Don’t rely on a gut feeling: investigating microbiota/human co-metabolism

A new trend gripping popular science (and business) is personal DNA testing. A host of companies sell the idea that your genetic heritage distinguishes you, and reveals who you really are. Do you really want to know what you are on a molecular level? If it’s a numbers game, you are mostly bacterial (that’s why you’re so cultured!). Bacteria outnumber our body’s cells 1.3:1. The majority of bacteria reside in the gastrointestinal tract, contributing to a microbiota of archea, eukaryotes and viruses that have a commensal relationship with the human body.

The microbiota has been linked to many vital physiological pathways including human nutrition (harvesting further energy and nutrients), immunity, inflammation and the detoxification of xenobiotic substances. Conversely, dysregulation of such pathways has been associated with diseases such as diabetes, cancer, inflammatory bowel syndrome and cardiovascular disease. Due to the number of pathways involved, it is hoped that studying the microbiota may identify enzyme targets for therapeutics or biomarkers for disease.

However, understanding of these pathways is limited, and research progress relies on advances in analytical tools. Headed by Dr Daniel Globisch at Uppsala University in Sweden, researchers have developed an analytical method to identify O-sulphated metabolites. Microbes are capable of a suite of metabolic reactions that complement the capabilities of human enzymes, and O-sulphate functionalization is characteristic of microbe/human co-metabolism as it can be catalysed by bacterial sulphotransferase enzymes.

O-sulfate functionalised molecules can be selectively analysed using sulphatase sulfatase treatment and UPLC-MS/MS

O-sulphate functionalised molecules can be selectively analysed using sulphatase treatment and UPLC-MS/MS

The researchers developed an assay to identify O-sulphated compounds in urine and faecal samples. The assay was designed using a sulphatase enzyme capable of hydrolysing the oxygen-sulfur bond in a wide variety of arylsulphate molecules. Samples were treated with this enzyme and the resulting mixtures were analysed by UPLC-MS/MS (ultra performance liquid chromatography/tandem mass spectrometry). Results were compared with the data output of control samples without enzymatic treatment and features in the spectra with a mass change of 79.9568 m/z (loss of the sulfate group) were identified, leading to the identification of 206 O-sulphated metabolites. This is a notable result as it triples the number of sulphated metabolites currently recorded in the human metabolome database.

A number of interesting compounds were identified: ferulic acid is a metabolite produced by the microbiota thought to prevent thrombosis and artherosclerosis, and indoxyl sulfate and p-cresylsulfate are biomarkers of chronic kidney disease and cardiovascular disease, respectively. Mentioned are three molecules of the 206 uncovered, giving a glimpse of the applications that further research, armed with the right analytical tools, might discover.

To find out more please read:

New enzymatic and mass spectrometric methodology for the selective investigation of gut microbiota-derived metabolites

Caroline Ballet, Mário S. P. Correia, Louis P. Conway, Theresa L. Locher, Laura C. Lehmann, Neeraj Garg, Miroslav Vujasinović, Sebastian Deindl, J.-Matthias Löhr, Daniel Globisch.
Chem. Sci., 2018, Advance Article
DOI: 10.1039/c8sc01502c

About the author

Zoë Hearne is a PhD candidate in chemistry at McGill University in Montréal, Canada, under the supervision of Professor Chao-Jun Li. She hails from Canberra, Australia, where she completed her undergraduate degree. Her current research focuses on transition metal catalysis to effect novel transformations, and out of the lab she is an enthusiastic chemistry tutor and science communicator.

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How Can We Stabilize Bismuth in Potassium-Ion Batteries? Add Salts!

The large-scale manufacturing and widespread demand of consumer electronics in modern societies call for batteries with affordable prices. Potassium-ion batteries are one of the economical alternatives to lithium-ion batteries, as the cost of potassium is much lower than lithium. However, these types of batteries have yet to be commercially available, partly due to the lack of high-performance and stable anode materials. Bismuth (Bi) is a promising anode material for potassium-ion batteries, because of its substantially higher theoretical charge-storage capacity than the conventional ones. Unfortunately, its poor durability severely hinders the applicability.

Now the drawback of Bi has been successfully addressed by increasing the electrolyte concentration. This breakthrough, demonstrated by Chuan-Fu Sun and coworkers from Chinese Academy of Sciences, China, was recently published in Chemical Science.

