Page - (000324) - in Biomedical Chemistry: Current Trends and Developments

the cis 3-phenyl-pyrrolidine moiety, the pharmacokinetic properties could be substantially improved and the binding affinity retained. It should be emphasized that although numerous strategies and attempts for transforming a bioactive peptide into small peptidomimetics have been reported, it is not straightforward, it is case dependent, and there is no guarantee of success. The decreasing number of approved drugs during recent years has put enormous pressure on the pharmaceutical industry, resulting in a revival of interest in peptides as potential drug candidates (Vlieghe, 2010). By using synthetic strategies to limit metabolism and exploring alternative routes of administration, a number of peptidic drugs have been brought to the market (Vlieghe, 2010), showing that it is not necessary to remove the peptide character completely, and that small pseudopeptides can be useful as drugs. Table 3.3.8: Active uptake and permeability data for the rigidified and C-terminal-modified H- Phe-Phe-NH2 analogs.