Boronic Acid Moieties Stabilize Adhesion of Microalgal Biofilms on Glassy Substrates: A Chemical Tool for Environmental Applications.

Photosynthetic organisms such as diatoms microalgae provide innovative routes to eco-friendly technologies for environmental pollution bioremediation. Living diatoms are capable to incorporate in vivo a wide variety of chemical species dispersed in seawater, thus being promising candidates for eco-friendly removal of toxic contaminants. However, their exploitation requires immobilization methods that allow to confine microalgae during water treatment. Here we demonstrate that a biofilm of Phaeodactylum tricornutum diatom cells grown on the surface of a glassy substrate bearing boronic acid protruding moieties is stably anchored to the substrate resisting mechanical stress and it is suitable for removal of up to 80 % metal ions (As, Cr, Cu, Zn, Sn, Pb, Sb) in a model polluted water sample. Control experiments also suggest that stabilization of the biofilm adhesion occurs by interaction of boronic acid surface groups of the substrate with the hydroxyl groups of diatoms extracellular polysaccharides.

Drug Delivery through Epidermal Tissue Cells by Functionalized Biosilica from Diatom Microalgae.

Diatom microalgae are a natural source of fossil biosilica shells, namely the diatomaceous earth (DE), abundantly available at low cost. High surface area, mesoporosity and biocompatibility, as well as the availability of a variety of approaches for surface chemical modification, make DE highly profitable as a nanostructured material for drug delivery applications. Despite this, the studies reported so far in the literature are generally limited to the development of biohybrid systems for drug delivery by oral or parenteral administration. Here we demonstrate the suitability of diatomaceous earth properly functionalized on the surface with n-octyl chains as an efficient system for local drug delivery to skin tissues. Naproxen was selected as a non-steroidal anti-inflammatory model drug for experiments performed both in vitro by immersion of the drug-loaded DE in an artificial sweat solution and, for the first time, by trans-epidermal drug permeation through a 3D-organotypic tissue that better mimics the in vivo permeation mechanism of drugs in human skin tissues. Octyl chains were demonstrated to both favour the DE adhesion onto porcine skin tissues and to control the gradual release and the trans-epidermal permeation of Naproxen within 24 h of the beginning of experiments. The evidence of the viability of human epithelial cells after permeation of the drug released from diatomaceous earth, also confirmed the biocompatibility with human skin of both Naproxen and mesoporous biosilica from diatom microalgae, disclosing promising applications of these drug-delivery systems for therapies of skin diseases.

Volatile Organic Compounds, Indole, and Biogenic Amines Assessment in Two Mediterranean Irciniidae (Porifera, Demospongiae).

Solid phase microextraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS) was employed for the headspace determination of the volatile organic fraction emitted by two of the most common Mediterranean demosponges, Ircinia variabilis and Sarcotragus spinosulus, and of indole and some biogenic amines released by sponges in an aqueous medium. A total of 50/30 µm divinylbenzene/carboxen/polydimethylsiloxane and 75 µm carboxen/polydimethylsiloxane fibers were used for the headspace extraction of low molecular weight sulfur compounds from a hermetically sealed vial containing sponge fragments, while the direct immersion determination of indole and biogenic amines was performed. The biogenic amines were extracted after in-solution derivatization with isobutyl chloroformate. All analytical parameters (linearity, limits of detection, and quantification, precision, and recovery) were evaluated for indole and biogenic amines. SPME-GC-MS proved to be a reliable means of highlighting the differences between molecules released by different sponges, principally responsible for their smell. The combined approaches allowed the identification of several volatile compounds in the headspace and other molecules released by the sponges in an aqueous medium, including indole and the BAs cadaverine, histamine, isobutylamine, isopentylamine, propylamine, 2-phenylethylamine, putrescine and tryptamine. The results obtained represent a further contribution to the picture of odoriferous molecules secreted by sponges.

Synthesis of Tailored Perfluoro Unsaturated Monomers for Potential Applications in Proton Exchange Membrane Preparation.

