Review on therapeutic potential of peptides: Advancements in synthesis methods, linear and cyclic peptides, and strategies for overcoming challenges

In the realm of therapeutic peptides, tremendous progress has been achieved in the last two decades. The building block of peptides that is, ‘Amino Acid’ has been modified by various chemical modifications such as side-chain alteration in linear peptides, cyclization, back-bone modification, pro-drug moiety, conjugation with heterocycles, and natural products to make peptides a foremost candidate as a therapeutic drug. Since the advent of insulin in 1922, peptides have immensely affected the development of the pharmaceutical industry giving rise to the peptide-based drug industry. In recent years, peptides having antimicrobial, antiviral, anti-tumor, anti-inflammatory, anti-aging, and antioxidant properties have developed. Also, it has now entered as a potent candidate in the field of oncology and also become a valuable tool as a radiolabeled peptide for the detection of various diseases. Generally, peptides were extracted from natural sources in the olden days, but presently work is directed towards finding alternate and sustainable ways for developing synthetic peptides. The present review covers the discussion about the historic evaluation of peptides, available effective synthetic processes, current advancements, use of bioinformatic tools, computational strategies, and the methodology to overcome the barrier for making peptides the potent candidate for the future world.