slideshow 16 slideshow 1 slideshow 2 slideshow 3 slideshow 4 slideshow 5 slideshow 6 slideshow 7 slideshow 8 slideshow 0 slideshow 9 slideshow 10 slideshow 11 slideshow 12 slideshow 13 slideshow 14 slideshow 15

Feed aggregator

Self-driving vesicles penetrate blood-brain barrier

Chemical News - 4 August, 2017 - 14:32
Potential drug carriers follow glucose gradients in mice

Dr. Reddy’s struggles to meet FDA concerns

Chemical News - 4 August, 2017 - 14:32
Indian drugmaker doesn’t expect to make facilities compliant before year-end

Polyladderenes unzip to form semiconducting polymers

Chemical News - 4 August, 2017 - 14:00
Molecules could report mechanical stress in materials

I gas intestinali vi creano problemi? Non preoccupatevi, potrebbe essere un segno di salute.

BLOG: LA CHIMICA E LA SOCIETA' - 4 August, 2017 - 08:51

Rinaldo Cervellati

Con questo titolo, imbarazzante in tutti i sensi, Tim Cutcliffe sintetizza, su NUTRAingredients newsletter-USA del 26 giugno u.s., i risultati di un dettagliato studio pubblicato da ricercatori giapponesi sulla rivista Journal of Functional Foods (M. Matsumoto et al., Effects of functional milk containing galactooligosaccharide, maltitol and glucomannan on the production of hydrogen gas in the human intestine, J. Funct. Food, 2017, 35, 13-23).

Secondo questo studio, una bevanda contenente fibre può favorire la produzione di idrogeno nell’intestino, un gas con effetti antiinfiammatori come affermano i ricercatori giapponesi in base anche a ricerche precedenti.

Kazuo Subota

Abbiamo sviluppato una bevanda composta da latte vaccino con galattooligosaccaridi (GOS), maltitolo e glucomannano e abbiamo esaminato la capacità di questo latte funzionale di incrementare la quantità di idrogeno prodotta nell’intestino umano.

I risultati dei test clinici effettuati per verificare gli effetti di questa bevanda confermano che il consumo del nostro latte induce concentrazioni più elevate di idrogeno nel respiro, inclusi picchi di concentrazione più alti e persistenza più lunga nel tempo rispetto al consumo del normale latte o di acqua saturata con idrogeno, dice il team di scienziati giapponesi provenienti da un’industria privata (Kyodo Milk Industry Co. Ltd., Tokio) e dalla Keyo University School of Medicine, Tokyo.

Il gruppo fa riferimento a studi risalenti a dieci anni fa che hanno evidenziato gli effetti fisiologici di H2 gas dopo la scoperta delle sue elevate proprietà antiossidanti e il suo uso potenziale nel ridurre i sintomi patologici di infarto cerebrovascolare in modelli animali (ratto). Inoltre studi precedenti hanno mostrato che H2 possiede effetti benefici come agente antiinfiammatorio nei casi di ischemia, nella prevenzione di sindrome metabolica, nel proteggere il sistema nervoso centrale e nel contrastare l’eccesso di radicali liberi in tutti i casi di stress ossidativo cellulare. Il 75% di questi studi è stato effettuato su modelli animali ma recentemente i test clinici sono in aumento.

I ricercatori affermano poi che tutti gli studi menzionati hanno utilizzato l’inalazione del gas o l’ingestione di acqua idrogenata come sorgenti rilascianti idrogeno. La prima modalità richiede apparecchiature specifiche, la seconda limita il tempo di permanenza del gas a un massimo di 30 minuti.

Poiché studi su modelli animali hanno evidenziato che l’idrogeno prodotto da battèri intestinali viene trasportato a organi come il fegato, Mastumoto e collaboratori hanno deciso di provare se l’ingestione di fibre alimentari potesse far aumentare produzione e durata nel tempo di idrogeno da parte dei battèri.

