An assay for secologanin in plant tissues based on enzymatic conversion into strictosidine
✍ Scribed by Didier Hallard; Robert van der Heijden; Adriana Contin; Emilia M. Tomas Jiménéz; Wim Snoeijer; Robert Verpoorte; Søren R. Jensen; M. Inês Lopes Cardoso; Giancarlo Pasquali; Johan Memelink; J. Harry C. Hoge
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 179 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0958-0344
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✦ Synopsis
The secoiridoid glucoside secologanin is the terpenoid building block in the biosynthesis of terpenoid indole alkaloids. A method for its determination in plant tissues and in cell suspension cultures has been developed. This assay is based on the condensation of secologanin with tryptamine, yielding strictosidine, in a reaction catalysed by the enzyme strictosidine synthase (STR; E.C. 4.3.3.2). Subsequently, the formation of strictosidine is quantified by high performance liquid chromatography (HPLC). STR was isolated from transgenic Nicotiana tabacum cells expressing a cDNA-derived gene coding for STR from Catharanthus roseus. The high specificity of STR for secologanin, in combination with a sensitive and selective HPLC system, allows a simple extraction of secologanin from plant tissue. The detection limit of this method is 15 ng secologanin. Using this assay, secologanin contents were determined in tissues of various plant species; Lonicera xylosteum hairy roots were found to contain 1% of secologanin on a dry weight basis.