Showing papers on "Color reaction published in 1994"
Patent•
22 Dec 1994
TL;DR: In this paper, a thermochromic color-memory composition consisting of a homogeneous solubilized mixture of essential three components of an electrondonating color-developing organic compound, an electron-accepting compound, and a reaction medium for controlling a color reaction of the component with the component was presented.
Abstract: A thermochromic color-memory compositions exhibiting high color contrast between high color density in a colored state and sufficiently low color density in a decolored state with high freedom of selection of the reaction medium, and highly useful as a thermochromic material. The thermochromic color-memory composition comprises a homogeneous solubilized mixture of essential three components of (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) a reaction medium for controlling a color reaction of the component (a) with the component (b); the component (c) being selected from aliphatic ketones of 10 to 22 total carbons and aryl alkyl ketones of 12 to 24 total carbons; and the composition changing the color thereof with a large hysteresis width (ΔH) of from 8° C. to 80° C.
30 citations
TL;DR: In this article, a highly selective spectrophotometric method for the determination of aqueous sulfite was developed, which is simple, very sensitive, and convenient for determination of as little as 5X10−6 M sulfite.
Abstract: A highly selective spectrophotometric method for the determination of aqueous sulfite was developed. Sulfite was found to react with o-phthaldialdehyde in presence of ammonia yielding a deep blue colored complex the absorbance of which is sensitive to trace sulfite concentrations. The method is simple, very sensitive, and convenient for the determination of as little as 5X10−6 M sulfite. The molar absorptivity of the colored complex is about 1.2X104 L cm−1 mol−1. The proposed method is more sensitive and selective for sulfite than the widely used Ellman reagent method. Absorbance is measured at 628 nm which is the best of the two absorption maxima that are exhibited by the compound.
24 citations
TL;DR: In this paper, a simple, rapid, selective, and sensitive spectrophotometric method for the determination of microgram amounts of gold, alone, or in the presence of associated metals, is developed, based on the color reaction between the metal ion and the reagent.
Abstract: The synthesis, spectral characteristics, and analytical application of 2,3-Dichloro-6-(3-carboxy-2-hydroxy-1-naphthylazo)quinoxaline (DCHNAQ) are described. A simple, rapid, selective, and sensitive spectrophotometric method for the determination of microgram amounts of gold, alone, or in the presence of associated metals, is developed, based on the color reaction between the metal ion and the reagent. The yellowish brown complex (λmax = 575 nm) has stoichiometric ratio (1 : 1) [metal : ligand] over the pH range 3.4 to 7.0. Beer’s law is obeyed over the concentration range 0.1—6.9 μg cm−3 of gold. The molar absorptivity and Sandell’s sensitivity of the method are 1.52 × 104 dm3 mol−1 cm−1 and 0.016 μg Au cm−1 respectively. The relative standard deviation for six replicate determination of 2.95 μg cm−3 of gold(III) is 1.37%. The interference of various ions has been studied and conditions were developed for the determination of gold in alloys and some synthetic samples without the need for extraction or he...
7 citations
TL;DR: In this paper, a spectrophotometric method for the determination of microgram amounts of some carbohydrates, thiocarbonyls and hydrazines was developed based on the reaction of these compounds with either cerium (IV) or dichromate.
Abstract: A spectrophotometric method for the determination of microgram amounts of some carbohydrates, thiocarbonyls and hydrazines was developed. It is based on the reaction of these compounds with either cerium (IV) or dichromate. The excess oxidant is allowed to react with iron (II) as a reductant and hexacyanoferrate (III) to develop Prussian blue colour with maximum absorption at 700 nm. The optimum procedural conditions and stoichiometry are investigated. Analysis of sample sizes down to 50 μg shows an average recovery of 97% and a relative standard deviation of 1%.
5 citations
Patent•
28 Jun 1994
TL;DR: In this article, a polysaccharide substance (NPS) was obtained from a cultured mixture of NPS-producing bacterium of the genus Lactobacillus.
