Fragment-baseajord drug design has become a novel paradigm for drug discovery in the last decade. The lack of molecular rigidity intrinsic to a majority of small organic molecules appears to be a serious obstacle for this promising approach. Conformationally restricted rigid molecules show higher reproducibility of results when used in projects utilizing in silico screening methods. Due to a predefined spatial orientation of the molecular fragments mounted on a conformationally rigid scaffold, a decrease in entropy of molecular binding with its biological target might be expected, thus leading to higher affinity of the potential drug candidate.
This issue of Enamine Product Focus highlights Lactams, cyclic amide building blocks. There are numerous examples of Lactams usage in drug discovery, e.g., β-lactam based antibiotics, oral anticoagulant Rivaroxaban, and anticonvulsant Levetiracetam.
Bifunctional building blocks are of special interest for drug design and organic synthesis due to three reasons, at least. First, these compounds can be used to tether two molecular fragments responsible for binding to the biological target, thus they can act as linkers. Second, if one functional group is not engaged in connection between the core of building block and the rest of a molecule being constructed, then it can participate in important interaction with a biological target. Finally, many bifunctional building blocks can undergo cyclization reactions, allowing rapid advance toward prospective heterocyclic units.
The intrinsic role of heterocyclic compounds in medicinal chemistry is now undoubtful as more than 90% of new drugs contain heterocycles. Compounds possessing heterocyclic cores have several advantages that make their use in drug design particulary effective.
- Aromatic rings are extremely rigid in conformation thus defining spatial orientation of attached functional groups and reducing entropy of binding of the molecule with potential biological target.
- In most cases, hetero atoms exhibit properties of strong hydrogen bond donors/acceptors enforcing interaction of the molecule with its biological target.
- The chemistry of heterocyclic compounds is undoubtedly the most explored area of organic chemistry. The synthetic methods for the construction of heterocycles are well-established, simple, highly efficient and easy-scalable.
- Heterocycles occupy an overwhelming majority of the available chemical space thus being the most diverse class of organic compounds. Therefore they represent the substantial possibilities for the design of novel scaffolds that are yet not protected by patents.
This issue of Enamine Product Focus represents a family of Building Blocks possessing sulfone moiety as a part of a cyclic unit. All the building blocks processing cyclic sulfone moiety have some common features that make the design of potential drug candidates particularly efficient.