The study focused on protective potential of phytochemicals applicable in prevention and health protection is of great importance. Various structures of these compounds and a wide range of their biological activities have inspired organic chemists to sythesize their effective analogues in order to further increase their efficacy. The aims of our study were (i) to synthesize phenylethanoid glycopyranosides: salidroside (SALI - tyrosol β-d-glucopyranoside), tyrosol β-d-galactopyranoside (TYBGAL), tyrosol α-d-galactopyranoside (TYAGAL), tyrosol α-d-mannopyranoside (TYAMAN), hydroxytyrosol α-d-mannopyranoside (HOTAMA), homosyringyl β-d-glucopyranoside (HSYGLU), hydroxytyrosol β-d-xylopyranoside (HOTXYL) and hydroxysalidroside (HOSALI); (ii) to determine their antioxidant capacities (cell-free approaches); (iii) to evaluate their cytotoxicity (MTT test), protectivity against hydrogen peroxide (H₂O₂; comet assay) and effect on the intracellular glutathione level (iGSH; flow cytometry) in experimental system utilizing human hepatoma HepG2 cells. HOSALI, HOTAMA, HOTXYL and HSYGLU manifested the highest antioxidant capacity in cell-free assays and they were most active in protection of HepG2 cells against H₂O₂. On the other hand, pre-treatment of HepG2 cells with SALI had protective effects even though SALI displayed almost no activity in cell-free assays. Differences in the efficacy of the analogues revealed that structures of their molecules in terms of aglycone combined with sugar moiety affect their activities.

Hydroxytyrosol (HT) is a diphenolic compound prevalent mainly in olives with pronounced antioxidant activity and proven benefits for human health. Current production limitations have motivated studies concerning the hydroxylation of tyrosol to HT with tyrosinase; however, accumulation of the diphenol is restricted due to its rapid subsequent oxidation to 3,4-quinone-phenylethanol. In this study, a continuous two-enzyme reaction system of sol-gel-immobilized tyrosinase and glucose dehydrogenase (GDH) was developed for the synthesis of HT. Purified tyrosinase from Bacillus megaterium (TyrBm) and E. coli cell extract expressing GDH from B. megaterium were encapsulated in a sol-gel matrix based on triethoxysilane precursors. While tyrosinase oxidized tyrosol to 3,4-quinone-phenylethanol, GDH catalyzed the simultaneous reduction of the cofactor NAD⁺ to NADH, which was the reducing agent enabling the accumulation of HT. Using 50 mM tyrosol, the immobilized system under optimized conditions, enabled a final HT yield of 7.68 g/L with productivity of 2.30 mg HT/mg TyrBm beads. Furthermore, the immobilized bi-enzyme system showed the feasibility for HT production from 1 mM tyrosol using a 0.5-L bioreactor as well as stable activity over 8 repeated cycles. The production of other diphenols with commercial importance such as L-dopa (3,4-dihydroxyphenylalanine) or piceatannol may be synthesized with this efficient approach.

Radiation of the plant pyridoxal 5'-phosphate (PLP)-dependent aromatic l-amino acid decarboxylase (AAAD) family has yielded an array of paralogous enzymes exhibiting divergent substrate preferences and catalytic mechanisms. Plant AAADs catalyze either the decarboxylation or decarboxylation-dependent oxidative deamination of aromatic l-amino acids to produce aromatic monoamines or aromatic acetaldehydes, respectively. These compounds serve as key precursors for the biosynthesis of several important classes of plant natural products, including indole alkaloids, benzylisoquinoline alkaloids, hydroxycinnamic acid amides, phenylacetaldehyde-derived floral volatiles, and tyrosol derivatives. Here, we present the crystal structures of four functionally distinct plant AAAD paralogs. Through structural and functional analyses, we identify variable structural features of the substrate-binding pocket that underlie the divergent evolution of substrate selectivity toward indole, phenyl, or hydroxyphenyl amino acids in plant AAADs. Moreover, we describe two mechanistic classes of independently arising mutations in AAAD paralogs leading to the convergent evolution of the derived aldehyde synthase activity. Applying knowledge learned from this study, we successfully engineered a shortened benzylisoquinoline alkaloid pathway to produce (S)-norcoclaurine in yeast. This work highlights the pliability of the AAAD fold that allows change of substrate selectivity and access to alternative catalytic mechanisms with only a few mutations.

