Alcohol-Selective Oxidation in Water under Mild Conditions via a Novel Approach to Hybrid Composite Photocatalysts

2015

Abstract The oxidation of alcohols to carbonyl compounds in a clean fashion (i.e., with water as a solvent or under solvent‐free conditions, and using O2 or H2O2 as the primary oxidant) is the subject of considerable research efforts. A new approach for the selective oxidation of soluble aromatic alcohols in water under mild conditions via a novel composite photocatalyst has been developed. The catalyst is synthesized by grafting 4‐(4‐(4‐hydroxyphenylimino)cyclohexa‐2,5dienylideneamino)phenol and silver nanoparticles onto the surface of moderately crystalline titanium dioxide. The titanium dioxide‐based composite was first extensively characterized and then employed in the catalytic oxidati…

Waste-free electrochemical oxidation of alchools in water

2006

We describe a new sol-gel molecular electrode made of a thin layer of organosilica doped with the nitroxyl radical TEMPO (2,2,6,6-tetrame-thylpiperidine-1-oxyl) electrodeposited on the surface of an ITO-coated glass and its employment as a selective and versatile oxidation catalyst in the electrochemical conversion of different alcohols to carbonyl compounds. Environmentally friendly water or a water/acetonitrile mixture buffered with bicarbonate is used as solvent. The electrode is highly stable and it can be reused for a prolonged period of time allowing easy separation from the products.

One-pot electrocatalytic oxidation of glycerol to DHA

2006

Abstract One-pot, waste-free oxidation of glycerol to 1,3-dihydroxyacetone (DHA) was achieved by simply applying a small electric potential (1.1 V vs Ag/AgCl) to a glycerol solution in water buffered at pH 9.1 in the presence of 15 mol % TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl). Prolonging the reaction time affords comparable amounts of hydroxypyruvic acid.

Enhanced Heterogeneous Catalytic Conversion of Furfuryl Alcohol into Butyl Levulinate

2014

We study the catalytic condensation of furfuryl alcohol with 1-butanol to butyl levulinate. A screening of several commercial and as-synthesized solid acid catalysts shows that propylsulfonic acid-functionalized mesoporous silica outperforms the state-of-the-art phosphotungstate acid catalysts. The catalyst is prepared via template-assisted sol-gel polycondensation of TEOS and MPTMS. It gives 96 % yield (and 100 % selectivity) of butyl levulinate in 4h at 110 °C. Reaction profiles before and after a hot filtration test confirm that the active catalytic species do not leach into the solution. The catalyst synthesis, characterization, and mode of operation are presented and discussed. Sour ca…

TiO2-Based Photocatalysis for Organic Synthesis

2010

A major aim of the contemporary chemistry is to replace old environmentally hazardous processes with new, energy efficient routes allowing to reduce or totally avoid the use and production of harmful chemicals and to maximise the quantity of raw material that ends up in the final product. This chapter gives an account of TiO2-based selective photocatalysis as a green synthetic tool for the production of organics. Some case studies of the most common transformations carried out by means of photocatalytic reactions are illustrated in a midway perspective between photochemistry and organic chemistry.

Cross-linked natural IntegroPectin films from citrus biowaste with intrinsic antimicrobial activity

2022

AbstractPectin recovered via hydrodynamic cavitation (IntegroPectin) from lemon and grapefruit agri-food waste intrinsically containing antimicrobial bioactive substances (flavonoids, phenolic acids, terpenes, and terpenoids) was used to generate innovative and eco-compatible films that efficiently inhibit the growth of Gram-negative pathogens. Extensive characterization of films confirmed the presence of these substances, which differently interact with the polysaccharide polymer (pectin), plasticizer (glycerol), surfactant (Tween 60), and cross-linker (Ca2+), conferring to these films a unique structure. Besides, IntegroPectin-based films constitute versatile systems for the sustained, co…

Heterogeneous vs Homogeneous Palladium Catalysts for Cross-Coupling Reactions

2012

A large number of immobilized-Pd-catalysts for cross-coupling reactions have been introduced in the last decade. Are the observed catalyzed reactions truly heterogeneous or are they homogeneous due to leached palladium? This account critically addresses the leaching issue by selectively referring to some of the newly developed catalytic systems in an attempt to evaluate said systems based on uniform criteria. The report is concluded by identifying the relevant chemical and structural challenges in the field.

