Molecular Diversity in Chemical Biology and Drug Discovery

Recent years have seen an increasing level of dialogue between chemists and biologists, the lines of communication consolidated by the availability of recombinant biotechnology tools for manipulating the chemical structure of genes, and the proteins they encode. This has led to an explosion of interdisciplinary activity at the chemistry/biology interface, now coined chemical biology.

The Chemical Biology Discussion Group brings together chemists and biologists interested in hearing about the latest ideas in this rapidly growing field. Meetings of this group will provide a forum for lively discussion and for establishing connections, and perhaps collaborations, between chemists armed with novel technologies and biologists receptive to using these approaches to solve their chosen biological problem.

Speakers: John A. Porco, Boston University; Kip Guy, St Jude Children's Research Hospital; Daniel Erlanson, Carmot Therapeutics, Inc.

Abstracts

New Approaches for the Discovery of Chemical Reactions and Chemotypes
John A. Porco, Boston University

At the Center for Chemical Methodology and Library Development at Boston University (http://cmld.bu.edu), Professor Porco and coworkers have recently focused on identification of reactions leading to complex chemotypes. Reaction development is generally guided by problems in total synthesis or interest in developing transformations of broad scope and utility. Chemical methodology development has increasingly relied on systematic evaluation of catalysts and other variables including solvent, temperature, and ligands. Screening has increased the efficiency of reaction development but has generally been focused on specific transformations. An emerging but underdeveloped method for chemical reaction discovery involves high-throughput screening. A few examples have been reported in which new reactions were discovered through screening of either multicomponent systems or reaction partners and catalysts. As a part of our overall interest in the synthesis of new structural frameworks, we have initiated a program to identify novel chemical transformations using both "multidimensional screening" and "reaction discovery" approaches. In this approach, substrates are reacted with various catalysts and reaction partners in an array format and analyzed for unique reaction processes. In this lecture, we will report our recent studies on this mode of reaction screening and identification of several new transformations discovered during initial screening efforts.

A Novel Inhibitor Of Thyroid Hormone Function
Kip Guy, St Jude Children's Research Hospital

The thyroid hormone receptors (TR) responds directly to circulating thyroid hormones to maintain homeostatic balance, particularly for energy metabolism, temperature regulation, and lipid metabolism. The signaling pathways regulated by the TR are very complex and the selective pharmacological regulation of those pathways is difficult to achieve. In an effort to better understand the events underlying regulation of signaling and provide for more closely tuned pharmacological approaches we have developed a set of tools for studying and regulating TR signaling. High throughput screening afforded several novel chemotypes that inhibited the interaction of liganded TR with its requisite cofactors. Careful lead optimization has allowed conversion of one of these hits into a validated leads useful in cellular studies and potentially in animal models.

Navigating Molecular Diversity with Fragment-based Ligand Discovery
Daniel Erlanson, Carmot Therapeutics, Inc.

In the past decade, fragment-based ligand discovery has established itself as a powerful method to identify drug leads and chemical probes. In contrast to conventional high-throughput screens, which typically require tens of thousands to millions of compounds to identify hits, fragment-based approaches require only hundreds to thousands of very small molecules, or fragments. This reduction in library size makes it easier for academic laboratories and small companies to initiate projects. Moreover, since there are fewer possible small molecules than large molecules, the strategy promotes more efficient exploration of the vastness of chemical diversity.