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.
Arthur Birch (organic chemist)
Birch developed the Birch reduction of aromatic rings (by treatment with lithium metal and ammonia) which is widely used in synthetic organic chemistry. The Birch Reduction enables the modification of steroids. In 1948 Birch published the first total synthesis of a male sex hormone (19-nortestosterone), as the first member of a new structural series. This series later comprised the first oral contraceptive pill, which was made by others. The Birch reduction also allows for the development of other steroid drugs and antibiotics – he also made the first simple synthesis of the ring A-B structure of cholesterol. Birch published over 440 scientific papers and reports.