Structural insight on organosilica electrodes for waste-free alcohol oxidations

2007

Organic modification of sol-gel catalytic glassy electrodes made of a thin layer of organosilica doped with nitroxyl radical TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) crucially enhances stability in the waste-free oxidation of alcohols to carbonyls in water. Structural comparison between analogous films made of organosilica and unmodified SiO2 shows that the origin of the pronounced stable activity of the ORMOSIL film lies in high hydrophobic and also in the pronounced low degree of hydrophilicity.

Protective, antioxidant and antiproliferative activity of grapefruit integropectin on sh-sy5y cells

2021

Tested in vitro on SH-SY5Y neuroblastoma cells, grapefruit IntegroPectin is a powerful protective, antioxidant and antiproliferative agent. The strong antioxidant properties of this new citrus pectin, and its ability to preserve mitochondrial membrane potential and morphology, severely impaired in neurodegenerative disorders, make it an attractive therapeutic and preventive agent for the treatment of oxidative stress-associated brain disorders. Similarly, the ability of this pectic polymer rich in RG-I regions, as well as in naringin, linalool, linalool oxide and limonene adsorbed at the outer surface, to inhibit cell proliferation or even kill, at high doses, neoplastic cells may have open…

Enhanced Mechanical Properties in Organofluorosilica Thin Films

2008

Fluorinated hybrid organic-inorganic silicates (ORMOSIL) thin films display exceptional mechanical properties in terms of both hardness and elastic modulus that can be finely tuned by varying the angular velocity of the spin coating process. Hence, as traditional alkyl-modified silica xerogels generally show poor mechanical behavior, these materials offer a solution to a major limitation to applicability of ORMOSIL-based films.

The chemical effects of molecular sol–gel entrapment

2007

Chemical conversions within the cages of doped sol-gel porous oxides take place with unique advantages over reactions in solution as the glassy matrix has tremendous effects on the reactivity of the entrapped molecules. The chemical properties of sol-gel materials can be tailored in an immense range of values and chemists are increasingly achieving control on reactions taking place within these matrices, including crucially important photovoltaics. Highlighting recent major advancements, we show in this tutorial review how this is actually taking place.

Graphite-supported TiO2 for 4-nitrophenol degradation in a photoelectrocatalytic reactor

2009

WOS: 000274769500044

A new class of heterogeneous Pd catalysts for synthetic organic chemistry

2011

A new series of leach-proof nanostructured Pd(0) catalysts able to catalyze a number of fundamental organic transformations including C–C bond formation has been developed. Reactions in general proceed with high yield and often at completion, while the catalysts can be reused in further reaction runs. This establishes a new class of relevant solid catalysts for synthetic organic chemistry trademarked SiliaCat Pd0 Hydrogel.

Grapefruit IntegroPectin isolation via spray drying and via freeze drying: A comparison

2022

The comparison of grapefruit IntegroPectin powders isolated via spray drying and via freeze drying in terms of phenolic content, quantification of the most representative flavonoids (naringin and hesperidin), radical scavenging activity, total protein content and pH of the aqueous solutions provides relevant information. Except for the protein content and the antioxidant power, the two drying methods afford similar pectins. Optimization of the spray drying parameters allowed to maximize the yield of isolated pectin that nearly approached (>95%) the quantitative yield obtained via freeze drying.

Towards a new treatment against polymicrobial infections: high antibacterial activity of lemon IntegroPectin against Pseudomonas aeruginosa and Esche…

2020

AbstractLemon IntegroPectin obtained via hydrodynamic cavitation of waste lemon peel in water only shows high antibacterial activity against two Gram-negative bacteria, Pseudomonas aeruginosa and Escherichia coli. The antibacterial effect against the ubiquitous pathogen P. aeruginosa was evaluated in terms of the minimal bactericidal (MBC) and minimal inhibitory concentration (MIC). Preliminary insight on the antibacterial mechanism of IntegroPectin originates from investigating its inhibitory activity against E. coli. Given the non-cytotoxic nature of citrus IntegroPectin and the ease of its reproducible production in large amounts, the route is open to the industrial development of a new …

