks--Crystal Violet, Methyl Violet, and Tetramethyl Para Rosaniline. Also, the amount of the various compounds formed by decomposition of these dyes on exposure to light was measured and employed for comparison of inks. An example of the use of the proposed method in casework is given.

In vitro toxicity of ethanol and acetaldehyde on human lymphocytes as well as gastric and colonic mucosal cells

channel blockers (i.e. nicard ipine , Cd2+ and Ni2+) did not block the spontaneous Caz+ transients. The specific Hz ago nist, amth amine dihydrobrom ide ( JO J.LM), increa sed the frequency and amplitude of Caz+ transients and STOCs. Caz+ -free solution and Caz+ channel blockers did not prevent the increase . The effects of Hzreceptor activation were blocked by tiotidine (JOJ.LM)a specific Hz antagon ist (10 J.LM ). cis N-(2-Phenylcyclopentil)-azacyclotridecIen-2-amine monoh ydrochloride (MDL 12,330A) a blocker of adenylyl cyclase, inhibited local ized Caz+ release events and the effect of amthamine. The spec ific HI agonist HTMT dirnaleatei lOuM) increased basal Caz+ levels and blocked spontaneous Caz+ release events and STOCs. Pretre atment with the specific HI antagonist trans-Triprolidine hydrochloride (I0J.LM) or 1-[6-[[1 7 13)-3-methoxyestra-I ,3,5(10)-trien-1 7-yl] amino]hexyl]-IH-pyrrole2,5-dione (U-73 122), an inhibitor of phospholipase C, prevented the effect of HTMT. These results demonstrate that activation of H I and H2 receptors and production of inositol IA ,5-triph osphate (lp) and adenylyl cyclase, respectively, initiate oppo site effects on intestinal macrophages in terms of localized Ca + signaling. (Supported by DK 4 1315)

Effect of CI-930 [3-(2 H)-pyridazinone-4,5-dihydro-6-[4-(1 H-imidazolyl) phenyl]-5-methyl-monohydrochloride] and rolipram on human coronary artery smooth muscle cell proliferation

Experiments were conducted to determine how selective inhibitors of certain cyclic nucleotide phosphodiesterase (PDE) families, namely CI-930 (PDE3 inhibitor; 3-(2 H)-pyridazinone-4,5-dihydro-6-[4-(1 H-imidazolyl) phenyl]-5-methyl monohydro chloride) and rolipram (PDE4 inhibitor), may affect human coronary artery smooth muscle cell (HCASMC) proliferation. CI-930- and rolipram-inhibitable PDEs accounted for most of the cyclic AMP hydrolyzing activity in HCASMC. Twenty micromolar CI-930 and 20 μM rolipram used individually attenuated proliferation of HCASMC from some, but not all donors, as measured by flow cytometry. The simultaneous addition of 10 μM CI-930 plus 10 μM rolipram caused greater attenuation. This attenuation represented a reduction of the number of cells entering the S phase of the cell cycle and not merely a delay in cell cycle traverse. No statistically significant elevation of cyclic AMP was detected following the addition of either PDE inhibitor individually, but the combination produced significant elevations. It is concluded that CI-930- and rolipram-inhibitable PDE isozymes are expressed in HCASMC and that selective inhibitors of these isozymes can attenuate HCASMC proliferation. The data suggest that selective PDE inhibitors may prevent restenosis in patients following percutaneous transluminal coronary angioplasty because of their effect on HCASMC proliferation, and they may also be useful in retarding the progression of atherosclerosis in individuals at risk. PDE3 and PDE4 inhibitors in combination are more effective than the inhibitors used individually.

Synthesis and Characterization of Heptamethine Cyanine Dyes

A series of meso-chlorine substituted heptamethine-cyanine dyes and related heptamethine cyanine dyes unsubstituted on the vinyl chain were synthesized by condensation of 2,3,3-trimethyl indolenium salts with reactive intermediates, 2-chloro-formyl-3-hydroxy-methylenecyclohexene or N-[5-(phenylamino)-2,4-phentadienylidene] aniline monohydro-c hloride. The structures of the dyes were characterized by virtue of 1HNMR, 13C-NMR, IR, MS, etc. The reaction conditions and physicochemical properties of the dyes were extensively explored with classical photo-physical techniques

Anti-tumour effect of aromatase inhibitor, CGS16949A, on human breast cancer cells

