Simultaneous analysis of indole-3-acetic acid and detection of 4-chloroindole-3-acetic acid and 5-hydroxyindole-3-acetic acid in plant tissues by high-performance liquid chromatography of their 2-methylindolo-α-pyrone derivatives

✍ Scribed by David Blakesley; John Frederick Hall; Geoffrey Donald Weston; Malcolm Charles Elliott

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 697 KB
• Volume: 258
• Category: Article
• ISSN: 1873-3778
• DOI: 10.1016/s0021-9673(00)96407-0

✦ Synopsis

The use of high-performance liquid chromatography in the reversed-phase mode coupled to a spectrophotofluorimetric detector allowed the selective detection of acidic indoles possessing a C-3 methylene side chain, following the reaction of a purified plant extract with acetic anhydride. Of these acidic indoles, only 4chloroindole-3-acetic acid and 5-hydroxyindole-3-acetic acid were found to have fluorescence activity greater than 1 y0 of that of indole-3-acetic acid, and good separation of these derivatives was obtained by high-performance liquid chromatography.

In purified tissue of both Pinus syivestris and Chamaecyparis lawsoniana, two fluorescing peaks were separated following derivatisation. The first had an identical fluorescence emission spectrum and retention time in high-performance liquid chromatography to the 2-methylindolo-a-pyrone derivative of indole-3-acetic acid. The second is so far unidentified. The presence of such unidentified compounds in extracts analysed by the standard spectrophotofluorimetric method would lead to an overestimate of the levels of indole-3-acetic acid. The use of high-performance liquid chromatography in the analysis of derivatised acidic indoles is discussed in relation to other published modifications of the method.