Peptides are short proteins formed by a chain consisting of 50 or less amino acids The term bioactive peptides is used to identify molecules of peptidic nature or origin which display a biological behaviour or activity which can be developed at the industrial level for pharmaceutical, diagnostic, chemical and agro-food applications. In this way it is possible to obtain modified peptides with superior properties for therapeutic applications. The great advantage of using modified peptides instead of classical peptidomimetics is a very high bioavailability, a long lasting activity in vivo, and limited toxicity. Beside this, the costs for setting-up the synthetic strategy are quite low, when compared to those of setting-up stereo-specific synthetic routs. Examples include various forms of peptides such as galanin, peptide YY, neuropeptide Y, secretin, cholecystokinin, insulin-like peptides, LEAP-2, and a number of others .