The aim of the present work is the synthesis and characterization of new perfluorinated monomers bearing, similarly to Nafion®, acidic groups for proton transport for potential and future applications in proton exchange membrane (PEM) fuel cells. To this end, we focused our attention on the synthesis of various molecules with (i) sufficient volatility to be used in vacuum polymerization techniques (e.g., PECVD)), (ii) sulfonic, phosphonic, or carboxylic acid functionalities for proton transport capacity of the resulting membrane, (iii) both aliphatic and aromatic perfluorinated tags to diversify the membrane polarity with respect to Nafion®, and (iv) a double bond to facilitate the polymerization under vacuum giving a preferential way for the chain growth of the polymer. A retrosynthetic approach persuaded us to attempt three main synthetic strategies: (a) organometallic Heck-type cross-coupling, (b) nucleophilic displacement, and (c) Wittig-Horner reaction (carbanion approach). Preliminary results on the plasma deposition of a polymeric film are also presented. The variation of plasma conditions allowed us to point out that the film prepared in the mildest settings (20 W) shows the maximum monomer retention in its structure. In this condition, plasma polymerization likely occurs mainly by rupture of the π bond in the monomer molecule.

Supercritical CO2 Extraction of Phytocompounds from Olive Pomace Subjected to Different Drying Methods.

Olive pomace is a semisolid by-product of olive oil production and represents a valuable source of functional phytocompounds. The valorization of agro-food chain by-products represents a key factor in reducing production costs, providing benefits related to their reuse. On this ground, we herein investigate extraction methods with supercritical carbon dioxide (SC-CO2) of functional phytocompounds from olive pomace samples subjected to two different drying methods, i.e., freeze drying and hot-air drying. Olive pomace was produced using the two most common industrial olive oil production processes, one based on the two-phase (2P) decanter and one based on the three-phase (3P) decanter. Our results show that freeze drying more efficiently preserves phytocompounds such as α-tocopherol, carotenoids, chlorophylls, and polyphenols, whereas hot-air drying does not compromise the ß-sitosterol content and the extraction of squalene is not dependent on the drying method used. Moreover, higher amounts of α-tocopherol and polyphenols were extracted from 2P olive pomace, while ß-sitosterol, chlorophylls, and carotenoids were more concentrated in 3P olive pomace. Finally, tocopherol and pigment/polyphenol fractions exerted antioxidant activity in vitro and in accelerated oxidative conditions. These results highlight the potential of olive pomace to be upcycled by extracting from it, with green methods, functional phytocompounds for reuse in food and pharmaceutical industries.

Development, Optimization, and Comparison of Different Sample Pre-Treatments for Simultaneous Determination of Vitamin E and Vitamin K in Vegetables.

The absence of vitamin E from the diet can lead to cardiovascular disease, cancer, cataracts, and premature aging. Vitamin K deficiency can lead to bleeding disorders. These fat-soluble vitamins are important nutritional factors that can be determined in different methods in vegetables. In this work, the simultaneous determination of α-tocopherol, α-tocopheryl acetate, phylloquinone, and menaquinone-4 by gas chromatography-mass spectrometry (GC-MS) has been optimized using both direct injection and solid phase microextraction (SPME). Three different sample pre-treatment approaches based on: (A) solid-liquid-liquid-liquid extraction (SLE-LLE), (B) SLE, and (C) SPME were then applied to extract the target analytes from vegetables samples using menaquinone as internal standard. All the procedures allowed the determination of the target analytes in onion, carrot, celery, and curly kale samples. Similar results were obtained with the three different approaches, even if the one based on SPME offers the best performance, together with a reduced use of solvent, time consumption, and experimental complexity, which makes it the preferable option for industrial applications.

Highly selective palladium-benzothiazole carbene-catalyzed allylation of active methylene compounds under neutral conditions.

The Pd-benzothiazol-2-ylidene complex I was found to be a chemoselective catalyst for the Tsuji-Trost allylation of active methylene compounds carried out under neutral conditions and using carbonates as allylating agents. The proposed protocol consists in a simplified procedure adopting an in situ prepared catalyst from Pd2dba3 and 3-methylbenzothiazolium salt V as precursors. A comparison of the performance of benzothiazole carbene with phosphanes and an analogous imidazolium carbene ligand is also proposed.

Palladium-catalyzed cross-coupling of styrenes with aryl methyl ketones in ionic liquids: direct access to cyclopropanes.

