Topic
Color reaction
About: Color reaction is a research topic. Over the lifetime, 1194 publications have been published within this topic receiving 19579 citations.
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Patent•
09 Mar 1993
TL;DR: In this article, a new bioactive substance derived from propolis and represented by the formula was obtained by extracting propolis with ethyl alcohol, etc., and subsequently isolating and purifying the resultant extract by the conventional method, e.g high-performance liquid chromatography method.
Abstract: PURPOSE:To provide the subject substance showing an excellent anti-neoplasitc effect. CONSTITUTION:A new bioactive substance derived from propolis and represented by the formula. This compound can be obtained by extracting propolis with ethyl alcohol, etc., and subsequently isolating and purifying the resultant extract by the conventional method, e.g high-performance liquid chromatography method. Behavior of the above-mentioned compound during the purification process can be followed by ultraviolet absorption spectra: lambdamax: 212nm (epsilon=4600) and 288nm (epsilon=2600) (in methanol). In addition, the above-mentioned compound is soluble in methanol, ethyl acetate, chloroform and DMSO and sparingly soluble in an acidic water. Color reaction is positive in iodine reagent, BCG reagent and cerium sulfate reagent and the appearance is colorless solid.
3 citations
TL;DR: A simple, precise, rapid-colour-forming and stable spectrometric method has been developed for determining free chlorine in water and it is satisfactory for the determination offree chlorine in aqueous solution.
3 citations
TL;DR: Pyridoxal as mentioned in this paper is a carbonyl-phenol-acid reaction system that yields color reactions with phenols and inorganic acids, and it can be distinguished by means of the sulfuric acid reaction from the other three compounds related to vitamin B6.
3 citations
TL;DR: The reaction product responsible for the characteristic coloration of the Seliwanoff reaction was isolated and determined to be 2, 7-diethyl-6-hydroxy-9-(5-methyl-2-furyl)-3H-xanthen-3-one.
Abstract: 4-Ethylresorcinol was found to be a very sensitive color-developing reagent for the detection of ketoses, and was used to elucidate the reaction mechanism of the Seliwanoff reaction. The reaction product (I) responsible for the characteristic coloration of the Seliwanoff reaction was isolated and determined to be 2, 7-diethyl-6-hydroxy-9-(5-methyl-2-furyl)-3H-xanthen-3-one. Compound I was also isolated as crystals from the reaction mixture obtained by Kulka's modified method using 4-ethylresorcinol as the color-developing reagent.
3 citations
TL;DR: This test seems to be useful for estimation of phenolic and indolic compounds in urine of patients with increased production of compounds of this nature, particularly in some tumors.
3 citations