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The phenolic composition of virgin olive oil (VOO) primarily depends on the phenolic content of the olive fruit. The purpose of this work was to characterize the first metabolic step in the synthesis of tyrosol (Ty) and hydroxytyrosol (HTy), whose derivatives are by far the predominant phenolics in both olive fruit and VOO. To this end, two genes encoding tyrosine/DOPA decarboxylase enzymes, OeTDC1 and OeTDC2, have been identified and functionally and physiologically characterized. Both olive TDC proteins exclusively accept aromatic amino acids with phenolic side chains, such as tyrosine and 3,4-dihydroxyphenylalanine (DOPA), as substrates to produce tyramine and dopamine, respectively. These proteins exhibited a higher affinity for DOPA than for tyrosine, and the catalytic efficiency of both proteins was greater when DOPA was used as a substrate. Both olive TDC genes showed a fairly similar expression profile during olive fruit ontogeny, with OeTDC1 consistently expressed at higher levels than OeTDC2. Expression was particularly intense during the first few weeks after fruit set, coinciding with the active accumulation of Ty and HTy derivatives. The data suggest that both olive TDCs are responsible for the initial step in the synthesis of the most important phenolics, both quantitatively and functionally, in VOO. [ABSTRACT FROM AUTHOR]

Within the circular economy framework, the valorisation of olive leaves as an effective source of organic compounds rather than an agricultural waste, represents a great opportunity. Olive leaves contain bioactive polyphenols, such as the health‐enhancing catechol hydroxytyrosol (HT), derived primarily from oleuropein. This study establishes a novel and sustainable approach for the extraction of HT from olive leaves, utilizing eco‐friendly deep eutectic solvents derived from natural sources (NADES). By optimizing the extraction process, the study highlights the efficacy of the eutectic mixture cholinium/glycerol (1:2 mol/mol) in achieving HT‐rich extracts from olive leaves (0.12 ± 0.03 g HT/g of dry extract). Indeed, the method demonstrates a remarkable yield of HT, reaching 12.3 ± 0.9 g/kg of leaf powder, under optimized conditions. The antioxidant properties of the extract are thoroughly assessed, suggesting its potential health benefits. Significantly, the study underscores the scalability of the extraction method, showcasing its viability for large‐scale production while maintaining excellent outcomes. Furthermore, the sustainability of the extraction method is boosted by the reuse of NADES across multiple extraction cycles, enhancing resource efficiency and reducing environmental impact. This research unlocks the potential of olive leaves as a valuable source of bioactive compounds and outlines a sustainable extraction approach aligning with the principles of the circular economy. [ABSTRACT FROM AUTHOR]

Simple Summary: Consumption of extra virgin olive oil (EVOO) is associated with many beneficial effects on human health as a result of its phenolic-derived compounds. This review explores the hepatoprotective properties and mechanisms of action of tyrosol and oleocanthal from extra virgin olive oil. Both compounds demonstrate antioxidant, anti-inflammatory, and modulatory effects on liver metabolism that improve chronic liver diseases, such as dysfunction-associated steatotic liver disease (MASLD) and liver fibrosis, and their progression to liver cancer. Mechanistic studies have suggested that these compounds exert their hepatoprotective effects through the regulation of multiple cellular pathways, including those involved in the antioxidant response and lipid metabolism. Understanding these mechanisms may provide valuable information for the development of therapeutic agents based on their chemical structures that are useful to improve liver health and prevent liver-related disorders. The Mediterranean diet and consumption of EVOO are associated with multiple beneficial effects for human health, e.g. reduction in cardiovascular risk and mortality, improvement in the lipid profile, and the prevention of chronic diseases, such as cancers and neurodegenerative diseases. In EVOO, more than 30 different phenolic-derived compounds have been identified, representing one of the most promising bioactive classes in olive oil. This review explores the hepatoprotective properties of two of these compounds, tyrosol and oleocanthal, focusing on their mechanisms of action. Recent studies have shown that these compounds, which share a similar chemical structure with a hydroxyl group attached to an aromatic hydrocarbon ring, can potentially mitigate chronic liver diseases, such as MASLD and liver fibrosis, as well as their progression to liver cancer. Consequently, they deserve attention for future pharmacological drug development. In vitro and in vivo studies have suggested that these compounds exert these effects through the regulation of cellular pathways involved in antioxidant response, lipid metabolism, transcription factor activity, and NF-κB signaling. Understanding the mechanisms underlying the hepatoprotective properties of tyrosol and oleocanthal may provide valuable information for the development of therapeutic agents based on their chemical structures capable of targeting chronic liver diseases. [ABSTRACT FROM AUTHOR]

Tyrosol and hydroxytyrosol are powerful phenolic antioxidants occurring in olive oil and in by-products from olive processing. Due to their high polarity, esterification or other lipophilization is necessary to make them compatible with lipid matrices. Hydroxytyrosol methyl carbonate is a more effective antioxidant than dibutylhydroxytoluene or α-tocopherol and together with tyrosol methyl carbonate exerts interesting pharmacological properties. The purpose of this work was the enzymatic preparation of alkyl carbonates of tyrosol and hydroxytyrosol. A set of 17 hydrolases was tested in the catalysis of tyrosol methoxycarbonylation in neat dimethyl carbonate to find an economically feasible alternative to the recently reported synthesis of methyl carbonates catalyzed by Novozym 435. Novozym 435 was, however, found to be the best performing catalyst, while Novozym 735, pig pancreatic lipase, lipase F-AK and Lipex 100T exhibited limited reactivity. No enzyme accepted 1,2-propylene carbonate as the acylation donor. Under optimized reaction conditions, Novozym 435 was used in the batch preparation of tyrosol methyl carbonate and hydroxytyrosol methyl carbonate in quantitative yields. The enzymatic methoxycarbonylation of tyrosol and hydroxytyrosol can also be used as a method for their selective protection in enzymatic syntheses of phenylethanoid glycosides catalyzed with enzymes comprising high levels of acetyl esterase side activity. [ABSTRACT FROM AUTHOR]

Background: Hydroxytyrosol (HT) is a bioactive compound present in a limited number of foods such as wines, olives, and olive oils. During alcoholic fermentation, yeast converts aromatic amino acids into higher alcohols such as tyrosol, which can undergo hydroxylation into HT. The aim of this study was to validate an analytical method using ultra performance liquid chromatography coupled with mass spectrometry (UPLC/MS‐MS) to quantify HT and its precursors (tyrosine, hydroxyphenylpyruvic acid, hydroxyphenylacetaldehyde, 4‐hydroxyphenylacetic acid, and tyrosol) in wines. Their occurrence was evaluated in a total of 108 commercial Spanish wine samples. Results: The validated method simultaneously determined both HT and its precursors, with adequate limits of detection between 0.065 and 21.86 ng mL−1 and quantification limits between 0.199 and 66.27 ng mL−1 in a 5 min run. The concentration of HT in red wines was significantly higher (0.12–2.24 mg L−1) than in white wines (0.01–1.27 mg L−1). The higher the alcoholic degree, the higher was the content of HT. The bioactive 4‐hydroxyphenylacetic acid was identified in Spanish wines for the first time at 3.90–127.47 mg L−1, being present in all the samples. Conclusion: The highest HT concentrations were found in red wines and in wines with higher ethanol content. These data are useful for a further estimation of the intake of these bioactive compounds and to enlarge knowledge on chemical composition of wines. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Background. Recently, it has been found that tyrosol and farnesol can replace antibiotics due to their known antimicrobial and medicinal effects. Niosomes have been extensively researched for drug delivery during the last few decades, and their efficiency has been proven. The current study aimed to investigate the physical properties and antibacterial effects of niosomes loaded with tyrosol and farnesol. Methods. Nanoniosomes loaded with farnesol and tyrosol were synthesized by the thin-layer hydration method. The physical properties of nanoformulations were measured using dynamic light scattering and scanning electron microscopy (SEM), and the release of farnesol and tyrosol from the nanocarrier was examined using a dialysis bag. In addition, Fourier-transform infrared spectroscopy was used to check the functional groups, and the stability studies of nanoniosomes were performed at temperatures of 25 °C and 4 °C for two months. Finally, its antimicrobial properties against the bacterial pathogens Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa) underwent investigation. The cytotoxicity of free and farnesol- and tyrosol-loaded nanoniosomes on human foreskin fibroblast cells was also evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide method. Results. The size of nanoniosomes and farnesol- and tyrosol-loaded nanoniosomes was estimated to be 208 nm and 240 nm, respectively. SEM results indicated the spherical structure of niosomes. The slow release of farnesol and tyrosol from niosomes was observed, so that almost half of the drug was released from nanoniosomes after 72 hours. Nanoniosomes loaded with the above-mentioned drugs demonstrated good stability at 4 °C for 60 days. The results of the minimum inhibitory and bactericidal concentrations confirmed the antibacterial effects of both free farnesol and tyrosol and nanoniosomes loaded with farnesol and tyrosol against all three bacterial species, although these effects were more considerable for the nanoniosomes formulation. Conclusion. Nanoniosomes loaded with farnesol and tyrosol have the potential to be used in the treatment of some common bacterial wound infections. However, clinical studies are needed in this field. Practical Implications. Farnesol- and tyrosol-loaded nanoniosomes had strong inhibitory effects on S. aureus, E. coli, and P. aeruginosa.