Parkinson's disease (PD) is a neurodegenerative condition that progresses as age increases, and some of its major symptoms include tremor and postural and movement-related difficulties. To date, the treatment of PD remains a challenge because available drugs only treat the symptoms of the disease or possess serious side effects. In light of this, new treatment options are needed; hence, this study investigates the neuroprotective effects of an organic <i>Boophone haemanthoides</i> extract (BHE) and its bioactive compounds using an in vitro model of PD involving the toxin 1-methyl-4-phenylpyridinium (MPP⁺) and SH-SY5Y neuroblastoma cells. A total of seven compounds were isolated from BHE, viz distichamine (<b>1</b>), 1α,3α-diacetylnerbowdine (<b>2</b>), hippadine (<b>3</b>), stigmast-4-ene-3,6-dione (<b>4</b>), cholest-4-en-3-one (<b>5</b>), <em>tyrosol</em> (<b>6</b>), and 3-hydroxy-1-(4'-hydroxyphenyl)-1-propanone (<b>7</b>). Six compounds (<b>1</b>, <b>2</b>, <b>4</b>, <b>5</b>, <b>6</b> and <b>7</b>) were investigated, and five showed neuroprotection alongside the BHE. This study gives insight into the bioactivity of the non-alkaloidal constituents of Amaryllidaceae, since the isolated compounds and the BHE showed improved cell viability, increased ATP generation in the cells as well as inhibition of MPP⁺-induced apoptosis. Together, these findings support the claim that the Amaryllidaceae plant family could be a potential reserve of bioactive compounds for the discovery of neuroprotective agents.

Keywords: Amaryllidaceae; Boophone haemanthoides; Parkinson’s disease; alkaloids; apoptosis; neuroprotection; terpenoids.

Neurodegenerative diseases lead to the death of nerve cells in the brain or the spinal cord. A wide range of diseases are included within the group of neurodegenerative disorders, with the most common ones being dementia, Alzheimer's, and Parkinson's diseases. Millions of older people are suffering from such pathologies. The global increase of life expectancy unavoidably leads to a consequent increase in the number of people who will be at some degree affected by neurodegenerative-related diseases. At this moment, there is no effective therapy or treatment that can reverse the loss of neurons. A growing number of studies highlight the value of the consumption of medical foods, and in particular olive oil, as one of the most important components of the Mediterranean diet. A diet based on extra virgin olive oil seems to contribute toward the lowering of risk of age-related pathologies due to high phenol concentration. The link of a polyphenol found in extra virgin olive oil, namely, tyrosol, with the protein tyrosinase, associated to Parkinson's disease is underlined as a paradigm of affiliation between polyphenols and neurodegenerative disorders.

Keywords: Computational biology; Neurodegenerative diseases; Neuropharmacology.

