Light in a Heartbeat: Bond Scission by a Single Photon above 800 nm.

Photocages enable scientists to take full control over the activity of molecules using light as a biocompatible stimulus. Their emerging applications in photoactivated therapies call for efficient uncaging in the near-infrared (NIR) window, which represents a fundamental challenge. Here, we report synthetically accessible cyanine photocages that liberate alcohol, phenol, amine, and thiol payloads upon irradiation with NIR light up to 820 nm in aqueous media. The photocages display a unique chameleon-like behavior and operate via two distinct uncaging mechanisms: photooxidation and heterolytic bond cleavage. The latter process constitutes the first example of a direct bond scission by a single photon ever observed in cyanine dyes or at wavelengths exceeding 800 nm. Modulation of the beating rates of human cardiomyocytes that we achieved by light-actuated release of adrenergic agonist etilefrine at submicromolar concentrations and low NIR light doses (∼12 J cm-2) highlights the potential of these photocages in biology and medicine.

Infliximab therapy decreases the expression of serum and faecal miR-126 and miR-20a in paediatric Crohn's disease: A pilot study.

AIM: We aimed to evaluate the serum and faecal expression of miR-126 and miR-20a in children with Crohn's disease (CD) during infliximab (IFX) therapy. METHODS: In this prospective observational study, serum and faeces from CD patients were collected before IFX therapy (T0), after induction (T1) and after 6 months from IFX (T2). IFX levels were determined by Enzyme-linked immunosorbent assay at T1 and T2. miRNAs were profiled through Real-Time RT-PCR. The activity of disease was evaluated through the Paediatric Crohn's disease activity index (PCDAI), serum C-reactive protein (CRP) and faecal calprotectin. RESULTS: Nine CD children were enrolled. Serum and faecal miR-126 and miR-20a levels were higher at T0 and showed a time-dependent decrease, being significantly down-regulated after IFX treatment at T2. Specifically, IFX levels recorded at T1 and T2 negatively correlated with the serum and faecal expression of miR-126 and miR-20a. Serum and faecal changes of miR-126 and miR20-a were positively associated with the decrease of the inflammatory marker CRP and PDCAI at all time points. CONCLUSION: In children with CD, IFX therapy decreases the expression of serum and faecal miR-126 and miR-20a, suggesting an involvement of these two miRNAs in the action of the drug.

Evaluating Male Patients' Understanding of Osteoporosis Evaluation and Treatment Following a Distal Radius Fracture.

PURPOSE: Current estimates suggest that 1-2 million men in the United States have osteoporosis, yet the majority of osteoporosis literature focuses on postmenopausal women. Our aim was to understand men's awareness and knowledge of osteoporosis and its treatment. METHODS: Semistructured interviews were conducted with 20 male patients >50 years old who sustained a low-energy distal radius fracture. The goal was to ascertain patients' knowledge of osteoporosis, its management, and experience discussing osteoporosis with their primary care physicians (PCP). RESULTS: Participants had little knowledge of osteoporosis or its treatment. Many participants regarded osteoporosis as a women's disease. Most participants expressed concern regarding receiving a diagnosis of osteoporosis. Several patients stated that they believe osteoporosis may have contributed to their fracture. Families, friends, or mass media served as the primary information source for participants, but few had good self-reported understanding of the disease itself. The majority of participants reported never having discussed osteoporosis with their PCPs although almost half had received a dual x-ray absorptiometry scan. Participants expressed general interest in being tested/screened and generally were willing to undergo treatment despite the perception that medication has serious side effects. One patient expressed concern that treatment side effects could be worse than having osteoporosis. CONCLUSION: Critical knowledge gaps exist regarding osteoporosis diagnosis and treatment in at-risk male patients. Specifically, most patients were unaware they could be osteoporotic because of the perception of osteoporosis as a women's disease. Most patients had never discussed osteoporosis with their PCP. CLINICAL RELEVANCE: Male patients remain relatively unaware of osteoporosis as a disease entity. Opportunity exists for prevention of future fragility fractures by improving communication between patients and physicians regarding osteoporosis screening in men following low-energy distal radius fractures.