Background and Aims: Quorum sensing is a mechanism of cell-to-cell communication for controlling virulence and the biofilm formation of microorganisms. Due to this new treatment requiring approaches for biofilm-related infections, this study aims to examine the biofilm formation properties of both Candida albicans and non-albicans (NAC) strains and to compare the effects of the quorum-sensing molecules (QSMs) farnesol and tyrosol with the widely used antifungal agent amphotericin B with regard to biofilm attachment and biofilm formation. Methods: Biofilm formation of 57 nonrepeat clinical isolates of Candida spp. (36 C. albicans and 21 NAC) was assessed through the crystal violet technique. Farnesol (300 μM), tyrosol (80 μM), and amphotericin B (4 μg/ml) were evaluated against biofilm attachment and biofilm formation (plates incubated 2, 4, 6 and 24 h). Results: All isolates displayed biofilm-forming capabilities. C. albicans demonstrated mostly weak biofilm formation (42.2%), whereas the NAC species showed strong biofilm formation (52.38%). Depending on the stage at which they were added, farnesol and tyrosol significantly inhibited the biofilm formation of C. albicans and NAC species, especially at 6 h, which is the early stage of biofilm development. Unfortunately, QSM activity decreased at 24 h. In addition, amphotericin B showed a stronger inhibitory effect than the QSMs at all time points studied, with up to 60% inhibition being observed. Conclusion: QSMs can significantly inhibit biofilm development in both C. albicans and NAC species depending on the stage when they are added, especially in the early stages of biofilm formation. [ABSTRACT FROM AUTHOR]

Tyrosol is a principle phenolic compound present in olive oil and wine with great pharmacological potentials due to its strong antioxidant property. Its application can be highly extended by increasing its lipophilicity through esterification. In this study, tyrosol esters were synthesized by enzymatic transesterification of tyrosol with vinyl esters, with a commercial lipase from Novozymes (Novozym 435, Candida antarctica lipase B (CALB) immobilized on macroporous acrylic resin beads) as the catalyst, both in organic solvents and in ionic liquids. Methyl tert-butyl ether (MTBE) was the best solvent, offering complete conversions towards the synthesis of tyrosol esters with varying chain lengths (C2-C18) within 1 h. Taking the enzymatic transesterification between tyrosol and vinyl acetate as the model reaction, 18 organic solvents and 24 ionic liquids were screened, and their solvent properties (i.e. hydrophobicity, polarity, viscosity, water activity, and partition coefficients of substrate and product) were correlated to the enzyme activity. Upon enzyme screening, four new lipases were found to be highly efficient, relative to the best-performed Novozym 435 and Lipozyme TLIM (Thermomyces lanuginosus lipase (TLL) immobilized on silica gel), in tyrosol ester synthesis. This work provides enzymatic methods of esterifying tyrosol that are much more efficient than those reported in literature, and will shed light on re-consideration of the roles of solvents in nonaqueous enzymology. [ABSTRACT FROM AUTHOR]

Utilizing Density Functional Theory (DFT) calculations at the B3LYP/QZVP level and incorporating the Conductor-like Polarizable Continuum Model (C-PCM) for solvation, the thermodynamic and chemical activity properties of 21-(hydroxymethoxy)henicosadecaenal, identified in cultured freshwater pearls from the mollusk Hyriopsis cumingii, have been elucidated. The study demonstrates that this compound releases formaldehyde, a potent antimicrobial agent, through dehydrogenation and deprotonation processes in both hydrophilic and lipophilic environments. Moreover, this polyenal exhibits strong anti-reductant properties, effectively scavenging free radicals. These critical properties classify the pearl-derived ingredient as a natural multi-functional compound, serving as a coloring, antiradical, and antimicrobial agent. The 2-(hydroxymethoxy)vinyl (HMV) moiety responsible for the formaldehyde release can be transferred to other compounds, thereby enhancing their biological activity. For instance, tyrosol (4-(2-hydroxyethyl)phenol) can be modified by substituting the less active 2-hydroxyethyl group with the active HMV one, and hinokitiol (4-isopropylotropolone) can be functionalized by attaching this moiety to the tropolone ring. A new type of meso-carrier, structurally modeled on pearls, with active substances loaded both in the layers and the mineral part, has been proposed. [ABSTRACT FROM AUTHOR]

The water-soluble part of the EtOH extract of Rhodiola rosea L. [Sedum roseum (L.) Scop., Crassulaceae] contained 15 compounds including six new glycosides 1–6. UV and NMR spectroscopic and mass spectrometric data and chemical transformations determined the structures of the new compounds as hydroquinone 1-O-(6′-O-α-L-arabinopyranosyl)-β-D-glucopyranoside (rhodirosin I, 1), hydroquinone 1-O-(6′-O-α-Larabinofuranosyl)-β-D-glucopyranoside (rhodirosin J, 2), tyrosol 1-O-(6′-O-α-L-arabinofuranosyl)-β-Dglucopyranoside (rhodirosin K, 3), tyrosol 1-O-(2′-O-acetyl)-β-D-glucopyranoside (rhodirosin L, 4), tyrosol 1-O-(2′,6′-di-O-acetyl)-β-D-glucopyranoside (rhodirosin M, 5), and rosiridol 1-O-(2′,6′-di-O-acetyl)-β-D-glucopyranoside (rhodirosin N, 6). [ABSTRACT FROM AUTHOR]

Introduction: In recent years, research has focused on identifying and studying natural bioactive compounds that may have potential implications in the prevention and treatment of cardiovascular diseases. Phenolic ingredients such as Tyrosol and hydroxytyrosol, found in olive oil, attract particular attention due to their potential cardioprotective properties. The aim of this study is to provide a comprehensive research review of the current knowledge of the cardioprotective effects of tyrosol and hydroxytyrosol, highlighting their potential health benefits and identifying research gaps for future research. Aim: The aim of this study is to investigate the cardioprotective effect of phenolic compounds found in olive oil, such as tyrosol and hydroxytyrosol, which is an important health care problem due to the prevalence of deaths caused by cardiovascular diseases. The aim of the study is to understand the effectiveness of natural ingredients in the prevention and treatment of cardiovascular diseases and to learn the specific effects of these compounds, which may contribute to the development of new therapeutic and preventive strategies and improve the quality of life of patients. Review methods: A non-systematic review of the scientific literature was carried out according to the following keywords: Tyrosol, hydroxytyrosol, cardioprotection, cardiovascular diseases, olive oil cardioprotective role, geriatric patients, elderly people. PubMed was searched and 34 sources published up to 2023 were analysed. It was done to ensure that the knowledge contained in this article includes the most up-to-date information. Abbreviated description of the state of knowledge: Tyrosol and hydroxytyrosol, prominent in olive oil, are studied for their potential cardioprotective properties. Linked to a Mediterranean diet, these compounds show promise in reducing cardiovascular disease risk. They counter oxidative stress, improve lipid profiles, and modulate inflammatory processes. Clinical studies suggest their positive impact, with tyrosol also explored as a potential anticoagulant. Ongoing research aims to uncover optimal doses and mechanisms, highlighting their significance in cardiovascular health. Conclusions: Tyrosol and hydroxytyrosol, found in olive oil, show promise in cardioprotection by combating oxidative stress, improving lipid profiles, and modulating inflammation. Clinical studies suggest their positive impact on cardiovascular health. Tyrosol has potential as a anticoagulant and exhibits antioxidant effects. These compounds present a compelling avenue for future therapeutic interventions, with emphasis on understanding mechanisms and optimizing supplementation. [ABSTRACT FROM AUTHOR]

