Author Archive

Size is important – OBC Cover Issue 4

Cyclophanes have been used as molecular systems in host-guest complexations due to their ability to encapsulate other molecules through various non-covalent interactions.
Cyclophanes  can be rationally designed by choosing the right components, similar to  Lego® bricks. However, the features of these ‘lego bricks’ required to build the desired cyclophanes with the requisite biomolecular recognition properties have not been widely explored.

Now, Danaboyina Ramaiah and colleagues at NIIST in India have revealed some of the features to bear in mind when designing cyclophanes. They concluded by saying that  that the cavity size and its rigidity, the aromatic surface and nature of bridging units dictate the stability of the supramolecular complex and thereby govern the biomolecular recognition properties of cyclophanes.

You can now download this article, which is free to access until mid-March.

Study of cavity size and nature of bridging units on recognition of nucleotides by cyclophanes
Prakash P. Neelakandan, Paramjyothi C. Nandajan, Baby Subymol and Danaboyina Ramaiah
Org. Biomol. Chem., 2011, 9, 1021-1029
DOI: 10.1039/C0OB00673D, Paper

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HOT: PBD-DNA adduct formation is reversible. Evidence by Thurston

PBDs (pyrrolo[2,1-c][1,4]benzodiazepines) and their interaction with DNA is an area of active research.

PBDs belong to a family of biologically active an DNA-interactive antibiotics having unique mechanism of action compared with other DNA-binding agents. Up until now, there have been several reports in literature suggesting that PBD-DNA adduct formation might be reversible; however, no evidence of this reversibility had been reported.

For the first time, in this paper, David Thurston and colleagues at the School of Pharmacy at University of London, investigate the adduct formation of PBDs with DNA and its reversibility using HPLC/MS methodology and polarised light spectroscopy.

Read about some of their findings in this OBC HOT paper which is free to access until the 22nd February.

Observation of the reversibility of a covalent pyrrolobenzodiazepine (PBD) DNA adduct by HPLC/MS and CD spectroscopy
Khondaker M. Rahman, Colin H. James and David E. Thurston
Org. Biomol. Chem., 2011, Advance Article
DOI: 10.1039/C0OB00762E, Paper

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Review: Copper catalysis in the construction of indole and benzo[b]furan rings

The impact of copper chemistry on indole and benzo[b]furan synthesis in the last years has been extraordinary. Heterocycles are very important structural motifs due to their presence in natural products, drug discovery and chemical comodities. Therefore, the search of suitable methods for the synthesis of heterocycles is a very important topic nowadays.

Copper is a relatively cheap metal with great catalytic properties. Copper catalysis has received a great deal of attention in organic synthesis recently and and a variety of new practical and efficient methods based on copper-catalyzed reactions have been developed.

In this review, Sandro Cacchi and colleagues at University of Rome highlight the many methods for indole and benzofuran construction by copper catalysis that has been described in recent years.

‘We believe that this brief summary can provide the reader with a helpful overview of the copper chemistry in this area and can be of value to chemists planning the construction of specific indole and benzo[b]furan derivatives’

At the editorial office we also believe that the reader will find this review very constructive and informative. Read it here.

Copper catalysis in the construction of indole and benzo[b]furan rings
Sandro Cacchi, Giancarlo Fabrizi and Antonella Goggiamani
Org. Biomol. Chem., 2011, 9, 641-652
DOI: 10.1039/C0OB00501K

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HOT: Double-headed nucleosides by the CuAAC reaction

Poul Nielsen and his group at University of Southern Denmark describe the synthesis of new double-headed nucleosides, using the CuAAC reaction, and their influence on the stability of the hybridization of oligonucleotides.

In this HOT paper they describe a new type of nucleosides that are able to stabilize three-way junctions. If you want to find out more about these interesting stabilising contacts download the article, which is free to access until the 8th February.

The synthesis of double-headed nucleosides by the CuAAC reaction and their effect in secondary nucleic acid structures
Anna S. Jørgensen, Khalil I. Shaikh, Gerald Enderlin, Elise Ivarsen, Surender Kumar and Poul Nielsen
Org. Biomol. Chem., 2011, Advance Article
DOI: 10.1039/C0OB00438C

To give you a better overview on Nielsen’s previous research, we have outlined below a collection of their latest OBC published papers. Enjoy!

Stabilisation of nucleic acid secondary structures by oligonucleotides with an additional nucleobase; synthesis and incorporation of 2′-deoxy-2′-C-(2-(thymine-1-yl)ethyl)uridine
Søren Ljungberg Pedersen and Poul Nielsen
Org. Biomol. Chem., 2005, 3, 3570-3575
DOI: 10.1039/B510167K

Synthesis and modelling of DNA junction and minor groove zipper motifs incorporating the double-headed nucleoside 5′(S)–C-(thymine-1-ylmethyl)thymidine
Mikkel S. Christensen, Charlotte M. Madsen and Poul Nielsen
Org. Biomol. Chem., 2007, 5, 1586-1594
DOI: 10.1039/B700852J

Nucleic acid secondary structures containing the double-headed nucleoside 5′(S)-C-(2-(thymin-1-yl)ethyl)thymidine
Charlotte Andersen, Pawan K. Sharma, Mikkel S. Christensen, Signe I. Steffansen, Charlotte M. Madsen and Poul Nielsen
Org. Biomol. Chem., 2008, 6, 3983-3988
DOI: 10.1039/B810930C

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HOT: Treasures from the Free Radical Renaissance Period

Carl Schiesser takes us through the evolution of Free Radical Chemistry in this very original and well written paper that highlights results from the Beckwith “golden era”.
Join us in this trip from the “Dark Ages” of Free Radical Chemistry to the Post-Renaissance period.  The paper will be free to access until 4th February.

