Unveiling the spatial distribution of aflatoxin B1 and plant defense metabolites in maize using AP-SMALDI mass spectrometry imaging.

In order to cope with the presence of unfavorable compounds, plants can biotransform xenobiotics, translocate both parent compounds and metabolites, and perform compartmentation and segregation at the cellular or tissue level. Such a scenario also applies to mycotoxins, fungal secondary metabolites with a pre-eminent role in plant infection. In this work, we aimed to describe the effect of the interplay between Zea mays (maize) and aflatoxin B1 (AFB1) at the tissue and organ level. To address this challenge, we used atmospheric pressure scanning microprobe matrix-assisted laser desorption/ionization mass spectrometry imaging (AP-SMALDI MSI) to investigate the biotransformation, localization and subsequent effects of AFB1 on primary and secondary metabolism of healthy maize plants, both in situ and from a metabolomics standpoint. High spatial resolution (5 µm) provided fine localization of AFB1, which was located within the root intercellular spaces, and co-localized with its phase-I metabolite aflatoxin M2. We provided a parallel visualization of maize metabolic changes, induced in different organs and tissues by an accumulation of AFB1. According to our untargeted metabolomics investigation, anthocyanin biosynthesis and chlorophyll metabolism in roots are most affected. The biosynthesis of these metabolites appears to be inhibited by AFB1 accumulation. On the other hand, metabolites found in above-ground organs suggest that the presence of AFB1 may also activate the biochemical response in the absence of an actual fungal infection; indeed, several plant secondary metabolites known for their antimicrobial or antioxidant activities were localized in the outer tissues, such as phenylpropanoids, benzoxazinoids, phytohormones and lipids.

Structural basis of the alternating-access mechanism in a bile acid transporter.

Bile acids are synthesized from cholesterol in hepatocytes and secreted through the biliary tract into the small intestine, where they aid in absorption of lipids and fat-soluble vitamins. Through a process known as enterohepatic recirculation, more than 90% of secreted bile acids are then retrieved from the intestine and returned to the liver for resecretion. In humans, there are two Na(+)-dependent bile acid transporters involved in enterohepatic recirculation, the Na(+)-taurocholate co-transporting polypeptide (NTCP; also known as SLC10A1) expressed in hepatocytes, and the apical sodium-dependent bile acid transporter (ASBT; also known as SLC10A2) expressed on enterocytes in the terminal ileum. In recent years, ASBT has attracted much interest as a potential drug target for treatment of hypercholesterolaemia, because inhibition of ASBT reduces reabsorption of bile acids, thus increasing bile acid synthesis and consequently cholesterol consumption. However, a lack of three-dimensional structures of bile acid transporters hampers our ability to understand the molecular mechanisms of substrate selectivity and transport, and to interpret the wealth of existing functional data. The crystal structure of an ASBT homologue from Neisseria meningitidis (ASBT(NM)) in detergent was reported recently, showing the protein in an inward-open conformation bound to two Na(+) and a taurocholic acid. However, the structural changes that bring bile acid and Na(+) across the membrane are difficult to infer from a single structure. To understand the structural changes associated with the coupled transport of Na(+) and bile acids, here we solved two structures of an ASBT homologue from Yersinia frederiksenii (ASBTYf) in a lipid environment, which reveal that a large rigid-body rotation of a substrate-binding domain gives the conserved 'crossover' region, where two discontinuous helices cross each other, alternating accessibility from either side of the cell membrane. This result has implications for the location and orientation of the bile acid during transport, as well as for the translocation pathway for Na(+).

The Metabolic Reprogramming Induced by Sub-Optimal Nutritional and Light Inputs in Soilless Cultivated Green and Red Butterhead Lettuce.

Sub-optimal growing conditions have a major effect on plants; therefore, large efforts are devoted to maximizing the availability of agricultural inputs to crops. To increase the sustainable use of non-renewable inputs, attention is currently given to the study of plants under non-optimal conditions. In this work, we investigated the impact of sub-optimal macrocations availability and light intensity in two lettuce varieties that differ for the accumulation of secondary metabolites (i.e., 'Red Salanova' and 'Green Salanova'). Photosynthesis-related measurements and untargeted metabolomics were used to identify responses and pathways involved in stress resilience. The pigmented ('Red') and the non-pigmented ('Green Salanova') lettuce exhibited distinctive responses to sub-optimal conditions. The cultivar specific metabolomic signatures comprised a broad modulation of metabolism, including secondary metabolites, phytohormones, and membrane lipids signaling cascade. Several stress-related metabolites were altered by either treatment, including polyamines (and other nitrogen-containing compounds), phenylpropanoids, and lipids. The metabolomics and physiological response to macrocations availability and light intensity also implies that the effects of low-input sustainable farming systems should be evaluated considering a range of cultivar-specific positive and disadvantageous metabolic effects in addition to yield and other socio-economic parameters.

