The Salk Institute for Biological Studies

Universidad De Chile

Universidad De La Frontera

Laboratorios Andromaco S.a.

Universidad Federal De Sao Paulo

Sociedad Agrícola Y Ganadera Pehuén Ltda.

Antonio De Miranda

Jean E Rivier

Wylie W Vale, Jr

Catherine L Rivier

Fernando Gonzalo Romero Mejia

Raúl Sanchez Gutierrez

Eduardo Bustos Obregón

Andrés Rudolphy Fontaine

Fernando Gonzalo Romero MEJÍA

Ignacio Andrés JofrÉ FERNÁNDEZ

Sergio Andrés Reyne Heise

Fernando Romero Mejia

The present invention is directed to an active agent with contraceptive properties which corresponds to a peptide fragment of thevenom. The peptide generally includes the amino acid sequence of SEQ ID NO 2 or sequences that are at least 85% similar, obtained by chemical synthesis or through recombinant DNA technologies. Furthermore, a pharmaceutical contraceptive composition comprising the peptide fragment and one or more pharmaceutically acceptable vehicles is also described. The peptide fragment and pharmaceutical compositions are useful as a contraceptive and spermicide agent.

[object Object]

Improved CRF peptide antagonists have the formula: ##STR1## wherein R.sub.20 is Cys or Glu; R.sub.23 is Cys, Lys or Orn; provided that when R.sub.20 is Cys, R.sub.23 is Cys and when R.sub.20 is Glu, R.sub.23 is Lys or Orn; or a nontoxic addition salt thereof. Specific CRF antagonists disclosed include (cyclo 20-23) [D-Phe.sup.12, Lys.sup.23, Nle.sup.21,38, ]rCRF(12-41); (cyclo 20-23) [D-Phe.sup.12, Orn.sup.23, Nle.sup.21,38 ]rCRF(12-41) and (cyclo 20-23) [D-Phe.sup.12, Cys.sup.20, Cys.sup.23, Nle.sup.21,38 ]rCRF(12-41).

Cyclic CRF analogs

Growing community of inventors

Sao Paulo, Brazil

Antonio De Miranda