Sun and coworkers investigated the interplay between the electrolyte concentration and the charge-storage performance stability of Bi nanoparticles (Figure 1a). They identified the optimal concentration of the solute, potassium bis(tri-fluoromethylsulfonyl)imide, to be 5 M. Under this condition, the irreversible electrolyte reduction reaction on the Bi surface experienced the highest resistance. Impeding this unwanted reaction thus elongated the lifespan of Bi electrodes. In addition, the concentrated electrolyte resulted in thin layers of the reduction products being deposited on the Bi surface. This allowed ions in the electrolyte to easily penetrate the surface coatings and interact with the encapsulated Bi nanoparticles, maintaining the intrinsically high capacity of Bi (Figure 1b). Other concentrations either led to rapid battery failure or significantly reduced capacity.

Figure 1. (a) A scanning electron microscopy image of the Bi nanoparticles. (b) The change of the Bi electrode capacity vs. charge-discharge cycle number with different electrolyte concentrations. CE: coulombic efficiency.

This work innovates the design and development of commercially viable potassium-ion batteries. The strategy of increasing the electrolyte concentration could possibly be adapted to solve electrode instability issues associated with other rechargeable batteries.

 

To find out more please read:

Concentrated Electrolytes Stabilize Bismuth-Potassium Batteries

Ruding Zhang, Jingze Bao, Yu-Huang Wang and Chuan-Fu Sun

Chem. Sci., 2018, DOI: 10.1039/c8sc01848k

 

About the blogger:

Tianyu Liu obtained his Ph.D. (2017) in Physical Chemistry from University of California, Santa Cruz in the United States. He is passionate about scientific communication to introduce cutting-edge research to both the general public and scientists with diverse research expertise. He is a blog writer for Chem. Commun. and Chem. Sci. More information about him can be found at http://liutianyuresearch.weebly.com/.

 

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Meet Stephen Goldup: Chemical Science Associate Editor

We are happy to introduce Professor Stephen Goldup as Chemical Science Associate Editor, handling submissions in the area of supramolecular chemistry.

Steve obtained an MChem degree from the University of Oxford where he began his research career with a Part II project in the group of Sir Prof. Jack Baldwin. He continued his research training with a PhD in natural product synthesis under the supervision of Prof. Tony Barrett before shifting focus to apply his synthetic skills to the realisation of mechanically interlocked non-natural products during post doctoral work with Prof. David Leigh at the University of Edinburgh where in 2007 he was appointed as Fixed Term Lecturer in Organic Chemistry. In 2008 he moved to Queen Mary with the award of a Leverhulme Trust Early Career Fellowship and in October 2009 he was awarded a Royal Society University Research Fellowship.

In October 2014 the group moved to the University of Southampton where Steve took up the position of Associate Professor. In August 2017, Steve was promoted to Professor of Chemistry. Research in the Goldup Group focusses on the synthesis of novel mechanically interlocked molecules and their application as sensors, catalysts and materials.

Steve is keen to receive submissions in his area of expertise, particularly in supramolecular chemistry, interlocked molecules, molecular machines, stimuli responsive systems, and sensing. Below is a list of Chemical Science articles which Steve would like to highlight – all free to read! We hope you enjoy them.

Variations in the fuel structure control the rate of the back and forth motions of a chemically fuelled molecular switch
Chiara Biagini, Simone Albano, Rachele Caruso, Luigi Mandolini, José Augusto Berrocal and Stefano Di Stefano
Chem. Sci., 2018,9, 181-188
DOI: 10.1039/C7SC04123C, Edge Article

Self-assembled orthoester cryptands: orthoester scope, post-functionalization, kinetic locking and tunable degradation kinetics
Henrik Löw, Elena Mena-Osteritz and Max von Delius
Chem. Sci., 2018,9, 4785-4793
DOI: 10.1039/C8SC01750F, Edge Article

Interfacing porphyrins and carbon nanotubes through mechanical links
Leire de Juan-Fernández, Peter Münich, Arjun Puthiyedath, Belén Nieto-Ortega, Santiago Casado, Luisa Ruiz-Gonzales, Emilio M Perez and Dirk M. Guldi
Chem. Sci., 2018, Accepted Manuscript
DOI: 10.1039/C8SC02492H, Edge Article

White-light emission from a single organic compound with unique self-folded conformation and multistimuli responsiveness
Dengfeng Li, Wende Hu, Jie Wang, Qiwei Zhang, Xiao-Ming Cao, Xiang Ma and He Tian
Chem. Sci., 2018,9, 5709-5715
DOI: 10.1039/C8SC01915K, Edge Article

Mechanochemistry of the mechanical bond
Guillaume De Bo
Chem. Sci., 2018,9, 15-21
DOI: 10.1039/C7SC04200K, Minireview

 

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HOT Chemical Science articles for June

We are happy to present a selection of our HOT articles over the past month. To see all of our HOT referee-recommended articles from 2018, please find the collection here.

