Congo during the 1960s, a Norwegian doctor, Lorents Gran, noted that during labor African women used a medicinal tea made from the leaves of the plant Oldenlandia affinis to induce labor and facilitate childbirth. The active ingredient was later determined to be a peptide, named kalata B1, after the traditional name for the native medicine, kalata-kalata. Although in vivo studies in rats confirmed the uterotonic activity of the purified peptide, it was another 20 years before the cyclic cystine knot motif and structure of the purified peptide were elucidated. See also Antimicrobial peptides Cyclic peptides References External links Cybase Peripheral membrane proteins Cyclic peptides