Archive for the ‘Hot articles’ Category

Fluorescent nucleosides provide flexibility in fine-tuning photophysical properties

The ubiquity of radioisotope-based bioprobes is being challenged by their nonradioactive counterparts. In recent years, they have gained significant popularity in life sciences due to major advances in available detection methods and enhanced analytical performance. Many would argue that radioactive labels offer superior results in experiments that require high sensitivity and resolution but their safe handling, stability and the proper disposal of radioactive materials limit speed and convenience of use.

The newest generation of fluorescent and chemifluorescent probes promise greater flexibility and versatility for a range of applications and the development of fully automated instrumentations and powerful imaging systems provide high throughput solutions to meet the increasing demands of the modern lab.

Unique photophysical properties can be incorporated into small biomolecules to generate fluorescent bioprobes. Fluorescently labeled nucleosides have distinct advantages over other synthetic molecules due to inherent fluorescence and minimal steric disruptions, and they can be tuned e.g. to form unusual base-pair preferences. They form noncovalent, highly specific duplexes with a complementary nucleic acid strand and are used to detect a defined DNA or RNA target sequence.

In a recent publication from the group of Yoshio Saito of Nihon University, the development of a novel nucleoside-based bioprobe containing a 3-deaza-2’-deoxyadenosine skeleton was reported. It behaves as an indicator for adenosine-cytosine base pair formation in oligodeoxynucleotide (ODN) duplexes by monitoring base-pair induced protonation. The probe displays distinct changes in its absorption and fluorescence activity as a result of its protonation state. In this way, the group is able to clearly discriminate cytosine from other bases on complementary strands based on absorption and fluorescence spectra.

The development of new biomarkers is providing insight to various genetic disorders, disease susceptibility, cancer predisposition and medication response. When fluorescent bioprobe imaging is coupled with genetic analytical techniques, such as single nucleoside polymorphism (SNP)-typing, the two synergize and provide a much more complete view than either one alone.

To find out more see:

Design and synthesis of a novel fluorescent benzo[g]imidazo[4,5-c]quinoline nucleoside for monitoring base-pair-induced protonation with cytosine: distinguishing cytosine via changes in the intensity and wavelength of fluorescence
Shogo Siraiwa, Azusa Suzuki, Ryuzi Katoh and Yoshio Saito
DOI:10.1039/C6OB00494F


Victoria Corless is currently completing her Ph.D. in organic chemistry with Prof. Andrei Yudin at The University of Toronto. Her research is centred on the synthesis of kinetically amphoteric molecules, which offer a versatile platform for the development of chemoselective transformations with particular emphasis on creating novel biologically active molecules.

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Improving total synthesis of modified histone proteins to elucidate epigenetic mechanisms

In their search to solve complex biological problems by bridging gaps between protein synthesis and biological application, Prof. Jennifer Ottesen and her group at Ohio State University have been successfully developing what they term a ‘chemical toolbox’ for histone protein synthesis.

Within the field of epigenetics, heritable changes in gene expression outside of the DNA sequence are tightly regulated by post-translational modifications (PTMs) of DNA and histone proteins–the proteins that package DNA. Known PTMs of histone proteins include methylation, acetlyation, phosphorylation, sulfonylation and ubiquitination and fall under a hypothesized “histone code” which suggests that combinations of these markers alter DNA accessibility through chromatin restructuring and ultimately regulate gene expression.

In building synthetic histone proteins with distinct combinations of chemical modifications, the role of a specific sequence of PTMs in gene expression and the molecular mechanisms by which they function can be elucidated and targeted. This is of particular interest as epigenetics has become a hot topic in recent years due to an ever-growing understanding of these markers and their potential to act as selective entry points for disease intervention.

Ottesen’s recent publication in Organic and Biomolecular Chemistry outlines a new hybrid phase ligation approach for the synthesis of modified histone proteins which overcomes some long standing issues inherent in histone total synthesis. This method combines both solid and solution-phase ligation chemistry to improve process efficiency and overall yield. The group even demonstrates its ability to produce previously challenging CpA-K12ac histone protein which could not be synthesized with standard approaches.

Key to their success is the application of a dual-linker strategy which led to an efficient, sequence-independent resin attachment that liberates the desired native carboxy terminus of the protein which had been previously difficult to accomplish. Below is a scheme describing the solid-phase native chemical ligation of one of their desired targets, histone H4. A single coupling cycle includes deprotection followed by ligation and cleavage from the resin may be accomplished at either the Rink linker (black), or at the HMBA linker (red) to generate the native terminus.

