Biotransformation of steroids by fungi has been raised as a successful, eco-friendly, and cost-effective biotechnological alternative for chemical derivatization. Endophytic fungi live inside vegetal tissues without causing damage to the host plant, making available unique enzymes that carry out uncommon reactions. Moreover, using nanofibrous membranes as support for immobilizing fungal cells is a powerful strategy to improve their performance by enabling the combined action of adsorption and transformation processes, along with increasing the stability of the fungal cell. In the present study, we report the use of polyacrylonitrile nanofibrous membrane (PAN NFM) produced by electrospinning as supporting material for immobilizing the endophytic fungus Penicillium citrinum H7 aiming the biotransformation of progesterone. The PAN@H7 NFM displayed a high progesterone transformation efficiency (above 90%). The investigation of the biotransformation pathway of progesterone allowed the putative structural characterization of its main fungal metabolite by GC-MS analysis. The oxidative potential of P. citrinum H7 was selective for the C-17 position of the steroidal nucleus.

• Klíčová slova
• Biotransformation, Electrospinning, Endophytic fungus, Fungal immobilization, GC–MS, Steroids,
• MeSH
• biotransformace MeSH
• nanovlákna * chemie   MeSH
• progesteron MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• progesteron MeSH

Flavonolignans occur typically in Silybum marianum (milk thistle) fruit extract, silymarin, which contains silybin, isosilybin, silychristin, silydianin, and their 2,3-dehydroderivatives, together with other minor flavonoids and a polymeric phenolic fraction. Biotransformation of individual silymarin components by human microbiota was studied ex vivo, using batch incubations inoculated by fecal slurry. Samples at selected time points were analyzed by ultrahigh-performance liquid chromatography equipped with mass spectrometry. The initial experiment using a concentration of 200 mg/L showed that flavonolignans are resistant to the metabolic action of intestinal microbiota. At the lower concentration of 10 mg/L, biotransformation of flavonolignans was much slower than that of taxifolin, which was completely degraded after 16 h. While silybin, isosilybin, and 2,3-dehydrosilybin underwent mostly demethylation, silychristin was predominantly reduced. Silydianin, 2,3-dehydrosilychristin and 2,3-dehydrosilydianin were reduced, as well, and decarbonylation and cysteine conjugation proceeded. No low-molecular-weight phenolic metabolites were detected for any of the compounds tested. Strong inter-individual differences in the biotransformation profile were observed among the four fecal-material donors. In conclusion, the flavonolignans, especially at higher (pharmacological) doses, are relatively resistant to biotransformation by gut microbiota, which, however, depends strongly on the individual structures of these isomeric compounds, but also on the stool donor.

• Klíčová slova
• UHPLC–MS, biotransformation, flavonolignans, gut microbiota, inter-individual differences, metabolites, silymarin,
• Publikační typ
• časopisecké články MeSH

The term "biotransformation" refers to the process by which various compounds are biocatalyzed and enzymatically modified, as well as the metabolic changes that occur in organisms as a result of exposure to xenobiotics [...].

• MeSH
• biologické přípravky * MeSH
• biotransformace MeSH
• fytonutrienty metabolismus   MeSH
• xenobiotika metabolismus   MeSH
• Publikační typ
• úvodníky MeSH
• Názvy látek
• biologické přípravky * MeSH
• fytonutrienty MeSH
• xenobiotika MeSH

Metabolism of styrene, an important industrial monomer, is reviewed. Attention is focused on the stereoselectivity of its oxidation to 7,8-styrene oxide as well as on further stereoselective biotransformation by hydrolytic and mercapturic acid pathway. Toxic effects such as mutagenicity, genotoxicity, hepatotoxicity, and pneumotoxicity may be related to the ratio of styrene oxide enantiomers at the target site. In rats formation of the less mutagenic (S)-styrene oxide and a faster detoxication of the (R)-enantiomer is favored. In mice metabolic activation of styrene favors the formation of (R)-styrene oxide but this more toxic enantiomer is detoxified faster, so that a nearly racemic styrene oxide results. Stereochemistry of biotransformation can contribute to the species differences in toxicity but can hardly be interpreted as a crucial factor. Due to lack of relevant data the stereochemistry of human metabolism cannot be interpreted in relation to the toxic effects.

• MeSH
• biotransformace MeSH
• lidé MeSH
• molekulární konformace MeSH
• styren chemie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• styren MeSH

Silybin and its congeners belong to a group of flavonolignans with strong biological activities. These compounds are potentially applicable in human medicine, e. g. due to their cytoprotective activity. As a part of herbal preparations available on the open market, they face the risk of potential negative drug-drug interactions. This review aims to evaluate current knowledge on the metabolism of these compounds by biotransformation enzymes, interactions with other drugs, their pharmacokinetics, and bioavailability. While silybin and its derivatives interact with cytochrome P450s, only metabolism of silybin by cytochrome P450 2C8 poses a risk of adverse effects. The main biotransformation route of silybin and derivatives was identified as conjugation, which is stereospecific in case of silybin. Studies of the metabolism, pharmacokinetics, potentional drug--drug interactions and increasing bioavailability of these flavonolignans play an important facet of possible therapeutical use of these compounds. The goal of our review is to aid future developments in the area of silybin research.