The combined use of Pd(OAc)2 , Cu(OAc)2 , and dioxygen in molten tetrabutylammonium acetate (TBAA) promotes an unusual cyclopropanation reaction between aryl methyl ketones and styrenes. The process is a dehydrogenative cyclizing coupling that involves a twofold CH activation at the α-position of the ketone. The substrate scope highlights the flexibility of the catalyst; a reaction mechanism is also proposed.

Supercritical Fluid Extraction of Bioactive Components from Apple Peels and Their Modulation of Complex I Activity in Isolated Mitochondria.

Supercritical fluid extraction (SFE) was used to extract bioactive compounds from apple (Malus domestica) peel waste from three different Italian cultivars. The bioactive fractions were extracted applying a temperature of 60 °C and a pressure of 250 bar for 15 min with 20% ethanol as co-solvent, at a flow rate of 2 mL/min. The total polyphenol (TP), anthocyanin (TA), ascorbic acid (AA), and antioxidant activity contents (TACs) were measured, while chromatographic analyses were performed to highlight the differences between the extracts. The Stark cultivar had the highest levels of polyphenols, anthocyanins, and ascorbic acid, while the Royal Gala cultivar showed the highest total antioxidant activity. SFE extracts were then tested for their effect on the mitochondrial NADH-ubiquinone oxidoreductase (Complex I) activity on mitochondria isolated from human embryonic kidney cells (HEK239). The Stark extract showed the most positive response in terms of NADH oxidation. The results obtained in this work highlight the potential of apple peel waste as a source of functional phytocompounds and suggest that Stark cultivar extracts may be exploited for pharmacological applications. This study supports the circular bioeconomy by promoting the use of waste products as a valuable resource.

Spotlight on Secondary Metabolites Produced by an Early-Flowering Apulian Artichoke Ecotype Sanitized from Virus Infection by Meristem-Tip-Culture and Thermotherapy.

Globe artichoke (Cynara cardunculus L. subsp. scolymus) is an important crop of the Mediterranean basin characterized by many properties, like hepatoprotective, anticarcinogenic, antioxidant, antibacterial, and beneficial to human health. The high bioactive compounds (BACs) content, as polyphenols, has attracted the research interest in artichoke extracts. We analysed the changes in polyphenol transcriptome profile between sanitized (S) virus-free and non-sanitized (NS) artichoke plants, focusing on genes involved in phenylpropanoid metabolic pathway and flavonoid biosynthesis. A total of 2458 upregulated and 2154 downregulated differentially expressed genes (DEGs) were functionally characterized. Among them, 31 and 35 KEGG orthology entries characterized by upregulated and downregulated DEGs, respectively, were involved in the biosynthesis of other secondary metabolites. A downregulation of PAL, C4H, 4CL, HST/HQT, C3'H, CCoAMT, CCR1, and F5H, was observed in S artichoke compared to NS one, whereas the CSE, CHS, and CHI genes were upregulated in S samples. Transcriptome results were compared to the polyphenols accumulation in S and NS artichoke leaves. A higher content of total polyphenols was observed in older leaves of NS samples, compared to extracts obtained from young leaves or from S plants, and this result was associated with the presence of viral infections in NS plants. In all the conditions tested, the most represented compound was chlorogenic acid, followed by luteolin-7-O-glucoside. The different composition of each extract was evaluated by a polyphenol dose-response treatment on the rodent hepatoma FaO cell line to the accumulation of reactive oxygen species (ROS). A significant reduction in ROS content ranging between -40% and -48% was observed when 10-20 mg/L of polyphenols from NS or S plants were used, characterized by a specific profile of compounds. To reduce MetOH residues in polyphenol extracts, a supercritical fluid CO2 extraction was evaluated to propose a sustainable green extraction.

A melanin-like polymer bearing phenylboronic units as a suitable bioplatform for living cell display technology.

Surface display of functional groups with specific reactivity around living cells is an emerging, low cost and highly eco-compatible technology that serves multiple applications, ranging from basic biochemical studies to biomedicine, therapeutics and environmental sciences. Conversely to classical methods exploiting hazardous organic synthesis of precursors or monovalent functionalization via genetics, here we perform functional decoration of individual living microalgae using suitable biocoatings based on polydopamine, a melanin-like synthetic polymer. Here we demonstrate the one-pot synthesis of a functional polydopamine bearing phenylboronic units which can decorate the living cell surfaces via a direct ester formation between boronic units and surface glycoproteins. Furthermore, biosorption of fluorescent sugars on functionalized cell membranes is triggered, demonstrating that these organic coatings act as biocompatible soft shells, still functional and reactive after cell engineering.

