A new sesquiterpene evoninoate alkaloid, hippocrateine III, was isolated together with the known compound mayteine from the root and stem barks of Hippocratea excelsa. The structures of both compounds were elucidated by interpretation of spectral data. The substitution pattern of the nicotinic acid moiety in hippocrateine III differs from that of emarginatine A and hippocrateines I and II.