• MeSH
• antioxidancia chemie   metabolismus   farmakokinetika   MeSH
• biologická dostupnost MeSH
• biotransformace MeSH
• glukuronidy metabolismus   MeSH
• lidé MeSH
• silibinin MeSH
• silymarin analogy a deriváty   chemie   metabolismus   farmakokinetika   MeSH
• stereoizomerie MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• antioxidancia MeSH
• glukuronidy MeSH
• silibinin MeSH
• silymarin MeSH

The use of unicellular algae to remove xenobiotics (including drugs) from wastewaters is one of the rapidly developing areas of environmental protection. Numerous data indicate that for efficient phycoremediation three processes are important, i.e. biosorption, bioaccumulation, and biotransformation. Although biosorption and bioaccumulation do not raise any serious doubts, biotransformation is more problematic since its products can be potentially more toxic than the parent compounds posing a threat to organisms living in a given environment, including organisms that made this transformation. Thus, two questions need to be answered before the proper algae strain is chosen for phycoremediation, namely what metabolites are produced during biotransformation, and how resistant is the analyzed strain to a mixture of parent compound and metabolites that appear over the course of culture? In this work, we evaluated the remediation potential of the model green alga Chlamydomonas reinhardtii in relation to non-steroidal anti-inflammatory drugs (NSAIDs), as exemplified by diclofenac. To achieve this, we analysed the susceptibility of C. reinhardtii to diclofenac as well as its capability to biosorption, bioaccumulation, and biotransformation of the drug. We have found that even at a relatively high concentration of diclofenac the algae maintained their vitality and were able to remove (37.7%) DCF from the environment. A wide range of phase I and II metabolites of diclofenac (38 transformation products) was discovered, with many of them characteristic rather for animal and bacterial biochemical pathways than for plant metabolism. Due to such a large number of detected products, 18 of which were not previously reported, the proposed scheme of diclofenac transformation by C. reinhardtii not only significantly contributes to broadening the knowledge in this field, but also allows to suggest possible pathways of degradation of xenobiotics with a similar structure. It is worth pointing out that a decrease in the level of diclofenac in the media observed in this study cannot be fully explained by biotransformation (8.4%). The mass balance analysis indicates that other processes (total 22%), such as biosorption, a non-extractable residue formation, or complete decomposition in metabolic cycles can be involved in the diclofenac disappearance, and those findings open the prospects of further research.

• Klíčová slova
• Biotransformation, Chlamydomonas reinhardtii, Diclofenac, Non-steroidal anti-inflammatory drug,
• MeSH
• antiflogistika nesteroidní analýza   MeSH
• biotransformace MeSH
• chemické látky znečišťující vodu * analýza   MeSH
• Chlamydomonas reinhardtii * metabolismus   MeSH
• diklofenak toxicita   metabolismus   MeSH
• voda MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antiflogistika nesteroidní MeSH
• chemické látky znečišťující vodu * MeSH
• diklofenak MeSH
• voda MeSH

Microsomal fraction of fungal cells grabs the attention of many researchers for it contains enzymes that play a role in biotechnologically relevant processes. Microsomal enzymes, namely, CYP450s, were shown to metabolize a wide range of xenobiotic compounds, including PAHs, PCBs, dioxins, and endocrine disruptors, and take part in other fungal biotransformation reactions. However, little is known about the nature and regulation of these membrane-associated reactions. Advanced proteomic and post-genomic techniques make it possible to identify larger numbers of microsomal proteins and thus add to a deeper study of fungal intracellular processes. In this work, proteins that were identified through a shotgun proteomic approach in fungal microsomes under various culture conditions are reviewed. However, further research is still needed to fully understand the role of microsomes in fungal biodegradation and biotransformation reactions.