Botanical Sources, Chemistry, Analysis, and Biological Activity of Furanocoumarins of Pharmaceutical Interest.

The aim of this work is to provide a critical review of plant furanocoumarins from different points of view, including their chemistry and biosynthetic pathways to their extraction, analysis, and synthesis, to the main biological activities found for these active compounds, in order to highlight their potential within pharmaceutical science. The limits and the possible improvements needed for research involving these molecules are also highlighted and discussed.

Identification of acetylated derivatives of zearalenone as novel plant metabolites by high-resolution mass spectrometry.

Zearalenone (ZEN) major biotransformation pathways described so far are based on glycosylation and sulfation, although acetylation of trichothecenes has been reported as well. We investigated herein the ZEN acetylation metabolism route in micropropagated durum wheat leaf, artificially contaminated with ZEN. We report the first experimental evidence of the formation of novel ZEN acetylated forms in wheat, attached both to the aglycone backbone as well as on the glucose moiety. Thanks to the advantages provided by high-resolution mass spectrometry, identification and structure annotation of 20 metabolites was achieved. In addition, a preliminary assessment of the toxicity of the annotated metabolites was performed in silico focusing on the toxicodynamic of ZEN group toxicity. All the metabolites showed a worse fitting within the estrogen receptor pocket in comparison with ZEN. Nevertheless, possible hydrolysis to the respective parent compounds (i.e., ZEN) may raise concern from the health perspective because these are well-known xenoestrogens. These results further enrich the biotransformation profile of ZEN, providing a helpful reference for assessing the risks to animals and humans. Graphical abstract ᅟ.

On the Mechanism of Action of Anti-Inflammatory Activity of Hypericin: An In Silico Study Pointing to the Relevance of Janus Kinases Inhibition.

St. John's Wort (Hypericum perforatum L.) flowers are commonly used in ethnomedical preparations with promising outcomes to treat inflammation both per os and by topical application. However, the underlying molecular mechanisms need to be described toward a rational, evidence-based, and reproducible use. For this purpose, the aptitude of the prominent Hypericum metabolite hypericin was assessed, along with that of its main congeners, to behave as an inhibitor of janus kinase 1, a relevant enzyme in inflammatory response. It was used a molecular modeling approach relying on docking simulations, pharmacophoric modeling, and molecular dynamics to estimate the capability of molecules to interact and persist within the enzyme pocket. Our results highlighted the capability of hypericin, and some of its analogues and metabolites, to behave as ATP-competitive inhibitor providing: (i) a likely mechanistic elucidation of anti-inflammatory activity of H. perforatum extracts containing hypericin and related compounds; and (ii) a rational-based prioritization of H. perforatum components to further characterize their actual effectiveness as anti-inflammatory agents.

Crystal structure of a potassium ion transporter, TrkH.

The TrkH/TrkG/KtrB proteins mediate K(+) uptake in bacteria and probably evolved from simple K(+) channels by multiple gene duplications or fusions. Here we present the crystal structure of a TrkH from Vibrio parahaemolyticus. TrkH is a homodimer, and each protomer contains an ion permeation pathway. A selectivity filter, similar in architecture to those of K(+) channels but significantly shorter, is lined by backbone and side-chain oxygen atoms. Functional studies showed that TrkH is selective for permeation of K(+) and Rb(+) over smaller ions such as Na(+) or Li(+). Immediately intracellular to the selectivity filter are an intramembrane loop and an arginine residue, both highly conserved, which constrict the permeation pathway. Substituting the arginine with an alanine significantly increases the rate of K(+) flux. These results reveal the molecular basis of K(+) selectivity and suggest a novel gating mechanism for this large and important family of membrane transport proteins.

Homologue structure of the SLAC1 anion channel for closing stomata in leaves.