Studies such as Prof. Ottesen’s are crucial as mechanisms by which certain genes are regulated must first be determined before developing targeted therapeutic approaches. Histone deacetylase (HDAC) inhibitors for example, interfere with histone deacetylase and have shown activity against various cancers, neurological diseases and immune disorders. The utility of this class of compound depends on their ability to target and modulate a subset of genes without causing global biological changes. Presently, additional work is required to define the human epigenome, its role in disease development and the processes that regulate it. Progress in the synthesis of highly desirable modified histone proteins brings us ever closer.

To find out more see:

Hybrid phase ligation for efficient synthesis of histone proteins
Ruixuan R. Yu, Santosh K. Mahto, Kurt Justus, Mallory M. Alexander, Cecil J. Howard, and Jennifer J. Ottesen
DOI: 10.1039/C5OB02195B


Victoria Corless is currently completing her Ph.D. in organic chemistry with Prof. Andrei Yudin at The University of Toronto. Her research is centred on the synthesis of kinetically amphoteric molecules, which offer a versatile platform for the development of chemoselective transformations with particular emphasis on creating novel biologically active molecules.

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Computational chemistry: Solving real-world chemical problems

Computational chemistry is a powerful tool for understanding real-world chemical problems. The gap between experiment and computational models is growing ever smaller. Calculated results for isolated molecules are becoming more relevant and reliable calculations for larger and larger molecular systems are becoming more accessible.

A computational study of enantioselective spiroacetalization catalyzed by phosphoric acids carried out by researchers at the Universidad de Salamanca and Oxford University effectively demonstrates the ability of advanced computational methods to elucidate key and often subtle factors that lead to different reaction outcomes.

The study uses a hybrid quantum mechanics (QM)/molecular mechanics (MM) method which makes computational simulations of large systems feasible by combining an accurate quantum mechanical description of the ‘interesting’ part of the system (i.e. the catalyst active site) with the computational efficiency of molecular mechanics applied to the surroundings. This way, one can assess the importance of environmental effects while avoiding a high computational cost. This is accomplished by partitioning the system’s total energy into inner (or active) and outer parts. The interactions within the inner part are then treated with the computationally higher quantum mechanics level and the outer parts are described using less expensive, lower level molecular mechanics methods.

The origin of greater enantioselectivity for the imidodiphosphoric acid (Figure, cat-II) over the binol phorophoric acid (Figure, cat-I) was determined through exhaustive analysis of transition state conformers using the QM/MM method. Ultimately,  it was determined that the source of chiral discrimination in catalyst II comes from a unique, bifunctional hydrogen bonding interaction between the catalyst and substrate. This confining interaction ends up limiting the accessible area to the imidodiphosphoric oxygen, resulting in an enantioselective outcome.

The significance of this work lies in the utility of theoretical models in explaining important empirical results. The ability to dissect a mechanism and identify the influential factors that determine a selective reaction outcome could not have been so easily accomplished without the use of computational analysis and will no doubt aid in the design of future organocatalysts for small, non-sterically demanding molecules.

To find out more see:

QM/MM study on the enantioselectivity of spiroacetalization catalysed by an imidodiphosphoric acid catalyst: how confinment works
Luis Simón and Robert S. Paton
DOI: 10.1039/C6OB00045B


Victoria Corless is currently completing her Ph.D. in organic chemistry with Prof. Andrei Yudin at The University of Toronto. Her research is centred on the synthesis of kinetically amphoteric molecules, which offer a versatile platform for the development of chemoselective transformations with particular emphasis on creating novel biologically active molecules.

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Continuous Flow Processes as an Enabling Technology in Synthesis

Recent advancements in reaction control and method development strategies have significantly impacted the way in which synthetic chemistry is performed. Arguably, one of the most widely amenable and enabling technologies is continuous flow chemistry, which can offer advantages over batch in terms of cost, reaction efficiency and safety. Its implementation is changing the way in which we think about and conduct chemistry and in some areas has expanded our synthetic capabilities.

As a result, numerous syntheses of commercially and pharmaceutically relevant compounds are being redesigned around flow processes in order to improve efficiency and reproducibility. In addition, the flow reactor configuration can be readily customized to meet specific reaction demands.