The growth inhibitory effect of a new non-steroidal aromatase inhibitor, CGS16949A (Fadrozole hydrochloride: {4-(5,6,7,8-tetrahydro-imidazo- [1,5a]-pyridin-5-yl) benzonitrile monohydro chloride}) was studied in human breast cancer cells MCF-7 and T47D. The aromatase activity of MCF-7 was inhibited by CGS16949A in a dose-dependent manner (IC50: 2.8 × 10 −9 M). The cells were incubated for 120 h in phenol red free RPMI 1640 containing 5% stripped foetal calf serum, 10 −8 M testosterone and various concentrations of CGS16949A. Testosterone-induced MCF-7 growth was inhibited by CGS16949A almost completely at the concentrations as low as 10 −9 M, but was not inhibited by antiandrogenic cyproterone acetate (6-cholor-1β,2β-dihydro-17-hydroxy- 3′H-cyclopropa[1,2]-pregna-1,4,6-triene-3,20-dione acetate: CPA). On the other hand, the growth of T47D stimulated by testosterone was not inhibited by CGS16949A, but was inhibited by CPA. These data suggested that the aromatization of androgens should participate in the growth of MCF-7 and that one of the growth inhibitory mechanisms of CGS16949A should be the inhibition of the intracellular aromatase activity.

A simple and rapid staining technique for plastic embedded cartilage and bone.

In this report we describe a simple and rapid staining technique for cartilage and bone embedded in Araldite. Semithin sections of embryonic vertebrae obtained from 15 to 17 day mouse fetuses were stained using an aqueous solution 0.25% with respect to methylene blue, 0.25% with respect to azure A, and 0.5% with respect to Na2 CO3, then counterstained with 1% aqueous pararosaniline chloride (MAP). Results were compared with toluidine blue stained sections. MAP permitted good discrimination of developmental stages of both cells and extracellular matrix within vertebral ossification centers during endochondral ossification. The technique is simple, rapid and applicable to plastic embedded sections, and can be used prior to ultrastructural examination.

Synthesis of bisaramil labelled with carbon‐14 and deuterium

Abstract[6,8‐14C2]‐Bisaramil: 3‐methyl‐7‐ethyl‐9α‐(4‐chlorobenzoyloxy)‐3,7‐diazabicyclo/3.3.1./nonane‐[6,8‐14C2] monohydrochloride and [7‐N‐D5‐ethyl]‐Bisaramil: 3‐methyl‐7‐[D5‐ethyl]‐9α‐(4‐chlorobenzoyloxy)‐3,7‐diazabicyclo/3.3.1./nonane monohydrochloride were synthesized in four steps from 14CO2 (6% overall yield) and in six steps from [D6]‐ethanol (4% overall yield), respectively.

Application of a Two-Dimensional Hadamard Encoding Mask for the Imaging of Thin-Layer Chromatography Plates by Laser-Induced Fluorescence or Surface-Enhanced Raman Scattering and for Use with a Photoacoustic Detector to Generate Three-Dimensional Photoacoustic Images

Spatial imaging of thin-layer chromatography plates using laser-induced fluorescence and surface-enhanced Raman scattering has been accomplished with a stationary two-dimensional Hadamard encoding mask. Detection of three nanograms of pararosaniline hydrochloride on a thin-layer chromatography plate was made possible by means of the surface-enhanced Raman phenomenon. The imaging capabilities of the stationary two-dimensional Hadamard encoding mask coupled with the depth profiling ability of photoacoustic detection allows for the three-dimensional photoacoustic imaging of a multiple analyte sample.

A simple procedure for crystallization of the Schiff reagent.

Formation of crystals in Schiff reagents prepared from SO2 gas previously has been reported either soon after preparation, using high dye concentrations and heating, or after long periods of storage at room temperature. With the first type of procedure only a low yield of crystals accompanied by dye precipitation was obtained. Crystallization without dye precipitation took place if the reagent, prepared with pararosaniline base or chloride in a saturated SO2 solution, was stored for a sufficient time at room temperature in partly filled flasks. These crystals remained colorless if washed with acid alcohol after being separated by filtration. Schiff reagents layered with paraffin oil or supplemented with 0.1 M hydroquinone took much longer to crystallize, suggesting that crystallization is promoted by the partial oxidation of sulfurous acid to sulfuric acid. A high yield of crystals can be obtained at room temperature after as little as 24 hr by adding 0.04 M of H2SO4 to a Schiff reagent prepared with 2% pararosaniline chloride in a saturated SO2 solution. A Schiff reagent prepared with only 0.2% of these crystals gives an intense staining in the Feulgen and in the Periodic acid-Schiff reactions.