The plant SLAC1 anion channel controls turgor pressure in the aperture-defining guard cells of plant stomata, thereby regulating the exchange of water vapour and photosynthetic gases in response to environmental signals such as drought or high levels of carbon dioxide. Here we determine the crystal structure of a bacterial homologue (Haemophilus influenzae) of SLAC1 at 1.20 Å resolution, and use structure-inspired mutagenesis to analyse the conductance properties of SLAC1 channels. SLAC1 is a symmetrical trimer composed from quasi-symmetrical subunits, each having ten transmembrane helices arranged from helical hairpin pairs to form a central five-helix transmembrane pore that is gated by an extremely conserved phenylalanine residue. Conformational features indicate a mechanism for control of gating by kinase activation, and electrostatic features of the pore coupled with electrophysiological characteristics indicate that selectivity among different anions is largely a function of the energetic cost of ion dehydration.

Phytotoxic Effects and Phytochemical Fingerprinting of Hydrodistilled Oil, Enriched Fractions, and Isolated Compounds Obtained from Cryptocarya massoy (Oken) Kosterm. Bark.

The hydrodistilled oil of Cryptocarya massoy bark was characterized by GC-FID and GC/MS analyses, allowing the identification of unusual C10 massoia lactone (3, 56.2%), C12 massoia lactone (4, 16.5%), benzyl benzoate (1, 12.7%), C8 massoia lactone (3.4%), δ-decalactone (5, 1.5%), and benzyl salicylate (2, 1.8%) as main constituents. The phytotoxic activities of the oil, three enriched fractions (lactone-rich, ester-rich, and sesquiterpene-rich), and four constituents (compounds 1, 2, 5, and δ-dodecalactone (6)) against Lycopersicon esculentum and Cucumis sativus seeds and seedlings were screened. At a concentration of 1000 µl/l, the essential oil and the massoia lactone-rich fraction caused a complete inhibition of the germination of both seeds, and, when applied on tomato plantlets, they induced an 85 and 100% dieback, respectively. These performances exceeded those of the well-known phytotoxic essential oils of Syzygium aromaticum and Cymbopogon citratus, already used in commercial products for the weed and pest management. The same substances were also evaluated against four phytopathogenic bacteria and ten phytopathogenic fungi, providing EC50 values against the most susceptible strains in the 100-500 µl/l range for the essential oil and in the 10-50 µl/l range for compound 6 and the lactone-rich fraction. The phytotoxic behavior was related mainly to massoia lactones and benzyl esters, while a greater amount of 6 may infer a good activity against some phytopathogenic fungi. Further investigations of these secondary metabolites are warranted, to evaluate their use as natural herbicides.

Investigating Metabolic Plant Response toward Deoxynivalenol Accumulation in Four Winter Cereals.

Deoxynivalenol (DON) is a phytotoxic agent supporting the spread of fungal diseases in cereals worldwide, i.e., fusarium head blight. It is known that DON accumulation may elicit changes in plant secondary metabolites in response to pathogen attack. This study maps the changes in selected secondary metabolite classes upon DON contamination occurring in fifteen Triticum spp. genotypes, among them emmer, spelt, and soft wheat, and 2 tritordeum varieties, cultivated in two different sites and over two harvest years. The main phenolic classes (i.e., alkylresorcinols, soluble, and cell-wall bound phenolic acids) were targeted analyzed, while changes in the lipidome signature were collected through untargeted HRMS experiments. The results, obtained across multiple Triticum species and in open fields, confirmed the modulation of first-line biological pathways already described in previous studies involving single cereal species or a limited germplasm, thus reinforcing the involvement of nonspecific chemical defenses in the plant response to pathogen attack.

Mycotoxin occurrence in kernels and straws of wheat, barley, and tritordeum.

Thirty-two varieties of common and durum wheat, hordeum, barley, and tritordeum collected over two harvesting years (2020 and 2021) were investigated for the presence of multiple Fusarium-related mycotoxins in asymptomatic plants. DON, 3-AcDON, 15-AcDON, T-2, HT-2, and ZEN together with the emerging mycotoxin ENN B and the major modified form of DON, namely DON3Glc, were quantified by means of UHPLC-MS/MS. Overall, DON and ENN B were the most frequently detected mycotoxins, albeit large inter-year variability was observed and related to different climate and weather conditions. Straws had higher mycotoxin contents than kernels and regarding DON occurrence tritordeum was found to be the most contaminated group on average for both harvesting years, while barley was the less contaminated one. Emerging mycotoxin ENN B showed comparable contents in kernels compared to straw, with a ratio close to 1 for tritordeum and barley. Regarding the occurrence of the other evaluated mycotoxins, T-2 and HT-2 toxins have been spotted in a few tritordeum samples, while ZEN has been frequently found only in straw from the harvesting year 2020. The data collected confirms the occurrence of multiple Fusarium mycotoxins in straws also from asymptomatic plants, highlighting concerns related to feed safety and animal health. The susceptibility of Tritordeum, hereby reported for the first time, suggests that careful measures in terms of monitoring, breeding, and cultural choices should be applied when dealing with his emerging crop.