Changes in Circulating Acylated Ghrelin and Neutrophil Elastase in Diabetic Retinopathy.

Background and Objectives: The role and the levels of ghrelin in diabetes-induced retinal damage have not yet been explored. The present study aimed to measure the serum levels of total ghrelin (TG), and its acylated (AG) and des-acylated (DAG) forms in patients with the two stages of diabetic retinopathy (DR), non-proliferative (NPDR) and proliferative (PDR). Moreover, the correlation between serum ghrelin and neutrophil elastase (NE) levels was investigated. Materials and Methods: The serum markers were determined via enzyme-linked immunosorbent assays in 12 non-diabetic subjects (CTRL), 15 diabetic patients without DR (Diabetic), 15 patients with NPDR, and 15 patients with PDR. Results: TG and AG serum levels were significantly decreased in Diabetic (respectively, p < 0.05 and p < 0.01 vs. CTRL), NPDR (p < 0.01 vs. Diabetic), and in PDR patients (p < 0.01 vs. NPDR). AG serum levels were inversely associated with DR abnormalities (microhemorrhages, microaneurysms, and exudates) progression (r = -0.83, p < 0.01), serum neutrophil percentage (r = -0.74, p < 0.01), and serum NE levels (r = -0.73, p < 0.01). The latter were significantly increased in the Diabetic (p < 0.05 vs. CTRL), NPDR (p < 0.01 vs. Diabetic), and PDR (p < 0.01 vs. PDR) groups. Conclusions: The two DR stages were characterized by decreased AG and increased NE levels. In particular, serum AG levels were lower in PDR compared to NPDR patients, and serum NE levels were higher in the PDR vs. the NPDR group. Together with the greater presence of retinal abnormalities, this could underline a distinctive role of AG in PDR compared to NPDR.

Inhibition of Galectins and the P2X7 Purinergic Receptor as a Therapeutic Approach in the Neurovascular Inflammation of Diabetic Retinopathy.

Diabetic retinopathy (DR) is the most frequent microvascular retinal complication of diabetic patients, contributing to loss of vision. Recently, retinal neuroinflammation and neurodegeneration have emerged as key players in DR progression, and therefore, this review examines the neuroinflammatory molecular basis of DR. We focus on four important aspects of retinal neuroinflammation: (i) the exacerbation of endoplasmic reticulum (ER) stress; (ii) the activation of the NLRP3 inflammasome; (iii) the role of galectins; and (iv) the activation of purinergic 2X7 receptor (P2X7R). Moreover, this review proposes the selective inhibition of galectins and the P2X7R as a potential pharmacological approach to prevent the progression of DR.

Structure-Photoreactivity Relationship of 3-Hydroxyflavone-Based CO-Releasing Molecules.

Carbon monoxide (CO) is an endogenous signaling molecule that regulates diverse physiological processes. The therapeutic potential of CO is hampered by its intrinsic toxicity, and its administration poses a significant challenge. Photoactivatable CO-releasing molecules (photoCORMs) are an excellent tool to overcome the side effects of untargeted CO administration and provide precise spatial and temporal control over its release. Here, we studied the CO release mechanism of a small library of derivatives based on 3-hydroxy-2-phenyl-4H-benzo[g]chromen-4-one (flavonol), previously developed as an efficient photoCORM, by steady-state and femto/nanosecond transient absorption spectroscopies. The main objectives of the work were to explore in detail how to enhance the efficiency of CO photorelease from flavonols, bathochromically shift their absorption bands, control their acid-base properties and solubilities in aqueous solutions, and minimize primary or secondary photochemical side-reactions, such as self-photooxygenation. The best photoCORM performance was achieved by combining substituents, which simultaneously bathochromically shift the chromophore absorption spectrum, enhance the formation of the productive triplet state, and suppress the singlet oxygen production by shortening flavonol triplet-state lifetimes. In addition, the cell toxicity of selected flavonol compounds was analyzed using in vitro hepatic HepG2 cells.

