A curare from the Upper Orinoco basin has been studied. The curare is found only on the arrow tips, called pei-namõ by Yanoáma Indians. From this curare one quaternary alkaloid and one tertiary alkaloid have been separated. The tertiary alkaloid has been proved to be (I) and has been called peinamine. The quaternary alkaloid was identified with the alkaloid macoline obtained by us at the same time from Abuta grisebachii wood, used by Sanama indians to prepare a hunting curare. Its structure was established as (II). In the same Abuta extract were found peinamine and tertiary alkaloids related to peinamine and to macoline.