June 7, 2012
Undiscovered Drugs In The Novemdecillions
Connie K. Ho for redOrbit.com
Novemdecillion — now that´s a huge number. A report published in the American Chemical Society journal Chemical Neuroscience estimates that scientists have barely synthesized one tenth of one percent of the possible medicines that could be made. The estimate of these “small molecules” is potentially 1 novemdecillion, which equals a one with 60 zeros or 1 million billion billion billion billion billion billion.The American Chemical Society is a nonprofit organization chartered under the U.S. Congress. It has over 164,000 members and is one of the world´s largest scientific societies in providing access to chemistry-related research. It provides information through multiple database, peer-reviewed journals, and scientific conferences.
In the article, researchers Jean-Louis Reymond and Mahendra Awale describe how the small molecules, which can cross cell walls and engage with biological molecules in the body, are the aims for scientists who are interested in developing new medicines. Most current medications are made up of small molecules.
“Small molecule drugs exert their action by binding to specific molecular constituents of the cell such as to modulate biochemical processes in a diseases modifying manner. The magnitude and specificity of binding depends on the complementarity between the drug molecule and its target in terms of shape, polarity, and chemical functionality,” explained the authors in the abstract of the report.
The authors highlighted how the “chemical space” of the small molecule could exist based on the laws of physics and chemistry. They have determined millions of the compounds and the ACS´ Chemical Abstracts Service database contains around 67 million substances. Reymond and Awale believe that the molecules synthesized and examined as potential drugs currently only represent less than 0.1 percent of chemical space.
“The number of known molecules is impressive and interesting; however, this number alone does not provide any information on what these molecules are,” commented the authors in the report.
The researchers wanted to look for the best methods to identify new small molecules in order to assist researchers in their work of investigating new ways to prevent and treat diseases. In the report, they stated that a key challenge in exploiting the resource would be determining the value of virtual screening. Virtual screening or computer screening is normally utilized to choose compounds from existing groups to focus time and resources on the most important molecules.
In the paper, Reymond and Awale contemplated the different ways of managing the chemical space, including by the size, shape, and makeup of different molecules. Their paper demonstrates how computers can assist researchers in quickly narrowing a search for a new drug candidate. In particular, computer modeling of chemical interactions assist researchers in looking for a group of promising molecules that can be synthesized and examined in the lab.
"Small molecule drugs are essential to the success of modern medicine," the authors wrote in the paper on the findings of the experiment.
The researchers propose that the methods they utilized and described may be useful in determining new pharmaceuticals that focus on the central nervous system. The University of Berne, the Swiss National Science Foundation, and the NCCR TransCure provided funding for the research.