Alkaloids exhibiting the hexahydropyrrolo[2,3-b]indole core are a growing class of natural products that display a broad range of biological activities. 1 Physostigmine (1) was first isolated in pure form from the African Calabar bean seeds Physostigma venenosum in 1864 by Jobst and Hesse. 2 It is one of the earliest compounds to be identified as an inhibitor of acetyl cholinesterase. (−)-Physostigmine is currently used to treat myasthenia gravis and ...
