Chemical Communications Blog

ISACS 14 Challenges in Organic Chemistry will bring together world leading experts in the field of organic chemistry and synthesis.

The best contribution will be awarded a fantastic prize from Chemistry World so don’t delay, be sure to submit your poster abstract by 2 June 2014.

Themes for the ISACS 14, Shanghai China are:

For more information on how to submit your poster abstract please visit our conferences and events homepage.

The synthesis and characterization of a new class of photochromic metal-organic framework (MOF) linkers is described in this communication. Dinesh Patel from Pennsylvania State University and collaborators from the Benedict Research Group at University of Buffalo demonstrate that additional functionality, such as photoswitching, can be designed into a ligand without affections the topology of MOFs.

Compounds that change their molecular and electronic structure upon application of light are ideal candidates for sensors, switches and optical data storage medial. These photochromic molecules are now being pursued for use in MOFs in the hope of affording photonic control over the physical properties of the crystalline host. Several instances of MOFs containing non-covalently attached photochromic molecule have been reported, but there is a lack of control over guest orientation and concentration. The use of photoactive linkers means that the photochromic groups are covalently attached to the framework leading to MOFs with well-defined stoichiometry.  In this report, a new class of photoswitchable linkers, based on diarylethene photochromes is introduced.

This article has been highlighted as a news story ‘metal organic frameworks react to light’ by Nina Notman in Materials Today

To read more about the full synthesis and characterization, including crystal structure analysis of reaction intermediates, download the full article for free*

Photoresponsive porous materials: the design and synthesis of photochromic diarlyethene-based linkers and a metal-organic framework

Dinesh G. (Dan) Patel, Ian M. Walton, Jordan M. Cox, Cody J. Gleason, David R. Butzer and Jason B. Benedict
DOI: 10.1039/C3CC49666J

*Access is free untill the 19th May 2014 through a registered RSC account – click here to register

Proteins L1 and L2 form pentamers that arrange to form the viral particle © Shutterstock

Researchers in China have disrupted the life cycle of the leading cause of cervical cancer – the human papilloma virus – using a macrocyclic molecule called a pillarene. The team hope their findings will offer new prophylactic avenues against the virus.There are over 100 different types of the human papilloma virus (HPV), 40 of which can be sexually transmitted. Most infections are symptomless and do not result in disease. However, a few types of the virus are known to cause changes in cells that can lead to cervical and throat cancer. HPV types 16 and 18 cause 70% of cervical cancer cases. 

Vaccination programmes against types 16 and 18 have recently become available to teenage girls in some countries. However, as one of the lead scientists on the pillarene project Ying-Wei Yang at Jilin University, China, explains, there is an urgent need for alternatives: ‘the current HPV vaccines are type-specific, expensive and require cold chain transportation, so are not very helpful, especially in developing countries where most cervical cancers occur.’ 

 HPV is made up of two proteins, L1 and L2. These assemble into pentamers to form the virus particles that then attach to cells, resulting in infection. Some researchers believe that disrupting the assembly of the virus using molecules that bind to these two proteins might be the key to stopping it in its tracks.  

 CP5A, a carboxylatopillar[5]arene sodium salt, has a 3D, rigid and π-rich cavity that binds to amino acids 

 The team hope to screen other small molecules to find inhibitors for more specific binding sites on the interface between L1 and L2. Their long term aim is to use one of these to produce a HPV vaccine. 

 Margaret Stanley, a leading expert on the life cycle of human papilloma viruses at the University of Cambridge in the UK sees this study as valuable research for investigations on viral assembly. However, she cautions that the therapeutic value of these approaches is not clear. ‘Inhibiting viral assembly will significantly block transmission, but will not necessarily have any effect on infection level since viral genomes will still be present and potentially able to reactivate after the end of any treatment with inhibitors.’ 

 You can also read this article in Chemistry World» 

Read the original journal article in ChemComm – it’s free to download until 28th March:
Efficient inhibition of human papillomavirus 16 L1 pentamer formation by a carboxylatopillarene and a p-sulfonatocalixarene
Dong-Dong Zheng, Ding-Yi Fu, Yuqing Wu, Yu-Long Sun, Li-Li Tan, Ting Zhou, Shi-Qi Ma, Xiao Zha and Ying-Wei Yang  
Chem. Commun., 2014, Advance Article, DOI: 10.1039/C3CC49789E