the n , n-dimethyl derivatives of several compounds , including tryptamine , 5-hydroxytryptamine , 4-hydroxytryptamine , 5-methoxytryptamine , tyramine , and mescaline , were only about ten times less effective than lysergic acid , even though these compounds lack some of the ring systems of lysergic acid .
C0036751
5-hydroxytryptamine
C0000589
5-methoxytryptamine