• MeSH
• biotransformace MeSH
• houby enzymologie   metabolismus   MeSH
• intracelulární membrány enzymologie   metabolismus   MeSH
• membránové proteiny metabolismus   MeSH
• mikrozomy enzymologie   metabolismus   MeSH
• proteomika metody   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• membránové proteiny MeSH

Arsenic is a ubiquitous toxic metalloid, the concentration of which is beyond WHO safe drinking water standards in many areas of the world, owing to many natural and anthropogenic activities. Long-term exposure to arsenic proves lethal for plants, humans, animals, and even microbial communities in the environment. Various sustainable strategies have been developed to mitigate the harmful effects of arsenic which include several chemical and physical methods, however, bioremediation has proved to be an eco-friendly and inexpensive technique with promising results. Many microbes and plant species are known for arsenic biotransformation and detoxification. Arsenic bioremediation involves different pathways such as uptake, accumulation, reduction, oxidation, methylation, and demethylation. Each of these pathways has a certain set of genes and proteins to carry out the mechanism of arsenic biotransformation. Based on these mechanisms, various studies have been conducted for arsenic detoxification and removal. Genes specific for these pathways have also been cloned in several microorganisms to enhance arsenic bioremediation. This review discusses different biochemical pathways and the associated genes which play important roles in arsenic redox reactions, resistance, methylation/demethylation, and accumulation. Based on these mechanisms, new methods can be developed for effective arsenic bioremediation.

• Klíčová slova
• Arsenic, Bacteria, Biochemical pathways, Bioremediation, Biosorption, Demethylation, Methylation, Microorganisms, Oxidation, Reduction,
• MeSH
• arsen * metabolismus   MeSH
• Bacteria genetika   metabolismus   MeSH
• biodegradace MeSH
• biotransformace MeSH
• lidé MeSH
• oxidace-redukce MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• arsen * MeSH

The determination of mycotoxins content in food is not sufficient for the prediction of their potential in vivo cytotoxicity because it does not reflect their bioavailability and mutual interactions within complex matrices, which may significantly alter the toxic effects. Moreover, many mycotoxins undergo biotransformation and metabolization during the intestinal absorption process. Biotransformation is predominantly the conversion of mycotoxins meditated by cytochrome P450 and other enzymes. This should transform the toxins to nontoxic metabolites but it may possibly result in unexpectedly high toxicity. Therefore, the verification of biotransformation and bioavailability provides valuable information to correctly interpret occurrence data and biomonitoring results. Among all of the methods available, the in vitro models using monolayer formed by epithelial cells from the human colon (Caco-2 cell) have been extensively used for evaluating the permeability, bioavailability, intestinal transport, and metabolism of toxic and biologically active compounds. Here, the strengths and limitations of both in vivo and in vitro techniques used to determine bioavailability are reviewed, along with current detailed data about biotransformation of mycotoxins. Furthermore, the molecular mechanism of mycotoxin effects is also discussed regarding the disorder of intestinal barrier integrity induced by mycotoxins.

• Klíčová slova
• bioavailability, biotransformation, cytochrome, intestinal transport, metabolism, mycotoxins, permeability,
• MeSH
• biologická dostupnost MeSH
• Caco-2 buňky MeSH
• epitelové buňky enzymologie   MeSH
• hodnocení rizik MeSH
• intestinální absorpce * MeSH
• lidé MeSH
• metabolická aktivace MeSH
• metabolická inaktivace MeSH
• mykotoxiny metabolismus   toxicita   MeSH
• permeabilita MeSH
• střevní sliznice enzymologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• mykotoxiny MeSH

Pharmaceutically active compounds (PhACs) have been shown to accumulate in aquatic and riparian food-webs. Yet, our understanding of how temperature, a key environmental factor in nature, affects uptake, biotransformation, and the subsequent accumulation of PhACs in aquatic organisms is limited. In this study, we tested to what extent bioconcentration of an anxiolytic drugs (temazepam and oxazepam) is affected by two temperature regimes (10 and 20 °C) and how the temperature affects the temazepam biotransformation and subsequent accumulation of its metabolite (oxazepam) in aquatic organisms. We used European perch (Perca fluviatilis) and dragonfly larvae (Sympetrum sp.), which represent predator and prey species of high ecological relevance in food chains of boreal and temperate aquatic ecosystems. Experimental organisms were exposed to target pharmaceuticals at a range of concentrations (0.2-6 µg L-1) to study concentration dependent differences in bioconcentration and biotransformation. We found that the bioconcentration of temazepam in perch was significantly reduced at higher temperatures. Also, temperature had a strong effect on temazepam biotransformation in the fish, with the production and subsequent accumulation of its metabolite (oxazepam) being two-fold higher at 20 °C compared to 10 °C. In contrast, we found no temperature dependency for temazepam bioconcentration in dragonfly larvae and no detectable biotransformation of the parent compound that would result in measurable concentrations of oxazepam in this organism. Our results highlight that while organisms may share the same aquatic ecosystem, their exposure to PhACs may change differently across temperature gradients in the environment.

• Klíčová slova
• Aquatic invertebrate, Benzodiazepine, Dragonfly, Drug, Fish, Temazepam,
• MeSH
• biotransformace MeSH
• chemické látky znečišťující vodu * MeSH
• ekosystém MeSH
• léčivé přípravky * MeSH
• okounovití * MeSH
• teplota MeSH
• vážky * MeSH
• voda MeSH
• vodní organismy MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• léčivé přípravky * MeSH
• voda MeSH