Supercritical fluid chromatography-tandem mass spectrometry of oxygen heterocyclic compounds in Citrus essential oils.

Oxygen heterocyclic compounds are secondary metabolites mainly present in the non-volatile fraction of cold-pressed Citrus essential oils. Under this denomination are included coumarins, furocoumarins, and polymethoxyflavones. These compounds possess numerous beneficial properties for human health, but the ingestion of large amounts of coumarins is often related to toxic effects, whereas the phototoxicity caused by furocoumarins and UVA exposure has been well known for a long time. This research has been aimed at the validation of an analytical approach, based on supercritical fluid chromatography coupled to tandem mass spectrometry, for the analysis of OHCs in Citrus essential oils. Among eight columns tested, packed with different stationary phases, the pentafluorophenyl allowed the best baseline separation in 8 min and by using less than 10% of methanol. Calibration curves of twenty-eight standards (coumarins, furocoumarins, polymethoxyflavones) were constructed on spiked lemon distilled essential oil and the method was validated according to the EURACHEM guidelines, by calculating linearity, limit of detection (LoD), limit of quantification (LoQ), accuracy, intra-day, and inter-day precision. Specifically, recoveries were in the 80.0-118.6% range, regression coefficients were between 0.9904 and 0.9998, the LoDs were in the 0.0004-0.0470 mg kg-1 range, the LoQs were in the 0.0014-0.1536 mg kg-1 range, and coefficients of variation were between 0.3 and 2.6% (intra-day) and 1.1 and 7.4% (inter-day). The quantitative profiles of thirteen cold-pressed Citrus essential oils were determined.

Clinically silent Plasmodium vivax infections in native Amazonians of northwestern Brazil: acquired immunity or low parasite virulence?

BACKGROUND: Malaria remains common among native Amazonians, challenging Brazil's elimination efforts. OBJECTIVES: We examined the epidemiology of malaria in riverine populations of the country's main hotspot - the upper Juruá Valley in Acre state, close to the Brazil-Peru border, where Plasmodium vivax accounts for > 80% of cases. METHODS: Participants (n = 262) from 10 villages along the Azul River were screened for malaria parasites by microscopy and genus-specific, cytochrome b (cytb) gene-based polymerase chain reaction. Positive samples were further tested with quantitative TaqMan assays targeting P. vivax- and P. falciparum-specific cytb domains. We used multiple logistic regression analysis to identify independent correlates of P. vivax infection. FINDINGS: Microscopy detected only one P. vivax and two P. falciparum infections. TaqMan assays detected 33 P. vivax infections (prevalence, 11.1%), 78.1% of which asymptomatic, with a median parasitaemia of 34/mL. Increasing age, male sex and use of insecticide-treated bed nets were significant predictors of elevated P. vivax malaria risk. Children and adults were similarly likely to remain asymptomatic once infected. MAIN CONCLUSIONS: Our findings are at odds with the hypothesis of age-related clinical immunity in native Amazonians. The low virulence of local parasites is suggested as an alternative explanation for subclinical infections in isolated populations.

Systemic Beta-Hydroxybutyrate Affects BDNF and Autophagy into the Retina of Diabetic Mice.

