Biotransformation of Tryptamine to Serotonin by Cell Suspension Cultures of Peganum harmala

Abstract

Cell suspension cultures of P. harmala, unable to form serotonin de-novo, hydroxylated fed tryptamine to serotonin independently of the growth cycle up to 20 mg per g dry mass per day. The best biotransformation yield of 80% was obtained with a high cell density (30 g fresh mass/100 ml) and a 5 mM tryptamine concentration in the transformation medium. Under these conditions the cells accumulated serotonin up to 7.5% per unit dry mass, and a maximum yield of 800 mg serotonin/l was achieved. Other indoleethylamines such as α-methyltryptamine, N-methyltryptamine, and 6-fluorotryptamine were also transformed to the corresponding 5-hydroxyl compounds, while N,N-dimethyltryptamine, 7-methyltryptamine, tyramine, and phenylethylamine were not hydroxylated.