Comprehensive Analysis of Berberis aristata DC. Bark Extracts: In Vitro and In Silico Evaluation of Bioaccessibility and Safety.

Berberine (BER) is an alkaloid found, together with other protoberberinoids (PROTBERs), in several species used in medicines and food supplements. While some herbal preparations containing BER and PROTBERs, such as Berberis aristata DC. bark extracts, have shown promising potential for human health, their safety has not been fully assessed. Recently, the EFSA issued a call for data to deepen the pharmacokinetic and pharmacodynamic understanding of products containing BER and PROTBERs and to comprehensively assess their safety, especially when used in food supplements. In this context, new data were collected in this work by assessing: (i) the phytochemical profile of 16 different commercial B. aristata dry extracts, which are among the most widely used preparations containing BER and PROTBERs in Europe; (ii) the In Vitro and In Silico investigation of the pharmacokinetic properties of BER and PROTBERs; (iii) the In Vitro cytotoxicity of selected extracts in different human cell lines, including tests on hepatic cells in the presence of CYP450 substrates; (iv) the effects of the extracts on cancer cell migration; and (v) the In Vitro molecular effects of extracts in non-cancer human cells. Results showed that commercial B. aristata extracts contain BER as the main constituent, with jatrorrhizine as main secondary PROTBER. BER and jatrorrhizine were found to have a good bioaccessibility rate, but they interact with P-gp. B. aristata extracts showed limited cytotoxicity and minimal interaction with CYP450 substrates. Furthermore, tested extracts demonstrated inhibition of cancer cell migration and were devoid of any pro-tumoral effects in normal cells. Overall, our work provides a valuable overview to better elucidate important concerns regarding botanicals containing BER and PROTBERs.

Structure and function of the human apoptotic scramblase Xkr4.

Phosphatidylserine externalization on the surface of dying cells is a key signal for their recognition and clearance by macrophages and is mediated by members of the X-Kell related (Xkr) protein family. Defective Xkr-mediated scrambling impairs clearance, leading to inflammation. It was proposed that activation of the Xkr4 apoptotic scramblase requires caspase cleavage, followed by dimerization and ligand binding. Here, using a combination of biochemical approaches we show that purified monomeric, full-length human Xkr4 (hXkr4) scrambles lipids. CryoEM imaging shows that hXkr4 adopts a novel conformation, where three conserved acidic residues create an electronegative surface embedded in the membrane. Molecular dynamics simulations show this conformation induces membrane thinning, which could promote scrambling. Thinning is ablated or reduced in conditions where scrambling is abolished or reduced. Our work provides insights into the molecular mechanisms of hXkr4 scrambling and suggests the ability to thin membranes might be a general property of active scramblases.

Lessons from a geriatric clinical case from the 19th century: a bridge to modern geriatric medicine.

Count Neipperg (1775-1829), the morganatic husband of Maria Luigia of Habsburg, Napoleon's former wife, presented with typical heart failure symptoms and died of bilateral bronchopneumonia. Neipperg's case is an example of the conflict in the medical field, which led to the birth of modern evidence-based medicine (EBM), and although Neipperg died almost 200 years ago, his case presents the same critical issues that more complex geriatric patients face today. First, the attending physicians provided divergent opinions without reaching an agreement. For example, Francesco Rossi correctly diagnosed heart disease by evaluating the patient's signs and symptoms, a clinical approach that is an early example of modern EBM. By contrast, Giacomo Tommasini made a misdiagnosis based on the philosophical principles of John Brown's vitalist theory, as reworded by Giovanni Rasori. Second, Tommasini's medical report also includes evidence of the Geriatric 5Ms for older patient care, such as multi-complexity, multimorbidity, medication, mobility, and the mind. Moreover, both physicians considered "what matters most" for the patient and his family. Third, the Count's status and political role were identified as the social and structural determinants of health (SSDoH) and used to justify the exceptional intensity of the health care provided. Subsequently, the ante litteram application of EBM and a clinical evaluation based on Geriatrics 5Ms principles anticipate current multidisciplinary management focused on the patient rather than a single disease. The systematic revision of past clinical cases not examined before could open new windows in the dissemination of the geriatric methodology and discipline.