Vitamin D3 in fish oil extracted with limonene from anchovy leftovers

2020

Abstract Aiming to identify and assess the amount of fat-soluble vitamins in anchovy oil extracted with d-limonene from anchovy fillet leftovers via the UHPLC–HESI–MS advanced mass spectrometry analytical technique, this study shows that only vitamin D3 is present in anchovy by-product oil. The sum of the quantities of the three isomers of vitamin D3 amounts to 0.0815 μg vitamin D3 per g oil, namely a 81.5 μg/kg content, in good agreement with the typical amounts of vitamin D3 in fish oils (ranging from 18 to 350 μg/kg).

Green and Direct Synthesis of Benzaldehyde and Benzyl Benzoate in One Pot

2018

High yields of valued benzaldehyde and benzyl benzoate are obtained in one pot starting from benzyl alcohol using oxygen as only oxidant under mild conditions (2 bar O2, 100 °C) along with an ultralow amount (0.02 mol %) of Au nanoparticles heterogenized over a spherical ORMOSIL mesoporous support. The process is remarkably selective and the catalyst is stable.

Neuroprotective and Mitoprotective Effects of Lemon IntegroPectin on SH-SY5Y Cells

2021

AbstractLemon IntegroPectin obtained via hydrodynamic cavitation of organic lemon processing waste in water shows significant neuroprotective activity in vitro, as first reported in this study investigating the effects of both lemon IntegroPectin and commercial citrus pectin on cell viability, cell morphology, reactive oxygen species (ROS) production and mitochondria perturbation induced by treatment of neuronal SH-SY5Y human cells with H2O2. Mediated by ROS including H2O2 and its derivatives, oxidative stress alters numerous cellular processes, including mitochondrial regulation and cell signaling, propagating cellular injury that leads to incurable neurodegenerative diseases. These result…

Heterogeneously catalyzed Suzuki-Miyaura conversion of broad scope

2012

The reaction tolerates a broad range of functional groups in the coupling partners and is usually performed in solution under homogeneous conditions at T ¢ 60 uC using 2–3 mol% catalytic amounts. The catalyst is often a Pd(0) complex with triarylphosphane ligands. 2 The catalytic cycle (Scheme 2) begins with the oxidative addition of an aryl halide to a Pd(0) species formed in situ to form an arylpalladium(II) halide intermediate. 3 Chloroarenes, especially nonactivated aryl chlorides, are notoriously less reactive due to the stability of the C–Cl bond (the relative reactivity of Ar–X is correlated to the respective bond dissociation energy: Ph–Cl: 96 kcal mol 21 ,P h–Br: 81 kcal mol 21 ,P …

New neuroprotective effect of lemon integropectin on neuronal cellular model

2021

Lemon IntegroPectin obtained via hydrodynamic cavitation of organic lemon processing waste in water shows significant neuroprotective activity in vitro, as first reported in this study investigating the effects of both lemon IntegroPectin and commercial citrus pectin on cell viability, cell morphology, reactive oxygen species (ROS) production, and mitochondria perturbation induced by treatment of neuronal SH-SY5Y human cells with H2O2. Mediated by ROS, including H2O2 and its derivatives, oxidative stress alters numerous cellular processes, such as mitochondrial regulation and cell signaling, propagating cellular injury that leads to incurable neurodegenerative diseases. These results, and t…

From Molecules to Systems: Sol-Gel Microencapsulation in Silica-Based Materials

2010

Pectin: A Long-Neglected Broad-Spectrum Antibacterial.