An elegant preconcentration method assumed sorption of polar analytes from complex non-polar matrices on a rotating disk based on hydrophilic deep eutectic solvent formation is presented for the first time. The surface of poly(vinylidene fluoride-co-tetrafluoroethylene) rotating disk was coated with choline chloride acted as a precursor of deep eutectic solvent (hydrogen bond acceptor). The rotating disk was immersed in vegetable oil sample and phenolic compounds (hydrogen bond donors) were efficient separated on the disk during its rotation due to deep eutectic solvent formation. Ability of hydrophilic deep eutectic solvent decomposition in aqueous phase was used for fast analytes elution from the disk surface (2 min). Finally, the obtained aqueous solution of phenolic compounds and choline chloride was analyzed by high-performance liquid chromatography with fluorescence detection. Under optimal conditions, the limits of detection for gallic acid, protocatechuic acid, tyrosol, vanillic acid, p-coumarinic acid, syringaldehyde and thymol were in the range of 10-60 μg L^-1. The developed approach allowed to significantly reduce sorption and elution time in comparison with previously reported rotating disk sorptive extraction approaches. The extraction mechanism based on deep eutectic solvent formation provided selective separation of target analytes with absolute extraction recovery in the range of 66-87%.

Keywords: Deep eutectic solvent; HPLC-FLD; Phenolic compounds; Rotating disk; Rotating disk sorptive extraction; Sorption; Vegetable oil.

The validation of a HPLC-PDA-MS/MS chromatographic method for the quali/quantitative characterization of histaminol, hydroxytyrosol, tyrosol, and tryptophol in wine has been described and discussed. Four standards showed a good linearity with high correlation coefficient values (over 0.9989) and LOD and LOQ were 0.001-0.015 mg/L and 0.004-0.045 mg/L, respectively. Furthermore, this study reported how factors such as temperature, alcoholic degree, and amino acids concentration are able to influence the formation of these four alcohols in Monastrell wines. The quantification values of these alcohols has been detected both at the half and end of alcoholic fermentation, and at the end of malolactic fermentation. In relation to interactions between factors, several significant variations emerged (p ⩽ 0.001). The impact of amino acids supplementation in Monastrell must it has been demonstrated, mainly in regards to histaminol and tryptophol.

Background: phenolic compounds are bioactive chemical species derived from fruits and vegetables, with a plethora of healthy properties. In recent years, there has been a growing interest in persimmon (Diospyros kaki L.f.) due to the presence of many different classes of phenolic compounds. However, the analysis of individual phenolic compounds is difficult due to matrix interferences.

Methods: the aim of this research was the evaluation of individual phenolic compounds and antioxidant capacity of the pulp of two varieties of persimmon (Rojo Brillante and Triumph) by an improved extraction procedure together with a UPLC-Q-TOF-MS platform.

Results: the phenolic compounds composition of persimmon was characterized by the presence of hydroxybenzoic and hydroxycinnamic acids, hydroxybenzaldehydes, dihydrochalcones, tyrosols, flavanols, flavanones, and flavonols. A total of 31 compounds were identified and 17 compounds were quantified. Gallic acid was the predominant phenolic compounds found in the Rojo Brillante variety (0.953 mg/100 g) whereas the concentration of p-hydroxybenzoic acid was higher in the Triumph option (0.119 mg/100 g).

Conclusions: the results showed that the Rojo Brillante variety had higher quantities of phenolic compounds than the Triumph example. These data could be used as reference in future phenolic compound databases when individual health effects of phenolic compounds become available.

Keywords: Diospyros kaki; Rojo Brillante; Triumph; UPLC-QTOF-MS; antioxidant capacity; persimmon; phenolic compounds.

Lung cancer is the leading cause of cancer death in both men and women in the worldwide. Metastasis is the leading cause of cancer mortality and is a major hurdle for lung cancer treatment. Salidroside, a glycoside of tyrosol, is isolated from Rhodiola rosea and shows anticancer functions in several cancers. Recently, studies have reported that salidroside could inhibit the proliferation and metastasis of lung cancer; however, we need to explore further mechanism to provide evidence for clinical treatment. MicroRNAs (miRNAs) are regulatory molecules frequently aberrantly expressed in cancers, and a key role in carcinogenesis through regulation of their target genes. Consistent with previous reports, we found that salidroside could inhibit the proliferation of nonsmall cell lung cancer (NSCLC) cells, and elevated the level of miR-103-3p. Furthermore, we showed that the level of miR-103-3p was significantly downregulated in NSCLC tissues and NSCLC cell lines A549 and H460 and was significantly correlated with NSCLC proliferation and metastasis. Further studies indicated that an endoplasmic reticulum calcium regulator Mzb1 (marginal zone B and B-1 cell-specific protein) was a direct target gene of miR-103-3p, evidenced by the direct binding of miR-103-3p with the 3' untranslated region of Mzb1. We have also shown that overexpressing Mzb1 was able to inhibit the suppression effect of miR-103-3p on A549 migration and metastasis. These results demonstrate that salidroside suppresses NSCLC proliferation and metastasis by regulating miR-103-3p/Mzb1.

