Abstract The β-carbolines flazin (1) and perlolyrine (2, substance YS) occuring in Japanese sake and soy sauce were synthesized starting with the methyl ester of L-tryptophan or tryptamine, respectively. The inhibition of the monoamine oxidases A and B by 1 and 2 were determined and compared with the inhibitory effects of harmine and harmaline.
![1-(5-Acetoxymethyl-2-furyl)-1,2,3,4-tetrahydro-9H-pyrido[3,4-b]indole Structure](https://image.chemsrc.com/caspic/223/115107-77-2.png)