Background: Diabetic retinopathy (DR) is a neurovascular disease, characterized by a deficiency of brain-derived neurotrophic factor (BDNF), a regulator of autophagy. Beta-hydroxybutyrate (BHB), previously reported as a protective agent in DR, has been associated with BDNF promotion. Here, we investigated whether systemic BHB affects the retinal levels of BDNF and local autophagy in diabetic mice with retinopathy; Methods: C57BL/6J mice were administered with intraperitoneal (i.p.) streptozotocin (STZ) (75 mg/kg) injection to develop diabetes. After 2 weeks, they received i.p. injections of BHB (25−50−100 mg/kg) twice a week for 10 weeks. Retinal samples were collected in order to perform immunofluorescence, Western blotting, and ELISA analysis; Results: BHB 50 mg/kg and 100 mg/kg significantly improved retinal BDNF levels (p < 0.01) in diabetic mice. This improvement was negatively associated with autophagosome−lysosome formations (marked by LC3B and ATG14) and to higher levels of connexin 43 (p < 0.01), a marker of cell integrity. Moreover, BHB administration significantly reduced M1 microglial activation and autophagy (p < 0.01); Conclusions: The systemic administration of BHB in mice with DR improves the retinal levels of BDNF, with the consequent reduction of the abnormal microglial autophagy. This leads to retinal cell safety through connexin 43 restoration.

Cyanine Renaissance: Tailoring the Properties to Applications.

In this account, we provide an overview of the applications that arose from the recently developed synthetic methodology that delivers heptamethine cyanines (Cy7) substituted at the central chain. The ability to easily introduce and manipulate various substituents in different substitution patterns along the cyanine chain enabled rational tailoring of the photophysical and photochemical properties. Exercising this control over the structure-property relationship proved to have a substantial impact in the field of cyanine dyes and was swiftly harnessed in a number of emerging applications in distinct areas, including fluorescent probes, biosensors, dye-sensitized upconversion nanoparticles, phototruncation of cyanines and photocages. While this method unlocked a number of new avenues, many synthetic challenges remain to be conquered in order to fully capitalize on the potential of cyanines, and we provide a short perspective that summarizes them at the end of this manuscript.

Photouncaging of Carboxylic Acids from Cyanine Dyes with Near-Infrared Light.

Near-infrared light (NIR; 650-900 nm) offers unparalleled advantages as a biocompatible stimulus. The development of photocages that operate in this region represents a fundamental challenge due to the low energy of the excitation light. Herein, we repurpose cyanine dyes into photocages that are available on a multigram scale in three steps and efficiently release carboxylic acids in aqueous media upon irradiation with NIR light up to 820 nm. The photouncaging process is examined using several techniques, providing evidence that it proceeds via photooxidative pathway. We demonstrate the practical utility in live HeLa cells by delivery and release of the carboxylic acid cargo, that was otherwise not uptaken by cells in its free form. In combination with modularity of the cyanine scaffold, the realization of these accessible photocages will fully unleash the potential of the emerging field of NIR-photoactivation and facilitate its widespread adoption outside the photochemistry community.

Seronegative Villous Atrophy in Children: Clinical and Immunohistochemical Features.

OBJECTIVES: Villous atrophy (VA) is not pathognomonic of celiac disease (CD). We aimed at reporting distribution, clinical, and immunohistochemical features of seronegative VA (SNVA) in a pediatric population. METHODS: We retrospectively collected data from patients who underwent intestinal biopsies between 2010 and 2017 and showed VA without serum CD-associated autoantibodies. Marsh-Oberhuber grading was used. Density of intraepithelial lymphocytes (IELs) expressing CD3 or TCRγδ+ receptor and of lamina propria CD25+ cells was assessed by immunohistochemistry. Intestinal deposits of anti-tissue tranglutaminase2 (anti-TG2) were also investigated by double immunofluorescence. RESULTS: Over a 7-year period, 64 out of 1282 patients with VA had negative serum CD serology. Diagnoses were: inflammatory bowel diseases (IBD) (21/64), Gastro-Esophageal Reflux Disease (GERD) (12/64), food allergy (8/64), infections (7/64, of which 3 HIV infections), immune deficiency (3/64), short bowel syndrome (3/64), congenital diarrhea (2/64), other/inconclusive diagnosis (8/64). Forty-four, 15, and 5 showed Marsh 3a, 3b, and 3c lesion, respectively. The latter category included 2 patients with Crohn disease, 2 with immunodeficiencies, 1 with lymphohistiocytosis. In 41/46 (89%) patients, mononuclear CD25+ cells were above the cut-off, indicating mucosal inflammation but only 18/46 (39%) had IELs and TCRγδ + IELs above limits of normality. In 10 of 46 (22%) patients, a positive immunofluorescence indicated the presence of anti-TG2 mucosal antibodies. CONCLUSIONS: SNVA is not rare representing up to 5% of the cases of VA. Most patients have a Marsh 3a lesion. Immunohistochemical analysis may be helpful in excluding CD, whereas the finding of mucosal anti-TG2, particularly with a weak staining, shows no absolute specificity for CD.

