This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: For more than a century, pharmaceutical companies have relied on flat structures called aromatic rings, which can help drugs bind to target sites in the body. They include benzene rings and other flat, nitrogen-containing rings.
But there are limits to their usefulness. Their flat, rigid shape can make it harder for them to fit cleanly into three-dimensional biological targets. Other drawbacks include poor solubility in water and interactions with unintended targets.
So drugmakers are trying to swap flat rings for rigid, three-dimensional structures. But building them from simple starting materials has been extremely difficult. Now, a team led by Varinder Aggarwal at the University of Bristol has come up with a novel solution.
The hurdle they sought to overcome was a natural chemistry rule called the rule-of-five. In this type of reaction, molecules strongly favor snapping shut in one way rather than another. This natural preference has long made it difficult for chemists to create some of the rigid 3D structures that could be useful for developing better, more targeted medicines.
All it took to break this rule was a simple chemical switch driven by blue light. The team started with basic, easy-to-source molecular building blocks called nitrogen-containing 1,5-dienes, as they write in their paper published in Nature Chemistry. These have a chemical group attached to the nitrogen atom that can be changed to control how the molecule reacts when it tries to form a ring.
Next, they added a light-absorbing photocatalyst and exposed the mixture to ordinary blue light. The photocatalyst absorbed the light and transferred its energy to the molecule, while an acetyl group attached to the nitrogen steered the molecule to snap shut in a different way. This left behind the desired 3D structure.
Extract — continue reading at the source.