Eriobotrya japonica, commonly known as loquat, has been used traditionally for the treatment of different diseases. Herein, untargeted profiling based on ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) was used to depict the phytochemical profile of loquat roots, leaves, stems, seeds, and fruits. This allowed the tentative annotation of 349 compounds, representing different phytochemical classes that included flavonoids, phenolic acids, lignans, stilbenes, and terpenoids. Among others, low molecular weight phenolics (tyrosol derivatives) and terpenoids were the most abundant phytochemicals. After that, in vitro antioxidant and enzyme inhibition assays were applied to investigate the biological activity of the different organs of Eriobotrya japonica. Roots of E. japonica exhibited the highest antioxidant capacity, showing 181.88, 275.48, 325.18, 169.74 mg Trolox equivalent (TE)/g in DPPH, ABTS, CUPRAC, and FRAP assays, respectively. Furthermore, the root extract of E. japonica strongly inhibited butyryl cholinesterase (3.64 mg galantamine equivalent (GALAE)/g), whereas leaves, stems, seeds, and fruits showed comparable inhibition of both acetyl and butyryl cholinesterases. All the investigated organs of E. japonica exhibited in vitro tyrosinase inhibition (57.27-71.61 mg Kojic Acid Equivalent (KAE)/g). Our findings suggest a potential food and pharmaceutical exploitation of different organs of E. japonica (mainly roots) in terms of enrichment with health-promoting phenolics and triterpenes.

Keywords: Antioxidants; Loquat; Nutraceuticals; Phytochemical profiling; Rosaceae; UHPLC-QTOF-MS.

Objective: Cosmetic films and patches are interesting forms to promote skin penetration of active ingredients as they ensure their long stay of the treated zone of the skin. Nevertheless, currently developed films and patches are most of all hydrophilic and are not adapted to the hydrophobic molecules. The aim of this study was to establish if nanodispersion of fatty-acid based active cosmetic ingredients (ACI) could be a manner to introduce high concentrations of those ACI in hydrophilic films.

Methods: Punica granatum seed oil hydroxyphenethyl ester (PHE) is a lipolytic agent obtained by enzymatic conjugation of tyrosol to long chain fatty acids and to enhance its skin diffusion. Nanodispersions of PHE were prepared by a green emulsion-solvent evaporation process and dispersed in polyvinyl alcohol films. Raman imaging coupled to multivariate analysis was used to study the distribution of PHE in the films.

Results: Nanodispersions of PHE combined with antioxidant vitamin E, and stabilized by Pluronic® F127 were successfully prepared. The nanodispersions show a spherical shape and a hydrodynamic diameter close to 100 nm. Raman images analysis with multivariate approaches showed a very homogeneous distribution of PHE nanodispersions in the films compared to free PHE introduced as an ethanol solution.

Conclusion: Nanodispersions of hydrophobic fatty-acid based ingredients seem to be relevant method to introduce this type of ingredient in hydrophilic film matrix. The co-suspension with vitamin E limits their degradation in time.

Keywords: Delivery/vectorization/penetration; Formulation/stability; Raman imaging; films; nanodispersion; polymers.