Application of deep eutectic solvents for the extraction of phenolic compounds from extra-virgin olive oil.

A HPLC-DAD/ESI-MS method has been developed and validated for the analysis of the most representative phenolic compounds in extra-virgin olive oil (EVOO) samples using a green extraction approach based on deep eutectic solvents (DESs) at room temperature. We examined ten DESs based on choline chloride and betaine in combination with different hydrogen bond donors comprising six alcohols, two organic acids, and one urea. Five phenolic compounds, belonging to the classes of secoiridoids and phenolic alcohols, were selected for the evaluation of extraction efficiency. A betaine-based DES with glycerol (molar ratio 1:2) was found to be the most effective for extracting phenolic compounds as compared to a conventional solvent. The optimization of the extraction method involved the study of the quantity of water to be added to the DES and evaluation of the sample-to-solvent ratio optimal condition. Thirty percent of water added to DES and sample to solvent ratio 1:1 (w/v) were selected as the best conditions. The chromatographic method was validated by studying LOD, LOQ, intraday and interday retention time precision, and linearity range. Recovery values obtained spiking seed oil sample aliquots with standard compounds at 5 and 100 µg/g concentration were in the range between 75.2% and 98.7%.

Cyanine-Flavonol Hybrids for Near-Infrared Light-Activated Delivery of Carbon Monoxide.

Carbon monoxide (CO) is an endogenous signaling molecule that controls a number of physiological processes. To circumvent the inherent toxicity of CO, light-activated CO-releasing molecules (photoCORMs) have emerged as an alternative for its administration. However, their wider application requires photoactivation using biologically benign visible and near-infrared (NIR) light. In this work, a strategy to access such photoCORMs by fusing two CO-releasing flavonol moieties with a NIR-absorbing cyanine dye is presented. These hybrids liberate two molecules of CO in high chemical yields upon activation with NIR light up to 820 nm and exhibit excellent uncaging cross-sections, which surpass the state-of-the-art by two orders of magnitude. Furthermore, the biocompatibility and applicability of the system in vitro and in vivo are demonstrated, and a mechanism of CO release is proposed. It is hoped that this strategy will stimulate the discovery of new classes of photoCORMs and accelerate the translation of CO-based phototherapy into practice.

Mechanisms of Orthogonal Photodecarbonylation Reactions of 3-Hydroxyflavone-Based Acid-Base Forms.

Carbon monoxide is a naturally occurring gasotransmitter combining inherent toxicity with a remarkable therapeutic potential and arduous administration. Photoactivatable carbon monoxide-releasing molecules (photoCORMs) are chemical agents that allow for precise spatial and temporal control over the CO release. In this work, we present a comprehensive mechanistic study of the photochemical CO release from 3-hydroxy-2-phenyl-4H-chromen-4-one, a π-extended 3-hydroxyflavone photoCORM, in methanol using steady-state and transient absorption spectroscopies and quantum chemical calculations. The multiplicity of the productive excited states and the role of oxygen (O2) in the CO production are emphasized, revealing a photoreaction dichotomy of the 3-hydroxyflavone acid and base forms. The utilization of three major orthogonal mechanistic pathways, all of which lead to the CO release, can fuel future endeavors to improve the CO release efficacy of 3-hydroxyflavone-based derivatives and refine their potential medical applications as photoCORMs.