Bioactive compounds that can be recovered by the solid wastes of the olive oil sector, such as polyphenols, are known for their significant antioxidant and antimicrobial activities with potential application in nutraceutical, cosmetic, and food industries. Given that industrial demands are growing, and the polyphenol market value is ever increasing, a systematic study on the recovery of natural antioxidant compounds from olive pomace using ultrasound-assisted extraction (UAE) was conducted. Single-factor parameters, i.e., the extraction solvent, time, and solid-to-liquid ratio, were investigated evaluating the total phenolic content (TPC) recovery and the antioxidant activity of the final extract. The acetone–water system (50% v/v, 20 min, 1:20 g mL−1) exhibited the highest total phenolic content recovery (168.8 ± 5.5 mg GAE per g of dry extract). The olive pomace extract (OPE) was further assessed for its antioxidant and antibacterial activities. In DPPH, ABTS, and CUPRAC, OPE exhibited an antioxidant capacity of 413.6 ± 1.9, 162.72 ± 3.36 and 384.9 ± 7.86 mg TE per g of dry extract, respectively. The antibacterial study showed that OPE attained a minimum inhibitory activity (MIC) of 2.5 mg mL−1 against E. coli and 10 mg mL−1 against B. subtilis. Hydroxytyrosol and tyrosol were identified as the major phenolic compounds of OPE. Furthermore, active chitosan–polyvinyl alcohol (CHT/PVA) films were prepared using different OPE loadings (0.01–0.1%, w/v). OPE-enriched films showed a dose-dependent antiradical scavenging activity reaching 85.7 ± 4.6% (ABTS) and inhibition growth up to 81% against B. subtilis compared to the control film. Increased UV light barrier ability was also observed for the films containing OPE. These results indicate that OPE is a valuable source of phenolic compounds with promising biological activities that can be exploited for developing multifunctional food packaging materials. [ABSTRACT FROM AUTHOR]

An eco-friendly approach towards the recovery of value-added extracts from olive tree leaves with the aid of supercritical CO2 at 30 MPa was carried out. The impact of extraction temperature (35–90 °C) and presence of co-solvents (ethanol, water, and aqueous ethanol) on the total phenolic, flavonoid, and pigment content, as well as oleuropein, hydroxytyrosol, tyrosol, and α-tocopherol content was determined. In addition, the antioxidant activity of extracts from tree leaves using DPPH, ABTS, and CUPRAC assays was investigated. The results of the study showed that the most effective supercritical CO2 extraction was at 90 °C with an addition of ethanol, which enabled the separation of extract with the highest content of tested compounds. Some of the highest recorded values were for oleuropein 1.9 mg/g, for carotenoids 5.3 mg/g, and for α-tocopherol 2.0 mg/g. Our results are expected to contribute to the efforts towards the valorization of olive leaves as a sustainable source of valuable compounds, and boost local economies as well as the interest of pharmaceutical, food, and cosmetic industries for novel food by-product applications. [ABSTRACT FROM AUTHOR]

Alien invasive species harbor specific endophytes that are not only rich resources of eco-friendly bioactive secondary metabolites but also might help explain their invasion success. In this study, 5 mycotoxins, i.e., tyrosol (1), sterigmatocystin (2), 1-hydroxy-3-methylxanthone (3), carpesterol (4), and mellein (5), were isolated from the endophytic fungus Dematiopleospora sp. of the invasive plant Xanthium spinosum. In general, all isolated compounds exhibited significant promotive activity on 4 receiver species in a dose-dependent manner when applied concentrations ranged between 5 ~ 100 µg/mL, whereas suppressive effect occurred when applied concentration reached 500 µg/mL. Among the tested species, Medicago sativa was the most sensitive plant, whose root length was twofold of the control when treated by 5 at 5 µg/mL, and promoted by 93.20% by 4 at 5 µg/mL, indicating that 5 possessed the most potent stimulatory activity; 1 and 2 showed similar moderate activity, whereas 3 and 4 exhibited equivalent potent activity. Further study revealed that 2 affected the phytohormone levels as well as the anti-oxidant system of M. sativa seedlings, including reducing the content of IAA, ABA, and MDA but increasing the content of CTK and the activities of SOD, POD, and CAT. Our work is the first report on the growth regulatory activity of 3 and 4, as well as elucidation on the mechanism of 2. [ABSTRACT FROM AUTHOR]

Background. Recently, it has been found that tyrosol and farnesol can replace antibiotics due to their known antimicrobial and medicinal effects. Niosomes have been extensively researched for drug delivery during the last few decades, and their efficiency has been proven. The current study aimed to investigate the physical properties and antibacterial effects of niosomes loaded with tyrosol and farnesol. Methods. Nanoniosomes loaded with farnesol and tyrosol were synthesized by the thinlayer hydration method. The physical properties of nanoformulations were measured using dynamic light scattering and scanning electron microscopy (SEM), and the release of farnesol and tyrosol from the nanocarrier was examined using a dialysis bag. In addition, Fourier-transform infrared spectroscopy was used to check the functional groups, and the stability studies of nanoniosomes were performed at temperatures of 25 °C and 4 °C for two months. Finally, its antimicrobial properties against the bacterial pathogens Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa) underwent investigation. The cytotoxicity of free and farnesoland tyrosol-loaded nanoniosomes on human foreskin fibroblast cells was also evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide method. Results. The size of nanoniosomes and farnesol- and tyrosol-loaded nanoniosomes was estimated to be 208 nm and 240 nm, respectively. SEM results indicated the spherical structure of niosomes. The slow release of farnesol and tyrosol from niosomes was observed, so that almost half of the drug was released from nanoniosomes after 72 hours. Nanoniosomes loaded with the above-mentioned drugs demonstrated good stability at 4 °C for 60 days. The results of the minimum inhibitory and bactericidal concentrations confirmed the antibacterial effects of both free farnesol and tyrosol and nanoniosomes loaded with farnesol and tyrosol against all three bacterial species, although these effects were more considerable for the nanoniosomes formulation. Conclusion. Nanoniosomes loaded with farnesol and tyrosol have the potential to be used in the treatment of some common bacterial wound infections. However, clinical studies are needed in this field. Practical Implications. Farnesol- and tyrosol-loaded nanoniosomes had strong inhibitory effects on S. aureus, E. coli, and P. aeruginosa. [ABSTRACT FROM AUTHOR]

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Olive anthracnose, caused by Colletotrichum fungi, and the olive fruit fly Bactrocera olea are, respectively, the most important fungal disease and pest affecting olive fruits worldwide, leading to detrimental effects on the yield and quality of fruits and olive oil. This study focuses on the content of hydroxytyrosol (HYT) and its derivatives (the "olive oil polyphenols" health claim) in olive oils extracted from fruits of 'Galega Vulgar' and 'Cobrançosa' cultivars, naturally affected by olive anthracnose and olive fly. The olives, with different damage levels, were harvested from organic rainfed orchards, located in the center of Portugal, at four harvest times over three years. Galega oils extracted from olives with a higher anthracnose and olive fly incidence showed no conformity for the extra virgin olive oil (EVOO) and virgin olive oil (VOO) categories, presenting high acidity and negative sensory notes accompanied by the disappearance of oleacein. Conversely, no sensory defects were observed in Cobrançosa oils, regardless of disease and pest incidence levels, and quality criteria were still in accordance with the EVOO category. The total HYT and tyrosol (TYR) content (>5 mg/20 g) allows for the use of the "olive oil polyphenols" health claim on the label of all the analyzed Cobrançosa olive oils. [ABSTRACT FROM AUTHOR]