In the paper, they determine the rate constant data and Arrhenius parameters for a series of substituted hexenyl radicals of differing electronic and steric demand.

This paper will be included in the special issue on ‘Free Radical Chemistry’ in memory of Athel Beckwith that will be published in Spring. Keep an eye on it.

Treasures from the Free Radical Renaissance Period – Miscellaneous hexenyl radical kinetic data
Athelstan L. J. Beckwith and Carl H. Schiesser
Org. Biomol. Chem., 2011, Advance Article
DOI: 10.1039/C0OB00708K, Paper

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HOT: A potential antihypertensive drug

Inhibition of angiotensin converting enzyme (ACE) is generally used as one of the methods for the treatment of hypertension. ‘Oxidative stress’ is another disease state caused by an imbalance in the production of oxidants and antioxidants. Hypertension and oxidative stress may be interdependent. Therefore, ACE inhibitors having antioxidant properties are considered beneficial for the treatment of hypertension.

Bhaskar J. Bhuyan and Govindasamy Mugesh at the Indian Institute of Science in Bangalore, India, synthesise in this paper a number of selenium analogues of captopril, an ACE inhibitor used as an antihypertensive drug. These analogues not only inhibit ACE activity but also effectively scavenge peroxynitrite, a strong oxidant found in vivo.

Read this paper which is free to access until the 4th February. The referees strongly recommended it and the editorial office as well.

Synthesis, characterization and antioxidant activity of angiotensin converting enzyme inhibitors Bhaskar J. Bhuyan and Govindasamy Mugesh
 Org. Biomol. Chem
., 2011, Advance Article
DOI: 10.1039/C0OB00823K, Paper

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HOT: Expanding the catalogue of emission colours

Bruce A. Armitage and his team at Carnegie Mellon University in Pittsburgh, USA, create a new family of blue fluoromodules with low nanomolar Kds and high quantum yields.
These fluoromodules provide a new technology for multicolour fluorescent labelling and cellular imaging.

This is a very interesting paper that has been rated as very significant by all the referees.

You don’t want to miss this one! Read it now – it is free to access until the 4th February.

Blue fluorescent dye-protein complexes based on fluorogenic cyanine dyes and single chain antibody fragments
Kimberly J. Zanotti, Gloria L. Silva, Yehuda Creeger, Kelly L. Robertson, Alan S. Waggoner, Peter B. Berget and Bruce A. Armitage
Org. Biomol. Chem., 2011
DOI: 10.1039/C0OB00444H

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Unnatural aromatic amino acids – Cover Issue 2

Gangadhar J. Sanjayan and his team at the National Chemical Laboratory in Pune, India, write about the development of conformationally constrained unnatural aromatic amino acids in this communication that is the cover of OBC Issue 2.

The strategy described within the paper will be useful for the construction of oligomers displaying novel molecular architectures with unique conformations, distinct from those classically observed.

Download this paper free to access for a limited period of time.

Congratulations to the authors for a beautiful cover and their interesting research.

Conformationally rigid aromatic amino acids as potential building blocks for abiotic foldamers
Veera V. E. Ramesh, Arup Roy, Kuruppanthara N. Vijayadas, Amol M. Kendhale, Panchami Prabhakaran, Rajesh Gonnade, Vedavati G. Puranik and Gangadhar J. Sanjayan
Org. Biomol. Chem., 2011, 9, 367-369
DOI: 10.1039/C0OB00593B, Communication

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HOT: Ferrocene-containing rotaxane: New chloride ion sensor

Nicholas H. Evans and Paul D. Beer at University of Oxford, describe in this paper the first example of a solution based redox-active interlocked host system capable of the electrochemical recognition of anions and most specifically chloride.

Read this HOT article, as rated by the referees, which will be free to access until 6th December.

A ferrocene functionalized rotaxane host system capable of the electrochemical recognition of chloride
Nicholas H. Evans and Paul D. Beer
Org. Biomol. Chem., 2011, 9, 92-100
DOI: 10.1039/C0OB00458H

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HOT: Synthesis and biological evaluation of 4,5-disubstituted isoquinolin-1-ones

Michael D. Threadgill and coworkers at University of Bath report a very interesting synthesis of 4,5-disubstituted isoquinolin-1-ones and their biological evaluation against PARP-2.

This paper is specially relevant because of the difficulties of working with this class of compound such as insolubility and lack of reactivity. This is a HOT paper that will be free to access until 6th December.

A very neat synthesis relevant for the synthetic and medicinal chemistry communities.

Synthesis of 4-alkyl-, 4-aryl- and 4-arylamino-5-aminoisoquinolin-1-ones and identification of a new PARP-2 selective inhibitor
Peter T. Sunderland, Archana Dhami, Mary F. Mahon, Louise A. Jones, Sophie R. Tully, Matthew D. Lloyd, Andrew S. Thompson, Hashim Javaid, Niall M. B. Martin and Michael D. Threadgill
Org. Biomol. Chem., 2011, Advance Article
DOI: 10.1039/C0OB00665C,

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