These changes are most evident within the pharmaceutical industry where increasing pressure to continually identify and optimize lead compounds has renewed interest in the development of sustainable and cost effective processes for both research and production purposes.1

A direct example of this comes from Prof. Ian Baxendale’s laboratory at Durham University.2 Heterocyclic motifs are prevalent in pharmaceuticals and have constituted one of the largest areas of research in organic chemistry. Through a convenient telescope continuous flow process, ethyl isocyanoacetate—a highly sensitive and reactive compound frequently used as a key building block in heterocycle synthesis—was generated in situ and used to synthesize diverse heterocyclic structures in a convergent manner.

General reaction scheme for the muti-step flow synthesis of 1,2,4-triazole and pyrrole[1,2-c]pyrimidine-based heterocycles.

Continuous flow limits issues related to hazardous exothermic processes, reaction scale-up and handling of highly reactive or toxic intermediates, overcoming numerous safety concerns inherent in batch chemistry. Furthermore, flow chemistries have also been combined with additional features such as microwave irradiation, solid-supported reagents or catalysts, photochemistry, inductive heating and electrochemistry, which greatly increase its application in synthetic organic chemistry.3,4

Significant developments within the last decade indicate that the full potential of flow chemistry has yet to be realized. As with any new up-and-coming technology, there exist limitations that more and more researchers are willing to tackle. This is evident in the prevalence of flow systems now being utilized not only within academic laboratories but also in industrial institutions.

Interesting and innovative examples of synthetic reactions translated to flow systems have recently been published in Organic and Biomolecular Chemistry and can also be found in the joint OBC/ChemComm collection ‘Recent Advances in Flow Synthesis and Continuous Processing’. Select examples are discussed below.


Establishing a multistep continuous flow process is a logical step forward in the development of flow technology. However, genuine applications remain limited due to inherent challenges such as solvent incompatibility, intermediate work-up and dilution effects. Prof. Floris Rutjes and his coworkers at Radboud University have provided a solution to this problem.5 They effectively integrated a two-step chemoenzymatic flow synthesis of incompatible reaction steps through the use of an inline liquid-liquid separation module.

Two step synthesis of cyanohydrins and schematic representation of the flow set up with integrated liquid-liquid phase separation module.

Homogenous metal catalysis has seen limited use in industrial processes due to difficult separation from product material and troublesome recovery of precious metals. To remedy this, an immobilised iridium hydrogen transfer catalyst was developed by Prof. Ian Baxendale and coworkers for use in flow based systems by incorporation of a ligand to a porous polymeric monolithic flow reactor, which limits metal leaching and catalyst deactivation.6

A monolith reactor testing configuration using immobilized iridium hydrogen transfer catalyst.

Finally, Prof. Bradely Pentelute and his group at the Massachusetts Institute of Technology very recently reported an efficient continuous-flow system for the challenging synthesis of peptides containing perfluoroaromatic molecules in place of labile disulfide bonds.7 Application of a rapid flow-based solid-phase peptide synthesis allowed the researchers to circumvent previously encountered problems associated with this chemistry and has resulted in an overall improvement in quality and isolated yield of the peptides.

Flow system for the synthesis of H2 relaxin fragment analogues using modified solid-phase peptide synthesis

To find out more see:

1 Flash chemistry: flow chemistry that cannot be done in batch. J. Yoshida, Y. Takahashi, A. Nagaki, Chem. Commun., 2013, 49, 9896. DOI: 10.1039/C3CC44709J

2 Flow synthesis of ethyl isocyanoacetate enabling the telescoped synthesis of 1,2,4-triazoles and pyrrolo-[1,2-c]pyrimidines. M. Baumann. A. M. Rodriguez Garcia, I. R. Baxendale, Org. Biomol. Chem., 2015, 13, 4231. DOI: 10.1039/C5OB00245A

3 Liquid phase oxidation chemistry in continuous-flow microreactors. H. P. L. Gemoets, Y. Su, M. Shang, V. Hessel, R. Luque, T. Noël, Chem. Soc. Rev.201645, 83. DOI: 10.1039/C5CS00447K

4 Flow chemistry syntheses of natural products. J. C. Pastre, D. L. Browne, S. V. Ley, Chem. Soc. Rev.201342, 8849. DOI: 10.1039/C3CS60246J

5 Chemoenzymatic flow cascade for the synthesis of protected mandelonitrile derivatives. M.M. Delville, K. Koch, J.C.M. van Hest, F.P.J.T. Ruties, Org. Biomol. Chem., 2015, 13, 1634. DOI: 10.1039/C4OB02128B