Lipophenols are an emerging subclass of phenolic compounds characterized by the presence of a lipid moiety. Recently, hydroxytyrosyl oleate (HtyOle), a derivative of hydroxytyrosol, has been identified in olive oil and by-products. Furthermore, HtyOle possesses anti-inflammatory, antioxidant, and tissue regenerating properties. In this work, the potential occurrence of tyrosyl oleate (TyOle) in olive oil was investigated based on the hypothesis that its precursors tyrosol and oleic acid, both present in relatively high amount can be coupled together. Moreover, TyOle effects have been investigated in human keratinocytes to verify its proliferative and antioxidant properties. The quantitative determination of TyOle was carried out by the external standard method in liquid chromatography coupled with mass spectrometry (LC/MS), in negative mode using multiple reaction monitoring (MRM). The proliferative properties of TyOle on immortalized human keratinocytes (HaCat) were evaluated by 3-(4,5-dimethylthiasol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Morphological changes were observed by fluorescent staining with phalloidin (for F-actin) or 4,6-diamidino-2-phenylindole (DAPI, for chromatin) dye. The antioxidant activity was assessed at the level of production of mitochondrial reactive oxygen species (ROS) induced with UV exposure. TyOle was identified in all the oil samples investigated. Interestingly, TyOle concentration was higher in defective or low-quality oils than in extra virgin oils. The formation of TyOle likely occurs during the crushing and kneading processes and its concentration is related to the increase of rancidity and of the concentration of free precursors. Herein we show that TyOle induced an increase in the viability of HaCat cells and cytoskeletal remodeling.

Keywords: antioxidant; fatty acid ester; hydroxytyrosol; lipophenol; phenolipid; polyphenol; proliferation; reactive oxygen species; reactive oxygen species (ROS); tyrosol.

Beer is a fermented beverage with beneficial phenolic compounds and is widely consumed worldwide. The current study aimed to describe the content of three families of phenolic compounds with relevant biological activities: prenylated flavonoids (from hops), simple phenolic alcohols (from fermentation) and alkylresorcinols (from cereals) in a large sample of beers (n = 45). The prenylated flavonoids analyzed were xanthohumol, isoxanthohumol, 6- and 8-prenylnaringenin. The total prenylated flavonoids present in beer ranged from 0.0 to 9.5 mg/L. The simple phenolic alcohols analyzed were tyrosol and hydroxytyrosol, ranging from 0.2 to 44.4 and 0.0 to 0.1 mg/L, respectively. Our study describes, for the first time, the presence of low amounts of alkylresorcinols in beer, in concentrations ranging from 0.02 to 11.0 µg/L. The results in non-alcoholic beer and the differences observed in the phenolic composition among different beer types and styles highlight the importance of the starting materials and the brewing process (especially fermentation) on the final phenolic composition of beer. In conclusion, beer represents a source of phenolic compounds in the diet that could act synergistically, triggering beneficial health effects in the context of its moderate consumption.

Keywords: alkylresorcinols; antioxidants; beer; hydroxytyrosol; prenylated flavonoids; tyrosol.

Background: Different physical-chemical parameters, the polyphenolic content, the volatile fraction, as well as the sensory profile of beers were studied using 5 different yeast strains (3 top-fermentation and 2 bottom-fermentation) and two different fermentation temperatures (12 and 18°C) for each of them.

Results: The results indicated that at lower fermentation temperatures the yeast strain factor was less significant on the different physical-chemical parameters considered. The polyphenolic content increased as the fermentation temperature decreased, and significantly higher amounts of tyrosol were found in the samples fermented at 12°C. However, the volatile content increased for beers fermented at 18°C, these beers being better evaluated from the sensory point of view.

Conclusion: No clear relationship was observed between the temperature used and the type of yeast, with more complex aroma and sensory profiles being found in beers fermented at higher temperatures, using yeasts that are supposedly suitable to be used at lower temperatures. This article is protected by copyright. All rights reserved.