Deciphering the Structure-Property Relations in Substituted Heptamethine Cyanines.

Heptamethine cyanines (Cy7) are fluorophores essential for modern bioimaging techniques and chemistry. Here, we systematically evaluated the photochemical and photophysical properties of a library of Cy7 derivatives containing diverse substituents in different positions of the heptamethine chain. A single substitution allows modulation of their absorption maxima in the range of 693-805 nm and photophysical properties, such as quantum yields of singlet-oxygen formation, decomposition, and fluorescence or affinity to singlet oxygen, within 2-3 orders of magnitude. The same substituent in different positions of the chain often exhibits distinctly contradictory effects, demonstrating that both the type and position of the substituent are pivotal for the design of Cy7-based applications. The combination of experimental results with quantum-chemical calculations provides insights into the structure-property relationship, the elucidation of which will accelerate the development of cyanines with properties tailored for specific applications, such as fluorescent probes and sensors, photouncaging, photodynamic therapy, or singlet-oxygen detection.

Exclusive enteral nutrition effect on the clinical course of pediatric Crohn's disease: a single center experience.

The aim of this study was to evaluate the short- and long-term outcomes of exclusive enteral nutrition (EEN) versus corticosteroids (CS) as induction therapy, in a cohort of pediatric patients with Crohn's disease (CD). A retrospective study of patients with CD has been conducted. Clinical characteristics, laboratory parameters, and pediatric Crohn's disease activity index (PCDAI) were evaluated at diagnosis and at different follow-up points. Subjects were divided in EEN-induction group, receiving EEN, and CS-induction group, treated with oral CS. We evaluated 47 patients in the EEN-induction group and 21 patients in the CS-induction group. After 8 weeks from diagnosis, we detected a significant improvement in CRP (p = 0.001) and albumin (p = 0.05), in EEN-induction group compared with the CS-induction group. PCDAI was significantly lower in the EEN-induction group versus the CS-induction group after 8 weeks (p = 0.04) and 1 year (p = 0.03) of follow-up. After 2 years from diagnosis, the number of subjects needing immunomodulators (IMM, azathioprine or methotrexate) was significantly higher in the CS-induction group compared with the EEN-induction group (p = 0.02).Conclusion: EEN has the same effectiveness of CS therapy in induction of remission but seems to have a more pronounced effect on disease activity. In our cohort, the need to use IMM seems to be reduced in subjects initially treated with EEN. What is Known: • Exclusive enteral nutrition (EEN) has the same effectiveness of corticosteroids (CS) in the induction of remission in pediatric Crohn's disease. • EEN offers numerous advantages over CS, in terms of improved nutrition and mucosal healing. What is New: • Induction of remission with EEN seems to have a more pronounced effect on disease activity compared to induction with CS. • In our cohort, induction of remission with EEN seems to reduce the need of therapy with immunomodulators at 2 years of follow-up.

Characterization of Phenolic Compounds, Vitamin E and Fatty Acids from Monovarietal Virgin Olive Oils of "Picholine marocaine" Cultivar.