Neuropilin-1 is a co-receptor for NGF and TrkA-evoked pain.

Nerve growth factor (NGF) monoclonal antibodies (mAb) are one of the few patient-validated non-opioid treatments for chronic pain, despite failing to gain FDA approval due to worsened joint damage in some osteoarthritis patients. Herein, we demonstrate that neuropilin-1 (NRP1) is a nociceptor-enriched co-receptor for NGF that is necessary for tropomyosin-related kinase A (TrkA) signaling of pain. NGF binds NRP1 with nanomolar affinity. NRP1 and G Alpha Interacting Protein C-terminus 1 (GIPC1), a NRP1/TrkA adaptor, are coexpressed with TrkA in human and mouse nociceptors. NRP1 small molecule inhibitors and blocking mAb prevent NGF-stimulated action potential firing and activation of Na+ and Ca2+ channels in human and mouse nociceptors and abrogate NGF-evoked and inflammatory nociception in mice. NRP1 knockdown blunts NGF-stimulated TrkA phosphorylation, kinase signaling and transcription, whereas NRP1 overexpression enhances NGF and TrkA signaling. As well as interacting with NGF, NRP1 forms a heteromeric complex with TrkA. NRP1 thereby chaperones TrkA from the biosynthetic pathway to the plasma membrane and then to signaling endosomes, which enhances NGF-induced TrkA dimerization, endocytosis and signaling. Knockdown of GIPC1, a PDZ-binding protein that scaffolds NRP1 and TrkA to myosin VI, abrogates NGF-evoked excitation of nociceptors and pain-like behavior in mice. We identify NRP1 as a previously unrecognized co-receptor necessary for NGF/TrkA pain signaling by direct NGF binding and by chaperoning TrkA to the plasma membrane and signaling endosomes via the adaptor protein GIPC1. Antagonism of NRP1 and GIPC1 in nociceptors offers a long-awaited alternative to systemic sequestration of NGF with mAbs for the treatment of pain.

An integrated dataset providing a landscape of the Italian Universities.

We provide data describing all the largest Italian Universities from several perspectives, including scientific research, administrative and economic point of view. In particular, associated with each University, we have the following data. (a) The list of the most representative research keywords (single words and bigrams), automatically extracted from titles, abstracts and other possible metadata of all the research publications available for that University in Scopus database at October 2022. (b) The Extended_name of the University, Status, University_Type, State_status, number of Managerial and Administrative Staff, Teaching Staff and Researchers, Phd Diplomas, Phd Enrollments, Enrolled Undergraduates, Enrolled Graduates, Graduates, Master I Lv Graduates, Enrolled Master's Degree I Lv, Master II Lv, Graduates Enrolled, Master II Lv, Graduates Specialistic Schools and Enrolled Specialistic Schools were extracted from USTAT database for the years 2016-2018. (c) The data of Educational Income, Income from Commissioned Research and Technology Transfer, Income from Research with competitive funding, Own Income, Contributions from others (private), Contributions from others (public), Contributions from universities, Contributions from the European Union and the Rest of the World, Contributions from other local governments, Contributions Regions and Autonomous Provinces, MIUR and other central government grants, Operating Costs, Current Management Costs, Managerial and administrative personnel costs, Research and teaching staff cost, Cost of Lecturers and Researchers, Cost Scientific Collaborators, Cost of Contract Teachers, Cost of Language Experts, Other research and teaching personnel costs, Personnel Costs, Scientific equipment, Concessions, licenses and trademarks, Patent rights are extracted from the unique University Balance Sheet of each university for the years 2016-2018. These data were of difficult availability; they have been extracted from several heterogeneous sources and have been automatically checked, cleaned from errors, integrated, and missing values have been imputed as much as possible. However, due to large missing portions in the sources, they still contain several missing parts. Nonetheless, they represent a powerful snapshot of the Italian Universities, and can be of interest to researchers for many analyses of the Italian academic world. All the sources of the openly available data are provided.

Anthocyanin Content and Fusarium Mycotoxins in Pigmented Wheat (Triticum aestivum L. spp. aestivum): An Open Field Evaluation.