6 A monolith immobilised iridium Cp* catalyst for hydrogen transfer reactions under flow conditions. M. V. Rojo, L. Guetzoyan, I. R. Baxendale, Org. Biomol. Chem., 2015, 13, 1768. DOI: 10.1039/C4OB02376E

7 A perfluoroaromatic abiotic analog of H2 relaxin enabled by rapid flow-based peptide synthesis. T. Luhmann, S. K. Mong, M. D. Smino, L. Meinel, B. L. Pentelute, Org. Biomol. Chem., 2016, 14, 3345. DOI: 10.1039/C6OB00208K


Victoria Corless is currently completing her Ph.D. in organic chemistry with Prof. Andrei Yudin at The University of Toronto. Her research is centred on the synthesis of kinetically amphoteric molecules, which offer a versatile platform for the development of chemoselective transformations with particular emphasis on creating novel biologically active molecules.

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Developing a fragment-based design-friendly methodology

Target-based approaches to drug discovery have dominated pharmaceutical research since the early 1990s because they allow for increased screening capacity and rational drug design. Advances in combinatorial chemistry, high-throughput screening and gene expression profiling have been effective in the development of novel treatments for validated targets; however, a link between the downward trend in the number of new chemical entities reaching commercialization and the predominance of target-based drug discovery methods in the pharmaceutical industry has been suggested.

To address these issues, new technologies are constantly being developed and fragment-based drug design (FBDD) has emerged as a way to improve the quality and (most importantly) the efficiency of the drug discovery process. FBDD identifies the binding of low molecular weight ligands using techniques such as X-ray crystallography or NMR spectroscopy, and the binding information is then used to assemble potent lead compounds with drug-like properties.

In a recent publication, researchers at Astex Pharmaceuticals have noted that the success of FBDD often relies on the development of new synthetic methodologies for ligand elaboration. Despite the simplicity of fragment-like compounds, challenges lie in their design and synthesis as well as in developing the methodology to combine and grow fragments into high affinity leads. It is therefore important to identify compounds with attractive ‘fragment properties’ which are used as part of a selection process for adding new fragments into the Astex screening library. These include incorporation of diverse polar groups, multiple synthetically accessible positions for fragment growth in three dimensions and synthetic tractability among others.

Dihydroisoquinolone and some of its derivatives were identified in this study as ideal fragment-like compounds for the development of a FBDD-friendly synthetic methodology.

Schematic representation of synthetic elaboration of fragment 1. Growth positions are shown as blue arrows and the incorporation of aromatic heteroatoms and polar binding groups are indicated.

As proof of concept, the previously reported synthesis of dihydroisoquinolone-based compounds using Rh(III)-catalyzed C-H bond activation1 was modified to incorporate additional potential binding groups as well as synthetic handles for efficient fragment-to-lead elaboration.

Their results illustrate an excellent example of how the application of FBDD-friendly synthetic methodology can be used to expand upon published methodologies to increase their utility in developing useful templates for fragment-based drug discovery. Although inventive ideas, such as this work, are making small contributions in pharmaceutical research, there is a need for more organic chemists to engage in these synthetic challenges if drug discovery techniques are to be fruitful in the long-run.

1 N. Guimond et al. J. Am. Chem. Soc., 2011, 133(16), 6449–6457


To find out more see:

Design and synthesis of dihydroisoquinolones for fragment-based drug discovery (FBDD)
Nick Palmer, Torren M. Peakman, David Norton and David C. Rees
DOI: 10.1039/C5OB02461G


Victoria Corless is currently completing her Ph.D. in organic chemistry with Prof. Andrei Yudin at The University of Toronto. Her research is centred on the synthesis of kinetically amphoteric molecules, which offer a versatile platform for the development of chemoselective transformations with particular emphasis on creating novel biologically active molecules.

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Revitalizing palladium-catalyzed α-arylation of enolates to generate diverse isoquinoline-based compounds

Research efforts carried out by Professor Timothy Donohoe of Oxford University have been focussed on connecting new methodologies in organic synthesis and catalysis with impactful applications to the fields of medicinal chemistry and natural product synthesis.

One of the group’s most recent endeavors includes the development of a generalized strategy to access highly functionalized and diverse isoquinoline cores without the use of expensive and highly-specialized starting materials.