Keywords: fermentation; handcrafted beer; phenolic compounds; sensory analysis; volatile compounds; yeast.

Cancer presents one of the leading causes of death in the world. Current treatment includes the administration of one or more anticancer drugs, commonly known as chemotherapy. The biggest issue concerning the chemotherapeutics is their toxicity on normal cells and persisting side effects. One approach to the issue is chemoprevention and the other one is the discovery of more effective drugs or drug combinations, including combinations with polyphenols. Olive oil polyphenols (OOPs), especially hydroxytyrosol (HTyr), tyrosol (Tyr) and their derivatives oleuropein (Ole), oleacein and oleocanthal (Oc) express anticancer activity on different cancer models. Recent studies report that phenolic extract of virgin olive oil may be more effective than the individual phenolic compounds. Also, there is a growing body of evidence about the combined treatment of OOPs with various anticancer drugs, such as cisplatin, tamoxifen, doxorubicin and others. These novel approaches may present an advanced strategy in the prevention and treatment of cancer.

Ascochyta lentis var. lathyri has recently been reported to be the causal agent of Ascochyta blight of grass pea ( Lathyrus sativus), a disease characterized by the appearance of necrotic lesions of leaves and stems. Considering the novelty of the pathogen and the possible involvement of secondary metabolites in symptom appearance, a study was carried out to ascertain the capability of this fungus to produce bioactive metabolites. Some phytotoxic phenols were isolated from the culture filtrates of the fungus. In particular, two new phytotoxic metabolites, named lathyroxins A and B, were characterized by spectroscopic methods as 4-(2-hydroxy-3,3-dimethoxypropyl)phenol and 3-(4-hydroxyphenyl)propane-1,2-diol, respectively, and the R absolute configuration of C-2 of their 2-dimethoxy- and 2,3-diol-propyl side chain was assigned. Moreover, other well-known fungal metabolites, namely, p-hydroxybenzaldehyde, p-methoxyphenol, and tyrosol, were also identified. Lathyroxins A and B showed interesting phytotoxic properties, being able to cause necrosis on leaves and to inhibit seed germination and rootlet elongation. Moreover, both of the new metabolites had no effect against bacteria, arthropods, and nematodes.

Two phytotoxic furan derivatives were isolated, together with the well-known fungal and plant phytotoxin tyrosol, from the culture filtrates of Stilbocrea macrostoma. This fungal pathogen isolated from Quercus brantii trees induced wood necrosis and decline symptoms on the host plant in Iran. The two furan derivatives, isolated for the first time from Stilbocrea macrostoma, were identified by spectroscopic methods (essentially 1 D and 2 D ¹H and ¹³C NMR and ESIMS spectroscopy) as 5-hydroxymethylfuraldehyde and 2,5-dihydroxymethylfuran. The phytotoxic activity of the three metabolites was evaluated by leaf puncture assay on holm oak (Quercus ilex L.) and tomato (Lycopersicon esculentum L.) leaves. All compounds induced necrosis on holm oak leaves while very low toxicity was showed against tomato leaves. The two furan derivatives were more toxic than tyrosol and particularly 5-hydroxymethylfuraldehyde was the most phytotoxic compound.

Keywords: Quercus brantii; 5-hydroxymethyl-2-furaldehyde and 2,5-dihyroxymetylfuran; Stilbocrea macrostoma; furan derivatives; oak trees; phytotoxins.

Hydroxytyrosol (HT), which is a polyphenol with a high antioxidant power and many associated health benefits, has been found in wines. Wine yeasts are capable of producing high amounts of the higher alcohol tyrosol, which is the precursor for HT synthesis. We have improved the ability of Saccharomyces cerevisiae to produce HT by heterologously expressing the HpaBC enzyme complex of Escherichia coli, which hydroxylates tyrosol into HT. By overexpressing the hpaB and hpaC genes, we achieved HT titers of 1.15 ± 0.05 mg/L and 4.6 ± 0.9 mg/L in a minimal medium in which either 1 mM tyrosine or 1 mM tyrosol were respectively added. This work demonstrates that the overexpression of HpaBC in yeast is a promising tool to overproduce HT at the expense of endogenous tyrosol through central carbon catabolism flux redirection to tyrosine catabolism.