2020

First reported in the late 1930s and first partly explained in 1970, the antibacterial activity of pectin remained almost ignored until the late 1990s. The concomitant emergence of research on natural antibacterials and on new usages of pectin polysaccharides, including those in medicine widely researched in Russia, has led to a renaissance of research in the physiological properties of this uniquely versatile polysaccharide ubiquitous in plants and fruits. Collecting scattered information, this study provides an updated overview on the subtle factors affecting the behaviour of pectin as antimicrobial. Less degraded pectin extracted via acid-free routes, we argue in the conclusions, will so…

ORMOSIL thin films: Tuning mechanical properties via a nanochemistry approach

2006

The mechanical properties (hardness and elastic modulus) of organically modified silicate thin films can be finely tuned by varying the degree of alkylation and thus the fraction of six- and four-membered siloxane rings in the organosilica matrix. This opens the way to large tunability of parameters that are of crucial practical importance for films that are finding increasing application in numerous fields ranging from microelectronics to chemical sensing.

C18 alkyl-modified silica: A suitable tool for olive biophenol green extraction

2017

Abstract A clean and straightforward methodology to assess the value of olive mill wastewater (OMWW) samples as well as to obtain biophenol-rich oils that can find employment in a variety of cosmetic, nutraceutical and pharmaceutical products is described. The method employs chromatographic spherical organosilica microparticles, coupled to advanced analytical techniques. OMWW samples obtained in Sicily from two different organically grown cultivars during the exceptional 2015/2016 olive oil season were analyzed, leading us to establish the conditions for optimal extraction of hydroxytyrosol and tyrosol.

Enhanced one-component spray polyurethane foams via sol-gel microspheres doped with aqueous glycerol

2013

The sol-gel microencapsulation of aqueous glycerol in silica-based microspheres affords functional materials that can be used to cure one-component polyurethane foams (OCF) formulations affording better and greener foam formation. These findings are important and may open the route to more sustainable materials, such as foams, coatings, adhesives, and sealants that are widely utilized in many industrial sectors. © 2013 American Chemical Society.

One-Pot, Clean Synthesis of Vanillic Acid from Ferulic Acid

2016

Ferulic acid dissolved in water is selectively oxidized to vanillic acid in high yield (≈60 %) under remarkably mild and green conditions, namely at room temperature with air as primary oxidant, over a catalytic amount of nanostructured Bi2WO6. The process is general and opens the route to the selective oxidation of natural substances into derivatives of significant applicative relevance.

Enhanced Heterogeneously Catalyzed Suzuki-Miyaura Reaction over SiliaCat Pd(0)

2013

Abstract The SiliaCat Pd(0) solid catalyst can be efficiently employed in the Suzuki–Miyaura cross-coupling of an ample variety of haloarenes, including economically viable chloroarenes. The catalyst can be extensively recycled without loss of activity and with low leaching of valued palladium, opening the route to widespread utilization of the method to afford high yields of biaryls devoid of contaminating by-products.

Heterogeneous Sonogashira Coupling over Nanostructured SiliaCat Pd(0)

2012

Sol–gel entrapped catalyst SiliaCat Pd(0) heterogeneously mediates the Sonogoashira coupling of different aryl halides and phenylacetylene either under thermal conditions or, much more efficiently, under microwave irradiation, affording good conversions of coupled products. Leaching of valued Pd is limited, and the catalyst can be reused.

Fragrant bioethanol: A valued bioproduct from orange juice and essential oil extraction

2018

Abstract We identify the composition of a less known, yet important bioproduct obtained in relatively high amount during orange fruit processing for juice and essential oil extraction comprised of bioethanol dissolving valued terpenes. Green cosmetic, perfume and biosolvent applications are anticipated.

Integral Extraction of Opuntia ficus-indica Peel Bioproducts via Microwave-Assisted Hydrodiffusion and Hydrodistillation

2019

The microwave-assisted hydrodiffusion extraction process affords high quality pectin and betanin from the peel of red and green Opuntia ficus-indica fruits under mild conditions. An aqueous mixture of valued bioproducts is readily obtained from the fruit peel cell water itself, without any water addition. The integral extract can be used as such to formulate nutraceutical beverages and products or, upon straightforward separation, to isolate pectin and betanin devoid of chemical contaminants suitable as ingredients for products ranging from food and beverage to cosmetic and pharmaceutical sectors. Betanin shows exceptional stability thanks to the high amounts of antioxidant polyphenols in t…

Nanochemistry Aspects of Titania in Dye Sensitized Solar Cells

2009

We analyze the main nanochemistry factors affecting photovoltaic performance in TiO2 employed as wide bandgap semiconductor in dye-sensitized solar cells (DSCs). What is the best morphology of the oxide? Which processes yield the required structures? Finally, putting the discussion in the context of the rapid evolution of photovoltaic technologies, we argue that new titania nanostructures will form the basic component of second-generation solar modules based on dye solar cells.

