Design and synthesis of metabolically stable peptide analogs that can either mimic or block the bioactivity of natural peptides or enzymes is an important constituent of bioorganic and medicinal chemistry research. Isosteric replacement of a scissile peptide bond represents a viable and popular approach in the rational design of peptidomimetics. Peptidomimetics find applications as drugs, in protein engineering and so on. This is evident from the wealth of therapeutically useful peptidomimetic leads incorporating any of the peptide isosteres that are currently available. In this review, we have given a brief account of the types of peptide isosteres widely known till date. With this background, we have described some of the recent developments in synthetic approaches. This includes methods involving a common intermediate to synthesize different possible isosteres and their peptide analogs, solid phase synthesis and combinatorial approach. One such method involving stereoselective nitrile oxide cycloaddition as the key step has been studied extensively in our research laboratory. Finally, we have also discussed about some of the recent reports on the design and inhibitory activities of peptidic or non-peptidic analogs against aspartic proteases (HIV-1, renin, ACE and pepsin) and peptide analogs of an immunomodulating hexapeptide.
Current Medicinal Chemistry covers all the latest and outstanding developments in medicinal chemistry and rational drug design. Each issue contains a series of timely in-depth reviews written by leaders in the field covering a range of the current topics in medicinal chemistry. Current Medicinal Chemistry is an essential journal for every medicinal chemist who wishes to be kept informed and up-to-date with the latest and most important developments.