Abstract: The present invention relates to synthetic and recombinant peptide primary structures including an amino acid sequence selected from the group consisting of SEQ ID NOs: 1 to 12, wherein the primary structure includes an +aa-Pro-Pro amino acid in which “+aa” is Lys, Arg, His or a modified amino acid having a positive charge at physiological pH. The present invention also relates to a pharmaceutical composition including at least one peptide having a primary structure as defined above.

Abstract: The present invention provides isoformes from a peptide family belonging to South American scorpion Tityus serrulatus that acts as hypotensive agents by potentiating Bradykinin and, therefore, can be used as anti-hypertensive drugs. A peptide was firstly isolated from Tityus serrulatus venom and showed a strong and long-lasted hypotensive activity when tested in rats. This peptide was first named TsHpt-I (Tityus serrulatus Hypotensin-I). Also, three more highly similar isoformes were identified and revealed a peptide family with very close primary structure. They were named TsHpt-II, TsHpt-III and TsHpt-IV.