TiO2/ORMOSIL Thin Films Doped with Phthalocyanine Dyes:  New Photocatalytic Devices Activated by Solar Light

2008

WOS: 000253222200065

Photocatalytic partial oxidation of limonene to 1,2 limonene oxide

2018

The silylation of crystalline TiO2 P25, commonly used for photocatalytic degradation of pollutants, results in an exceptionally selective catalyst for the aerobic limonene epoxidation to 1,2-limonene oxide under solar light irradiation. The hypothesized mechanism involves the singlet oxygen generated through energy transfer from the excited TiO2 to adsorbed O2 molecules. The reaction product is the valued precursor of bio-based poly(limonene carbonate), a thermoplastic polymer of superior thermal and optical properties whose industrial production is in need of an efficient green synthesis of limonene oxide.

Quick assessment of the economic value of olive mill waste water

2016

Background: Olive biophenols are emerging as a valued class of natural products finding practical application in the food, pharmaceutical, beverage, cosmetic and nutraceutical industries due to their powerful biological activity which includes antioxidant and antimicrobial properties. Olive mill waste water (OMWW), a by-product in olive oil manufacturing, is rich in biophenols such as hydroxytyrosol and tyrosol. The amount of biophenols depends on the cultivar, the geographical area of cultivation, and the seasonal conditions. The goal of this study was to develop a straightforward method to assess the economic value of OMWW via quantification of hydroxytyrosol and tyrosol. Results: The amo…

Sol-gel entrapped visible light photocatalysts for selective conversions

2014

A general method to heterogenize, stabilize and significantly enhance the activity of selective visible light photocatalysts for aerobic oxidation of glycerol is devised. The new method makes use of the sol-gel encapsulation of photocatalytic species in silica-based matrices to afford leach-proof catalysts capable to afford valued products at low cost with little or no waste generation. In particular, the photocatalytic selective conversion of glycerol is performed in water solvent under ambient conditions with molecular oxygen as oxidant and visible light as the driving energy source, thereby meeting all requirements for a green chemical process. Entrapment of the semiconductor-based photo…

High Yields of Shrimp Oil Rich in Omega-3 and Natural Astaxanthin from Shrimp Waste

2020

A valued marine oil rich in omega-3 lipids and natural astaxanthin is obtained with remarkably high yield (up to S wt %) extending to pink shrimp waste (head and carapace) using the approach to extract fish oil from fish processing byproducts using D-limonene. Biobased limonene is an excellent solvent for both unsaturated lipids and astaxanthin-based carotenoids preventing oxidative degradation during the extraction cycle including solvent separation at 85 degrees C. Explaining the deep red color of the shrimp oil obtained, computational simulation suggests that D-limonene is also a good solvent for natural astaxanthin abundant in shrimp.

Characterization of Nanostructured SilicaCat Pd0

2011

Structural investigation on nanostructured SiliaCat Pd0 palladium catalyst sheds light into the origins of the remarkable activity of these new catalytic materials.

Self-assembled titania-silica-sepiolite based nanocomposites for water decontamination

2009

WOS: 000264524200020

Freeze drying versus Spray drying to obtain Grapefruit IntegroPectin powder

Background: IntegroPectin is a new family of citrus pectins of broad biological activity obtained via hydrodynamic cavitation of citrus biowaste carried out in water only. These pectins have already been isolated by freeze drying, a time-consuming and expensive procedure difficult to be scaled up. Since recently the spray drying technique has been greatly appreciated for food and pharmaceutical applications, this work proposes a comparison between Grapefruit IntegroPectin powders isolated via spray drying (SD) and via freeze drying (FD). Methods: A mini Spray Dryer B-290 with B-295 inert loop (Büchi) and a FreeZone 2.5 Liter freeze dry system (Labconco) were used. Dried powders comparison w…