The isoquinoline motif and its derivatives are ubiquitous in a number of natural products, pharmaceutical agents, and chiral catalyst ligands. However, classical syntheses are often centered on electrophilic aromatic substitution of electron-rich systems, resulting in limited chemical diversity in accessible products. New routes are still highly desirable and a resurgence in synthetic efforts has resulted in a number of notable contributions using modern synthetic methodology.

In 2012, Prof. Donohoe and coworkers reported a sequential palladium-catalyzed α-arylation of enolates and cyclization to access isoquinolines based on chemistry originally and independently reported by Buckwald, Hartwig and Miura in 1997. Though a powerful reaction, it remained underutilized in the assembly of complex aromatic compounds. Using clever reaction engineering, Donohoe and coworkers envisioned synthesizing a psuedo-1,5-dicarbonyl accessible through α-arylation of enolizable ketones with aryl halides possessing a protected aldehyde or ketone in the ortho-position. In addition, trapping with reactive electrophiles resulted in functionalization at the C4 position. This methodology can be carried out in one pot, tolerates a wide range of substituents and most notably, provides a route to synthetically challenging electron-deficient isoquinoline scaffolds.

Palladium-catalyzed enolate arylation as a key C–C bond-forming reaction for the synthesis of isoquinolines

Their current study presents significant extensions of this earlier work and further demonstrates the innovation possible through transition metal catalysis in enabling the construction of complex architectures in interesting ways. The three- and four-component coupling procedures involve multiple bond formations in one pot from largely commercially available starting materials. Reaction versatility is demonstrated through the use of ketone, ester or nitrile enolates as well as electron-rich, electron-deficient or even sterically hindered aryl halides and in situ functionalization of intermediates to directly access a number of highly functionalized isoquinoline based compounds.

In addition to rejuvenating interesting and underexplored chemistry, Prof. Donohoe and coworkers have appreciably impacted the areas of natural product synthesis and medicinal chemistry through their innovative and streamlined synthesis of isoquinoline-based compounds and it will be interesting to see where their future endeavours will lead.


To find out more see:

Palladium-catalyzed enolate arylation as a key C–C bond-forming reaction for the synthesis of isoquinolines
Ben S. Pilgrim, Alice E. Gatland, Carlos H. A. Esteves, Charlie T. McTernan, Geraint R. Jones, Matthew R. Tatton, Panayiotis A. Procopiou and Timothy J. Donohoe
DOI: 10.1039/C5OB02320C


Victoria Corless is currently completing her Ph.D. in organic chemistry with Prof. Andrei Yudin at The University of Toronto. Her research is centred on the synthesis of kinetically amphoteric molecules, which offer a versatile platform for the development of chemoselective transformations with particular emphasis on creating novel biologically active molecules.

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Applying old tricks to new problems: Acyl Fluorides in Sterically Hindered Amide Coupling

It comes as no surprise to those with a background in organic or medicinal chemistry that one of the most important and often-overlooked synthetic transformations is the formation of amide bonds.

Amide linkages are one of the most prolific moieties in the synthesis of pharmaceuticals and biologically active molecules. However, despite their prevalence there remain synthetic challenges, as even the simplest amides can be difficult to make.

A group at the University of Southern Denmark led by Prof. Trond Ulven has developed a protocol for amide coupling through in situ formation of acyl fluorides.

Initially, the researchers were working toward the synthesis of a molecular inhibitor for the free fatty acid receptor 2 (FFA2/GPR43), which has recently generated some interest as a target for treating various metabolic disorders.

While attempting the synthesis of an intermediate, coupling between their sterically hindered and sensitive carboxylic acid with an electron deficient and hindered amide understandably led to unsatisfactory results using standard coupling procedures.

Given the multiple steps required to generate both intermediates, the group decided to explore alternative methods to solve their problem. Indeed, acyl fluorides proved to be ideal as they behave like activated esters due to the unique nature of the carbonyl-fluoride bond while also minimizing steric hindrance between the two coupling partners.

Literature protocols are available for the generation of acyl fluorides and there are disadvantages associated with some. In recent years however, a number of alternative fluorinating agents have been reported that are capable of generating the acyl fluoride in situ under mild reaction conditions.

Prof. Ulven’s group was able to further improve the efficiency of this methodology by utilizing an alternative fluorinating agent, BTFFH, which is normally used in solid-phase peptide synthesis. This reagent reduces byproduct formation observed with reagents such as DAST, Deoxo-Fluor and XtalFluor-E. High conversions and isolated yields were obtained as a result and Ulven’s method was also successfully applied to amide coupling reactions previously reported as low yielding.