Acer tegmentosum Maxim (AT) is a medicinal plant used to treat hepatic, neurological diseases, and cancer. However, the beneficial effects of AT on endothelial dysfunction have not been reported yet. In this study, we evaluated the effects of AT and the main compounds against TNF-α-mediated inflammatory responses and their possible mechanism of action. The anti-inflammatory effect and its molecular mechanism were analyzed by adhesion assay, immunoblotting, promoter-luciferase assay, ELISA, RT-PCR, immunocytochemistry, immunoprecipitation, siRNA gene knockdown, docking, and molecular dynamics simulation. AT and its compounds salidroside and tyrosol reduced TNF-α-induced adhesion between monocytes and endothelial cells. Fermentation of AT with Bacillus subtilis converted salidroside to tyrosol, which is salidroside’s aglycone. The fermented AT product (ATF) potently inhibited TNF-α-mediated monocyte adhesion with higher potency than AT. AT or ATF abrogated TNF-α-induced expression of adhesion molecules (VCAM-1 and ICAM-1) and production of MCP-1 with the inhibition of phosphorylated MAP kinases. TNF-α-mediated NF-κB transactivation and RelA/p65 acetylation were suppressed by AT and ATF through the interaction of NF-κB with sirtuin-1 (SIRT1), an NAD+-dependent histone deacetylase. Sirt1 gene knockdown diminished the protective effects of AT and ATF against TNF-α-mediated signaling and inflammatory response. Interestingly, SIRT1 protein expression was significantly increased by ATF and tyrosol rather than by AT and salidroside, respectively. Molecular docking showed that the tyrosol moiety is critical for the interaction with Glu230 of SIRT1 (PDB ID: 4ZZH and 4ZZJ) for the deacetylase activity. Molecular dynamics revealed that tyrosol can induce the movement of the N-terminal domain toward the catalytic domain of SIRT1. This study demonstrates the potential of AT and ATF to prevent endothelial inflammation and vascular dysfunction of the retina by the MAPK/NF-κB/SIRT1 signaling pathways and targeting of the tyrosol moiety to Glu230 in SIRT1.

Ovarian cancer is a widespread type of cancer among gynecologic cancers and has a very high mortality rate. For this reason, the search for new treatments continues. Tyrosol is a phenolic compound with antioxidant and anti–inflammatory activity. The study, it was investigated the effect of Tyrosol on oxidative stress and inflammatory parameters in cisplatin–induced ovarian inflammation and oxidative stress in rats. For this purpose, twenty–four female Wistar albino rats were divided into four groups: control, Cisplatin, Tyrosol, and Cisplatin+Tyrosol. Cisplatin was administered intraperitoneally at 6 mg·kg-1 twice, once a week. Tyrosol (20 mg·kg-1) was administered daily by oral gavage for fourteen d. Oxidative stress and inflammatory biomarkers were measured in ovarian tissue. Cisplatin administration increased Malondialdehyde (MDA), tumor necrosis factor alpha (TNF–α), interleukin 6 (IL–6), and interleukin 1 beta (IL–1β) levels in the ovaries, while Glutathione (GSH), Glutathione Peroxidase (GSH–Px), and Catalase levels were decreased. Tyrosol administration was shown to decrease oxidative stress parameters and inflammatory cytokines. In conclusion, it can be say that the protective activity of Tyrosol against Cisplatin–Induced ovarian inflammation and oxidative stress is realised through antioxidant and anti–inflammatory mechanisms.

Abstract Background Ulcerative colitisis (UC) classified as a form of inflammatory bowel diseases (IBD) characterized by chronic, nonspecific, and recurrent symptoms with a poor prognosis. Common clinical manifestations of UC include diarrhea, fecal bleeding, and abdominal pain. Even though anti-inflammatory drugs can help alleviate symptoms of IBD, their long-term use is limited due to potential side effects. Therefore, alternative approaches for the treatment and prevention of inflammation in UC are crucial. Methods This study investigated the synergistic mechanism of Lactobacillus plantarum SC-5 (SC-5) and tyrosol (TY) combination (TS) in murine colitis, specifically exploring their regulatory activity on the dextran sulfate sodium (DSS)-induced inflammatory pathways (NF-κB and MAPK) and key molecular targets (tight junction protein). The effectiveness of 1 week of treatment with SC-5, TY, or TS was evaluated in a DSS-induced colitis mice model by assessing colitis morbidity and colonic mucosal injury (n = 9). To validate these findings, fecal microbiota transplantation (FMT) was performed by inoculating DSS-treated mice with the microbiota of TS-administered mice (n = 9). Results The results demonstrated that all three treatments effectively reduced colitis morbidity and protected against DSS-induced UC. The combination treatment, TS, exhibited inhibitory effects on the DSS-induced activation of mitogen-activated protein kinase (MAPK) and negatively regulated NF-κB. Furthermore, TS maintained the integrity of the tight junction (TJ) structure by regulating the expression of zona-occludin-1 (ZO-1), Occludin, and Claudin-3 (p

BackgroundAromatic compounds derived from tyrosine are important and diverse chemicals that have industrial and commercial applications. Although these aromatic compounds can be obtained by extraction from natural producers, their growth is slow, and their content is low. To overcome these problems, many of them have been chemically synthesized from petroleum-based feedstocks. However, because of the environmental burden and depleting availability of feedstock, microbial cell factories are attracting much attention as sustainable and environmentally friendly processes.ResultsTo facilitate development of microbial cell factories for producing tyrosine derivatives, we developed simple and convenient tyrosine-producing Escherichia coli platforms with a bacterial phenylalanine hydroxylase, which converted phenylalanine to tyrosine with tetrahydromonapterin as a cofactor, using a synthetic biology approach. By introducing a tetrahydrobiopterin-regeneration system, the tyrosine titer of the plasmid-based engineered strain was 4.63 g/L in a medium supplemented with 5.00 g/L phenylalanine with a test tube. The strains were successfully used to produce industrially attractive compounds, such as tyrosol with a yield of 1.58 g/L by installing a tyrosol-producing module consisting of genes encoding tyrosine decarboxylase and tyramine oxidase on a plasmid. Gene integration into E. coli chromosomes has an advantage over the use of plasmids because it increases genetic stability without antibiotic feeding to the culture media and enables more flexible pathway engineering by accepting more plasmids with artificial pathway genes. Therefore, we constructed a plasmid-free tyrosine-producing platform by integrating five modules, comprising genes encoding the phenylalanine hydroxylase and tetrahydrobiopterin-regeneration system, into the chromosome. The platform strain could produce 1.04 g/L of 3,4-dihydroxyphenylalanine, a drug medicine, by installing a gene encoding tyrosine hydroxylase and the tetrahydrobiopterin-regeneration system on a plasmid. Moreover, by installing the tyrosol-producing module, tyrosol was produced with a yield of 1.28 g/L.ConclusionsWe developed novel E. coli platforms for producing tyrosine from phenylalanine at multi-gram-per-liter levels in test-tube cultivation. The platforms allowed development and evaluation of microbial cell factories installing various designed tyrosine-derivative biosynthetic pathways at multi-grams-per-liter levels in test tubes.

Platelet activating factor (PAF) is a potent lipid mediator involved in inflammation, among other pathophysiological conditions. Bioactive compounds from foods have been suggested to suppress inflammation as well as regulate PAF biosynthesis. Phenolics, such as resveratrol and tyrosol, and their acetylated derivatives, inhibited PAF biosynthetic enzymes' activity, namely acetyl-coenzyme A: lyso–platelet-activating factor acetyltransferases (lysoPAF-AT), and 1-alkyl-2-acetyl-sn-glycerol cholinephosphotransferase (PAF-CPT) under inflammatory stimuli. This study investigates whether resveratrol and tyrosol lipophilic derivatives are capable of affecting the activity of the two isoforms of lysoPAF-AT along with the activity of PAF-CPT compared with the initial compounds under basal conditions. The derivatives were chemically synthesized and the experiments were conducted either with or without pre-incubation of homogenized U-937 cells and the phenolics and the enzyme activities were determined. Pre-incubation experiments resulted in lower half inhibitory concentration (IC50) than those without pre-incubation, reaching a 5-fold difference between them. Moreover, there were differences among parent compounds and their derivatives, suggesting a dependence on the differently substituted groups of the phenolics. PAF-CPT tends to be less phenolic structure dependent than lysoPAF-ATC, whereas the other isoform, lysoPAF-ATE, was less sensitive in general. Resveratrol and its derivatives were more potent than the tyrosolic compounds, regardless of the enzyme test or the conditions of the experiment. The use of phenolic lipophilic derivatives in pharmaceuticals and in food preparation may overcome the limitations of natural phenolics with regard to their weak solubility and stability in a lipophilic environment. [ABSTRACT FROM AUTHOR]

