Two new bioactive indole alkaloids, 5-hydroxytryptamine (serotonin) N-4-oxobutanoic acid and 5-hydroxytryptamine N-acetyl-N-pyrrolecarboxarnide , named as bufobutanoic acid (2) and bufopyramide (3), respectively, were isolated from the Chinese traditional drug Ch'an Su in addition to known bufotenine (1).The structures were elucidated on the basis of spectroscopic data.Bufobutanoic acid (2) and...