Olive oil is an important product in the Mediterranean diet, due to its health benefits and sensorial characteristics. Picholine marocaine is the most cultivated variety in Morocco. The present research aims to evaluate the phenolic compounds, vitamin E and fatty acids of commercial Picholine marocaine virgin olive oils (VOOs) from five different North Moroccan provinces (Chefchaouen, Taounate, Errachidia, Beni Mellal and Taza), using HPLC-photodiode array (PDA)/electrospray ionization (ESI)-MS, normal phase (NP)-HPLC/ fluorescence detector (FLD) and GC-flame ionization detector (FID)/MS, respectively. The obtained results showed an average content of 130.0 mg kg-1 of secoiridoids (oleuropein aglycone, 10-hydroxy-oleuropein aglycone and ligstroside aglycone, oleocanthal and oleacein), 108.1 mg kg-1 of phenolic alcohols (tyrosol and hydroxytyrosol), 34.7 mg kg-1 of phenolic acids (caffeic acid, ferulic acid and elenolic acid), and 8.24 mg kg-1 of flavonoids (luteolin, luteolin glucoside, apigenin). With regard to vitamin E, α-tocopherol was the most abundant vitamin E (57.9 mg kg-1), followed by α-tocotrienol (2.5 mg kg-1), γ-tocopherol (4.5 mg kg-1) and ß-tocopherol (1.9 mg kg-1), while δ-tocopherol was not detected. Moreover, 14 fatty acids were found and, among them, oleic acid (76.1%), linoleic acid (8.1%) palmitic acid (8.7%) and stearic acid (2.5%) were the major fatty acids detected. Finally, heat map and principal component analysis allowed us to classify the studied provinces in terms of VOO chemical composition: Chefchaouen (tyrosol and hydroxytyrosol), Taounate (oleuropein aglycone), Errachidia (ferulic acid, w-3 and w-6), Beni Mellal (oleocanthal) and Taza (luteolin and oleic acid).

Proposal of a Linear Retention Index System for Improving Identification Reliability of Triacylglycerol Profiles in Lipid Samples by Liquid Chromatography Methods.

The retention index system was proposed in 1958 by Kováts. It is based on the correlation between the retention time of the analytes and the ones of a series of reference standards, making retention data dependent on the chromatographic phenomenon only, viz., on the three-term interaction analyte-stationary phase-mobile phase. Particularly in GC, because the mobile phase has a negligible influence, the retention of the analytes depends almost entirely on the stationary phase and it is as independent as possible from operating conditions. This makes retention index databases usable in samples identification at both the intra- and interlaboratory levels. The scope of this research was to create a similar identification system in LC, where the identification of unknowns is still a challenge because of the unavailability of spectral databases related to the low reproducibility of mass spectra generated by means of the atmospheric pressure ionization technique normally interfaced to LC. Lipid compounds, specifically triacylglycerols, were selected as target analytes mainly due to their regular chromatographic LC profile under reversed phase conditions. The odd carbon chain number triacylglycerol series from trinonain to trinonadecanoin was chosen as the basis of the retention index scale and a database of 209 triacylglycerols was built. For this purpose an ultra high-performance LC method, able to maximize the baseline separation of triacylglycerols in different real-world samples (vegetable oils, fish, and milk samples) was developed.

Effect of solvent on the extraction of phenolic compounds and antioxidant capacity of hazelnut kernel.

Hazelnut kernel phenolic compounds were recovered applying two different extraction approaches, namely ultrasound-assisted solid/liquid extraction (UA-SLE) and solid-phase extraction (SPE). Different solvents were tested evaluating total phenolic compounds and total flavonoids contents together to antioxidant activity. The optimum extraction conditions, in terms of the highest value of total phenolic compounds extracted together to other parameters like simplicity and cost were selected for method validation and individual phenolic compounds analysis. The UA-SLE protocol performed using 0.1 g of defatted sample and 15 mL of extraction solvent (1 mL methanol/1 mL water/8 mL methanol 0.1% formic acid/5 mL acetonitrile) was selected. The analysis of hazelnut kernel individual phenolic compounds was obtained by HPLC coupled with DAD and MS detections. Quantitative analysis was performed using a mixture of six phenolic compounds belonging to phenolic classes' representative of hazelnut. Then, the method was fully validated and the resulting RSD% values for retention time repeatability were below 1%. A good linearity was obtained giving R2 no lower than 0.997.The accuracy of the extraction method was also assessed. Finally, the method was applied to the analysis of phenolic compounds in three different hazelnut kernel varieties observing a similar qualitative profile with differences in the quantity of detected compounds.