Analytical Investigation of Phthalates and Heavy Metals in Edible Ice from Vending Machines Connected to the Italian Water Supply.

Edible ice is often produced by special machines that can represent a source of significant chemical and microbiological contamination. In this work, the presence of phthalic acid esters (phthalates, PAEs) and heavy metals in ice cubes distributed by 77 vending machines installed in two different zones in southern Italy and fed by water from the public water supply was investigated. Solid-phase microextraction coupled to gas chromatography-mass spectrometry (SPME-GC/MS) was used to evaluate contamination with four PAEs, which were selected because they are commonly used in the production of food-contact plastics, while inductively coupled plasma mass spectrometry (ICP/MS) was used to quantify the heavy metals. It was found that ice samples, especially those from one of the two considered zones (zone 2), exceeded the dibutyl phthalate (DBP) threshold limit value; some ice cubes from the other zone (zone 1) instead showed levels of both lead (Pb) and nickel (Ni) up to one order of magnitude higher than those observed in samples collected in zone 2 and higher than the maximum permitted values (European Directive n. 2184/2020). Since the water source connected to the ice vending machines was found to be free from significant levels of all considered target compounds and metals, the high levels of DBP, Ni, and Pb in ice cubes could be attributed to the components and/or to the state of repair of the ice vending machines themselves.

Pd nanoparticle catalysed one-pot sequential Heck and Suzuki couplings of bromo-chloroarenes in ionic liquids and water.

Pd nanoparticles generated in green reaction media (viz. ionic liquids and water) catalyze the one-pot sequential Heck and Suzuki coupling reactions of bromo-chloroarenes to afford unsymmetrically substituted arenes in good yields.

Use of Biochar to Improve the Sustainable Crop Production of Cauliflower (Brassica oleracea L.).

In agriculture, biochar (B) application has been suggested as a green technology to reduce nitrate pollution from agricultural origins and improve crop yield. The agronomic impact of B use on soil has been extensively studied, while knowledge of its possible effects on horticultural cultivation is still scarce. A greenhouse experiment was conducted to evaluate the effect of using biochar in soils treated with two different rates of nitrogen fertilizers on soil properties and nitrogen (N) leachate. This study also investigated the vegetative parameters during the crop growing season of Brassica oleracea L. var. botrytis. Soil mesocosms were set up to test the following treatments: untreated/control (C); normal dose of N fertilizer (130 kg N ha-1) (ND); ND+B; high dose of N fertilizer (260 kg N ha-1) (HD); and HD+B. Principal component analysis and cluster analysis were exploited to assess biochar's ability to reduce nitrate leaching and enhance soil-vegetative properties. Biochar addition affected the soil chemical properties of the fertilized microcosms (ND and HD). Biochar increased the NH4+ content in HD soil and the NO3- content in ND soil by 26 mg/L and 48.76 mg/L, respectively. The results showed that biochar application increased the marketable cauliflower yield. In ND+B and HD+B, the curd weight was 880.68 kg and 1097.60 kg, respectively. In addition, a small number of nitrogenous compounds in the leachate were quantified in experimental lines with the biochar. Therefore, biochar use improves the marketable yield of horticulture, mitigating the negative impacts associated with the mass use of N fertilizers in agriculture.

Enhanced Natural Attenuation of Groundwater Cr(VI) Pollution Using Electron Donors: Yeast Extract vs. Polyhydroxybutyrate.

