Q: The first of which class of drug was extracted from the venom of the Brazillian Arrow-headed viper?

A: Angiotensin-Converting Enzyme Inhibitors Mauricio Oscar Rocha e Silva was the pharmacologist who discovered bradykinin, a peptide hormone that lowers blood pressure, in the venom of the Brazillian pit viper Bothrops jararaca. This discovery led to the development of ACE inhibitors by Sérgio Ferreira