As always, Chemical Science articles are free to access.

Chiral Brønsted acid-catalyzed intramolecular SN2′ reaction for enantioselective construction of a quaternary stereogenic center
Masahiro Shimizu, Jun Kikuchi, Azusa Kondoh and Masahiro Terada
Chem. Sci., 2018,9, 5747-5757
DOI: 10.1039/C8SC01942H, Edge Article

_____________________________________________________________

Deciphering the mechanism of O2 reduction with electronically tunable non-heme iron enzyme model complexes
Roshaan Surendhran, Alexander A. D’Arpino, Bao Y. Sciscent, Anthony F. Cannella, Alan E. Friedman, Samantha N. MacMillan, Rupal Gupta and David C. Lacy
Chem. Sci., 2018,9, 5773-5780
DOI: 10.1039/C8SC01621F, Edge Article

_____________________________________________________________

Weak interactions but potent effect: tunable mechanoluminescence by adjusting intermolecular C–H⋯π interactions
Zongliang Xie, Tao Yu, Junru Chen, Eethamukkala Ubba, Leyu Wang, Zhu Mao, Tongtong Su, Yi Zhang, Matthew P. Aldred and Zhenguo Chi
Chem. Sci., 2018,9, 5787-5794
DOI: 10.1039/C8SC01703D, Edge Article

_____________________________________________________________

Shaping excitons in light-harvesting proteins through nanoplasmonics
Stefano Caprasecca, Stefano Corni and Benedetta Mennucci
Chem. Sci., 2018, Advance Article
DOI: 10.1039/C8SC01162A, Edge Article

_____________________________________________________________

Highly Luminescent Phosphine Oxide-Containing Bipolar Alkynylgold(III) Complexes for Solution-Processable Organic Light-Emitting Devices with Small Efficiency Roll-Offs
Chin-Ho Lee, Man-Chung Tang, Wai-Lung Cheung, Shiu-Lun Lai, Mei-Yee Chan and Vivian Wing-Wah Yam
Chem. Sci., 2018, Advance Article
DOI: 10.1039/C8SC02265H, Edge Article

_____________________________________________________________

New enzymatic and mass spectrometric methodology for the selective investigation of gut microbiota-derived metabolites
Caroline Ballet, Mário S. P. Correia, Louis P. Conway, Theresa L. Locher, Laura C. Lehmann, Neeraj Garg, Miroslav Vujasinovic, Sebastian Deindl, J.-Matthias Löhr and Daniel Globisch
Chem. Sci., 2018, Advance Article
DOI: 10.1039/C8SC01502C, Edge Article

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Meeting of Inorganic Chemists Recently Appointed

Chemical Communications, Chemical Science and Dalton Transactions are pleased to sponsor the 2018 Meeting of Inorganic Chemists Recently Appointed (MICRA). This biennial event is being organised by Dr Timothy Easun and Dr Rebecca Melen from Cardiff University, and is taking place on 10 – 12 September 2018 at Cardiff University in Wales.

The meeting brings together junior inorganic chemistry academics from across the UK to help aid their development into independent researchers through networking and exchanging experiences. MICRA 2018 will have exciting talks from experts such as Paul Saines (University of Kent), Timothy Easun (Cardiff University) and Rebecca Melen (Cardiff University).

For more information and to register, go to: https://www.micra2018.com/

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Chemical Science poster prize winner at the 16th Symposium for Host-Guest and Supramolecular Chemistry

The 16th Symposium for Host-Guest and Supramolecular Chemistry was held on 2 – 3 June 2018 at the Tokyo University of Science in Japan.

This annual symposium covers all aspects of the chemical sciences related to molecular recognition and supramolecular chemistry, including the discussion of topics around intermolecular interactions. The event included a special lecture by Dr Shigeki Sasaki and invited lectures by Dr Takashi Hayashi and Dr Katsuhiko Ariga.

Chemical Science is delighted to announce that the Chemical Science poster prize was awarded to Ayaka Yoshioka for a poster entitled Hydrogen-bonding Net-Tubes based on Ring-fused malonamides: Guest Dependence of Tubular Structure Formation and Guest Adsorption/Desorption Assembly’.

Well done Ayaka from everyone at Chemical Science!

Ayaka Yoshioka (left) with Hiromitsu Urakami from the Royal Society of Chemistry (right)

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Welcoming a New Member into the Aluminum Battery Family

Yu and coworkers from The University of Queensland, Australia have introduced an aluminum-selenium (Al-Se) battery as a new member of the rechargeable Al-ion battery family. This battery reported in Chemical Science exhibited a capacity of 178 mAh per gram of Se, high discharging voltage above 1.5 V and satisfactory lifetime.

