Biotransformation of tryptophan by Phaseolus vulgaris suspension culture"The carboline alkaloids, harman and norharman, detected in the culture filtrate of Phaseolus vulgaris suspension culture are the two major products of the biotransformation of tryptophan by this culture."
Microbial metabolites of harman alkaloids"Several microorganisms showed the ability to transform the harman alkaloids, harmaline (1), harmalol (2) and harman (5). Harmaline (1) and harmalol (2) were converted by Rhodotorula rubra ATCC 20129 into the tryptamines, 2-acetyl-3-(2-acetamidoethyl)-7-methoxyindole (3) and 2-acetyl-3-(2-acetamidoethyl)-7-hydroxyindole (4), respectively. Harman (5) was biotransformed by Cunninghamella echinulata NRRL 3655 into 6-hydroxyharman (6) and harman-2-oxide (7)."
Not sure how practical these procedures are, but I found the results interesting nonetheless.