Abstract: PURPOSE:To obtain a physiologically active polysaccharide substance, NPS having excellent anti-inflammatory action, myeloid cell proliferation-promoting effect and B lymphocyte proliferation-suppressing effect by separating and collecting the substance from a cultured mixture of NPS-producing bacterium of the genus Lactobacillus. CONSTITUTION:An NPS-producing bacterium belonging to the genus Lactobacillus is cultured in a medium and a polysaccharide substance, NPS, is produced and accumulated in the cultured mixture and collected. This polysaccharide substance NPS has the following physicochemical properties. Elementary analysis: C: 40.2+ or -6, H: 6.3+ or -0.8, N: 1.3+ or -0.4, O: 53.1+ or -10; molecular weight: about 2000000-1000000; melting point: decomposed to black brown at nearly 270 deg.C; infrared ray spectrum: 3413, 2925, 1649 and 1550cm ; solubility, soluble in water and insoluble in methanol, acetone, etc.; color reaction: Molisch reaction +; anthrone reaction +; cysteine-sulfuric acid reaction -; carbazole-sulfuric acid -; Elson-Morgan's reaction -; ninhydrin reaction -; 0.5% aqueous solution of the substance exhibits pH7.2; the lyophilized substance is white and fibrous; glucose: galactose: N-acetylglucosamine = (2.5-3.5):(2.5-3.5):1.
5 citations
Patent•
01 Nov 1994
TL;DR: In this paper, a novel compound having proliferation inhibiting activity against tumor cells, excellent in carcinostatic effect and useful for tumor treatment, etc., was provided to provide a new compound having a proliferation inhibition activity.
Abstract: PURPOSE:To provide a novel compound having proliferation inhibiting activity against tumor cells, excellent in carcinostatic effect and useful for tumor treatment, etc. CONSTITUTION:The compound of formula [R1 is H or hydroxy; R2 is (CH2)10CH3, (CH2)12CH3, (CH2)5CH=CH(CH2)7CH3, (CH2)10CH3 or (CH2)3CH=CH (CH2)7CH3]. BE-32030A of the group of said compound has following properties. Appearance: colorless and syrupy; molecular formula: C39H61O10N5; specific angle of rotation: [alpha]D -40.3(C1.00-CHCl3); IR spectrum (KBr, cm ): 3303, 3197, 2927, 2856, 1735, 1641, 1525, 1492, 1456, 1365, 1307, 1257, 1224, 1064, 968 and 756; solubility: soluble in methanol, chloroform and dimethylformamide and insoluble in water; nature classified into acidic, neutral or basic substance: acidic substance; color reaction: positive in sulfuric acid reaction and iron(III) chloride reaction. This compound is obtained by an aerobic fermentation of an organism belonging to the genus Nocardia and capable of producing the compound of formula [A32030 (FERM-P-13395)].
4 citations
Patent•
12 Apr 1994
TL;DR: In this paper, a semi-opaque needle-like crystal was obtained by culturing a fungus belonging to the genus Talaromyces, capable of producing the compound of the formula, such as Talaris retardatus F24811 (FERM P-14-103).
Abstract: PURPOSE: To obtain new substance BE-24811 useful as an antitumor agent, etc., having an inhibitory effect on proliferation. CONSTITUTION: A compound of the formula has the following properties. Properties: semi-opaque needle-like crystal. Molecular formula: C 18 H 21 O 4 Cl. Mass spectrum (high resolution E1-MS, m/z): 336. 1133 [M + ]. Ultraviolet light absorption spectrum: λ max [MeOH, nm(e)] 230 (22900), 293 (10900), 3,44 (5300). Infrared light absorption spectrum: ν max (KBr, cm -1 : 3167, 2927, 1672, 1628, 1608, 1421, 1248, 1113. Solubility: readily soluble in dimethyl sulfoxide, soluble in chloroform, ethyl acetate and methanol, insoluble in water. Distinction of acid, neutral or basic substance: acidic substance. Color reaction: positive in iodine reaction, potassium permanganate reaction and 2,4dinitrophenylhydrazine reaction. The compound of the formula is obtained by culturing a fungus belonging to the genus Talaromyces, capable of producing the compound of the formula, such as Talaromyces retardatus F24811 (FERM P-14,103). COPYRIGHT: (C)1995,JPO
4 citations
Patent•
[...]