Maltitolo

Glucomannano

Essi hanno analizzato l’effetto di diversi prodotti indigeribili per la loro potenzialità di rilasciare idrogeno per effetto batterico, come pure quello di diverse combinazioni di fibre alimentari. La capacità di un solo tipo di fibra dipende dal microbioma del singolo individuo e quindi può risultare inefficace.

Matsumoto e il suo gruppo hanno trovato che opportune combinazioni di galattooligosaccaridi, maltitolo e glucomannano sono induttori efficaci per la produzione di idrogeno.

Negli studi clinici la concentrazione di idrogeno nel respiro è risultata significativamente maggiore nel gruppo di volontari cui è stato somministrato il latte contenente le fibre rispetto al gruppo controllo e strettamente correlata con quella prodotta nell’intestino.

Oltre a lievi sintomi di flatulenza (comunque noiosi nota di RC), nessun altro effetto collaterale è stato rilevato dai volontari dell’esperimento, un solo soggetto si è lamentato di avere “lo stomaco gorgogliante”.

Infine, dicono Matsumoto e collaboratori:

I test clinici sono stati del tipo open-label, cioè senza ospedalizzazione, quindi saranno necessari ulteriori studi più approfonditi e controllati per verificare l’efficacia di bevande contenenti fibre per incrementare la produzione di idrogeno intestinale.

Nota di R.C. Confesso che nonostante le mie ricerche sulla determinazione dell’attività antiossidante di estratti e sostanze isolate da piante officinali e alimenti funzionali con metodi chimico fisici questa faccenda dell’idrogeno mi è giunta nuova. Così sono andato a cercare nella recente bibliografia e ho trovato due interessanti riferimenti:

  1. Ohta, Molecular hydrogen as a novel antioxidant: overview of the advantages of hydrogen for medical applications. Methods Enzymol., 2015, 555, 289-317.

J.M. Lee et al., Headspace –solid phase microextraction (HS_SPME) analysis of oxidized volatiles from free fatty acids (FFA) and application for measuring hydrogen donating antioxidant activity, Food Chem., 2007, 105, 414-420.

 


Tagged: galattooligosaccaridi, maltitolo

Dow, investors tussle over Dow Corning’s future

Chemical News - 4 August, 2017 - 04:36
Activist investors want a better breakup plan for the DowDuPont split

Semiconductor industry to begin using MOFs

Chemical News - 4 August, 2017 - 03:28
Start-up technology will enhance gas purity and safety

Synthesis of <i>N,N</i>-Bis-Sulfonylated and <i>N</i>-Alkyl-<i>N</i>-Sulfonylated G1 Dendrimers <i>via</i> Click Reaction: Application of Thiocarbamide based Cu<sup>I</sup> Catalysts

Articles from Wiley - 4 August, 2017 - 00:00

 Application of Thiocarbamide based CuI Catalysts

Designing of thiocarbamide based CuI catalysts and their application in synthesis of 1,2,3-triazole based N,N-bis-sulfonylated and N-alkyl-N-sulfonylated G1 dendrimers have been reported. The designed catalysts showed the better catalytic activity under liquid assisted grinding (LAG) using 0.05 - 0.06 mole percent. Yield of dendrimers was observed from good to excellent in short reaction time period.

[Full Paper]
Shaziya Khanam, Sunil K. Pandey, Sunil K. Rai, Deepshikha Verma, Jerry P. Jasinski, Seema Pratap, Ashish K. Tewari
ChemistrySelect, August 04, 2017, https://doi.org/10.1002/slct.201701591 Read article

Facile Hydrothermal Synthesis of Sn-Mn Mixed Oxide Nano-rods with Exposed (110) Facets and Remarkable Catalytic Performance

Articles from Wiley - 4 August, 2017 - 00:00

Facile Hydrothermal Synthesis of Sn‐Mn Mixed Oxide Nano‐rods with Exposed (110) Facets and Remarkable Catalytic Performance

Solid Solution Rods: Though mono-metal oxides exposed special facets can be easily prepared via various approaches, the synthesis of mixed metal oxides exposed special facets are still a challenge to date. In this work, Sn−Mn mixed oxide nano-rods exposed (110) facet have been successfully synthesized by a facile one step hydrothermal method for the first time and showed superior CO catalytic oxidation performance.