Combined Modified Periodic Acid-Schiff and Batch Staining Method

AbstractA modified periodic acid-Schiff method is presented. The sections were oxidized with 1.0% periodic acid, then stained with a modified Schiff solution. The modified solution contained pararosaniline hydrochloride in a concentration of about one-tenth of that normally used for basic fuchsin. The concentration of sodium meta-bisulphite was doubled, and sodium hydrosulfite was included to decolorize effectively the pararosaniline hydrochloride. Concentrated hydrochloric acid was added. The solution was treated with charcoal and filtered. This reagent was stored in special dropping bottles to prevent loss of the sulfurous acid content and diluted just before use with an equal volume of water to maximize its stability. A modified baking tin was used in the staining of up to 20 slides at a time in a paraffin oven at 60°C. The stained sections were developed in warm water and counterstained in modified Mayer hematoxylin. Microwave and room temperature methods were effective, as well.This modified Schiff c...

A Detector for Liquid Chromatography and Flow Injection Analysis Using Surface-Enhanced Raman Spectroscopy

A successful interface between a high-performance liquid chromatograph and a Raman spectrometer is described. Surface-enhanced techniques are utilized to overcome the sensitivity problem inherent to conventional Raman spectrometry by adding a Ag sol to the chromatographic effluent in a post-column mixing coil. The system is designed so that Raman spectra may be obtained from chromatographic effluent or from flow injection analysis effluent. A common organic dye (pararosaniline hydrochloride) is used to evaluate the reproducibility, dynamic range, and analytical capabilities of the system. The SERS instrument is found to be a viable detector for HPLC and FIA, capable of providing structural information with a sensitivity comparable to that of other commonly used HPLC detectors.

A Laboratory Evaluation of Two Methods for Measuring Low Levels of Formaldehyde in Indoor Air

Two methods for measuring formaldehyde at ppb levels–the modified pararosaniline (PRA) and the modified chromotropic acid (CTA)–were evaluated in a laboratory study. A dynamic double dilution system was used to generate controlled test atmospheres of formaldehyde by the catalytic depolymerization of trioxane. Impinger samples were collected from the sampling manifold and analyzed accordingly. Both methods demonstrated good precision (3.5% for the PRA and 3.4% for the CTA) but differed in accuracy and collection efficiency. Accuracy was 87.7±7.5% for the PRA and 92.5±4.2% for the CTA, while collection efficiency was 91.9±6.9% and 98.7±4.7% respectively. These differences were mainly due to the use of 1% NaHSO3 as the absorbing solution in the CTA method. Additionally, the NaHSO3 solution has the advantage of long sample preservation, making the modified CTA the method of choice in most non-industrial indoor air sampling situations.

Thermodynamic functions and stability constants of l-lysine monohydrochloride

Constantes de stabilite, stœchiometrie, parametres thermodynamiques des complexes de Pd(II), Rh(III), Pt(IV)

Fluorometric determination of atmospheric sulfur dioxide without tetrachloromercurate(II)

1-Naphthylammonium chloride is substituted for pararosaniline hydrochloride for a fluorometric version (excitation 342 nm, emission 442 nm) of the Schiff reaction used for the determination of sulfur dioxide. The sensitivity is 2 orders of magnitude better than the colorimetric method; in all other aspects the two methods are analogous.

A simplified method for staining mast cells with astra blue.

The copper phthalocyanin dye astra blue has been used to stain differentially mast cells of the intestine; however; the procedure has not been used widely because of the difficulty in preparing and using the dye solution. Described here is a simple, reliable, and consistent method for selectively staining mast cells using a dye solution that may be prepared in any laboratory without the aid of sophisticated pH metering equipment. Astra blue is mixed with an alcoholic solution containing MgCl2-6H2O and the pH indicator pararosaniline hydrochloride. Concentrated hydrochloric acid is added dropwise, changing the dye mixture from purple to violet and then to blue. In this low range the weakly ionizing ethanol provides a more stable hydrogen ion concentration than the corresponding aqueous solutions used previously. Alcoholic acid fuchsin is a convenient counterstain, and this simple procedure then provides good contrast between the blue staining mast cell granules and the red tissue background.

Copper(lll) as an Oxidative Titrant for Alanine, 2-aminobutyric Acid and Arginine mono hydrochloride

Copper(lll) as an Oxidative Titrant for Alanine, 2-aminobutyric Acid and Arginine mono hydrochloride