Four triterpenes, three lupanes, and a germanicane were isolated from
Machaerocereus eruca. The germanicane derivative (1) was determined to
be 3 beta,19 alpha-dihydroxygermanican-28-oic acid and named machaero
ceric acid. The three new lupane derivatives were identified as 21-ket
obetulinic acid (2), 16 beta-hydroxybetulinic acid (3), and 22 beta-hy
droxystellatogenin (4), respectively, on the basis of their spectrosco
pic data.