[Full Paper]
Honggen Peng, Li Zhang, Qi Sun, Jiating Shen, Xianglan Xu, Xiuzhong Fang, Wenming Liu, Zheng Wang, Ning Zhang, Xiang Wang
ChemistrySelect, August 04, 2017, https://doi.org/10.1002/slct.201701457 Read article

Hollow Co<sub>3</sub>O<sub>4</sub> Nanocages Decorated Graphene Aerogels Derived from Carbon Wrapped Nano-Co for Efficient Oxygen Reduction Reaction

Articles from Wiley - 4 August, 2017 - 00:00

Hollow Co3O4 Nanocages Decorated Graphene Aerogels Derived from Carbon Wrapped Nano‐Co for Efficient Oxygen Reduction Reaction

In our work, we report a kind of tiny hollow nano-Co3O4 decorated 3D graphene aerogels (3DG) in the first time, which derived from direct oxidation carbon wrapped Co/3DG through Kirkendall effect. Due to its unique structure, the hollow Co3O4/3DG shows excellent ORR catalytic activity with almost four-electron reduction pathway.

[Full Paper]
Zhao-Yang Chen, Ya-Nan Li, Min-Qiang Wang, Mao-wen Xu, Shu-Juan Bao
ChemistrySelect, August 04, 2017, https://doi.org/10.1002/slct.201701355 Read article

Three-Component Cascade Reaction in a Tube: In Situ Synthesis of Pd Nanoparticles Supported on mpg-C<sub>3</sub>N<sub>4</sub>, Dehydrogenation of Ammonia Borane and Hydrogenation of Nitroarenes

Articles from Wiley - 4 August, 2017 - 00:00

 In Situ Synthesis of Pd Nanoparticles Supported on mpg‐C3N4, Dehydrogenation of Ammonia Borane and Hydrogenation of Nitroarenes

With this report, a three-component cascade reaction encompassing in situ synthesis of Pd NPs supported on mpg-C3N4, dehydrogenation of AB and the transfer hydrogenation of nitroarenes were achieved in a commercially available pressure tube at room temperature within only 1–2 min. Besides the tandem reactions, the mpg-C3N4/Pd catalyst was isolated from the reaction medium to be tested as catalyst in the hydrolytic dehydrogenation of AB.

[Full Paper]
Bilal Ni&#x15F;anc&#x131;, Muhammet Turgut, Melike Sevim, Önder Metin
ChemistrySelect, August 04, 2017, https://doi.org/10.1002/slct.201701188 Read article

Efficient Degradation of Endocrine Disruptors Using 1D and 3D Copper (I) Oxide Nanostructures

Articles from Wiley - 4 August, 2017 - 00:00

Efficient Degradation of Endocrine Disruptors Using 1D and 3D Copper (I) Oxide Nanostructures

1D and 3D copper (I) oxide nanostructures were synthesized using wet chemical method and their photocatalytic activities towards degradation of endocrine disruptors were studied under visible light irradiation at different pH. 1D nanostructures showed best degradation ability with t1/2 value of 11.6 minutes at pH ∼ 7.