A New Water-Soluble Bactericidal Agent for the Treatment of Infections Caused by Gram-Positive and Gram-Negative Bacterial Strains

2020

Grapefruit and lemon pectin obtained from the respective waste citrus peels via hydrodynamic cavitation in water only are powerful, broad-scope antimicrobials against Gram-negative and -positive bacteria. Dubbed IntegroPectin, these pectic polymers functionalized with citrus flavonoids and terpenes show superior antimicrobial activity when compared to commercial citrus pectin. Similar to commercial pectin, lemon IntegroPectin determined ca. 3-log reduction in Staphylococcus aureus cells, while an enhanced activity of commercial citrus pectin was detected in the case of Pseudomonas aeruginosa cells with a minimal bactericidal concentration (MBC) of 15 mg mL&minus

Volatile Compounds of Lemon and Grapefruit IntegroPectin

2020

An HS-SPME GC-MS analysis of the volatile compounds adsorbed at the outer surface of lemon and grapefruit pectins obtained via the hydrodynamic cavitation of industrial waste streams of lemon and grapefruit peels in water suggests important new findings en route to understanding the powerful and broad biological activity of these new pectic materials. In agreement with the ultralow degree of esterification of these pectins, the high amount of highly bioactive &alpha

Economic and Technical Feasibility of Betanin and Pectin Extraction from Opuntia ficus-indica Peel via Microwave-Assisted Hydrodiffusion

2019

Investigating the feasibility of betanin and pectin extraction from Opuntia ficus-indica peel via microwave-assisted hydrodiffusion and gravity, this study identifies selected important economic and technical aspects associated with this innovative production route starting from prickly pear fruit discards. Which benefits would be derived from this process? Would production be limited to Opuntia-growing countries or, likewise to what happens with dried lemon peel chiefly imported from Argentina, would production take place abroad also? Can distributed manufacturing based on clean extraction technology compete with centralized production using conventional chemical processes?

Omega-3 Extraction from Anchovy Fillet Leftovers with Limonene: Chemical, Economic, and Technical Aspects

2019

International audience; We investigate selected chemical, technical, and economic aspects of the production of fish oil rich in polyunsaturated omega-3 fatty acids from anchovy filleting leftovers using d-limonene as the extraction solvent at ambient temperature and pressure. Entirely derived from the orange peel prior to orange squeezing for juice production, the bio-based solvent is easily recovered, affording a circular economy process with significant potential for practical applications.

Beer produced via hydrodynamic cavitation retains higher amounts of xanthohumol and other hops prenylflavonoids

2017

Abstract Some of the most valuable bioactive compounds in beer comes from hops polyphenols, mainly flavonoids, some of which are unique to inflorescences of that flowering plant. Although far from pharmacologically relevant concentrations, low doses of xanthohumol and related prenylflavonoids found in beer contribute to the overall antioxidant activity of the product, as well as to significant chemopreventive action about certain diseases, such as cardiovascular, neurodegenerative, and some cancer types. Hence, the efforts to explore both ingredients and brewing methods aimed at enhancing the concentration of such bioactive compounds. In this study, a novel brewing method assisted by hydrod…

Superior Antibacterial Activity of Integral Lemon Pectin Extracted via Hydrodynamic Cavitation

2020

Abstract Pectin extracted via hydrodynamic cavitation in water only from waste lemon peel and further isolated via freeze drying displays significant antibacterial activity against Staphylococcus aureus, a Gram positive pathogen which easily contaminates food. The antibacterial effect of the new IntegroPectin is largely superior to that of commercial citrus pectin, opening the way to advanced applications of a new bioproduct now obtainable in large amounts and at low cost from citrus juice industry's waste.

