RIBOFLAVIN, A TESTOSTERONE 5a-REDUCTASE INHIBITOR

glycerol 3%, soybean meal 1% corn steep liquor 0.5%, dried yeast extract 0.5%, CaCO3 0.2% (pH 6.5) for 3 days at 30°C under aeration of 20 liters per minute and agitation of 250rpm. Testosterone 5a-reductase inhibition activity was assayed by the method we reported previously1*. The whole broth (20 liters) was extracted with an equal volume of acetone at neutral pH, and filtered with diatomaceous aid (1 kg). After the filtrate was concentrated in vacuo to removeacetone, the active compound was adsorbed on a column of Dowex1-X2 (OH~, 1.5 liters, Dow Chemicals) at pH 7.0 and eluted with 2%CH3COOH. The eluate was concentrated in vacuo and freeze-dried to give a crude powder. The powder was dissolved in water and passed through a column of Dowex 50W-X2 (H+, 1.0 liter, Dow Chemicals) and developed with water. A biologically active component was further purified by preparative TLC (Kieselgel 60 F254, Merck), and eluted with BuOH-CH3COOH-H2O (4:1:1). The Rf