The fungus Aspergillus fumigatus Fresnius metabolized o-coumaric 
acid to 4-hydroxycoumarin and dicoumarol. From sequential induction, 
mass spectroscopy, co-chromatography and ultraviolet absorption spectra, 
it was deduced that 3-hydroxy-3-(2-hydroxyphenyl) propionic acid was 
an intermediate in the formation of 4-hydroxycoumarin. The latter was 
then converted non-enzymatically to dicoumarol (1660). 

0 
=() 
gs 
Coumarin 
Arthrobacter sp. Sudet. Clover 
Rabbit, rat 
QOH 
i“ 
| 0 
4 
~. Ee 
o-Coumaric Acid OH Dihydrocoumarin 
~OH 
0 
& 
~CH,-CH,~C™ 
OH 
Melilotic Acid 
Ticideuliah sp. 
0 
‘CH ~cH-c7 
2 kn, 
HO- 
H 
Ty rosine 
104 

