Biotransformation of 1-benzoylindole (BI) by the strains Aspergillus flavus
VKM F-1024 and Aspergillus oryzae VKM F-44 was studied. The major metaboli
tes isolated were identified as 4-hydroxyindole (4-HI), 5-hydroxyindole (5-
HI), 4-hydroxy-1-benzoylindole, 4-hydroxy-1-(4'-hydroxy)-benzoylindole and
indole. The structure of the metabolites was determined by mass spectrometr
y and proton nuclear magnetic resonance spectroscopy. The pathways of BI me
tabolism via initial monohydroxylation at C-4 and C-5 followed by cleavage
of the benzoyl substituent to yield 4-HI and 5-HI were proposed. Indole was
formed as a by-product, and its role as a potent inhibitor of BI hydroxyla
tion at C-4 and C-5 is discussed.