There is still a need for chemists to develop better ways to synthesize complex amide-containing structures without the need for external reagents. In the meantime, solutions such as these overcome synthetic challenges and are critical to further development and understanding in organic reaction design.


To find out more see:

A protocol for amide bond formation with electron deficient amines and sterically hindered substrates
Maria E. Due-Hansen, Sunil K. Pandey, Elisabeth Christiansen, Rikke Andersen, Steffen V. F. Hansen and Trond Ulven
DOI: 10.1039/C5OB02129D


Victoria Corless is currently completing her Ph.D. in organic chemistry with Prof. Andrei Yudin at The University of Toronto. Her research is centred on the synthesis of kinetically amphoteric molecules, which offer a versatile platform for the development of chemoselective transformations with particular emphasis on creating novel biologically active molecules.

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Tagetitoxin – real structure finally revealed?

For centuries, natural products have been linked to medicine through traditional remedies and since played an important role in drug discovery.

New structure of tagetitoxin

New tagetitoxin structure based on 2D NMR correlations

Despite competition from other drug discovery methods, natural products have provided their fair share of clinical candidates and commercial drugs. Furthermore, the isolation, synthesis and biological evaluation of natural products often lead to lasting impressions in science.

In a recent study lead by Dr Abil Aleiv of the University College London, the structure of the known natural product tagetitoxin has been revised based on a detailed analysis of newly acquired NMR and MS data. The group employed 2D 1H–13C HMBC correlations and long-range JCH couplings in conjunction with computational analysis to correlate JCH couplings with predicted values.

For several years, the structure of tagetitoxin remained a mystery. First identified in 1981 by Mitchell, the structure was only partially characterized by MS and was proposed to be an 8-membered heteroatomic ring.  Revised structures have since been published by Mitchel (1989), Vassylyev (2005) and Gronwald (2005). Despite all these efforts, conflicting results and incomplete analyses resulted in the absolute configuration remaining undetermined.

Structures of tagetitoxin previously published by Mitchel (1989), Vassylyev (2005) and Gronwald (2005)

Early analysis of complex structures was generally difficult as spectrometers were relatively insensitive and experiments were performed at low-fields strengths. Through the increasing prevalence and utility of modern 2D NMR experiments in the past decade, NMR has become a powerful and enabling tool for structure elucidation and confirmation.

In addition, the key to Dr Aliev’s findings lies in confirming the purity of the tagetitoxin sample the group had acquired. They noted that the compound gradually decomposed in aqueous solutions if left for prolonged periods of time, which they suspect led to additional peaks being observed in previously reported NMR spectra.

This exciting work showcases the importance of technical advances in determining the structure of biologically active natural products with greater ease and confidence. As a result, advances in lead development and the identification of important families of pharmacophores for drug discovery can be attained with greater efficiency, which may contribute to a revival of interest in natural products for drug discovery purposes.

To find out more see:

The structure of tagetitoxin
Abil E. Aliev, Kersti Karu, Robin E. Mitchell and Michael J. Porter
DOI: 10.1039/c5ob02076j


Victoria Corless is currently completing her Ph.D. in organic chemistry with Prof. Andrei Yudin at The University of Toronto. Her research is centred on the synthesis of kinetically amphoteric molecules, which offer a versatile platform for the development of chemoselective transformations with particular emphasis on creating novel biologically active molecules.

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Entry into Mitochondria to reveal oxidative secrets

Recently, researchers from The University of Sydney, under the leadership of Dr. Elizabeth New, have reported a novel redox probe that selectively localises in Mitochondria. This fluorescent probe, NpFR2, has been used to identify the variations in the oxidative capacity of the haematopoietic cells.

Targeting Mitochondria has become one of the most important research protocols due to its immense importance to organelle-specific drug delivery. Mitochondria, being the power house of a cell, are the focus of researchers working in the area. Similarly, reactive oxygen species (ROS) have a key role and their levels are important in maintaining the redox homeostasis of the cell. A number of biological processes have been linked to mitochondrial ROS levels. These include response to hypoxia, immune responses, cellular differentiation and maturation, autophagy and ageing.