Although tyrosol is a quorum-sensing molecule of Candida species, it has antifungal activity at supraphysiological concentrations. Here, we studied the effect of tyrosol on the physiology and genome-wide transcription of Aspergillus nidulans to gain insight into the background of the antifungal activity of this compound. Tyrosol efficiently reduced germination of conidia and the growth on various carbon sources at a concentration of 35 mM. The growth inhibition was fungistatic rather than fungicide on glucose and was accompanied with downregulation of 2199 genes related to e.g. mitotic cell cycle, glycolysis, nitrate and sulphate assimilation, chitin biosynthesis, and upregulation of 2250 genes involved in e.g. lipid catabolism, amino acid degradation and lactose utilization. Tyrosol treatment also upregulated genes encoding glutathione-S-transferases (GSTs), increased specific GST activities and the glutathione (GSH) content of the cells, suggesting that A. nidulans can detoxify tyrosol in a GSH-dependent manner even though this process was weak. Tyrosol did not induce oxidative stress in this species, but upregulated "response to nutrient levels", "regulation of nitrogen utilization", "carbon catabolite activation of transcription" and "autophagy" genes. Tyrosol may have disturbed the regulation and orchestration of cellular metabolism, leading to impaired use of nutrients, which resulted in growth reduction. • Tyrosol had strong growth inhibitory effect against Aspergillus nidulans. • Tyrosol upregulated glutathione dependent detoxification processes. • Tyrosol treatment did not cause oxidative stress but upregulated autophagy genes. • According to RNAseq data tyrosol disturbed nutrient sensing and utilization. [ABSTRACT FROM AUTHOR]

Hydroxytyrosol (HT) is a well-known compound for its bioactive properties. It is naturally present in olives, olive oil, and wine. Its presence in wines is partly due to its production during alcoholic fermentation by yeast through a hydroxylation of tyrosol formed through the Ehrlich pathway. This work aims to explore the influence of yeast assimilable nitrogen (YAN) and glucose content as precursors of HT formation during alcoholic fermentation. Commercial Saccharomyces cerevisiae QA23 and its metabolically engineered strain were used to ferment synthetic must. Each strain was tested at two different YAN concentrations (210 and 300 mg L−1) and two glucose concentrations (100 and 240 g L−1). This work confirms that the less YAN and the more glucose, the higher the HT content, with fermentations carried out with the metabolically engineered strain being the ones with the highest HT content (0.6 mg L−1). [ABSTRACT FROM AUTHOR]

Objective: Salidroside is an important plant-derived aromatic compound with diverse biological properties. The main objective of this study was to synthesize salidroside from tyrosol using UDP-glucosyltransferase (UGT) with in situ regeneration of UDP-glucose (UDPG). Results: The UDP-glucosyltransferase 85A1 (UGT85A1) from Arabidopsis thaliana, which showed high activity and regioselectivity towards tyrosol, was selected for the production of salidroside. Then, an in vitro cascade reaction for in situ regeneration of UDPG was constructed by coupling UGT85A1 to sucrose synthase from Glycine max (GmSuSy). The optimal UGT85A1-GmSuSy activity ratio of 1:2 was determined to balance the efficiency of salidroside production and UDP-glucose regeneration. Different cascade reaction conditions for salidroside production were also determined. Under the optimized condition, salidroside was produced at a titer of 6.0 g/L with a corresponding molar conversion of 99.6% and a specific productivity of 199.1 mg/L/h in a continuous feeding reactor. Conclusion: This is the highest salidroside titer ever reported so far using biocatalytic approach. [ABSTRACT FROM AUTHOR]

We studied the efficacy of different formulations of polyphenol extracts (mainly containing hydroxytyrosol and tyrosol) from olive mill vegetation water on the microflora on the surfaces of game meat cuts with high or low initial bacterial loads. Meat with a high microbial load (>5 Log cfu/g; mean value = 6.83 ± 0.45 standard deviation) was immersed for 10 or 60 sec into 25% and 10% solutions of microencapsulated freeze-dried and non-encapsulated polyphenolic extracts. Aerobic colony, Enterobacteriaceae, Pseudomonas spp., and lactic acid bacteria counts were determined on treated samples compared to controls after 7 days of storage (in vacuum-packed conditions at +3 °C). Significant differences were registered only for aerobic colony count for a 10% liquid extract treatment (0.64 log reduction). In contrast, the dipping or immersion of game meat with low initial microbial loads (<5 Log cfu/g; mean value = 3.58 ± 0.72 standard deviation) in 10% solutions of the polyphenol extracts effectuated significant reductions in all bacteria counts (p < 0.002) at 7 and 14 days of storage for different extracts, independently from the application methods. The use of the extracts to inhibit bacterial growth in game meat should only be considered if a good hygienic baseline is guaranteed. [ABSTRACT FROM AUTHOR]

The utmost aim of this study is the determination of the optimum ratio and the amount of almond gum (AL), sodium alginate (SA), and sodium caseinate (SC) in the formulation of tyrosol-nanoparticles. Indeed, the increase in the ratio of AL enhanced the encapsulation efficiency and significantly reduced the mean particle diameter (dp) of tyrosol-nanoparticles. Moreover, increasing the ratio of SC at an amount of 2.0% improved the polydispersity index of tyrosol nanodispersions. Besides, the high proportions of AL at the amount of 2.0% and SC at the amount of 1.0% enhanced the antioxidant activities of tyrosol nanoparticles. Hence, the statistical results showed that the mixture of 51.20% AL and 48.80% SC at the amount of 2.0% was proven to be the optimum condition which was confirmed in practice. Under these conditions, the experimental values of encapsulation efficiency, mean dp, polydispersity index, and antioxidant activity (IC50) were: 98.10%, 91.57 nm, 0.18, and 87.90 µM, respectively. Their molecular interaction was also confirmed by FTIR and thermal analysis which proved the encapsulation of tyrosol in an amorphous form. [ABSTRACT FROM AUTHOR]

The Mediterranean diet and consumption of EVOO are associated with multiple beneficial effects for human health, e.g. reduction in cardiovascular risk and mortality, improvement in the lipid profile, and the prevention of chronic diseases, such as cancers and neurodegenerative diseases. In EVOO, more than 30 different phenolic-derived compounds have been identified, representing one of the most promising bioactive classes in olive oil. This review explores the hepatoprotective properties of two of these compounds, tyrosol and oleocanthal, focusing on their mechanisms of action. Recent studies have shown that these compounds, which share a similar chemical structure with a hydroxyl group attached to an aromatic hydrocarbon ring, can potentially mitigate chronic liver diseases, such as MASLD and liver fibrosis, as well as their progression to liver cancer. Consequently, they deserve attention for future pharmacological drug development. In vitro and in vivo studies have suggested that these compounds exert these effects through the regulation of cellular pathways involved in antioxidant response, lipid metabolism, transcription factor activity, and NF-κB signaling. Understanding the mechanisms underlying the hepatoprotective properties of tyrosol and oleocanthal may provide valuable information for the development of therapeutic agents based on their chemical structures capable of targeting chronic liver diseases.

