A Versatile Synthetic Approach toward Diversity Libraries using Monosaccharide Scaffolds

Investigations into the decomposition of aminoacyl-substituted monosaccharide scaffolds from a drug discovery library

Decomposition of aminoacyl-substituted d-galactoside scaffolds under acidic conditions is dependent on the length of the side chain and is accelerated by the presence of a free hydroxyl group at C-6. In the latter case, evidence is provided that the reaction occurs via an N- to O-acyl transfer.

Fighting obesity with a sugar-based library: discovery of novel MCH-1R antagonists by a new computational-VAST approach for exploration of GPCR binding sites

Obesity is an increasingly common disease. While antagonism of the melanin-concentrating hormone-1 receptor (MCH-1R) has been widely reported as a promising therapeutic avenue for obesity treatment, no MCH-1R antagonists have reached the market. Discovery and optimization of new chemical matter targeting MCH-1R is hindered by reduced HTS success rates and a lack of structural information about the MCH-1R binding site. X-ray crystallography and NMR, the major experimental sources of structural information, are very slow processes for membrane proteins and are not currently feasible for every GPCR or GPCR-ligand complex. This situation significantly limits the ability of these methods to impact the drug discovery process for GPCR targets in "real-time", and hence, there is an urgent need for other practical and cost-efficient alternatives. We present here a conceptually pioneering approach that integrates GPCR modeling with design, synthesis, and screening of a diverse library of sugar-based compounds from the VAST technology (versatile assembly on stable templates) to provide structural insights on the MCH-1R binding site. This approach creates a cost-efficient new avenue for structure-based drug discovery (SBDD) against GPCR targets. In our work, a primary VAST hit was used to construct a high-quality MCH-1R model. Following model validation, a structure-based virtual screen yielded a 14% hit rate and 10 novel chemotypes of potent MCH-1R antagonists, including EOAI3367472 (IC50 = 131 nM) and EOAI3367474 (IC50 = 213 nM).

1,2,4-trisubstituted cyclopentanes as platforms for diversity

Despite their simplicity, relatively few examples of 1,2,4 (1,3,4)-amino-, azido-, and hydroxy-substituted cyclopentanes are reported in the literature. We found that cyclopent-3-en-1-ol can be transformed into a significant variety of compounds of this class by relatively common and efficient synthetic procedures. Stereochemical control of epoxidation of the cyclopentene double bond can be achieved by varying the substitutents at C4. The C4 substituent and epoxide functional group can be converted into a variety of intermediates with differential protection designed for use in applications requiring regiospecific control for further elaboration of the cyclopentane scaffold.

Orthogonally Protected Monosaccharide Building Blocks for Solid Phase Production of Diversity Oriented Libraries

The large scale synthesis of three orthogonally protected monosaccharide scaffolds suitable for use in the solid phase preparation of large diversity libraries is presented. Scaffolds based on 2-amino-2-deoxy-d-glucopyranose, 2-amino-2-deoxy-d-allopyranose, and 2,4-diamino-2,4-dideoxy-d-galactopyranose were prepared in good yield and with minimal chromatographic purification from commercially available methyl 2-azido-2-deoxy-1-thio-β-d-glucopyranose and methyl 2-amino-2-deoxy-1-thio-β-d-glucopyranose.