Bradykinin (BK) and three of its analogs, (DAla)⁷ BK, (Gly)⁷ BK and (Pro)⁶ BK were synthesized by the continuous flow method. Polystyrene-polyethylene glycol graft copolymer was employed as modified polymeric support. The effect of the replacement of Pro⁷ by DAla, Gly and Ser⁶ by Pro on the 3--->1 intramolecular hydrogen bond present in BK chain, between the carbonyl oxygen of Ser⁶ and the amide proton of Phe⁸ bridging Pro⁷, was investigated. Although there are remarkable changes in the CD spectral features of these analogs compared to that of BK, they exhibited comparable biological activities.