Tyrosol (4-hydroxyphenylethanol) is a phenolic compound used in the pharmaceutical and chemical industries. However, current supply methods, such as extraction from natural resources and chemical synthesis, have disadvantages from the viewpoint of cost and environmental protection. Here, we developed a tyrosol-producing Escherichia coli cell factory from a high-tyrosine-producing strain by expressing selected tyrosine decarboxylase-, tyramine oxidase (TYO)-, and medium-chain dehydrogenase/reductase (YahK)-encoding genes. The genes were controlled by the strong T7 promoter and integrated into the chromosome because of the advantages over plasmid-based systems. The strain produced a melanin-like pigment as a by-product, which is suggested to be formed from 4-hydroxyphenylacetaldehyde (a TYO product/YahK substrate). By using a culture medium containing a high concentration of glycerol, which was reported to enhance NADH supply required for YahK activity, the final titer of tyrosol reached 2.42 g/L in test tube-scale cultivation with a concomitant decrease in the amount of pigment. These results indicate that chromosomally integrated and T7 promoter-controlled gene expression system in E. coli is useful for high production of heterologous enzymes and might be applied for industrial production of useful compounds including tyrosine and tyrosol. [Display omitted] [ABSTRACT FROM AUTHOR]

Yeasts are feasible and effective bioreactors and, therefore, there is a great interest in their industrial employment for the production of a wide range of molecules. In this study, the production by Saccharomyces cerevisiae of bioactive compounds such as hydroxytyrosol (HT), tyrosol (TYR) and melatonin (MEL) vs. volatile compounds in fermented must was studied. The concentration of the bioactive compounds HT and MEL in fermented must employing different yeast strains revealed that the higher the concentrations, the lower the amount of volatile compounds determined. This inverse correlation was especially remarkable with respect to the production of higher alcohols, especially 2-phenylethanol (2-PE) and esters. Furthermore, the employment of a modified Aro4pK229LS. cerevisiae QA23 yeast strain which overproduces HT, gave rise to fermented must also higher in 2-PE and their corresponding esters but with an outstanding less presence of other important esters such as ethyl hexanoate and ethyl octanoate. Both premises could point out that S. cerevisiae might have different approaches to handling cell stress/toxicity due to their nitrogen metabolism. One detoxifying pathway could be through the production of higher alcohols and these in turn to esters and the other be more related to synthesizing antioxidant molecules such as MEL and HT. [ABSTRACT FROM AUTHOR]

In this work, pilot-scale nanofiltration was used to obtain aqueous solutions rich in hydroxytyrosol and tyrosol from olive oil by-products. A large-scale simple process involving olive mill standard machinery (blender and decanter) was used for the olive pomace pre-treatment with water. The aqueous extract was then directly fed to a nanofiltration unit and concentrated by reverse osmosis. Final concentration factors ranged between 7 and 9 for hydroxytyrosol and between 4 and 7 for tyrosol. The final aqueous solution, obtained as retentate stream of reverse osmosis, was highly concentrated in hydroxytyrosol and tyrosol and their concentrations remained stable over at least 14 months. [ABSTRACT FROM AUTHOR]

Although diclofenac (DCF) is a nonsteroidal anti‐inflammatory drug that is considered safe, its chronic use and overdose may show some toxic effects. The protective effect of tyrosol (Tyr) pretreatment against DCF‐induced renal damage was investigated in this study. The 32 rats used in the study were randomly divided into four groups of eight rats each. According to the data obtained, it was determined that creatinine, urea, and blood urea nitrogen (BUN) levels increased in serum samples of the DCF group. Besides, the levels of reduced glutathione (GSH) and glutathione peroxidase (GPx) activity decreased and the malondialdehyde (MDA) level increased in the kidney tissue. However, no change was observed in catalase (CAT) activity. Cyclooxygenase‐2 (COX‐2), nuclear factor kappa B (NF‐κB), and tumor necrosis factor‐alpha (Tnf‐α) levels increased and nuclear factor erythroid 2‐related factor 2 (Nrf‐2) levels decreased. No change was detected in the level of interleukin 1 beta (IL‐1β). When the DCF+Tyr group and the DCF group were compared, it was assessed that Tyr had a curative effect on all biochemical parameters. Also, kidney damages, such as degeneration and necrosis of tubular epithelium and congestion of veins, were obviated by treatment with tyrosol in histopathological examinations. It was determined that Tyr pretreatment provided a protective effect against nephrotoxicity induced by DCF with its anti‐inflammatory and antioxidant properties. [ABSTRACT FROM AUTHOR]

Aging is an important risk factor for cardiovascular diseases and convincing data have shown that chronic low-grade inflammation, which develops with advanced age, contributes significantly to cardiovascular risk. The present study aimed to use 18F-FDG/18F-NaF-PET/CT imaging to, respectively, gauge arterial inflammation and microcalcification in a healthy elderly population and to assess the potential benefits of a tyrosol- and hydroxytyrosol-rich diet on these two markers of atherosclerotic plaque fragility. Eleven healthy participants (mean age 75 ± 5.67 years) were supplemented for 6 months with high polyphenol-rich extra virgin olive oil (HP-EVOO), extra virgin olive oil (EVOO), or refined olive oil (ROO). The participants underwent PET/CT imaging with 18F-FDG and 18F-NaF radiotracers at baseline and after 6 months. 18F-FDG and 18F-NaF uptakes were quantified using standardized uptake values (SUV) and were categorized based on artery calcification and olive oil type. A total of 324 slices of the aortas of the imaged participants were analyzed for arterial inflammation and 327 slices were analyzed for microcalcification. 18F-FDG uptake was significantly higher in the non-calcified segments than in the calcified segments (SUVmax = 2.70 ± 0.62 and SUVmax = 2.54 ± 0.44, respectively, p < 0.042). Conversely, the non-calcified segments displayed significantly lower 18F-NaF uptake than the calcified segments (SUVmax = 1.90 ± 0.37 and 2.09 ± 0.24, respectively, p < 0.0001). The 6-month supplementation with HP-EVOO induced a significant reduction in 18F-FDG uptake in both the non-calcified (2.93 ± 0.23 to 2.75 ± 0.38, p < 0.004) and calcified segments of the aortas (2.25 ± 0.29 to 2.15 ± 0.19, p < 0.02). 18F-NaF uptake was also significantly lower in patients supplemented with HP-EVOO (SUVmax = 1.98 ± 0.33 at baseline compared to 1.85 ± 0.28, after the 6-month supplementation, p < 0.004), whereas no significant effect was observed with EVOO. Conversely, participants supplemented with ROO displayed a significant increase in 18F-NaF uptake (SUVmax = 1.78 ± 0.34 to 1.95 ± 0.34, p < 0.0001). The present study confirmed that a phenolic-compound-rich diet reduces both arterial inflammation and atherosclerotic lesion microcalcification and demonstrated that 18F-FDG/18F-NaF-PET/CT imaging is a valuable approach for assessing age-related arterial damage. [ABSTRACT FROM AUTHOR]

The consumption of fermented foods has become an important dietary strategy to improve human health, and today, they account for a significant share in the international food market, with special emphasis on traditional or ethnic foods. Among fermented foods, table olives have a key position in the dietary preference of consumers around the Mediterranean basin and beyond. Greece has a long tradition in the production of table olives according to local craft-based processing methods. However, an extensive effort has been undertaken in the last decade to modernize the table olive industry and adopt scientifically based processing methods to produce the final products of high quality and consistency. During processing, the majority of components present in raw olives are transformed to render the product edible. Among these components, phenolic compounds have significant functional properties that may enhance the nutritional value of the final product. This review paper provides an up-to-date overview regarding the transformation of phenolic compounds during processing of the most economically important varieties of Greek table olives, including Halkidiki green olives, Kalamata and Conservolea natural black olives, and Thassos natural black dry-salted olives. The functional and antioxidant potential of Greek table olive varieties as well as their nutritional implications are also discussed. [ABSTRACT FROM AUTHOR]

Tyrosol robinobioside was prepared under catalysis of robinobiosidase-containing seed meal from common buckthorn Rhamnus cathartica. Robinin, a flavonoid isolated from the flowers of black locust (Robinia pseudoacacia) served as a robinobiosyl donor. The glycosylation proceeded predominantly on the primary hydroxyl of tyrosol, typically yielding mixtures of isomeric glycosides in ratios of 5:1 to 8:1 with overall yields of robinobiosides higher than 20%. This is the first robinobiosylation promoted under enzymatic catalysis. [ABSTRACT FROM AUTHOR]

Objectives: The applicability of a simple and high-throughput method for quantitative characterization of biofilm formation by Candida boidinii was tested in order to evaluate the effects of exogenous tyrosol on yeast growth and biofilm formation capacity. Results: Significant concentration-, temperature and time-dependent effect of tyrosol (2-(4-hydroxyphenyl)ethanol) was demonstrated, but it differentially affected the growth and biofilm formation (characterized by crystal violet staining and XTT-reduction assay) of Candida boidinii. Testing biofilm based on metabolic activity displayed sensitively the differences in the intensity of biofilm in terms of temperature, tyrosol concentration, and exposure time. At 22 °C after 24 h none of the tyrosol concentrations had significant effect, while at 30 °C tyrosol-mediated inhibition was observed at 50 mM and 100 mM concentration. After 48 h and 72 h at 22 °C, biofilm formation was stimulated at 6.25–25 mM concentrations, meanwhile at 30 °C tyrosol decreased the biofilm metabolic activity proportionally with the concentration. Conclusions: The research concludes that exogenous tyrosol exerts unusual effects on Candida boidinii growth and biofilm formation ability and predicts its potential application as a regulating factor of various fermentations by Candida boidinii. [ABSTRACT FROM AUTHOR]