30 Aug 1994
TL;DR: In this paper, a new compound having an NGF action enhancing effect and useful, eg as a medicine for improving dementia or sequella of cerebral hemorrhage, was obtained by aerobically culturing Stachybotrys-parvispora- F-4708 (FERM-P-12660) in a culture medium containing nutritive substances.
Abstract: PURPOSE:To obtain a new compound having an NGF action enhancing effect and useful, eg as a medicine for improving dementia or sequella of cerebral hemorrhage CONSTITUTION:A compound of the formula (R is CH2COCH2CH2OH or CH2 CH20H) In addition, NG-242 (R is CH2COCH2CH2OH) has following physical properties: SI mass spectrum: 472 (M+H) ; molecular weight: 471; ultraviolet absorption spectrum (in methanol solution): lambdamax 214nm (g: 41800), 258nm (epsilon=9600), 306 nm (g : 3300); IR spectrum: as shown in the figure; solvent solubility: soluble in methanol, ethanol and acetone, sparingly soluble in n-hexane and benzene and insoluble in water; color reaction: positive to H2SO2, I2 or FeCl3 and negative to ninhydrin reaction; classification of basic, acidic or neutral: acidic; color of substance; white powder In addition, the compound of the formula can be obtained by aerobically culturing Stachybotrys-parvispora- F-4708 (FERM-P-12660) in a culture medium containing nutritive substances
3 citations
TL;DR: In this article, a modified colorimetric determination of ascorbic acid was developed, where three absorption peaks were found to appear between 500-630 nm instead of a single peak at 630 nm.
2 citations
TL;DR: The influence of climate and analytical environment on the uronic acid assay of Blumenkrantz and Asboe-Hansen (Anal. Biochem., 54 (1973) 484-9) is described as mentioned in this paper.
2 citations
Patent•
30 Aug 1994
TL;DR: In this article, a new substance FR901,537 having an aromatase inhibitory activity useful for treating diseases caused by estrogendependent diseases and estrogen excessive disease was obtained from a culture mixture obtained by culturing a bacterium belonging to the genus Bacillus.
Abstract: PURPOSE:To obtain a new substance FR901,537 having an aromatase inhibitory activity useful for treating diseases caused by estrogen-dependent diseases and estrogen excessive disease CONSTITUTION:New substance FR901,537 Appearance: colorless needle-like crystal Molecular formula: C23H29N3O6S2 Elemental analysis: C 5215, H 603, N 781, S 1147 Melting point: 144-146 degC Molecular weight: 507 Specific rotatory power: [alpha] =137 deg C (C=10 DMSO) Solubility: readily soluble in dimethyl sulfoxide, methanol, ethanol and acetone, slightly soluble in ethyl acetate, dichloromethane and n-hexane, insoluble in water Color reaction: positive in reaction with cerium sulfate, iodine vapor and Ehrlich reaction, negative in ninhydrin reaction, Molish reaction and ferric chloride reaction The substance RR90l,537 has an estimated formula of the formula The new substance RR901,537 is collected from a culture mixture obtained by culturing a bacterium (eg Bacillus sp No3072) belonging to the genus Bacillus, capable of producing new substance FR901,537 in a nutritive medium
Patent•
13 Dec 1994
TL;DR: In this paper, the objective method is characterized by eliminating reductive substances hampering the reaction using an electron acceptor selected from the group consisting of benzoic acid, p-hydroxybenzoic acids, paminobenzoic acyclic acid and dibromophenol.
Abstract: PURPOSE:To conduct a determination in high accuracy by eliminating the influence of reductive substances in a biological specimen. CONSTITUTION:In such a system as to optically determine the components in a biological specimen through the oxidative color reaction of peroxidase, the objective method is characterized by eliminating reductive substances hampering the reaction using an electron acceptor selected from the group consisting of benzoic acid, p-hydroxybenzoic acid, p-aminobenzoic acid and dibromophenol.
Journal Article•
01 Jan 1994
TL;DR: A method is described for the spectrophotometric determination of 2,6-lutidine using p-dimethylaminocinnamaldehyde in acidic medium and an initial attempt has been made to postulate the mechanism of this complex system.
Abstract: A method is described for the spectrophotometric determination of 2,6-lutidine using p-dimethylaminocinnamaldehyde in acidic medium An initial attempt has been made to postulate the mechanism of this complex system