Flavonoids in Lemon and Grapefruit IntegroPectin

2021

Abstract Following the analysis of terpenes present in new lemon and grapefruit “IntegroPectin” pectins obtained via the hydrodynamic cavitation of industrial lemon and grapefruit processing waste, the HPLC‐MS analysis of flavonoid and other phenolic compounds reveals the presence of eriocitrin, naringin, hesperidin and kaempferol typical of the respective citrus fruits. The pectic fibers rich in rhamnogalacturonan‐I regions act as chemical sponges adsorbing and concentrating at their outer surface highly bioactive citrus flavonoids and terpenes. These findings, together with the unique molecular structure of these new whole citrus pectins, provide preliminary insight into the broad‐scope b…

Hemicellulose hydrolysis catalysed by solid acids

2013

Depolymerising hemicellulose into platform sugar molecules is a key step in developing the concept of an integrated biorefinery. This reaction is traditionally catalysed by either enzymes or homogeneous mineral acids. We compared various solid catalysts for hemicellulose hydrolysis, running reactions in water, under neutral pH and relatively mild temperature and pressure (120°C and 10 bar) conditions. Sulphonated resins are highly active, but they leach out sulphonic groups. Sulphonated silicas are less active, but more stable. They have weakly and strongly bound sites and the strongly bound ones do not leach. Zeolites are moderately active and stable. Among them, H-ferrierite especially, d…

Oxidation of aminodiols mediated by homogeneous and heterogeneous TEMPO

2004

The conversion of amino diols to aminohy- droxy acids by oxidation of the primary hydroxy group mediated by homogeneous and heterogeneous TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl radi- cal) is reported. The synthesis uses NaOCl as primary oxidant and TEMPO, either dissolved in the homoge- neous phase or entrapped in a sol-gel matrix, as cata- lytic mediator. Homogeneous TEMPO is suitable for the oxidation of aliphatic methylamino diols, while the hybrid organic-inorganic silica sol-gel catalysts are more selective mediators for the oxidation of ben- zylic amino diols like the potent antibiotic chloram- phenicol which, under homogeneous conditions, are unselectively oxidized to benzoic ac…

Neuroprotective, antioxidant and antiproliferative activity of grapefruit IntegroPectin on SH-SY5Y cells

2021

AbstractTested in vitro on SH-SY5Y neuroblastoma cells, grapefruit IntegroPectin is a powerful neuroprotective, antioxidant and antiproliferative agent. The strong antioxidant properties of grapefruit IntegroPectin, and its ability to preserve mitochondrial membrane potential and morphology, severely impaired in neurodegenerative disorders, make this new biopolymer highly soluble in water an attractive therapeutic agent for oxidative stress-associated brain disorders. Similarly, the ability of this new citrus pectin rich in naringin, linalool, linalool oxide and limonene adsorbed at the outer surface to inhibit cell proliferation or even kill, at high doses, neoplastic cells, coupled to its…

Photocatalysis: a promising route for 21st century organic chemistry

2007

One of the main goals of 21st century chemistry is to replace environmentally hazardous processes with energy efficient routes allowing to totally avoid the use and production of harmful chemicals and to maximise the quantity of raw material that ends up in the final product. Selective photocatalytic conversions will play a major role in this evolution and this account shows how photocatalysis is offering an alternative green route for the production of organics.

Sicilian Opuntia ficus‐indica Seed Oil: Fatty Acid Composition and Bio‐Economical Aspects

2017

The fatty acid composition of the seed oil from the yellow fruit of Opuntia ficus-indica widely grown in Sicily shows several distinctive features. The oil obtained comprises significant amounts of vaccenic acid along with several other unsaturated fatty acids showing several health benefits, including linolenic, trans-13-octadecenoic, gondoic, 7Z,10Z-hexadecadienoic, and gadoleic acid. The economic analysis shows the significant advantage of carrying out the extraction from fruits considered unfit for consumption. Practical applications: The fatty acid composition of Sicilian Opuntia ficus-indica seed oil is similar to that of fruits grown in Tunisia, while it has a completely different pr…

Sol–Gel Microcapsulation in Silica-Based Particles: A Comparative Study

2011

Comparison between the two main sol–gel/emulsion methods to prepare microparticles made of organosilica doped with a lipophilic molecule shows that entrapment only takes place starting from O/W emulsions. In this case, however, formation of spherical microcapsules, observed when the sol–gel polycondensation is carried out in a W/O microemulsion, does not take place.

