Prothoracicotropic hormone
Prothoracicotropic hormone (PTTH) was the first insect hormone to be discovered. It was originally described simply as "brain hormone" by early workers such as Stefan Kopeć (1922) and Vincent Wigglesworth (1934), who realized that ligation of the head of immature insects could prevent molting or pupation of the body region excluded from the head if the ligation was performed before a critical age in the lifestage was reached. After a certain point the ligation had no effect and both sections of the insect would molt or pupate. However, implantation of a conspecific brain to a sessile ligated abdomen or an abdomen under diapause would induce molting or pupation. Thus, the brain was originally thought to be the source of the hormone that induces molting in insects.
Estetrol (medication)
Estetrol was discovered in 1965 by Egon Diczfalusy and coworkers at the Karolinska Institute in Stockholm, Sweden, via isolation from the urine of pregnant women. Basic research on estetrol was conducted from 1965 to 1984. It was established that estetrol is exclusively synthesized in the fetal liver and hence that it is a fetal estrogen. By 1984, estetrol was regarded as a weak estrogen; interest fell, and research was virtually abandoned. Subsequently a project at Pantarhei Bioscience was started to investigate estetrol with state-of-the-art technologies in 2001, with the sole reasoning that estetrol must have some biological role or function of importance as it would not be produced in such high quantities in the fetus otherwise. By 2008, estetrol was of major interest for potential clinical use, and development was in-progress. As of 2018, it is in mid- to late-stage clinical development for a variety of indications.https://adisinsight.springer.com/drugs/800034634 It was initially developed by Pantarhei Bioscience and Estetra SA (subsequently renamed Estetra SPRL), and is now being developed by Mithra Pharmaceuticals.