Graphic 1Graphic 2

In this paper, Dr. Elizabeth New et al., presents this novel compound that can be used reversibly and has a reduction potential within the biologically relevant range. To target mitochondria, a triphenyl phosphonium (TPP) group is been incorporated into the molecule. Further, they test this molecule in haematopoietic cells and can identify the mitochondrial ROS levels of different types of cells such as bone marrow macrophages, thymus and spleen.

NpFR2 can further be combined with other fluorescent probes and antibodies for further understanding of mitochondrial ROS in different cell processes.

Find out more in their Communication:

Mitochondrially targeted redox probe reveals the variations in oxidative capacity of the haematopoietic cells
Amandeep Kaur, Kurt W. L. Brigden, Timothy F. Cashman, Stuart T. Fraser and Elizabeth J. New
DOI: 10.1039/C5OB00928F

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HOT Organic & Biomolecular Chemistry articles

The following Organic & Biomolecular Chemistry articles have all been recommened by the reviewers of the articles as being particularly interesting or particularly significant research. These have all been made free to access until 20th April 2015. The order they appear in the list holds no special meaning or ranking.

Silver catalysed decarboxylative alkylation and acylation of pyrimidines in aqueous media
Wen-Peng Mai, Bin Sun, Li-Qin You, Liang-Ru Yang, Pu Mao, Jin-Wei Yuan, Yong-Mei Xiao and Ling-Bo Qu
DOI: 10.1039/C4OB02524E

10.1039/C4OB02524E


Templating carbohydrate-functionalised polymer-scaffolded dynamic combinatorial libraries with lectins
Clare S. Mahon, Martin A. Fascione, Chadamas Sakonsinsiri, Tom E. McAllister, W. Bruce Turnbull and David A. Fulton
DOI: 10.1039/C4OB02587C

10.1039/C4OB02587C


Oxidative asymmetric umpolung alkylation of Evans’ β-ketoimides using dialkylzinc nucleophiles
Tom A. Targel, Jayprakash N. Kumar, O. Svetlana Shneider, Sukanta Bar, Natalia Fridman, Shimon Maximenko and Alex M. Szpilman
DOI: 10.1039/C4OB02601B

10.1039/C4OB02601B


Cyclopropanation using flow-generated diazo compounds
Nuria M. Roda, Duc N. Tran, Claudio Battilocchio, Ricardo Labes, Richard J. Ingham, Joel M. Hawkins and Steven V. Ley
DOI: 10.1039/C5OB00019J, Communication

10.1039/C5OB00019J


Supramolecular control of transition metal complexes in water by a hydrophobic cavity: a bio-inspired strategy
Olivia Bistri and Olivia Reinaud
DOI: 10.1039/C4OB02511C

10.1039/C4OB02511C


Cyclopenta[b]naphthalene cyanoacrylate dyes: synthesis and evaluation as fluorescent molecular rotors
Laura S. Kocsis, Kristyna M. Elbel, Billie A. Hardigree, Kay M. Brummond, Mark A. Haidekker and Emmanuel A. Theodorakis
DOI: 10.1039/C4OB02563F

10.1039/C4OB02563F


Chiral nanostructuring of multivalent macrocycles in solution and on surfaces
Marco Caricato, Arnaud Delforge, Davide Bonifazi, Daniele Dondi, Andrea Mazzanti and Dario Pasini
DOI: 10.1039/C4OB02643H

10.1039/C4OB02643H


Physicochemical studies on the copper(II) binding by glycated collagen telopeptides
Meder Kamalov, Paul W. R. Harris, Christian G. Hartinger, Gordon M. Miskelly, Garth J. S. Cooper and Margaret A. Brimble
DOI: 10.1039/C4OB02536A
Regiodivergent Lewis base-promoted O- to C-carboxyl transfer of furanyl carbonates
Craig D. Campbell, Caroline Joannesse, Louis C. Morrill, Douglas Philp and Andrew D. Smith
DOI: 10.1039/C4OB02629B

10.1039/C4OB02536A


Total syntheses of five uvacalols: structural validation of uvacalol A, uvacalol B and uvacalol C and disproval of the structures of uvacalol E and uvacalol G
Adiyala Vidyasagar and Kana M. Sureshan
10.1039/C4OB0266310.1039/C4OB02663B B


Direct biosynthetic cyclization of a distorted paracyclophane highlighted by double isotopic labelling of L-tyrosine
Alexandre Ear, Séverine Amand, Florent Blanchard, Alain Blond, Lionel Dubost, Didier Buisson and Bastien Nay
DOI: 10.1039/C5OB00114E

10.1039/C5OB00114E


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