Twelve Triticum aestivum L. spp. aestivum varieties with pigmented grain, namely one red, six purple, three blue, and two black, were grown in open fields over two consecutive years and screened to investigate their risk to the accumulation of multiple Fusarium-related mycotoxins. Deoxynivalenol (DON) and its modified forms DON3Glc, 3Ac-DON, 15Ac-DON, and T-2, HT-2, ZEN, and Enniatin B were quantified by means of UHPLC-MS/MS, along with 14 different cyanidin, petunidin, delphinidin, pelargonidin, peonidin, and malvidin glycosides. A significant strong influence effect of the harvesting year (p = 0.0002) was noticed for DON content, which was more than doubled between harvesting years growing seasons (mean of 3746 µg kg-1 vs. 1463 µg kg-1). In addition, a striking influence of varieties with different grain colour on DON content (p < 0.0001) emerged in combination with the harvesting year (year×colour, p = 0.0091), with blue grains being more contaminated (mean of 5352 µg kg-1) and red grain being less contaminated (mean of 715 µg kg-1). The trend was maintained between the two harvesting years despite the highly variable absolute mycotoxin content. Varieties accumulating anthocyanins in the pericarp (purple coloration) had significantly lower DON content compared to those in which aleurone was involved (blue coloration).

Metabolite Profiling and Bioactivities of Leaves, Stems, and Flowers of Rumex usambarensis (Dammer) Dammer, a Traditional African Medicinal Plant.

The comprehensive identification of secondary metabolites represents a fundamental step for the assessment of bioactivities and pharmacological properties of traditional herbal drugs. Rumex usambarensis (Dammer) Dammer has been described as a multipurpose remedy in different African traditional pharmacopoeias, but its phytochemical profile has not been properly investigated. Herein we report a high throughput metabolomic screening, based on ultra-high performance liquid chromatography-travelling wave ion mobility spectrometry quadrupole time-of-flight (UHPLC-TWINS-QTOF), which was performed for the first time on different R. usambarensis plant parts. By applying high-resolution mass spectrometry-based metabolomics and chemometric analysis, a complete discrimination of different aerial parts was obtained, with the annotation of 153 significant metabolites in leaves, stems, and flowers, suggesting an easy authentication and discrimination route. Phytochemical data were correlated to antimicrobial and antioxidant properties. Flavonoids, benzopyranes, chromones, and xanthones derivatives, along with a richer phytocomplex, might be responsible for the stronger bioactivities obtained from flowers.

Implementing the Use of Collision Cross Section Database for Phycotoxin Screening Analysis.

The increased consumption of blue-green algae (BGA)-based dietary supplements has raised concern about their food safety, especially about cyanotoxin presence. The hyphenation of liquid chromatography with ion mobility mass spectrometry represents a relevant tool to screen several compounds in a large variety of food matrices. In this work, ultrahigh-performance liquid chromatography coupled to traveling wave ion mobility spectrometry/quadrupole time-of-flight mass spectrometry (UHPLC-TWIMS-QTOF) was employed to establish the first comprehensive TWIMS-derived collision cross section database (TWCCSN2) for phycotoxins. The database included 20 cyanotoxins and 1 marine toxin. Accurate m/z, retention times, and TWCCSN2 values were obtained for 81 adducts in positive and negative electrospray (ESI+/ESI-) modes. Reproducibility and robustness of the TWCCSN2 measurements were determined to be independent of the matrix. A screening was carried out on 19 commercial BGA dietary supplements of different composition. Cyanotoxins were confidently identified in five samples based on retention time, m/z, and TWCCSN2.

Colonic metabolism of polyphenols from coffee, green tea, and hazelnut skins.

Dietary polyphenolic compounds are poorly absorbed in the small intestine. The absorbed fraction follows the common metabolic pathway of drugs, undergoing phase II enzymatic detoxification with the conjugation of glucuronic acid, sulfate, and methyl groups. However, the unabsorbed fraction can reach the colon, becoming available for the wide array of enzymes produced by the local commensal microbiota. Gut bacteria can hydrolyze glycosides, glucuronides, sulfates, amides, esters, and lactones and are able to break down the polyphenolic skeleton and perform reactions of reduction, decarboxylation, demethylation, and dehydroxylation. These complex modifications generate several low-molecular-weight metabolites that can be efficiently absorbed in situ, subsequently undergoing further phase II metabolism, locally and/or at the liver level, before entering the systemic blood circulation and finally being excreted in urine in substantial quantities that exceed the excretion of phenolic metabolites formed in the upper gastrointestinal tract. This brief work focuses on the phenolic composition and colonic microbial transformation of 2 of the most polyphenol-rich dietary sources, namely, green tea and coffee, and a new interesting and innovative ingredient, hazelnut skin, recently evaluated as one of the richest edible sources of polyphenolic compounds.