Monovarietal olive oils, known for their distinct aromatic profiles, face challenges in preserving their initial quality due to variations in stability and susceptibility to oxidative deterioration. This study focused on the storage stability of two Italian cultivars, ‘Biancolilla’ and ‘Cerasuola’, from Sicily, chosen for their aromatic complexity and divergent storage stability. Oils, whether filtered or unfiltered, underwent storage at two thermal regimes (18 °C and – 20 °C) over a year. The combination of filtration and low-temperature storage was employed to mitigate oxidative deterioration and hydrolytic processes, as filtration removes suspended particles and emulsified water, while low temperatures slow down enzymatic activities and oxidative reactions, thereby enhancing the overall stability and shelf life of the olive oils. Unfiltered samples at room temperature showed a significant increase in secoiridoid aglycone derivatives (Hydroxytyrosol and Tyrosol) due to hydrolytic processes, along with a decrease in secoiridoid aglycone. Filtration delayed these processes, with a more pronounced effect observed when combined with −20 °C storage. Sensory analysis identified the emergence of the “fusty” defect in the less resilient ‘Biancolilla’ cultivar after six months, a phenomenon mitigated by filtration and freezing. Consumer tests validated these findings. In summary, the synergistic approach of combining filtration with low-temperature storage emerges as a promising strategy for maintaining high-quality standards, especially for less stable monovarietal extra virgin olive oils. This strategy ensures compliance with EU regulations beyond the conventional 12-month shelf life, offering a practical solution for preserving the nutritional and sensory quality of olive oil.

Abstract Background Epigenetic age is an estimator of biological age based on DNA methylation; its discrepancy from chronologic age warrants further investigation. We recently reported that greater polyphenol intake benefitted ectopic fats, brain function, and gut microbiota profile, corresponding with elevated urine polyphenols. The effect of polyphenol-rich dietary interventions on biological aging is yet to be determined. Methods We calculated different biological aging epigenetic clocks of different generations (Horvath2013, Hannum2013, Li2018, Horvath skin and blood2018, PhenoAge2018, PCGrimAge2022), their corresponding age and intrinsic age accelerations, and DunedinPACE, all based on DNA methylation (Illumina EPIC array; pre-specified secondary outcome) for 256 participants with abdominal obesity or dyslipidemia, before and after the 18-month DIRECT PLUS randomized controlled trial. Three interventions were assigned: healthy dietary guidelines, a Mediterranean (MED) diet, and a polyphenol-rich, low-red/processed meat Green-MED diet. Both MED groups consumed 28 g walnuts/day (+ 440 mg/day polyphenols). The Green-MED group consumed green tea (3–4 cups/day) and Mankai (Wolffia globosa strain) 500-ml green shake (+ 800 mg/day polyphenols). Adherence to the Green-MED diet was assessed by questionnaire and urine polyphenols metabolomics (high-performance liquid chromatography quadrupole time of flight). Results Baseline chronological age (51.3 ± 10.6 years) was significantly correlated with all methylation age (mAge) clocks with correlations ranging from 0.83 to 0.95; p

An eco-friendly approach towards the recovery of value-added extracts from olive tree leaves with the aid of supercritical CO2 at 30 MPa was carried out. The impact of extraction temperature (35–90 °C) and presence of co-solvents (ethanol, water, and aqueous ethanol) on the total phenolic, flavonoid, and pigment content, as well as oleuropein, hydroxytyrosol, tyrosol, and α-tocopherol content was determined. In addition, the antioxidant activity of extracts from tree leaves using DPPH, ABTS, and CUPRAC assays was investigated. The results of the study showed that the most effective supercritical CO2 extraction was at 90 °C with an addition of ethanol, which enabled the separation of extract with the highest content of tested compounds. Some of the highest recorded values were for oleuropein 1.9 mg/g, for carotenoids 5.3 mg/g, and for α-tocopherol 2.0 mg/g. Our results are expected to contribute to the efforts towards the valorization of olive leaves as a sustainable source of valuable compounds, and boost local economies as well as the interest of pharmaceutical, food, and cosmetic industries for novel food by-product applications.

Abstract Tyrosol, a secondary metabolite of Candida species, regulates fungal morphogenesis, and its application may represent a novel innovative therapy against emerging multi-resistant fungal superbug such as Candida auris. In the current study, the effects of tyrosol on growth, redox homeostasis, intracellular microelement contents and activities of virulence-related enzymes released by C. auris were examined. To gain further information about the effect of tyrosol exposure, we revealed gene transcriptional changes using total transcriptome sequencing (RNA-Seq). At a concentration of 15 mM, tyrosol significantly decrease the growth of fungal cells within 2 h of its addition (5.6 × 107±1.2 × 107 and 2.5 × 107±0.6 × 107 colony forming unit/mL for control and tyrosol-treated cells, respectively). Furthermore, it enhanced the release of reactive oxygen species as confirmed by a dichlorofluorescein (DCF) assay (7.3 ± 1.8 [nmol DCF (OD640)−1] versus 16.8 ± 3.9 [nmol DCF (OD640)−1]), which was coincided with elevated superoxide dismutase, catalase and glutathione peroxidase activities. Tyrosol exerted in a 37%, 25%, 34% and 55% decrease in intracellular manganese, iron, zinc and copper contents, respectively, compared to control cells. The tyrosol treatment led to a 142 and 108 differentially transcripted genes with at least a 1.5-fold increase or decrease in transcription, respectively. Genes related to iron and fatty acid metabolism as well as nucleic acid synthesis were down-regulated, whereas those related to the antioxidative defence, adhesion and oxoacid metabolic processes were up-regulated. This study shows that tyrosol significantly influences growth, intracellular physiological processes and gene transcription in C. auris, which could highly support the development of novel treatment approaches against this important pathogen.

Abstract Background Aromatic compounds derived from tyrosine are important and diverse chemicals that have industrial and commercial applications. Although these aromatic compounds can be obtained by extraction from natural producers, their growth is slow, and their content is low. To overcome these problems, many of them have been chemically synthesized from petroleum-based feedstocks. However, because of the environmental burden and depleting availability of feedstock, microbial cell factories are attracting much attention as sustainable and environmentally friendly processes. Results To facilitate development of microbial cell factories for producing tyrosine derivatives, we developed simple and convenient tyrosine-producing Escherichia coli platforms with a bacterial phenylalanine hydroxylase, which converted phenylalanine to tyrosine with tetrahydromonapterin as a cofactor, using a synthetic biology approach. By introducing a tetrahydrobiopterin-regeneration system, the tyrosine titer of the plasmid-based engineered strain was 4.63 g/L in a medium supplemented with 5.00 g/L phenylalanine with a test tube. The strains were successfully used to produce industrially attractive compounds, such as tyrosol with a yield of 1.58 g/L by installing a tyrosol-producing module consisting of genes encoding tyrosine decarboxylase and tyramine oxidase on a plasmid. Gene integration into E. coli chromosomes has an advantage over the use of plasmids because it increases genetic stability without antibiotic feeding to the culture media and enables more flexible pathway engineering by accepting more plasmids with artificial pathway genes. Therefore, we constructed a plasmid-free tyrosine-producing platform by integrating five modules, comprising genes encoding the phenylalanine hydroxylase and tetrahydrobiopterin-regeneration system, into the chromosome. The platform strain could produce 1.04 g/L of 3,4-dihydroxyphenylalanine, a drug medicine, by installing a gene encoding tyrosine hydroxylase and the tetrahydrobiopterin-regeneration system on a plasmid. Moreover, by installing the tyrosol-producing module, tyrosol was produced with a yield of 1.28 g/L. Conclusions We developed novel E. coli platforms for producing tyrosine from phenylalanine at multi-gram-per-liter levels in test-tube cultivation. The platforms allowed development and evaluation of microbial cell factories installing various designed tyrosine-derivative biosynthetic pathways at multi-grams-per-liter levels in test tubes.