The effects of fermentation by autochthonous microbial starters on phenolics composition of Apulian table olives, Bella di Cerignola (BDC), Termite di Bitetto (TDB) and Cellina di Nardò (CEL) were studied, highlighting also the cultivars influence. In BDC with starter, polyphenols amount doubled compared with commercial sample, while in TDB and CEL, phenolics remain almost unchanged. The main phenolics were hydroxytyrosol, tyrosol, verbascoside and luteolin, followed by hydroxytyrosol-acetate detected in BDC and cyanidine-3-glucoside and quercetin in CEL. Scavenger capacity in both DPPH and CAA assays, assessed the highest antioxidant effect for CEL with starters (21.7 mg Trolox eq/g FW; 8.5 μmol hydroxytyrosol eq/100 g FW). The polyphenols were highly in vitro bioaccessible (>60%), although modifications in their profile, probably for combined effect of environment and microorganisms, were noted. Finally, fermented table olives are excellent source of health promoting compounds, since hydroxytyrosol and tyrosol are almost 8 times more than in olive oil.

Our previous research was focused on the effects of hydrophobicity on the antioxidant (AO) efficiency of series of homologous antioxidants with the same reactive moieties. In this work we evaluate the antioxidant efficiency of hydrophobic phenolipids in 4:6 olive oil-in-water emulsions, with different phenolic moieties (derived from caffeic, 4-hydroxycinnamic, dihydrocaffeic acids, tyrosol and hydroxytyrosol), with alkyl chains of 8 and 16 carbons, and compare the antioxidant efficiency with that of the parent compounds. All catecholic phenolipids, in particular the C8 derivatives, have proven to be better antioxidants for the oxidative protection of emulsions than their parental compounds with octyl dihydrocafffeate being the most efficient (16-fold increase in relation to the control). To understand the importance of some factors on the antioxidant efficiency of compounds in emulsions, Pearson's correlation analysis was carried out between antioxidant activity and the first anodic potential (E_pa), reducing capacity (FRAP value), DPPH radical scavenging activity (EC₅₀) and the concentration of antioxidants in each region of the emulsified system. Results confirm the importance of the effective concentration of AOs in the interfacial region (AO_I) (ρ = 0.820) and of the E_pa (ρ = -0.677) in predicting their antioxidant efficiency in olive oil-in-water emulsions.

Keywords: antioxidants; caffeic acid; catechols; dihydrocaffeic acid; emulsions; hydroxytyrosol; interfacial concentration; oxidative stability.

The role attributed to polyphenols on human-health need to be correlated with their plasmatic concentrations after food consumption. Then, a method based on liquid-liquid extraction followed by highly sensitive LC-ESI-MS/MS analysis was developed to determinate 16 phenolic compounds in plasma. Validation gave appropriate recovery, matrix effect (80-120%), linear correlation (R²>0.995), precision (<15%), LOQ (0.04-2.51nM), and short chromatographic run. The method was verified after the administration of Arbequina table olives to rats. A single dose of destoned olives was given by gavage and plasmatic concentrations of polyphenols were analysed at 30-min. Interestingly, the profile found in plasma greatly differed from olives. Plasmatic concentrations, from highest to lowest, were salidroside, p-coumaric acid, hydroxytyrosol, verbascoside, tyrosol, luteolin and luteolin-7-O-glucoside. In conclusion, a simple and robust method was developed enabling the identification and quantification of unaltered polyphenols in plasma after olives consumption, thus demonstrating its suitability for pharmacokinetics studies.