[Full Paper]
Indrani Mukherjee, Anushka Mishrra, Rajnarayan Saha, Sriparna Chatterjee
ChemistrySelect, August 04, 2017, https://doi.org/10.1002/slct.201701181 Read article

Scavenging Pd<sup>2+</sup> on Amine-Functionalized SBA-15: A Facile Synthesis of Leach-Free Pd<sup>0</sup> Nanocatalyst for Base-Free Chemoselective Transfer Hydrogenation of Olefins

Articles from Wiley - 4 August, 2017 - 00:00

 A Facile Synthesis of Leach‐Free Pd0 Nanocatalyst for Base‐Free Chemoselective Transfer Hydrogenation of Olefins

Amine-functionalized SBA-15 act as effective Pd2+ scavenger and as-generated surface bound Pd0 NPs are found to be highly active heterogeneous catalyst for base-free transfer hydrogenation of styrene to ethylbenzene using formic acid as an environmentally benign hydrogen source. The optimized reaction protocol for styrene also yielded excellent results for various substituted styrene and other alkenes. The role of free propylamine is found to be very crucial for higher conversion and selectivity of the desired alkane products.

[Full Paper]
Diganta Bhuyan, Lakshi Saikia
ChemistrySelect, August 04, 2017, https://doi.org/10.1002/slct.201701158 Read article

Graphene as Metal-Free Catalyst for Aqueous Phase Reforming of Ethylene Glycol

Articles from Wiley - 4 August, 2017 - 00:00

Graphene as Metal‐Free Catalyst for Aqueous Phase Reforming of Ethylene Glycol

In the context of valorization of biomass waste water containing polyols, it is reported that graphene in the absence of any metal catalyzes the decomposition of ethylene glycol into hydrogen and carbon dioxide due to the presence of hydrogenating/dehydrogenating sites. Control experiments have shown that the presence of acid or bases influences the activity of graphene as catalyst, while the reaction is not influenced by the presence of radical quenchers

[Communication]
Iván Esteve-Adell, Nadia Bakker, Ana Primo, Emiel J. M. Hensen, Hermenegildo García
ChemistrySelect, August 04, 2017, https://doi.org/10.1002/slct.201701138 Read article

Fabrication of Chitosan-Reinforced Zr<sub>x</sub>Al<sub>1-x</sub>OOH Nanocomposites and Their Arsenite and Fluoride Depollution Densities from Single/Binary Systems

Articles from Wiley - 4 August, 2017 - 00:00

Fabrication of Chitosan‐Reinforced ZrxAl1‐xOOH Nanocomposites and Their Arsenite and Fluoride Depollution Densities from Single/Binary Systems

The goal of this research was to understand the mechanism of AsO33− and F− removal using the chitosan (CS) reinforced ZrxAl1-xOOH material. A detailed batch experimental study was performed to understand the nature of the interactions that exist between CS@ZrxAl1-xOOH and F−/AsO33− in aqueous solution. The developed material is environmentally benign as it offers several advantages like simple way of preparation, quick and high uptake capacities, cost effective with the added benefit of recyclability.

[Full Paper]
Subbaiah Muthu Prabhu, Keiko Sasaki
ChemistrySelect, August 04, 2017, https://doi.org/10.1002/slct.201701072 Read article

Electrochemical Reaction Mechanism for Bi<sub>1-<i>x</i></sub>Ba<sub><i>x</i></sub>F<sub>3-<i>x</i></sub> (<i>x</i>=0, 0.1, 0.2, and 0.4) Electrodes in Lithium-Ion Batteries

Articles from Wiley - 4 August, 2017 - 00:00

Electrochemical Reaction Mechanism for Bi1‐xBaxF3‐x (x=0, 0.1, 0.2, and 0.4) Electrodes in Lithium‐Ion Batteries

The electrochemical reaction mechanism for Bi1-xBaxF3-x (x=0, 0.1, 0.2, and 0.4) electrode materials, which have several crystal structure types such as orthorhombic, hexagonal, and cubic was investigated. Regardless of the crystal structure in the pristine state, the crystal structure changes into the hexagonal phase after one cycle, which is the most reactive structure type of the three phases.

