Anthraquinone Residues in Dried Walnut ( Juglans regia ) Leaves for Herbal Infusions: Proof of Endogenous Origin via a Sampling-Driven and GC-MS/MS-Based Strategy
Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Anthraquinone residues in tea have been linked to atmospheric deposition. However, anthraquinones can also be biosynthesized in plants. In this work, we report on a sample-driven and GC-MS/MS-based analytical strategy to differentiate between endogenous and exogenous anthraquinones in dried walnut ( Juglans regia ) leaves. Anthraquinone and seven of its derivatives were quantified in 9 dried and 128 fresh samples of leaves from walnut and other deciduous trees from three different countries and nine sampling sites. The drying of walnut leaves in a hot-air electric oven eliminated 80% of anthraquinone concentration. Among the fresh walnut leaf samples, 94% exceeded the 0.01 mg/kg maximum residue limit of anthraquinone, with values up to 0.3 mg/kg. Most derivatives were also present above 0.01 mg/kg. However, in the leaves from other deciduous trees, the compounds were much lower than 0.01 mg/kg. We conclude that the low anthraquinone base levels in most samples may result from atmospheric pollution, whereas the higher anthraquinone residues in walnut leaves likely have an endogenous origin.
Institution: University of Regensburg
Language: English
Topic: Heavy Metals in Plants
Subfield: Analytical Chemistry
Field: Chemistry
Domain: Physical Sciences
SDG: Zero hunger
Open Access status: hybrid
Estimated APC paid: $4,500
OpenAlex ID: W4404534679