Rotifers have been widely used as well-characterized models of aging, since their multiorgan character makes them suitable as in vivo toxicological and lifespan models. Here we report the assessment of four adaptogenic plants and their extracts for the first time in this model. The effects on rotifer viability of extracts and characteristic active markers of Panax ginseng, Withania somnifera, Leuzea carthamoides, and Rhodiola rosea were tested in vivo. The crude extracts were nontoxic to Philodina acuticornis bdelloid rotifers; however, the pure substances of the plants influenced negatively the viability. Ginsenoside Rb1 and secondary metabolites of Withania somnifera exerted deleterious effect on the animals. The aglycone tyrosol and cinnamyl alcohol (from Rhodiola rosea) were more toxic than their glycosides salidroside and rosavin. Although the 20-OH-ecdysone and ajugasterone C (from Leuzea carthamoides) are chemically very similar, the latter was less toxic.

A novel liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI MS/MS) method was developed and validated for the simultaneous determination of the bioactive substances hydroxytyrosol, tyrosol and 2-(5-ethylidene-2-oxo-tetrahydro-2H-pyran-4-yl)acetic acid in olive oil mill wastewater samples (OMW). The chromatographic separation was performed on a RP-C8 column using a water-acetonitrile gradient program and the detection was achieved by tandem MS in the negative ion mode. Calibration curves were linear for all bioactive compounds over the range of 1-100 ng injected, while the method exhibited good accuracy, intra- and inter-day precision. The limit of detection and the limit of quantification were in the low to mid pg range and the method was simple and rapid. Because the disposal of OMW is an environmental problem and on the other hand OMW are rich in biologically active compounds that could be recovered and exploited in various applications, the developed method was applied to the monitoring of OMW samples and the quantitative determination of the aforementioned substances. In this way, the original content in bioactive compounds could be assigned in the raw matrix, and the enrichment of the samples by various pretreatment methods could be assessed. Also, full-scan ESI MS was applied to OMW samples for the identification of several compounds known to be present in OMW.

The study of negative effects potentially exerted by the exposure to oxygen and/or light and, thus, also by the type of container on the quality of extra virgin olive oil (EVOO) during its prolonged storage requires an appropriate choice of analytical methods and components to be monitored. Here, reverse-phase liquid chromatography coupled to high-resolution/accuracy Fourier transform mass spectrometry with electrospray ionization was exploited to study oxidative/hydrolytic degradation processes occurring on the important bioactive components of EVOO known as secoiridoids, i.e., oleuropein and ligstroside aglycones, oleacin, and oleocanthal, during storage up to 6 months under controlled conditions. Specifically, isomeric oxidative byproducts resulting from the transformation of a carbonylic group of the original secoiridoids into a carboxylic group and compounds resulting from hydrolysis of the ester linkage of secoiridoids, i.e., elenolic and decarboxymethyl elenolic acids and tyrosol and 3-hydroxytyrosol, were monitored, along with their precursors. Data obtained from EVOO storage at room temperature in glass bottles with/without exposure to light and/or oxygen indicated that, although it was more relevant if a periodical exposure to oxygen was performed, a non-negligible oxidative degradation occurred on secoiridoids also when nitrogen was used to saturate the container headspace. In a parallel experiment, the effects of storage of the same EVOO (250 mL) for up to 6 months in containers manufactured with different materials/shapes were considered. In particular, a square dark glass bottle, a stainless-steel can, and a ceramic jar, typically used for EVOO commercialization, and a clear polyethylene terephthalate bottle, purposely chosen to prompt secoiridoid degradation through exposure to light and oxygen, were compared. Dark glass was found to provide the best combined protection of major secoiridoids from oxidative and hydrolytic degradation, yet the lowest levels of oxidized byproducts were observed when the stainless-steel can was used.

Keywords: extra virgin olive oil; high-resolution mass spectrometry; olive oil storage; oxidative/hydrolytic degradation; secoiridoids.