Catalysis with Doped Sol-Gel Silicates

2011

Silicates doped with catalytic species have only been slowly adopted by the fine chemicals and pharmaceutical industries, in spite of their remarkable and unique properties such as pronounced physical and chemical stability; high (enantio)selective activity and ease of materials production and application. This is now changing thanks to stricter safety regulations and to concomitant success of the first commercial catalysts. In this account we tell the story of these materials and identify some deficiencies in the innovation process that may serve as lesson in guiding the future management of innovation in these relevant industries.

Visible-light driven oxidation of gaseous aliphatic alcohols to the corresponding carbonyls via TiO2 sensitized by a perylene derivative

2013

Sensitized P25 TiO2 was prepared by wet impregnation with a home-prepared perylene dye, i.e., N,N?-bis(2-(1- piperazino)ethyl)-3,4,9,10-perylene-tetracarboxylic acid diimide dichloride (PZPER). Energy levels of PZPER were found to be compatible with those of TiO2 allowing fast electron transfer. The obtained catalyst has been characterized and used in the gas-phase partial oxidation of aliphatic primary and secondary alcohols, i.e., methanol, ethanol, and 2- propanol. The reaction was carried out under cut-off (?> 400 nm) simulated solar radiation in O2 atmosphere. The perylene derivative allowed a good absorbance of visible radiation thanks to its low optical energy gap (2.6 eV) which was …

NanoMORALs: Metal Nanoparticles Doped with Organic Molecules

2009

A new class of nanosized metal–organic alloys (MORALs) has been synthesized for the first time. Silver nanoparticles doped with Cu(II) and Fe(III) phthalocyanines were thus synthesized in the presence of sodium dodecyl sulfate (SDS). The resulting materials were characterized by means of XRD, SEM, TEM coupled to energy dispersive X-ray analysis, and thermogravimetric analysis. No leaching of the photoactive dopant species was observed in water or in common organic solvents.

Green and Quick Extraction of Stable Biophenol-Rich Red Extracts from Grape Processing Waste

2021

The extraction of grape processing waste (wine pomace) via microwave-hydrodiffusion and gravity (MHG) from three different cultivars grown in Sicily (Syrah, Perricone and Nero d’Avola) rapidly affords aqueous extracts highly concentrated in valued biophenols including flavonoids, anthocyanins and phenolic acids. The method does not employ organic solvent, acid or base and does not require grinding or freeze drying of the wine pomace nor separation of the grape skins from seeds and stem. All the extracts have a pronounced stability as shown by their red-violet color fully retained after storage for more than a year (15 months) in freezer under air. Concentrations of phenolics up to…

Tuning the photocatalytic activity of bismuth wolframate: Towards selective oxidations for the biorefinery driven by solar-light

2017

The sol–gel entrapment of nanostructured Bi2WO6 enhances the activity and the selectivity of the short-gap semiconductor in the sunlight-driven photo-oxidation of trans-ferulic and trans-cinnamic acid dissolved in water with air as the primary oxidant. Valuable products such as vanillin, benzaldehyde, benzoic acid and vanillic acid are obtained. This provides the proof of concept that photocatalysis could be a promising technology in tomorrow's solar biorefineries.

Polymers of Limonene Oxide and Carbon Dioxide: Polycarbonates of the Solar Economy

2018

Limonene epoxide (1,2 limonene oxide) readily reacts with carbon dioxide in a ring opening copolymerization reaction with insertion of CO2 and formation of polycarbonates of exceptional chemical and physical properties. Both poly(limonene carbonate) and poly(limonene dicarbonate) can be synthesized using low cost Zn or Al homogeneous catalysts. This study addresses selected relevant questions concerning the technical and economic feasibility of limonene and carbon dioxide polymers en route to the bioeconomy.

A Circular Economy Approach to Fish Oil Extraction

2019

Fish oil rich in polyunsaturated omega-3 fatty acids is extracted in high yield from anchovy filleting waste using d-limonene as green biosolvent in a simple solid-liquid extraction performed by mechanically stirring and maceration followed by limonene removal via evaporation under reduced pressure. As limonene is renewably obtained from waste orange peel, this method closes the materials cycle and establishes a circular economy process to obtain high quality fish oil from biowaste available worldwide in several million t/year amount. Significant economic, social and environmental benefits are anticipated.