Al-ion batteries have attracted increasing attention as next-generation energy-storage devices. They are potentially more affordable and safer than Li-ion batteries, due to the natural abundance and the existence of native oxide surface layers of aluminum, respectively. One of the major challenges hindering the wide application of Al-ion batteries is the lack of feasible cathode materials. Previously investigated cathodes have drawbacks of low charge-storage capacity, low discharging voltage, poor electrical conductivity or chemical instability.

Inspired by sulfur, Yu and coworkers selected selenium as a cathode material for Al-ion batteries. Selenium has substantially higher electrical conductivity and lower ionization potential than sulfur, which is expected to improve the energy-storage capacity of batteries. However, a major drawback of selenium is that the oxidation product generated upon charging batteries, Se2Cl2, can dissolve quickly in electrolytes and lead to battery failure. Solving this problem would make selenium a promising cathode for Al-ion batteries.

To resolve this issue, the authors introduced a mesoporous carbon named CMK-3, nanorods that are capable of physically adsorbing Se2Cl2. The cathode, composed of Se nanowires and CMK-3 nanoparticles, is thus anticipated to improve the lifespan of batteries, as any Se2Cl2 that is generated will be confined inside the pores of CMK-3 (Figure 1).

Figure 1. A schematic illustrating the CMK-3’s capability of trapping Se2Cl2. The chemical equation below shows how selenium reacts with aluminum during charge and discharge processes.

As expected, the performance of these Al-Se batteries was stable. They retained more than 80% of the initial capacity after 50 consecutive charge-discharge cycles at 100 mA/g (Figure 2a). Additionally, the discharging capacity of the batteries reached 178 mAh per gram of selenium at 100 mA/g, and the discharging potential was above 1.5 V (Figure 2b).

Figure 2. (a) The specific capacity of the Al-Se batteries of each cycle at different current densities. (b) The variation of battery potential with specific capacity of the 2nd, 5th, 10th, and 30th charge-discharge cycles.

These promising Al-Se batteries could encourage future work to continue progress into the development of affordable and durable Al-ion batteries.

 

To find out more please read:

Rechargeable Aluminum-Selenium Batteries with High Capacity

Xiaodan Huang, Yang Liu, Chao Liu, Jun Zhang, Owen Noonan and Chengzhong Yu

Chem. Sci., 2018, DOI: 10.1039/C8SC01054D

About the blogger:

Tianyu Liu obtained his Ph.D. (2017) in Physical Chemistry from University of California, Santa Cruz in the United States. He is passionate about scientific communication to introduce cutting-edge research to both the general public and scientists with diverse research expertise. He is a blog writer for Chem. Commun. and Chem. Sci. More information about him can be found at http://liutianyuresearch.weebly.com/.

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Bioelectrochemistry with nitrogenase-loaded electrodes for nitrogen fixation

We happily breathe our dinitrogen-rich atmosphere all day, but to access nitrogen for the biosynthesis of molecules such as DNA, RNA and proteins, we rely on nitrogen fixation to reduce dinitrogen into bioavailable molecules like ammonia. In nature, nitrogen-fixing bacteria and archaea equipped with nitrogenase enzymes are responsible for providing plants with reduced nitrogen, which makes its way back to us. Nitrogenase is an enzyme complex of two proteins. The first consists of an iron-containing reductase that supplies electrons to the iron/molybdenum-containing catalytic protein, which carries out the N2 to NH3 conversion.

The Haber Bosch process, an industrial method for fixing dinitrogen into ammonia, was first applied in the early 1900’s and generated a huge supply of nitrogen-based fertilizers to synthetically provide plants with this essential nutrient. The population boom that resulted, and with it the global importance of this reaction, has yet to abate. Albeit an efficient reaction, this iron-catalysed process requires high temperatures (450 °C) and pressures (200 atm). In comparison, enzymes can operate under conditions synthetic chemists can only dream of, as researchers at the University of Utah have demonstrated in their work on the bioelectrochemical reduction of dinitrogen under ambient conditions using the catalytic nitrogenase protein.

The researchers synthesised an electrode/enzyme aggregate by trapping the nitrogenase enzyme in a hydrogel, then binding the hydrogel via π-stacking of incorporated pyrene motifs to carbon paper electrodes coated in multi-walled carbon nanotubes. If the enzyme is oriented in the hydrogel in such a way that the distance between the catalytic iron/molybdenum centre of the enzyme and the electrode is within 14 Å, direct electron transfer can take place. Direct electrical contact with enzymes allows researchers to take advantage of the high efficiency and selectivity of enzymes for conducting chemical reactions under mild conditions.