Introduction: Recent research are focused on natural compounds for preventing cardiovascular diseases, with emphasis on tyrosol and hydroxytyrosol in olive oil. Cardiovascular diseases are linked to risk factors, and adopting a Mediterranean diet rich in these compounds is recognized for reducing risks. Understanding these compounds' actions may inform new strategies for preventing and treating cardiovascular diseases. Aim: The aim of this paper is a systematic review of articles and research regarding the Role of tyrosol and hydroxytyrosol in Cardioprotection Review methods: An systematic review of scientific literature was conducted using the following keywords: Tyrosol, hydroxytyrosol, cardioprotection, cardiovascular diseases, olive oil cardioprotective role. Thirty-four articles published until 2023 were searched and analyzed. Abbreviated description of the state of knowledge: Tyrosol and hydroxytyrosol, prominent in olive oil, are studied for their potential cardioprotective properties. Linked to a Mediterranean diet, these compounds show promise in reducing cardiovascular disease risk. They counter oxidative stress, improve lipid profiles, and modulate inflammatory processes. Clinical studies suggest their positive impact, with tyrosol also explored as a potential anticoagulant. Ongoing research aims to uncover optimal doses and mechanisms, highlighting their significance in cardiovascular health. Conclusions: Tyrosol and hydroxytyrosol, found in olive oil, show promise in cardioprotection by combating oxidative stress, improving lipid profiles, and modulating inflammation. Clinical studies suggest their positive impact on cardiovascular health. Tyrosol has potential as a anticoagulant and exhibits antioxidant effects. These compounds present a compelling avenue for future therapeutic interventions, with emphasis on understanding mechanisms and optimizing supplementation.

Background: Epigenetic age is an estimator of biological age based on DNA methylation; its discrepancy from chronologic age warrants further investigation. We recently reported that greater polyphenol intake benefitted ectopic fats, brain function, and gut microbiota profile, corresponding with elevated urine polyphenols. The effect of polyphenol-rich dietary interventions on biological aging is yet to be determined. Methods: We calculated different biological aging epigenetic clocks of different generations (Horvath2013, Hannum2013, Li2018, Horvath skin and blood2018, PhenoAge2018, PCGrimAge2022), their corresponding age and intrinsic age accelerations, and DunedinPACE, all based on DNA methylation (Illumina EPIC array; pre-specified secondary outcome) for 256 participants with abdominal obesity or dyslipidemia, before and after the 18-month DIRECT PLUS randomized controlled trial. Three interventions were assigned: healthy dietary guidelines, a Mediterranean (MED) diet, and a polyphenol-rich, low-red/processed meat Green-MED diet. Both MED groups consumed 28 g walnuts/day (+ 440 mg/day polyphenols). The Green-MED group consumed green tea (3–4 cups/day) and Mankai (Wolffia globosa strain) 500-ml green shake (+ 800 mg/day polyphenols). Adherence to the Green-MED diet was assessed by questionnaire and urine polyphenols metabolomics (high-performance liquid chromatography quadrupole time of flight). Results: Baseline chronological age (51.3 ± 10.6 years) was significantly correlated with all methylation age (mAge) clocks with correlations ranging from 0.83 to 0.95; p < 2.2e − 16 for all. While all interventions did not differ in terms of changes between mAge clocks, greater Green-Med diet adherence was associated with a lower 18-month relative change (i.e., greater mAge attenuation) in Li and Hannum mAge (beta = − 0.41, p = 0.004 and beta = − 0.38, p = 0.03, respectively; multivariate models). Greater Li mAge attenuation (multivariate models adjusted for age, sex, baseline mAge, and weight loss) was mostly affected by higher intake of Mankai (beta = − 1.8; p = 0.061) and green tea (beta = − 1.57; p = 0.0016) and corresponded with elevated urine polyphenols: hydroxytyrosol, tyrosol, and urolithin C (p < 0.05 for all) and urolithin A (p = 0.08), highly common in green plants. Overall, participants undergoing either MED-style diet had ~ 8.9 months favorable difference between the observed and expected Li mAge at the end of the intervention (p = 0.02). Conclusions: This study showed that MED and green-MED diets with increased polyphenols intake, such as green tea and Mankai, are inversely associated with biological aging. To the best of our knowledge, this is the first clinical trial to indicate a potential link between polyphenol intake, urine polyphenols, and biological aging. Trial registration: ClinicalTrials.gov, NCT03020186. [ABSTRACT FROM AUTHOR]

The corrosion of materials remains a critical challenge with significant economic and infrastructural impacts. A comprehensive understanding of adsorption characteristics of phytochemicals can facilitate the effective design of high-performing environmentally friendly inhibitors. This study conducted a computational exploration of hydroxytyrosol (HTR) and tyrosol (TRS) (potent phenolic compounds found in olive leaf extracts), focusing on their adsorption and reactivity on iron surfaces. Utilizing self-consistent-charge density-functional tight-binding (SCC-DFTB) simulations, molecular dynamics (MD) simulations, and quantum chemical calculations (QCCs), we investigated the molecules' structural and electronic attributes and interactions with iron surfaces. The SCC-DFTB results highlighted that HTR and TRS coordinated with iron atoms when adsorbed individually, but only HTR maintained bonding when adsorbed alongside TRS. At their individual adsorption, HTR and TRS had interaction energies of −1.874 and −1.598 eV, which became more negative when put together (−1.976 eV). The MD simulations revealed parallel adsorption under aqueous and vacuum conditions, with HTR demonstrating higher adsorption energy. The analysis of quantum chemical parameters, including global and local reactivity descriptors, offered crucial insights into molecular reactivity, stability, and interaction-prone atomic sites. QCCs revealed that the fraction of transferred electron ∆N aligned with SCC-DFTB results, while other parameters of purely isolated molecules failed to predict the same. These findings pave the way for potential advancements in anticorrosion strategies leveraging phenolic compounds. [ABSTRACT FROM AUTHOR]

Tyrosol (T) and hydroxytyrosol (HT) are phenyl alcohol polyphenols with well-recognized health-promoting properties. They are widely diffused in several vegetables, especially in olive products (leaves, fruits and oil). Therefore, they could be present in food produced from herbivorous animals such as in milk and cheese. In this study, an analytical method to determine T, HT and some of their phase II metabolites (sulphates and glucuronides) in cheese was developed and validated. Samples were extracted with an acidic mixture of MeOH/water 80/20 (v/v) and, after a low temperature clean-up, the extracts were evaporated and injected in a liquid-chromatography coupled with high resolution mass spectrometry (LC-Q-Orbitrap). A validation study demonstrated satisfactory method performance characteristics (selectivity, linearity, precision, recovery factors, detection and quantification limits). The developed protocol was then applied to analyze 36 Italian cheeses made from ewe, goat and cow milk. The sum of detected compounds (T, tyrosol sulfate, hydroxytyrosol-3-O-sulfate and hydroxytyrosol-4-O-sulfate) reached as high as 2300 µg kg−1 on a dry weight basis, although in about 45% of cow cheeses it did not exceed 50 µg kg−1. Ewe cheeses were significantly richer of polyphenols (sum) as well as HT sulfate metabolites than cow cheeses. In conclusion, results shows that cheese cannot be considered an important dietary source of these valuable compounds. [ABSTRACT FROM AUTHOR]

Hydroxytyrosol (HT) is a well-known compound for its bioactive properties. It is naturally present in olives, olive oil, and wine. Its presence in wines is partly due to its production during alcoholic fermentation by yeast through a hydroxylation of tyrosol formed through the Ehrlich pathway. This work aims to explore the influence of yeast assimilable nitrogen (YAN) and glucose content as precursors of HT formation during alcoholic fermentation. Commercial Saccharomyces cerevisiae QA23 and its metabolically engineered strain were used to ferment synthetic must. Each strain was tested at two different YAN concentrations (210 and 300 mg L−1) and two glucose concentrations (100 and 240 g L−1). This work confirms that the less YAN and the more glucose, the higher the HT content, with fermentations carried out with the metabolically engineered strain being the ones with the highest HT content (0.6 mg L−1).