[Full Paper]
Hiroaki Konishi, Taketoshi Minato, Takeshi Abe, Zempachi Ogumi
ChemistrySelect, August 04, 2017, https://doi.org/10.1002/slct.201701001 Read article

Experimental and Theoretical Study for the Assessment of the Conformational Analysis of Pyrazolone Derivatives: Employing Quantitative Analysis for Intermolecular Interactions

Articles from Wiley - 4 August, 2017 - 00:00

 Employing Quantitative Analysis for Intermolecular Interactions

The Crystallographic studies of pyrazolone derivative linked with pthalimido through oxapolymethylene linker have been carried out for conformational study. The influences of folded and open conformation depend upon oxaploymethylene linker but no effect of substitution (methyl and benzene) on pyrazolone ring. The compounds 5 and 6 had shown folded conformation linked through oxaethylene spacer but compounds 7 had shown open conformation linked through oxapropylene linkers. However, DFT calculation revealed that all molecules have shown folded conformation. Further, the intermolecular interactions that stabilized crystal packing have been studied through pixel calculation and Hirshfeld surface analysis.

[Full Paper]
Ranjeet Kumar, Praveen Singh, Simon Parsons, Ashish K. Tewari
ChemistrySelect, August 04, 2017, https://doi.org/10.1002/slct.201700764 Read article

Accessing Single Enantiomer Strigolactones: Progress and Opportunities

Articles from Wiley - 4 August, 2017 - 00:00

 Progress and Opportunities

[Microreview]
Liam J. Bromhead, Christopher S. P. McErlean
Eur. J. Org. Chem., August 04, 2017, https://doi.org/10.1002/ejoc.201700865 Read article

Gold-Nanoparticle-Catalyzed Mild Diboration and Indirect Silaboration of Alkynes without the Use of Silylboranes

Articles from Wiley - 4 August, 2017 - 00:00

Gold‐Nanoparticle‐Catalyzed Mild Diboration and Indirect Silaboration of Alkynes without the Use of Silylboranes

[Full Paper]
Marios Kidonakis, Manolis Stratakis
Eur. J. Org. Chem., August 04, 2017, https://doi.org/10.1002/ejoc.201700754 Read article

Efficient Synthesis of 4- and 5-Substituted 2-Aminopyrimidines by Coupling of β-Chlorovinyl Aldehydes and Guanidines

Articles from Wiley - 4 August, 2017 - 00:00

Efficient Synthesis of 4‐ and 5‐Substituted 2‐Aminopyrimidines by Coupling of &#x3B2;‐Chlorovinyl Aldehydes and Guanidines

A condensation of ambident electrophilic &#x3B2;-chlorovinyl aldehydes with guanidines was developed for the synthesis of a library of 4- and 5-substituted 2-aminopyrimidines derivatives under mild conditions by employing potassium carbonate in methanol.

[Communication]
Anna S. Komendantova, Alexander V. Komkov, Yulia A. Volkova, Igor V. Zavarzin
Eur. J. Org. Chem., August 04, 2017, https://doi.org/10.1002/ejoc.201700737 Read article

Perfluorinated Pyridinium and Imidazolium Ionic Liquids

Articles from Wiley - 4 August, 2017 - 00:00

Perfluorinated Pyridinium and Imidazolium Ionic Liquids

Pyridinium and imidazolium ionic liquids with perfluorinated side chains and different anions were prepared and the wettabilities of the materials were investigated by water contact angle measurements. The compounds were investigated in an effort to develop perfluorinated compounds for textile impregnation as alternatives for environmentally persistent commonly used perfluoroalkyl carboxylic and sulfonic acids.

[Full Paper]
Torben Alpers, Marc Schmidtmann, Thomas W. T. Muesmann, Oliver Temme, Jens Christoffers
Eur. J. Org. Chem., August 04, 2017, https://doi.org/10.1002/ejoc.201700717 Read article

Copyright © 2012 Società Chimica Italiana. All Rights Reserved.