Two methods for immobilization of proteins on an electrode: the docking strategy (upper) and the hydrogel strategy (middle). Active protein is green, while inactive/denatured protein is grey. Pi-stacking of pyrene moieties to bind the hydrogel to the carbon nanotubes (lower).

Two methods for immobilization of proteins on an electrode: the docking strategy (upper) and the hydrogel strategy (middle). Active protein is green, while inactive/denatured protein is grey. π-stacking of pyrene moieties within the polymer binds the hydrogel to the carbon nanotubes (lower).

To minimise the distance between the enzyme’s redox centre and the electrode, prior strategies have focused on docking enzymes in the desired configuration; however low enzyme activities can result due to protein denaturation. The authors of this work designed a system under the hypothesis that if they focussed on preserving enzymatic activity, the statistical mixture of configurations adopted by enzymes in the hydrogel would still contain a large proportion capable of participating in direct electron transfer.

Bioelectrical activity of the electrode/nitrogenase aggregate was assessed under bubbling N2 at room temperature, and 180 nmol of NH3 (1.1 μmol/mg nitrogenase enzyme) was produced, marking the first bioelectrochemical reduction of N2 in the absence of ATP. The bioelectrical activity of laccase for the reduction of O2 was also measured using the same method. In this experiment 15% of laccase proteins remained active, compared to 0.3% using a reference method applying an enzyme docking technique. This translated to increased current densities of 390 – 1880 μA cm-2 mg-1 (depending on the enzyme concentration, 1-10 mg mL-1) compared to 45 μA cm-1 mg-1 for the reference docking method.

Without being too grandiose, synthetic nitrogen fixation is vital for the continued survival of people on the planet (how did I do?). Beyond nitrogen fixation, this research offers a general method to achieve contact between a conductive electrode and the highly complex catalytic machinery that nature offers: enzymes. Beyond synthesis, opportunities broaden; technology such as this might pave the way for the production of biosensors, biofuel cells and biomolecular electronic components.

 

 

To find out more please read:

Pyrene hydrogel for promoting direct bioelectrochemistry: ATP-independent electroenzymatic reduction of N2

David P. Hickey, Koun Lim, Rong, Cai, Ashlea R. Patterson, Mengwei Yuan, Selmihan Sahin, Sofiene Abdellaoui, Shelley D. Minteer
Chem. Sci., 2018, 9, 5172-5177
DOI: 10.1039/c8sc01638k

About the author:

Zoë Hearne is a PhD candidate in chemistry at McGill University in Montréal, Canada, under the supervision of Professor Chao-Jun Li. She hails from Canberra, Australia, where she completed her undergraduate degree. Her current research focuses on transition metal catalysis to effect novel transformations, and out of the lab she is an enthusiastic chemistry tutor and science communicator.

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RSC Chemical Nanoscience & Nanotechnology Group Annual Symposium 2018: Nanotechnology for Energy and Environment

Chemical Science, Nanoscale and Nanoscale Horizons are delighted to sponsor the RSC Chemical Nanoscience & Nanotechnology (RSC-CNN) Group Annual Symposium 2018, taking place on 6 – 7 September 2018 in London, UK. This event on nanotechnology for energy and environment is organised by the RSC-CNN Group and chaired by Professor Junwan Tang (UCL) and Professor Radim Beranek (Ulm University).

The symposium covers recent developments in fundamental studies, novel material development and reactor engineering in the field, and aims to provide a forum for researchers to exchange ideas as well as discuss recent advances and challenges. A programme consisting of international experts in the field will cover topics from thermal catalysis to water splitting.

Don’t miss out on your chance to attend this exciting symposium – find out more and register here!

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The 4th International Symposium on C-H Activation

Chemical Science, Catalysis Science and Technology, Organic Chemistry Frontiers, and Organic and Biomolecular Chemistry are proud to sponsor the 4th International Symposium on C-H Activation (ISCHA). The conference takes place every two years and allows researchers to discuss the latest discoveries in C-H activation chemistry. This year, it is chaired by Professor Fumitoshi Kakiuchi (Keio University) and is being held 30th August – 2nd September at Keio University in Japan.

The symposium will encompass a range of topics, from biomimetic C-H functionalization to emerging technologies in photoredox catalysis and flow chemistry. With an exciting list of international speakers including John Bower (University of Bristol), Debabrata Maiti (Indian Institute of Technology Bombay) and Michel Etienne (CNRS), the ISCHA provides a great opportunity to become acquainted with prestigious scientists in the field.

Don’t miss out on your chance to attend this symposium – register now!

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