Potential metabolism of pharmaceuticals in radish : Comparison of in vivo and in vitro exposure

Metabolism of pharmaceuticals in plants is important to evaluate their fate and accumulation in vegetables, and subsequently the risks to human health. However, limited knowledge is available to evaluate metabolism of pharmaceuticals in plants due to the lack of appropriate research approaches. In this study, radish was selected as a model plant to investigate metabolism of pharmaceuticals in intact plants (in vivo) growing in hydroponic solution and in plant tissue enzyme extracts (in vitro). For caffeine, six phase-I demethylation metabolites identified in the intact radish plant were also found in the plant enzyme extracts. After 7 days of in vivo exposure, the amount of the identified metabolites was about 5.4 times greater than the parent compound caffeine in radish roots. Furthermore, the metabolism potential of fifteen pharmaceuticals in radish was evaluated on the basis of mass balance. After 7 days of hydroponic exposure, oxytetracycline, trimethoprim, carbamazepine, lincomycin, monensin and tylosin manifested relatively less extent of metabolism with the mass recoveries ranging from 52.3 to 78.2%. In contrast, 17 β-estradiol, sulfamethoxazole, sulfadiazine, estrone, triclosan, acetaminophen, caffeine, carbadox and lamotrigine underwent extensive metabolism with only 3.0 to 32.1% of the parent compound recovered. In the in vitro system, 17 β-estradiol, estrone, triclosan, oxytetracycline, acetaminophen, sulfadiazine and sulfamethoxazole were readily metabolized in radish root enzyme extracts with 1.8 to 34.0% remaining after 96-h exposure. While in the leaf enzyme extracts, only triclosan was rapidly metabolized with 49.2% remaining, and others pharmaceuticals were ≥60%, indicating that the varying extents of metabolism occurred in different plant parts. This study highlights the importance of pharmaceutical metabolism in plants, and suggests that plant tissue enzyme extracts could serve as an alternative tool to assess pharmaceutical metabolism in plants. Similar metabolism patterns were observed for rapidly metabolized pharmaceuticals in both in vivo (radish tissue enzyme extracts) and in vivo (the intact plant) exposure

First report of orchid fleck virus in the orchid collection of Jardin du Luxembourg, Paris, France.

Na publicação: J. Freitas-Astúa, D. Navia

The Journey of Human Drugs from Their Design at the Bench to Their Fate in Crops

The topic of this book is dedicated to the analysis, fate, metabolism, effects, and remediation of pharmaceutically active compounds in water-soil-biota systems. While the majority of readers are likely to already have a broad understanding of potential entry points, flows, transformation pathways, and temporary and permanent sinks of drugs in the environment, the objectives of this first chapter are fourfold: (a) to provide a concise overview of the journey a drug takes from its inception at the laboratory bench to the desk of the reviewer at the regulatory agency; (b) to understand the biological and physiological processes a drug undergoes from administration to humans – or to the animal in case of veterinary medicines – to their excretion and ultimately discharge into wastes; (c) to describe the physico-chemical space small-molecule drugs reside in as this characteristic largely governs their later environmental fate; (d) to review their presence, fate, and metabolism in crops and plants determined using innovative analytical methods; as well as (e) to evaluate the effects and remediation of drugs in crops and biota.Peer reviewe

Metabolism of Pharmaceuticals in Plants and Their Associated Microbiota

With the increasing use of wastewater for irrigation of farmland, and thus the potential uptake and translocation of pharmaceuticals and their metabolites in crops, concerns about food safety are growing. After their uptake, plants are able to metabolize drugs to phase I, phase II, and phase III metabolites. Phase I reactions closely resemble those encountered in human drug metabolism, including oxidations, reductions, and hydrolysis. Phase II reactions, in turn, encompass conjugations with glutathione, carbohydrates, malonic acid, and amino acids. In phase III, these conjugates are transported and stored in the vacuole or bound to the cell wall. Pharmaceutical metabolism in plants has been investigated by using different approaches, namely, the use of whole plants grown in soil or hydroponic cultures, the use of plant tissues, and the incubation of specific plant cell suspensions. While studies relying on whole plants require long growth periods and more complex analytical procedures to isolate and detect metabolites, they constitute more realistic scenarios with the ability to determine site-specific metabolism and the translocation within the plant. The advantage of in vitro studies lies in their rapid setup. Recent advances in plant-microbiota investigations have shown that the plant microbiome modulates the response of the plant towards pharmaceuticals. Rhizospheric and endophytic bacteria can directly contribute to pharmaceutical metabolism and influence plant uptake and translocation of pharmaceuticals and their metabolites. Additionally, they can have beneficial properties for the host, contributing to plant health and fitness. This chapter gives an overview of human and plant drug metabolism followed by a comparison of different models used to identify pharmaceutical metabolites and their metabolic pathways in plants. A description of the mechanisms and reactions originating these metabolites is concisely presented. Finally, the role of the microbiome is critically discussed with examples of synergies between plants and their associated microbiota for pharmaceutical degradation.Peer reviewe

Enantioselective synthesis of tetrafluorinated ribose and fructose

A perfluoroalkylidene lithium mediated cyclisation approach for the enantioselective synthesis of a tetrafluorinated aldose (ribose) and of a tetrafluorinated ketose (fructose), both in the furanose and in the pyranose form, is described