Himbacine is a piperidine alkaloid with a tricyclic lactone scaffold isolated from Galbulimima sp. (Himantandra sp.) by Ritchie and Taylor, University of Sydney, Australia in 1956. Himbacine is a potent M2 muscarinic receptor antagonist with selectivity for cardiac receptors and a thrombin (PAR1) receptor inhibitor. Its analog, vorapaxar is marketed for secondary prevention of thrombotic cardiovascular events.