Remediation interventions based on the native bacteria's capability to reduce Cr(VI) represent a valid strategy in terms of economic and environmental sustainability. In this study, a bioremediation test was carried out using viable microcosms set with groundwater and deep soil (4:1), collected from the saturated zone of an industrial site in Southern Italy that was polluted by ~130 µg L-1 of Cr(VI). Conditions simulating the potential natural attenuation were compared to the enhanced natural attenuation induced by supplying yeast extract or polyhydroxybutyrate. Sterile controls were set up to study the possible Cr(VI) abiotic reduction. No pollution attenuation was detected in the unamended viable reactors, whereas yeast extract provided the complete Cr(VI) removal in 7 days, and polyhydroxybutyrate allowed ~70% pollutant removal after 21 days. The incomplete abiotic removal of Cr(VI) was observed in sterile reactors amended with yeast extract, thus suggesting the essential role of native bacteria in Cr(VI) remediation. This was in accordance with the results of Pearson's coefficient test, which revealed that Cr(VI) removal was positively correlated with microbial proliferation (n = 0.724), and also negatively correlated with pH (n = -0.646), dissolved oxygen (n = -0.828) and nitrate (n = -0.940). The relationships between the Cr(VI) removal and other monitored parameters were investigated by principal component analysis, which explained 76.71% of the total variance.

Chemical characterisation of PM10 from ship emissions: a study on samples from hydrofoil exhaust stacks.

A chemical characterization of PM10 collected at hydrofoil exhaust stacks was performed conducting two on-board measuring campaigns, with the aim of assessing the ship emission impact on PM10 collected in the coastal area of Naples (Southern Italy) and providing information about the characteristics of this important PM emission source.Samples were analysed determining the contribution of different chemical parameters to PM10's mass, which consisted of polycyclic aromatic hydrocarbons (PAHs) (0.10 ± 0.12%), total carbon (61.9% ± 20.0%, with 40.4% of organic carbon, OC, and 21.5% of elemental carbon, EC) and elemental fraction (0.44% ± 1.00%). Differences in terms of composition and chemical parameter profiles were observed between samples collected during offshore navigation (Off) and samples collected during shunting operations (SO), the latter of higher concern on a local scale. For SO samples, lower contributions of OC and EC were observed (39.7% and 19.6% respectively) compared to Off samples (41.5% and 24.2%), and an increase in terms of elements (from 0.32 to 0.51%) and PAHs (from 0.06 to 0.12%) concentrations was observed. In addition, enrichment factors (EFs) for some elements such as V, Zn, Cd, Cu, Ag and Hg as well as PAHs profile varied significantly between SO and Off. Data presented here were compared with data on chemical composition of PM10 sampled in a tunnel, in a background site and in an urban site in the city of Naples. Results indicated that shipping activities contributed significantly to the emission of V and, in some extent, Zn and Cd; in addition, PAH profiles indicated a greater contribution to urban PM10 from vehicular traffic than shipping emissions. These results can significantly contribute to the correct evaluation of the influence of shipping emission on PM10 generation in urban coastal areas and can be a useful reference for similar studies. The coastal area of Naples is an important example of the coexistence of residential, touristic and natural areas with pollutants emission sources including, among the others, shipping emissions. In this and similar contexts, it is important to distinguish the contribution of each emission source to clearly define environmental control policies.

Anti-fouling activity and toxicity of the Mediterranean alien sponge Paraleucilla magna Klautau, Monteiro & Borojevic, 2004 (Porifera, Calcarea).

Poriferans, as sessile organisms without rigid external covering, use secondary metabolites for protection from predators and fouling organisms. The present study tested the antifouling activity of ethanolic extract of the Mediterranean alien calcareous sponge Paraleucilla magna towards juvenile mussels Mytilus galloprovincialis. Furthermore, toxicity tests on nauplii of brine shrimp Artemia salina and two microalgae strains, Nannochloropsis sp. and Tetraselmis suecica, were also conducted. A total attachment inhibition of M. galloprovincialis was achieved at a concentration of 400 µg/mL of sponge extract. The 50% mortality of A. salina nauplii was recorded at a concentration of 500 µg/mL of ethanolic extract. The growth inhibitory effect on both marine microalgae strains has been registered at a concentration of 300 µg/mL. Our results suggest promising natural antifouling activity and low toxicity of the ethanolic extract of P. magna that could be used as antifouling compound.

Concerning Synthesis of New Biobased Polycarbonates with Curcumin in Replacement of Bisphenol A and Recycled Diphenyl Carbonate as Example of Circular Economy.

