The separation of indole-3-acetic acid and related compounds in plant extracts by sephadex chromatography

• Published in: Analytical biochemistry Vol. 103; no. 2; pp. 419 - 425
• Main Authors: Magnus, Volker, Šoškić, Milan, Iskrić, Sonja, Kveder, Sergije
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.1980
• Subjects: Chromatography, Gel - methods; Chromatography, Thin Layer; Fabaceae - analysis; Hydrogen-Ion Concentration; Indoleacetic Acids - isolation & purification; Indoles - isolation & purification; Plants - analysis; Plants, Medicinal
• ISSN: 0003-2697; 1096-0309
• DOI: 10.1016/0003-2697(80)90633-8

Eleven indole derivatives of biological significance were added to an extract of etiolated pea seedlings and the mixture was separated on a column of Sephadex G-15, by the following sequence of eluants: ethylenediamine-acetate, pH 4.2, ethylenediamine-acetate, pH 7.4, distilled water, and a methanol-water gradient. The bulk of plant constituents was eluted before the indolic compounds. Tryptophan and indole-3-acetic and indole-3-carboxylic acids, as well as indole-3-carboxaldehyde, emerged in separate peaks. Three further peaks contained mixtures of indolic compounds, easily separable by thin-layer chromatography, i.e.: 1, tryptamine and tryptophol glucoside (2-(indol-3-ylethyl)-β- d-glucopyranoside); 2, indole-3-acetamide, indole-3-acetic acid methyl ester, and tryptophol; and 3, indole-3-acetonitrile and indole-3-carboxylic acid methyl ester. Detection limits in combined Sephadex and thin-layer chromatographies ranged from 0.1 to 10.0 μg. Estimated recoveries were above 50% for indole-3-carboxaldehyde and above 80% for five other representative compounds. Thus, the described method permits the isolation, from plant extracts, of acidic, neutral, and basic indolic compounds of widely different polarity.