Hydroxyl and Methoxyl Derivatives of Benzylglucosinolate in Lepidium densiflorum with Hydrolysis to Isothiocyanates and non-Isothiocyanate Products: Substitution Governs Product Type and Mass Spectral Fragmentation
| Autor: | Eleonora Pagnotta, Niels Agerbirk, Carl Erik Olsen, Luca Lazzeri, Susanna Cinti, Luisa Ugolini |
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| Rok vydání: | 2017 |
| Předmět: |
0106 biological sciences
0301 basic medicine Lepidium densiflorum Thioglucosides Lepidium 01 natural sciences Syringaldehyde 03 medical and health sciences chemistry.chemical_compound Hydrolysis Isothiocyanates Tandem Mass Spectrometry Organic chemistry Molecular Structure biology Plant Extracts Chemistry Myrosinase Brassicaceae General Chemistry biology.organism_classification Sinalbin Plant Leaves 030104 developmental biology Glucosinolate Seeds Isothiocyanate General Agricultural and Biological Sciences Thiocyanates 010606 plant biology & botany |
| Zdroj: | Journal of Agricultural and Food Chemistry. 65:3167-3178 |
| ISSN: | 1520-5118 0021-8561 |
| Popis: | A system of benzylic glucosinolates was found and characterized in common pepperweed, Lepidium densiflorum Schrad. The major glucosinolate was the novel 4-hydroxy-3,5-dimethoxybenzylglucosinolate (3,5-dimethoxysinalbin), present at high levels in seeds, leaves, and roots. Medium-level glucosinolates were 3,4-dimethoxybenzylglucosinolate and 3,4,5-trimethoxybenzylglucosinolate. Minor glucosinolates included benzylglucosinolate, 3-hydroxy- and 3-methoxybenzylglucosinolate, 4-hydroxybenzylglucosinolate (sinalbin), the novel 4-hydroxy-3-methoxybenzylglucosinolate (3-methoxysinalbin), and indole-type glucosinolates. A biosynthetic connection is suggested. NMR, UV, and ion trap MS/MS spectral data are reported, showing contrasting MS fragmentation of p-hydroxyls and p-methoxyls. Additional investigations by GC-MS focused on glucosinolate hydrolysis products. Whereas glucosinolates generally yielded isothiocyanates, the dominating 3,5-dimethoxysinalbin with a free p-hydroxyl group produced the corresponding alcohol and syringaldehyde (4-hydroxy-3,5-dimethoxybenzaldehyde). After thermal deactivation of the endogenous myrosinase enzyme, massive accumulation of the corresponding nitrile was detected. This case study points out how non-isothiocyanate glucosinolate hydrolysis products are prevalent in nature and of interest in both plant-pathogen interactions and human health. |
| Databáze: | OpenAIRE |
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