Curcumin (CM) is a natural polyphenol wellknown for its antioxidant and pharmaceutical properties, that can represent a renewable alternative to bisphenol A (BPA) for the synthesis of biobased polycarbonates (PC). In the presented strategy, preparation of the CMbased PC was coupled with chemical recycling of the fossilbased BPA polycarbonate (BPAPC) conducting a twosteps transpolymerization that replaces BPA monomer with CM or its tetrahydrogenated colorless product (THCM). In the first step of synthetic strategy, depolymerization of commercial BPAPC was carried out with phenol as nucleophile, according to our previous procedure based on zinc derivatives and ionic liquids as catalysts, thus producing quantitatively diphenyl carbonate (DPC) e BPA. In the second step, DPC underwent a melt transesterification with CM or THCM monomers affording the corresponding biobased polycarbonates, CMPC and THCMPC, respectively. THCM was prepared by reducing natural bisphenol with cyclohexene as a hydrogen donor and characterized by 1H-NMR and MS techniques. Polymerization reactions were monitored by infrared spectroscopy and average molecular weights and dispersity of the two biobased polymers THCMPC and CMPC were determined by means of gel permeation chromatography (GPC). Optical properties of the prepared polymers were also measured.

Advanced Gel Permeation Chromatography system with increased loading capacity: Polycyclic aromatic hydrocarbons detection in olive oil as a case of study.

Gel permeation chromatography (GPC) is herein used as size exclusion clean-up technique for highly sensitive and straightforward detection of Polycyclic Aromatic Hydrocarbons (PAHs) in olive oil samples. An advanced chromatographic system has been developed to isolate a series of PAHs with cancerogenic potential, including PAH4 (benzo(a)pyrene BaP, benzo(a)anthracene BaA, benzo(b)fluoranthene BbF and chrysene Chry) reported in the European Regulation. The system avails of two glass chromatographic columns and a switching valve, that allow removal of interfering analytes in olive oil without resorting to any preliminary extraction process. A seven-fold increase of the loaded sample amount versus conventional chromatographic systems (1 g vs 0.150 g) has been pursued, as well as improved PAHs detection and quantification limits (LOD-LOQ for PAH4: 0.21-0.70 ng/g for BaA, 0.26-0.86 ng/g for Chry, 0.23-0.76 ng/g for BbF, 0.32-1.06 ng/g for BaP), in accordance with the continuous need of more and more reducing these limits in food analysis by the European Regulation. The protocol developed represents a highly innovative and efficient analytical method for organic pollutants in complex biological matrices as olive oil, that can have huge impact on technology for PAHs detection in food samples, being suitable for both industrial and small-scale laboratories.

Occurrence and spatial distribution of dioxin and dioxin-like compounds in topsoil of Taranto (Apulia, Italy) by GC-MS analysis and DR-CALUX® bioassay.

The aim of the present study was to assess the occurrence and spatial distribution of PCDD/Fs and dioxin-like compounds in topsoils of Taranto (Apulia Region), one of the most heavily industrialized and contaminated area of Southern Italy. A combined approach of chemical analysis by GC-MS/MS and AhR reporter gene bioassay was applied in a subset of topsoil samples (n = 20) collected in 2017-18 from ten sites embracing three levels of risk (from high to low) in the framework of a large survey inside Taranto municipality. TCDD-BEQs and GC-MS/MS TEQWHO and TEQTHEORETICAL revealed a decreasing trend with the distance from main industrial settings and landfill areas. A strong correlation between TCDD-BEQs and TEQWHO values (R2 = 0.85) and TEQTHEORETICAL (R2 = 0.88) was also found. In 3 out of 10 topsoil investigated, BEQs and TEQWHO/THEORETICAL resulted above Italian National Regulatory Limits for ∑PCDD/Fs in green, private and recreational used soils (10 ng TEQ/kg d.w. D.Lgs 152/2006) and for ∑PCDD/F/dl-PCBs in agricultural and farming soil (6 ng TEQ/kg d.w. D.M. 46/2019). GC-MS/MS pattern revealed the highest prevalence of dl-PCBs in 6 out of 10 sites, followed by PCDFs and PCDDs. Those sites are all located in proximity of main industrial steel and iron ore sinter plant, steel plant's landfills and illegal dumping sites. An update on occurrence and spatial distribution of PCDD/Fs and dl-PCBs contamination of Taranto urban soils was obtained and the DR-CALUX® bioassay was further recommended as a suitable screening tool for environmental and human risk assessment.